Paraquat resistance gene
2 claims: 2 independent, 0 dependent
- 1A method for screening for a transgenic plant, comprising introducing a recombinant vector comprising a nucleic acid encoding a protein of the following (a) or (b) and a foreign gene or a foreign DNA fragment into a plant and screening for a transgenic plant on the basis of paraquat resistance as an indicator:(a) a protein consisting of the amino acid sequence represented by SEQ ID NO: 2, and(b) a protein consisting of an amino acid sequence having a substitution, deletion or addition of 1 to 10 amino acids relative to the amino acid sequence as described in (a) and imparting paraquat resistance. Procédé de dépistage d'une plante transgénique, comprenant le fait d'introduire un vecteur recombinant comprenant un acide nucléique codant une protéine de (a) ou (b) suivants et un gène étranger ou un fragment d'ADN étranger dans une plante et de dépistage d'une plante transgénique sur la base d'une résistance à la paraquat comme un indicateur: (a) une protéine consistant en la séquence d'acides aminés représentée par SEQ ID NO: 2, et(b) une protéine consistant en une séquence d'acides aminés ayant une substitution, une suppression ou une addition de 1 à 10 acides aminés par rapport à la séquence d'acides aminés comme décrite dans (a) et transmettant une résistance à la paraquat. Verfahren für das Screening auf eine transgene Pflanze, welches das Einführen eines rekombinanten Vektors mit einer Nukleinsäure, die für ein Protein von den folgenden (a) oder (b) kodiert, und eines fremden Gens oder eines fremden DNS-Fragments in eine Pflanze und Screening auf eine transgenen Pflanze auf der Grundlage einer Paraquatresistenz als ein Indikator umfasst: (a) ein Protein bestehend aus der Aminosäuresequenz dargestellt durch die SEQ ID NO: 2 und(b) ein Protein aufgebaut aus einer Aminosäuresequenz mit einer Substitution, Deletion oder Addition von 1 bis 10 Aminosäuren relativ zu der Aminosäuresequenz wie in (a) beschrieben, und das eine Paraquatresistenz verleiht.
- 2A method for imparting paraquat resistance to a plant, comprising introducing a recombinant vector comprising a nucleic acid encoding a protein of the following (a) or (b) into a plant and imparting paraquat resistance to the plant:(a) a protein consisting of the amino acid sequence represented by SEQ ID NO: 2, and(b) a protein consisting of an amino acid sequence having a substitution, deletion or addition of 1 to 10 amino acids relative to the amino acid sequence as described in (a) and imparting paraquat resistance. Procédé pour transmettre une résistance à la paraquat à une plante, comprenant le fait d'introduire un vecteur recombinant comprenant un acide nucléique codant une protéine de (a) ou (b) suivants dans une plante et transmettant à la plante une résistance à la paraquat: (a) une protéine consistant en la séquence d'acides aminés représentée par SEQ ID NO : 2, et(b) une protéine consistant en une séquence d'acides aminés ayant une substitution, une suppression ou une addition de 1 à 10 acides aminés par rapport à la séquence d'acides aminés comme décrits dans (a) et transmettant une résistance à la paraquat. Verfahren für die Verleihung einer Paraquatresistenz an eine Pflanze, welches das Einbringen eines rekombinanten Vektors, der eine Nukleinsäure umfasst, die für ein Protein der folgenden (a) oder (b) kodiert, in eine Pflanze und das Verleihen einer Paraquatresistenz an die Pflanze umfasst: (a) ein Protein bestehend aus der Aminsäuresequenz dargestellt durch die SEQ ID NO: 2 und(b) ein Protein aufgebaut aus einer Aminosäuresequenz mit einer Substitution, Deletion oder Addition von 1 bis 10 Aminosäuren relativ zu der Aminosäuresequenz wie in (a) beschrieben, und das eine Paraquatresistenz verleiht.
Independent claims2
92 paragraphs in 5 sections, as filed
BACKGROUND OF THE INVENTION
Field of the Invention
The present invention relates to a method for screening for a transgenic plant and to a method for imparting paraquat resistance to a plant.
Background Art
Plants are exposed to various environmental stresses on a regular basis including high and low temperatures, drought, high light intensity, salinity, air pollutant gases, pathogenic microbes and the like. Therefore, if useful plants that can grow sufficiently even under such types of environmental stresses such as, for example, crops, can be developed, food production will become possible even in regions in which crops and the like can not currently grow due to environmental stresses, and the possibility of being prepared for a grave food crisis that is forecast in the future will be increased. Consequently, the production of plants that have improved resistance to such kinds of environmental stresses is underway on a global basis. For example, plants have been produced that were imparted with chilling resistance (<nplcit id="ncit0001" npl-type="s"><text>Nature, 356, 710-703, 1992</text></nplcit>; <nplcit id="ncit0002" npl-type="s"><text>Plant Physiol., 105, 601-605, 1994</text></nplcit>), drought resistance (<nplcit id="ncit0003" npl-type="s"><text>Plant Physiol., 107, 125-130, 1995</text></nplcit>; <nplcit id="ncit0004" npl-type="s"><text>Nature, 379, 683-684, 1996</text></nplcit>; <nplcit id="ncit0005" npl-type="s"><text>Nature Biotech., 17, 287-291, 1999</text></nplcit>), salt resistance (<nplcit id="ncit0006" npl-type="s"><text>Science, 259, 508-510, 1993</text></nplcit>; <nplcit id="ncit0007" npl-type="s"><text>Biotechnology, 14, 177-180, 1996</text></nplcit>; <nplcit id="ncit0008" npl-type="s"><text>Plant J., 12, 133-142, 1997</text></nplcit>), air pollutants resistance (<nplcit id="ncit0009" npl-type="s"><text>Plant Cell Physiol., 34, 129-135, 1993</text></nplcit>; <nplcit id="ncit0010" npl-type="s"><text>Biotechnology, 12, 165-168, 1994</text></nplcit>), disease resistance (<nplcit id="ncit0011" npl-type="s"><text>Kagaku to Seibutsu (Chemistry and Organisms), 37, 295-305, 385-392, 1999</text></nplcit>) and the like by genetic recombination techniques. Further, some plants that have been imparted with resistance to agricultural chemicals by genetic recombination techniques are in practical use (<nplcit id="ncit0012" npl-type="s"><text>Nature, 317, 741-744, 1985</text></nplcit>; <nplcit id="ncit0013" npl-type="s"><text>Proc. Natl. Acad. Sci. USA, 85, 391-395, 1988</text></nplcit>; <nplcit id="ncit0014" npl-type="s"><text>EMBO J., 6, 2513-2518, 1987</text></nplcit>; <nplcit id="ncit0015" npl-type="s"><text>EMBO J., 7, 1241-1248, 1988</text></nplcit>).
These environmental stresses are closely related with <i>in vivo</i> generation of active oxygen species (superoxide radical (O<sub>2</sub>), hydrogen peroxide (H<sub>2</sub>O<sub>2</sub>), hydroxy radical (OH<sup>-</sup>)). Active oxygen species are generated by respiration, photosynthesis, environmental stresses and the like, and impart fatal damage to cells by excessive oxidation of proteins, nucleic acids, membrane structure or the like. It has also been reported that an active oxygen-resistant plant produced by genetic recombination techniques showed improved resistance to the aforementioned environmental stresses (<nplcit id="ncit0016" npl-type="s"><text>Plant Physiol., 111, 1177-1181, 1996</text></nplcit>; <nplcit id="ncit0017" npl-type="s"><text>FEBS Letters, 428,47-51,1998</text></nplcit>).
To produce an active oxygen-resistant plant, a method is principally employed in which a gene of enzyme scavenging active oxygen species (superoxide dismutase, ascorbate peroxidase, catalase and glutathione reductase and the like) is introduced into the plant.
Paraquat is a non-selective and potent herbicide that can kill all plants by continuously generating active oxygens in the photosystems. Paraquat resistance can thus be used as an indicator of the resistance to active oxygens, and analysis concerning the mechanism of paraquat resistance in plants has been conducted (<nplcit id="ncit0018" npl-type="s"><text>Pestic. Biochem. Physiol., 26, 22-28, 1986</text></nplcit>; <nplcit id="ncit0019" npl-type="s"><text>Theor. Appl. Genet. 75, 850-856, 1988</text></nplcit>; and <nplcit id="ncit0020" npl-type="s"><text>Plant Physiol., 91, 1174-1178, 1989</text></nplcit>).
Meanwhile, an apoptosis suppressor gene (JP Patent Publications (Kokai) No. <patcit id="pcit0001" dnum="JP10309142A"><text>10-309142</text></patcit>; <patcit id="pcit0002" dnum="JP2000023583A"><text>No. 2000-23583</text></patcit>; and <patcit id="pcit0003" dnum="JP2002300822A"><text>No. 2002-300822</text></patcit>), a gene encoding a protein homologous to aldose reductase (JP Patent Publication (Kohyo) No. <patcit id="pcit0004" dnum="JP2001523466A"><text>2001-523466</text></patcit>) and a gene encoding an iron-binding protein (ferritin) (JP Patent Publication (Kohyo) No. <patcit id="pcit0005" dnum="JP2001519671A"><text>2001-519671</text></patcit>) have been disclosed as genes that can impart paraquat resistance. Further, in JP Patent Publications (Kokai) No. <patcit id="pcit0006" dnum="JP2002281979A"><text>2002-281979</text></patcit> and <patcit id="pcit0007" dnum="JP2001095585A"><text>No. 2001-95585</text></patcit>, peroxidase derived from paraquat resistant callus is disclosed as a gene capable of imparting resistance to paraquat.
"Arabidopsis thaliana clone 122632 mRNA, complete sequence." XP002309600 retrieved from EBI accession no. EM_PRO:AY084949; Database accession no. AY084949, and "Arabidopsis thaliana DNA chromosome 4, contig fragment No. 73" XP002309601 retrieved from EBI accession no. EM_PRO:AL161577 Database accession no. AL161577 disclose a gene encoding the protein having the amino acid sequence according to SEQ ID NO.2. Both amino acid sequences are derived from <i>Arabidopsis thaliana.</i>
<patcit id="pcit0008" dnum="KR1020010009592"><text>Korean patent publication No. 10-2001-0009592</text></patcit> discloses a paraquat resistant gene as well as it use in a screening method of a transformed plant.
It had been believed that if a paraquat resistance gene that can impart strong resistance to paraquat could be isolated, it would be useful in the development of plants with high resistance to active oxygens generated under various kinds of environmental stress conditions (high and low temperatures, drought, high light intensity, salinity, air pollutant gases, pathogenic microbes and the like). However, recently it has been revealed that active oxygens fulfill an important role as a molecule regulating the growth and stress response of a plant. Therefore, to avoid influencing important characteristics such as crop yield, it is important to increase the resistance of a plant to stresses such as paraquat without affecting the growth and physiological control mechanisms of a plant dependent on active oxygens.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide the methods defined in claims 1 and 2.
BRIEF DESCRIPTION OF THE DRAWINGS
<ul id="ul0001" list-style="none" compact="compact"><li><figref idref="f0001">FIG. 1</figref> is a photograph of electrophoresis of cDNA derived from an AtMVR gene transformant;</li><li><figref idref="f0002">FIG. 2A</figref> is a schematic diagram showing the location of an AtMVR gene transformant and a non-transformant in <figref idref="f0002">FIGS. 2B and 2C. FIG. 2B</figref> is a photograph showing the growth of an AtMVR gene transformant and a non-transformant in a 1/2 MS culture medium without paraquat. <figref idref="f0002">FIG. 2C</figref> is a photograph showing the growth of an AtMVR gene transformant and a non-transformant in a 1/2 MS culture medium with paraquat;</li></ul>
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention will be described in detail below.
The gene used in the methods according to the present invention is a gene encoding the protein of the following (a) or (b): <ol id="ol0001" compact="compact" ol-style=""><li>(a) a protein consisting of the amino acid sequence represented by SEQ ID NO: 2; and</li><li>(b) a protein consisting of an amino acid sequence having a substitution, deletion or addition of 1 to 10 amino acids relative to the amino acid sequence represented by SEQ ID NO: 2 and imparting paraquat resistance.</li></ol>
The gene encoding the protein described in the above (a) is a gene (hereafter, referred to as "AtMVR gene") encoding a protein imparting paraquat resistance which consists of the amino acid sequence represented by SEQ ID NO: 2.
The present inventors performed a search on databases having the entire nucleotide sequence of <i>Arabidopsis thaliana</i> (for example, GenBank, EMBL, DDBJ, tair: The Arabidopsis Information Resource) based on the nucleotide sequence of the AtMVR gene and found that there are 13 genes homologous to the AtMVR gene (AtMVR 3-1 to AtMVR 3-13) present on the <i>Arabidopsis thaliana</i> genome. The nucleotide sequence of each of these AtMVR homologous genes and the putative amino acid sequence encoded by the relevant AtMVR homologous gene are represented by the SEQ ID NOs. listed in Table 1 below. Table 1 also lists the results of homology analysis between the AtMVR gene and each AtMVR homologous gene. The homology analysis was conducted using BLAST P at the amino acid level. Amino acids may be classified based on the chemical properties of their side chains. In the BLOSUM62 amino acid substitution matrix (<nplcit id="ncit0021" npl-type="s"><text>Proc. Natl. Acad. Sci., 89, 10915-10919, 1992</text></nplcit>), amino acids are classified into: an amino acid with a mercapto group (C); hydrophilic amino acids that have low molecular weight (S, T, P, A, G); acidic amino acids (N, D, E, Q); basic amino acids (H, R, K); hydrophobic amino acids that have low molecular weights (M, I, L, V); and aromatic amino acids (F, Y, W). In Table 1, the term "Identities" refers to 100% correspondence in terms of amino acids and the term "Positives" refers to the numerical value when amino acids having a positive score in the BLOSUM 62 amino acid substitution matrix are added to those having 100% correspondence (see <nplcit id="ncit0022" npl-type="b"><text>Bioinfomatics (in Japanese), Eds. Okazaki Y. & Bono H. (published by Medical Science International</text></nplcit>)). <tables id="tabl0001" num="0001"><table frame="all"><title>[Table 1]</title><tgroup cols="5"><colspec colnum="1" colname="col1" colwidth="51mm" /><colspec colnum="2" colname="col2" colwidth="35mm" /><colspec colnum="3" colname="col3" colwidth="35mm" /><colspec colnum="4" colname="col4" colwidth="23mm" /><colspec colnum="5" colname="col5" colwidth="23mm" /><thead><row><entry valign="top">Name of AtMVR homologous gene</entry><entry align="center" valign="top">Nucleotide sequence</entry><entry align="center" valign="top">Amino acid sequence</entry><entry align="center" valign="top">Identities (%)</entry><entry align="center" valign="top">Positives (%)</entry></row></thead><tbody><row><entry>AtMVR3-1</entry><entry>SEQ ID NO: 4</entry><entry>SEQ ID NO: 5</entry><entry align="center">57</entry><entry align="center">70</entry></row><row><entry>AtMVR3-2</entry><entry>SEQ ID NO: 6</entry><entry>SEQ ID NO: 7</entry><entry align="center">55</entry><entry align="center">69</entry></row><row><entry>AtMVR3-3</entry><entry>SEQ ID NO: 8</entry><entry>SEQ ID NO: 9</entry><entry align="center">39</entry><entry align="center">56</entry></row><row><entry>AtMVR3-4</entry><entry>SEQ ID NO: 10</entry><entry>SEQ ID NO: 11</entry><entry align="center">39</entry><entry align="center">55</entry></row><row><entry>AtMVR3-5</entry><entry>SEQ ID NO: 12</entry><entry>SEQ ID NO: 13</entry><entry align="center">37</entry><entry align="center">54</entry></row><row><entry>AtMVR3-6</entry><entry>SEQ ID NO: 14</entry><entry>SEQ ID NO: 15</entry><entry align="center">36</entry><entry align="center">52</entry></row><row><entry>AtMVR3-7</entry><entry>SEQ ID NO: 16</entry><entry>SEQ ID NO: 17</entry><entry align="center">34</entry><entry align="center">52</entry></row><row><entry>AtMVR3-8</entry><entry>SEQ ID NO: 18</entry><entry>SEQ ID NO: 19</entry><entry align="center">34</entry><entry align="center">51</entry></row><row><entry>AtMVR3-9</entry><entry>SEQ ID NO: 20</entry><entry>SEQ ID NO: 21</entry><entry align="center">37</entry><entry align="center">58</entry></row><row><entry>AtMVR3-10</entry><entry>SEQ ID NO: 22</entry><entry>SEQ ID NO: 23</entry><entry align="center">25</entry><entry align="center">44</entry></row><row><entry>AtMVR3-11</entry><entry>SEQ ID NO: 24</entry><entry>SEQ ID NO: 25</entry><entry align="center">33*</entry><entry align="center">51*</entry></row><row><entry>AtMVR3-12</entry><entry>SEQ ID NO: 26</entry><entry>SEQ ID NO: 27</entry><entry align="center">25</entry><entry align="center">41</entry></row><row><entry>AtMVR3-13</entry><entry>SEQ ID NO: 28</entry><entry>SEQ ID NO: 29</entry><entry align="center">22</entry><entry align="center">41</entry></row></tbody></tgroup><tgroup cols="5" rowsep="0"><colspec colnum="1" colname="col1" colwidth="51mm" /><colspec colnum="2" colname="col2" colwidth="35mm" /><colspec colnum="3" colname="col3" colwidth="35mm" /><colspec colnum="4" colname="col4" colwidth="23mm" /><colspec colnum="5" colname="col5" colwidth="23mm" /><tbody><row><entry namest="col1" nameend="col5" align="justify">*The comparison with AtMVR3-11 shows the homology result for comparison with a partial sequence of AtMVR3-11.</entry></row></tbody></tgroup></table></tables>
As shown in Table 1, the homology of AtMVR with the 13 AtMVR homologous genes ranged from 22 to 57% for Identities and from 41 to 70% for Positives. These AtMVR homologous genes are considered to impart paraquat resistance in the same manner as the AtMVR gene.
Further, the AtMVR gene has homology to a senescence-associated protein, DSA 5 (GenBank accession number AF082030) (<nplcit id="ncit0023" npl-type="s"><text>Plant Molecular Biology 40, 237-248, 1999</text></nplcit>). The result of homology analysis using BLAST X showed the protein encoded by the AtMVR gene has identity of 89% at the amino acid level to the protein encoded by DSA 5. It is reported that DSA 5 is a gene that expresses upon aging of the petal of lily (<i>Hemerocallis</i> hybrid cultivar) (<nplcit id="ncit0024" npl-type="s"><text>Plant Molecular Biology 40, 237-248, 1999</text></nplcit>). However, since the protein encoded by DSA 5 has no homology with any known protein, it is unclear which functions the protein has. Accordingly, the AtMVR gene is a novel gene imparting paraquat resistance.
As used herein, the term "paraquat resistance" refers to having resistance to paraquat. More specifically, the term "paraquat-resistant plant" refers to a plant requiring a larger quantity of paraquat than a non-resistant plant in order to obtain a given effect from paraquat. Paraquat is a non-selective and potent herbicide that kills all plants by continuously generating active oxygens in the photochemical system. It is possible to confirm whether the AtMVR gene is a paraquat resistance gene imparting paraquat resistance by examining whether a transformant into which the gene was introduced can grow in the presence of paraquat.
The gene encoding the protein described in the above (b) is a gene encoding a protein consisting of an amino acid sequence having a substitution, deletion or addition of 1 to 10 (or 1 to 5) relative to the amino acid sequence represented by SEQ ID NO: 2 and imparting paraquat resistance.
Once the nucleotide sequence of the gene according to the present invention has been determined, it is then possible to obtain the gene according to the present invention by chemical synthesis, or by polymerase chain reaction (hereafter, referred to as "PCR") employing as a template a clone that has been cloned, or by performing hybridization employing a DNA fragment having the nucleotide sequence as a probe. Further, it is possible to synthesize a mutant of the gene according to the present invention having equivalent functions as those prior to mutation by a technique such as site-directed mutagenesis.
Examples of the method for introducing a mutation into the gene according to the present invention include a known method such as the Kunkel method or the gapped duplex method or a method in accordance with such methods. For example, introduction of a mutation can be performed using a kit for introducing a mutation (for example, Mutant-K (manufactured by TAKARA, Inc.), or Mutant-G (manufactured by TAKARA, Inc.)) utilizing site-directed mutagenesis or using LA PCR <i>in vitro</i> Mutagenesis series kit manufactured by TAKARA, Inc.
A protein imparting paraquat resistance according to the present invention is the protein encoded by the gene according to the present invention. For example, the gene according to the present invention is integrated into a vector derived from <i>Escherichia coli</i> or the like, and <i>E. coli</i> is then transformed with the obtained recombinant vector. Thereafter, the protein according to the present invention can be obtained by extracting the protein synthesized within <i>E. coli.</i>
Further, a recombinant vector according to the present invention is a recombinant vector comprising the gene according to the present invention. The recombinant vector according to the present invention can be obtained by inserting the gene according to the present invention into an appropriate vector. A vector used for inserting the gene according to the present invention is not particularly limited as long as it is capable of replication within a host, and examples thereof include a plasmid, a shuttle vector, and a helper plasmid. In addition, when the vector itself is not capable of replication, a DNA fragment that is capable of replication by a method such as insertion into the chromosome of a host may be used.
Examples of plasmid DNA include a plasmid derived from E. <i>coli</i> (pBI221 and the like, for example, pET system such as pET30b, pBR system such as pBR322 and pBR325, pUC system such as pUC118, pUC119, pUC 18 and pUC 19, pBluescript, and pBI221), a plasmid derived from <i>Bacillus subtilis</i> (for example, pUB 110 and pTP5), a binary plasmid derived from <i>Agrobacterium tumefaciens</i> (for example, pBI system derived from pBIN19, pBI101, or pBI121), a plasmid derived from yeast (for example, YEp system such as YEp13, or YCp system such as YCp50) or the like. Examples of phage DNA include λ phage (Charon 4A, Charon 21A, EMBL3, EMBL4, λgt10, λgt11, λZAP and the like). Further, an animal virus vector such as retrovirus or vaccinia virus, a plant virus vector such as cauliflower mosaic virus, or an insect virus vector such as baculovirus can also be used.
To insert the gene according to the present invention into a vector, a method may be used in which cDNA of the gene according to the present invention is first cleaved using an appropriate restriction enzyme and then inserted into a restriction enzyme site or multicloning site of an appropriate vector DNA and ligated into the vector. Further, a method may be used in which a homologous region is respectively provided in one part of a vector and cDNA of the gene according to the present invention, and the vector and the cDNA are connected by an <i>in vitro</i> method using PCR or the like or an <i>in vivo</i> method using yeast or the like.
A recombinant vector according to the present invention can also include a foreign gene or a foreign DNA fragment in addition to the gene according to the present invention. A method for inserting a foreign gene or a foreign DNA fragment into a vector is the same as the method for inserting a DNA fragment according to the present invention into a vector. Any gene or DNA fragment may be used as a foreign gene or a foreign DNA fragment. Thus, the gene according to the present invention can be used as a selective marker gene to indicate paraquat resistance, for example, as with an antibiotic resistance gene for kanamycin or hygromycin or the like.
A transformant according to the present invention is a transformant having the recombinant vector according to the present invention. The transformant according to the present invention can be obtained by introducing the recombinant vector according to the present invention into a host. A host is not particularly limited as long as it is capable of expressing the gene according to the present invention, however a plant is preferred. When the host is a plant, it is possible to obtain a transgenic plant in the manner described below.
A "plant" to be transformed in the present invention may be any of: a whole plant, a plant organ (for example, leaf, petal, stem, root, or seed), plant tissue (for example, epidermis, phloem, parenchyma, or xylem) or a plant culture cell. Examples of the plant that can be used in the transformation include, but are not limited to, a plant belonging to the family <i>Poaceae, Brassicaceae, Solanaceae,</i> or <i>Leguminosae</i> (see below). <i>Poaceae: Oryza sativa, Zea mays</i><i>Brassicaceae: Arabidopsis thaliana</i><i>Solanaceae: Nicotiana tabacum</i><i>Leguminosae: Glycine max</i>
The recombinant vector according to the present invention can be introduced into a plant by a conventional transformation method such as, for example, the electroporation method, Agrobacterium method, particle gun method, or PEG method.
For example, when using the electroporation method, the recombinant vector according to the present invention is introduced into a host by conducting the treatment using an electroporation apparatus equipped with a pulse controller under conditions of a voltage of 500 to 1600 V, at 25 to 1000 µF, for 20 to 30 msec.
When using the particle gun method, the whole plant, a plant organ or plant tissue itself may be used without any treatment, a section thereof may be prepared and then used, or protoplast may be prepared and used. The prepared sample can then be treated using a gene transfer device (for example, PDS-1000/He manufactured by Bio-Rad Inc.). Although the treatment conditions may vary depending on the plant or sample used, the treatment is normally conducted at a pressure of approximately 450 to 2000 psi and a distance of approximately 3 to 12 cm.
A method using the Ti plasmid or Ri plasmid of <i>Agrobacterium</i> takes advantage of a characteristic whereby, when a bacterium belonging to the genus <i>Agrobacterium</i> infects a plant, one part of plasmid DNA possessed by the bacterium is transferred into the genome of the plant. This method can thus be used to introduce the gene according to the present invention into a plant host. Among the bacteria belonging to the genus <i>Agrobacterium,</i> when <i>Agrobacterium tumefaciens</i> infects a plant, it causes the formation of a tumor that is referred to as "crown gall." Further, when <i>Agrobacterium rhizogenes</i> infects a plant, it incites generation of a capillary root. These are caused by a region referred to as a "T-DNA (Transferred DNA) region" of a Ti plasmid or Ri plasmid transferring into a plant at the time of infection to be integrated into the genome of the plant. Accordingly, the DNA to be integrated into a plant genome is first inserted into the T-DNA region of a Ti plasmid or Ri plasmid, and then the DNA can be integrated into the plant genome by infecting the plant host with a bacterium of the genus <i>Agrobacterium.</i>
Examples of the method for transforming a bacterium of the genus <i>Agrobacterium</i> into a plant host include the above described electroporation method, patent gun method and PEG method, as well as an <i>in planta</i> method. Examples of the <i>in planta</i> method include a direct Agrobacterium inoculation method and an infiltration method.
Tumor tissue or shoot, capillary root or the like obtained as the result of the transformation can be used without any treatment for cell culture, tissue culture or organ culture. Alternatively, it can be regenerated in a plant body by administration of a plant hormone (auxin, cytokinin, gibberellin, abscisic acid, ethylene, brassinolide or the like) of an appropriate concentration using a conventional plant tissue culture method.
The gene according to the present invention may also be introduced into a plant by utilizing a plant virus as a vector. Examples of the plant virus that can be used include cauliflower mosaic virus. First, the viral genome is inserted into a vector derived from E. <i>coli</i> or the like to produce a recombinant, and then the gene according to the present invention is inserted into the viral genome. The viral genome modified in this manner is subsequently cleaved from the recombinant using a restriction enzyme, and the gene according to the present invention can then be introduced into a plant host by inoculating the viral genome into the plant host.
In addition to introduction into a plant host as described above, the recombinant vector according to the present invention may also be introduced into bacteria belonging to the genus <i>Escherichia</i> such as <i>E</i>. <i>coli,</i> the genus <i>Bacillus</i> such as <i>Bacillus subtilis,</i> or the genus <i>Pseudomonas</i> such as <i>Pseudomonas putida,</i> as well as yeast such as <i>Saccharomyces cerevisiae</i> and <i>Schizosaccharomyces pombe,</i> animal cells such as COS cell or CHO cell, and insect cells such as Sf9. When using a bacterium such as E. <i>coli</i> or yeast or the like as a host, it is preferable that the recombinant vector according to the present invention is capable of autonomous replication in the bacterium and that it is comprised of a promoter, a ribosome binding sequence, a transcription termination sequence and the gene according to the present invention. It may also comprise a gene regulating the promoter.
The method for introducing the recombinant vector according to the present invention into a bacterium is not particularly limited as long as it is a method that can introduce DNA into a bacterium, and for example a method using calcium ion or the electroporation method may be mentioned.
The method for introducing the recombinant vector according to the present invention into yeast is not particularly limited as long as it is a method that can introduce DNA into yeast, and for example the electroporation method, spheroplast method and lithium acetate method may be mentioned.
When using an animal cell as a host, monkey cell COS-7, Vero, Chinese hamster ovary cell (CHO cell), mouse L-cells or the like can be used. The method for introducing the recombinant vector according to the present invention into an animal cell is not particularly limited as long as it is a method that can introduce DNA into an animal cell, and for example the electroporation method, calcium phosphate method and lipofection method may be mentioned.
When using an insect cell as a host, an Sf9 cell or the like can be used. The method for introducing the recombinant vector according to the present invention into an insect cell is not particularly limited as long as it can introduce DNA into an insect cell, and for example the calcium phosphate method, lipofection method and electroporation method may be mentioned.
It is possible to confirm whether or not the gene according to the present invention has been integrated into a host by using the PCR method, Southern hybridization method, Northern hybridization method or the like. For example, PCR can be conducted after preparing DNA from the transformant and designing a DNA-specific primer. Next, the amplification product is subjected to agarose gel electrophoresis, polyacrylamide gel electrophoresis or capillary electrophoresis or the like, and the product thereof is then stained with ethidium bromide, SYBR Green solution or the like. Thereafter, whether or not transformation has occurred can be confirmed by the detection of the amplification product as a single band. It is also possible to detect the amplification product after conducting PCR using a primer that has been labeled previously with a fluorescent dye or the like. In addition, a method may be employed in which the amplification product is bound to a solid phase of a microplate or the like to enable confirmation of the amplification product by fluorescence or enzyme reaction or the like.
A plant body according to the present invention is one having a recombinant vector comprising the gene according to the present invention and having paraquat resistance. As used herein, the term "plant body" refers to a whole plant transformed with a recombinant vector comprising the gene according to the present invention. The plant body according to the present invention can be obtained by introducing the above recombinant vector into a plant cell or the like and regenerating a transgenic plant body from the obtained transgenic plant cell. As a regeneration method, a method may be employed in which transformed cells in a callus form are transferred to a culture medium in which the type and concentration of hormones have been modified and allowed to culture, and an adventitious embryo is allowed to form to obtain a complete plant body. Examples of the culture medium to be used include LS medium and MS medium. Introduction of a recombinant vector into a plant cell or the like can be performed by a method similar to the method described above.
In the plant body according to the present invention, a protein imparting paraquat resistance that is encoded by the gene according to the present invention is overexpressed throughout the whole plant body. Thus, the plant body according to the present invention can have resistance to paraquat.
A method of screening for transgenic plants according to the present invention is a method in which the recombinant vector according to the present invention is introduced into plants and paraquat resistance is used as an indicator to screen for transgenic plants. Transformation can be verified by employing the gene according to the present invention as a selective marker gene to indicate paraquat resistance. Examples of the screening method include a method in which plants transformed by the recombinant vector according to the present invention are grown in a paraquat-containing medium and the screening is carried out based on variations in the life and death as well as growth of the plants. The concentration of paraquat used for the screening may vary depending on the species and size of plants and the like, however, for example, when <i>Arabidopsis thaliana</i> is used as a host, paraquat may be present in a medium at a concentration of preferably 0.1 to 3.0 µM, more preferably 1.0 to 3.0 µM, and most preferably 3.0 µM. A non-transgenic plant, i.e., a wild-type plant, develops chlorosis and dies in a paraquat-containing medium. In contrast, a plant transformed with the recombinant vector according to the present invention remains green even in a paraquat-containing medium. Thus, it is possible to verify a clear difference in growth in a paraquat-containing medium between a non-transgenic plant and a plant transformed with the recombinant vector according to the present invention.
When employing antibiotic resistance or herbicide resistance as an indicator, false positivity may be observed at the screening stage because of the existence of a difference in sensitivity among the plant. In contrast, paraquat is a non-selective and potent herbicide that can kill all plants. Consequently, in the method of screening transgenic plants according to the present invention, false positivity is not observed in the screening stage. Further, according to the method of screening transgenic plants according to the present invention, resistance can be effectively confirmed at an early stage of growth.
[Examples]
The present invention will be explained in detail further below with reference to the following examples. However, the examples are not intended to limit the technical scope of the invention.
[Example 1] Isolation of paraquat resistance gene
In this example, Weigel T-DNA lines acquired from Nottingham Arabidopsis Stock Center (http://nasc.nott.ac.uk/) were used as activation tag lines of <i>Arabidopsis thaliana.</i>
(1) Screening of individuals capable of growing in paraquat-containing medium using activation-tagged lines of <i>Arabidopsis thaliana</i> (Weigel T-DNA lines)
Seeds of Weigel T-DNA lines were sterilely inoculated in 1/2 MS agar (1 %) culture medium (2.3 g/l of Murashige and Skoog Plant Salt Mixture (manufactured by Wako Pure Chemical Industries Ltd.), 1.5 mg/l of thiamine hydrochloride, 2.5 mg/l of nicotinic acid, 0.25 mg/l of pyridoxine hydrochloride, 1.5% of sucrose, 1% of agar) containing 3 µM of paraquat (methyl viologen, manufactured by Sigma Chemical Co.), and cultured at 22°C under irradiation of light of 60 µE/m<sup>2</sup>/s (cycle of 16 hrs photoperiod/8 hrs dark period). Approximately 10 days after culture, individuals growing in the paraquat-containing medium were screened.
(2) Estimation of insertion sites of T-DNA from the screened activation-tagged lines by the TAIL-PCR method
Seeds of Weigel T-DNA lines from which screened individuals originated were planted in a pot containing vermiculite (manufactured by Asahi Kagaku Kogyo Co., Ltd.) and grown for approximately one month at 23°C under a light intensity of 100 µE/m<sup>2</sup>/s with a photoperiod condition of 16 hrs photoperiod/8 hrs dark period.
Genome DNA was prepared from leaves of cultivated individuals using the DNeasy Plant Mini Kit (manufactured by QIAGEN), and three types of specific primers (TL1: SEQ ID NO: 31; TL2: SEQ ID NO: 32; TL3: SEQ ID NO: 33) were designed for the vicinity of a T-DNA left sequence (T-DNA left border: SEQ ID NO: 30) of an activation-tagging vector (pSKI015: GenBank accession No. AF187951) used with the Weigel T-DNA lines. TAIL-PCR (<nplcit id="ncit0025" npl-type="b"><text>Shokubutsu No PCR Jikken Purotokoru (Protocols of PCR Experiments for Plants), (Eds. Shimamoto K. & Sasaki T.), New Edition, 2000, pp 83-89, Shujunsha Co., Ltd., Tokyo</text></nplcit>; <nplcit id="ncit0026" npl-type="s"><text>Genomics, 25, 674-681, 1995</text></nplcit>; <nplcit id="ncit0027" npl-type="s"><text>Plant J., 8, 457-463, 1995</text></nplcit>) was then performed using the specific primers and a random primer 1 (SEQ ID NO: 34) and the PCR reaction mixture and reaction conditions described below to amplify genome DNA bordering the T-DNA. In SEQ ID NO: 34, n represents a, g, c, or t (location: 1 and 11), s represents g or c (location: 7), and w represents a or t (location: 8 and 13).
The composition of the reaction mixture and the PCR conditions for the first-round PCR are listed in tables 2 and 3. <tables id="tabl0002" num="0002"><table frame="none"><title>[Table 2]</title><tgroup cols="2" colsep="0"><colspec colnum="1" colname="col1" colwidth="77mm" /><colspec colnum="2" colname="col2" colwidth="18mm" /><tbody><row rowsep="0"><entry>Template (genome DNA):</entry><entry>10 ng</entry></row><row rowsep="0"><entry>10x PCR buffer (manufactured by TAKARA BIO Inc.):</entry><entry>2 µl</entry></row><row rowsep="0"><entry>2.5 mM dNTPs (manufactured by TAKARA BIO Inc.):</entry><entry>1.6 µl</entry></row><row rowsep="0"><entry>First specific primer (TL1: SEQ ID NO: 31):</entry><entry>3 pmol</entry></row><row rowsep="0"><entry>Random primer 1 (SEQ ID NO: 34):</entry><entry>80 pmol</entry></row><row><entry>AmpliTaq (manufactured by Applied Biosystems):</entry><entry>0.8 units</entry></row><row rowsep="0"><entry>Total volume</entry><entry>20 µl</entry></row></tbody></tgroup></table></tables><tables id="tabl0003" num="0003"><table frame="none"><title>[Table 3]</title><tgroup cols="2" colsep="0" rowsep="0"><colspec colnum="1" colname="col1" colwidth="10mm" /><colspec colnum="2" colname="col2" colwidth="95mm" /><tbody><row><entry>#1:</entry><entry>94°C (1 min)/95°C (1 min)</entry></row><row><entry>#2:</entry><entry>94°C (1 min)/65°C (1 min)/72°C (3 min) x 5 cycles</entry></row><row><entry>#3:</entry><entry>94°C (1 min)/25°C (3 min) → to 72°C at 3 min/72°C (3 min) x 1 cycle</entry></row><row><entry>#4:</entry><entry>94°C (30 sec)/68°C (1 min)/72°C (3 min)</entry></row><row><entry /><entry>94°C (30 sec)/68°C (1 min)/72°C (3 min)</entry></row><row><entry /><entry>94°C (30 sec)/44°C (1 min)/72°C (3 min) x 14 cycles</entry></row><row><entry>#5</entry><entry>72°C (5 min)</entry></row></tbody></tgroup></table></tables>
The composition of the reaction mixture and the PCR conditions for the second-round PCR are listed in tables 4 and 5. <tables id="tabl0004" num="0004"><table frame="none"><title>[Table 4]</title><tgroup cols="2" colsep="0"><colspec colnum="1" colname="col1" colwidth="83mm" /><colspec colnum="2" colname="col2" colwidth="18mm" /><tbody><row rowsep="0"><entry>Template (a 50-fold dilution of product of first-round PCR):</entry><entry>1 µl</entry></row><row rowsep="0"><entry>10x PCR buffer:</entry><entry>2 µl</entry></row><row rowsep="0"><entry>250 µM dNTPs:</entry><entry>2 µl</entry></row><row rowsep="0"><entry>Second specific primer (TL2: SEQ ID NO: 32):</entry><entry>4 pmol</entry></row><row rowsep="0"><entry>Random primer 1 (SEQ ID NO: 34):</entry><entry>60 pmol</entry></row><row><entry>AmpliTaq:</entry><entry>0.6 units</entry></row><row rowsep="0"><entry>Total volume</entry><entry>20 µl</entry></row></tbody></tgroup></table></tables><tables id="tabl0005" num="0005"><table frame="none"><title>[Table 5]</title><tgroup cols="2" colsep="0" rowsep="0"><colspec colnum="1" colname="col1" colwidth="10mm" /><colspec colnum="2" colname="col2" colwidth="74mm" /><tbody><row><entry>#6:</entry><entry>94°C (30 sec)/64°C (1 min)/72°C (3 min)</entry></row><row><entry /><entry>94°C (30 sec)/64°C (1 min)/72°C (3 min)</entry></row><row><entry /><entry>94°C (30 sec)/44°C (1 min)/72°C (3 min) x 10 cycles</entry></row><row><entry>#5</entry><entry>72°C (5 min)</entry></row></tbody></tgroup></table></tables>
The composition of the reaction mixture and the PCR conditions for the third-round PCR are listed in tables 6 and 7. <tables id="tabl0006" num="0006"><table frame="none"><title>[Table 6]</title><tgroup cols="2" colsep="0"><colspec colnum="1" colname="col1" colwidth="89mm" /><colspec colnum="2" colname="col2" colwidth="18mm" /><tbody><row rowsep="0"><entry>Template (a 50-fold dilution of product of second-round PCR):</entry><entry>1 µl</entry></row><row rowsep="0"><entry>10x PCR buffer:</entry><entry>10 µl</entry></row><row rowsep="0"><entry>2.5 mM dNTPs:</entry><entry>1 µl</entry></row><row rowsep="0"><entry>Third specific primer (TL3: SEQ ID NO: 33):</entry><entry>30 pmol</entry></row><row rowsep="0"><entry>Random primer 1 (SEQ ID NO: 34):</entry><entry>300 pmol</entry></row><row><entry>AmpliTaq:</entry><entry>3 units</entry></row><row rowsep="0"><entry>Total volume</entry><entry>100 µl</entry></row></tbody></tgroup></table></tables><tables id="tabl0007" num="0007"><table frame="none"><title>[Table 7]</title><tgroup cols="2" colsep="0" rowsep="0"><colspec colnum="1" colname="col1" colwidth="10mm" /><colspec colnum="2" colname="col2" colwidth="74mm" /><tbody><row><entry>#7:</entry><entry>94°C (1 min)/44°C (1 min)/72°C (3 min) x 20 cycles</entry></row><row><entry>#5</entry><entry>72°C (5 min)</entry></row></tbody></tgroup></table></tables>
Next, after subjecting the reaction products from the second-round PCR and third-round PCR to electrophoresis on agarose gel, the presence or absence of amplification and the specificity of the reaction products were verified.
Further, using the specific primer TL3 (SEQ ID NO: 33), the amplification product of the third-round PCR was directly sequenced using the ABI PRISM Dye Terminator Cycle Sequencing Kit (Applied Biosystems) and the nucleotide sequence was then determined using the ABI PRISM 310 genetic analyzer (Applied Biosystems). As a result, 278-bp sequence information was obtained (SEQ ID NO: 35). In SEQ ID NO: 35, n represents a, g, c, or t (location: 13, 35, 73, 108, 156, 190, 198 and 201). A search was performed for the obtained sequence on databases having the entire nucleotide sequence of <i>Arabidopsis thaliana,</i> and it was found that the insertion site is located at 77240 bp of BAC clone F17123.
(3) Isolation of cDNA of paraquat resistance gene
Seeds of <i>Arabidopsis thaliana (Arabidopsis thaliana</i> ecotype Columbia (Col-0)) were planted in a pot containing vermiculite (Asahi Kagaku Kogyo Co., Ltd.) and allowed to grow for approximately one month at 23°C under a light intensity of 100 µE/m<sup>2</sup>/s with a photoperiod condition of 16 hrs photoperiod/8 hrs dark period.
After growing, leaves of individuals were frozen using liquid nitrogen. Subsequently, total RNA was extracted using the RNeasy Plant Mini Kit (manufactured by QIAGEN). Thereafter, cDNA was synthesized from the extracted total RNA using the ProSTAR First Strand RT-PCR Kit (manufactured by STRATAGEN).
Based on the sequence of a putative open reading frame (ORF) gene present within an adjacent 10 kb of a structural gene having the nucleotide sequence (SEQ ID NO: 35) obtained in the above (2), a primer 141dF (SEQ ID NO: 36) and a primer 141dR (SEQ ID NO: 37) were designed for the putative structural gene, and PCR was then performed using these primers and the following reaction mixture (Table 8) containing Takara EX-Taq (manufactured by TAKARA BIO Inc.) employing the above synthesized cDNA as a template. <tables id="tabl0008" num="0008"><table frame="none"><title>[Table 8]</title><tgroup cols="2" colsep="0"><colspec colnum="1" colname="col1" colwidth="56mm" /><colspec colnum="2" colname="col2" colwidth="16mm" /><tbody><row rowsep="0"><entry>Template (cDNA):</entry><entry>50 ng</entry></row><row rowsep="0"><entry>10x Ex Taq buffer (TAKARA BIO Inc.):</entry><entry>2 µl</entry></row><row rowsep="0"><entry>dNTPs:</entry><entry>200 µM</entry></row><row rowsep="0"><entry>Each primer:</entry><entry>0.2 µM</entry></row><row><entry>Takara EX-Taq:</entry><entry>1 unit</entry></row><row rowsep="0"><entry>Total volume</entry><entry>20 µl</entry></row></tbody></tgroup></table></tables>
Thirty cycles of 94°C (30 sec)/55°C (30 sec)/72°C (60 sec) were employed as the reaction conditions.
The amplification product was cloned into the pGEM-T Easy vector (manufactured by Promega), and the nucleotide sequence was then determined using the ABI PRISM 310 genetic analyzer (Applied Biosystems). As a result, a cDNA fragment of 857 bp was obtained (SEQ ID NO: 1). This cDNA fragment was designated as AtMVR gene, and the pGEM-T Easy vector containing AtMVR gene was designated as pAtMVR. The amino acid sequence encoded by the AtMVR gene is shown in SEQ ID NO: 2.
[Example 2] Search for AtMVR homologous gene with respect to AtMVR gene
The search was made on databases having the entire nucleotide sequence of <i>Arabidopsis thaliana</i> based on the nucleotide sequence of the AtMVR gene and found that in addition to the nucleotide sequence of the AtMVR gene there are 13 AtMVR homologous genes on the <i>Arabidopsis thaliana</i> genome.
The respective AtMVR homologous genes were designated as AtMVR3-1 to AtMVR3-13. The nucleotide sequence of each of the AtMVR homologous genes and the putative amino acid sequence encoded by the relevant AtMVR homologous gene are shown by the SEQ ID NOs. listed in Table 9 below. Table 9 also lists the results of homology analysis between the AtMVR gene and each AtMVR homologous gene. The homology analysis was conducted using BLAST P at the amino acid level. The term "Identities" refers to 100% correspondence in terms of amino acids. Amino acids may be classified based on the chemical properties of their side chains. In the BLOSUM62 amino acid substitution matrix, amino acids are classified into: an amino acid with a mercapto group (C); hydrophilic amino acids that have low molecular weights (S, T, P, A, G); acidic amino acids (N, D, E, Q); basic amino acids (H, R, K); hydrophobic amino acids that have low molecular weights (M, I, L, V); and aromatic amino acids (F, Y, W). In Table 9, the term "Identities" refers to 100% correspondence in terms of amino acids and the term "Positives" refers to the numerical value when amino acids having a positive score in the BLOSUM 62 amino acid substitution matrix are added to those having 100% correspondence. <tables id="tabl0009" num="0009"><table frame="all"><title>[Table 9]</title><tgroup cols="5"><colspec colnum="1" colname="col1" colwidth="51mm" /><colspec colnum="2" colname="col2" colwidth="35mm" /><colspec colnum="3" colname="col3" colwidth="35mm" /><colspec colnum="4" colname="col4" colwidth="23mm" /><colspec colnum="5" colname="col5" colwidth="23mm" /><thead><row><entry valign="top">Name of AtMVR homologous gene</entry><entry align="center" valign="top">Nucleotide sequence</entry><entry align="center" valign="top">Amino acid sequence</entry><entry align="center" valign="top">Identities (%)</entry><entry align="center" valign="top">Positives (%)</entry></row></thead><tbody><row><entry>AtMVR3-1</entry><entry>SEQ ID NO: 4</entry><entry>SEQ ID NO: 5</entry><entry align="center">57</entry><entry align="center">70</entry></row><row><entry>AtMVR3-2</entry><entry>SEQ ID NO: 6</entry><entry>SEQ ID NO: 7</entry><entry align="center">55</entry><entry align="center">69</entry></row><row><entry>AtMVR3-3</entry><entry>SEQ ID NO: 8</entry><entry>SEQ ID NO: 9</entry><entry align="center">39</entry><entry align="center">56</entry></row><row><entry>AtMVR3-4</entry><entry>SEQ ID NO: 10</entry><entry>SEQ ID NO: 11</entry><entry align="center">39</entry><entry align="center">55</entry></row><row><entry>AtMVR3-5</entry><entry>SEQ ID NO: 12</entry><entry>SEQ ID NO: 13</entry><entry align="center">37</entry><entry align="center">54</entry></row><row><entry>AtMVR3-6</entry><entry>SEQ ID NO: 14</entry><entry>SEQ ID NO: 15</entry><entry align="center">36</entry><entry align="center">52</entry></row><row><entry>AtMVR3-7</entry><entry>SEQ ID NO: 16</entry><entry>SEQ ID NO: 17</entry><entry align="center">34</entry><entry align="center">52</entry></row><row><entry>AtMVR3-8</entry><entry>SEQ ID NO: 18</entry><entry>SEQ ID NO: 19</entry><entry align="center">34</entry><entry align="center">51</entry></row><row><entry>AtMVR3-9</entry><entry>SEQ ID NO: 20</entry><entry>SEQ ID NO: 21</entry><entry align="center">37</entry><entry align="center">58</entry></row><row><entry>AtMVR3-10</entry><entry>SEQ ID NO: 22</entry><entry>SEQ ID NO: 23</entry><entry align="center">25</entry><entry align="center">44</entry></row><row><entry>AtMVR3-11</entry><entry>SEQ ID NO: 24</entry><entry>SEQ ID NO: 25</entry><entry align="center">33*</entry><entry align="center">51*</entry></row><row><entry>AtMVR3-12</entry><entry>SEQ ID NO: 26</entry><entry>SEQ ID NO: 27</entry><entry align="center">25</entry><entry align="center">41</entry></row><row><entry>AtMVR3-13</entry><entry>SEQ ID NO: 28</entry><entry>SEQ ID NO: 29</entry><entry align="center">22</entry><entry align="center">41</entry></row></tbody></tgroup><tgroup cols="5" rowsep="0"><colspec colnum="1" colname="col1" colwidth="51mm" /><colspec colnum="2" colname="col2" colwidth="35mm" /><colspec colnum="3" colname="col3" colwidth="35mm" /><colspec colnum="4" colname="col4" colwidth="23mm" /><colspec colnum="5" colname="col5" colwidth="23mm" /><tbody><row><entry namest="col1" nameend="col5" align="justify">* The comparison with AtMVR3-11 shows the result of homology comparison with a partial sequence of AtMVR3-11.</entry></row></tbody></tgroup></table></tables>
As shown in Table 9, homology between AtMVR and the 13 AtMVR homologous genes ranged from 22 to 57% for Identities and from 41 to 70% for Positives.
[Example 3] Construction of AtMVR expression vector for plant and production of AtMVR transgenic plant
The transformation techniques applied herein were in accordance with a vector system described by <nplcit id="ncit0028" npl-type="s"><text>Pellegrineschi et al. (Biochemical Society Transitions 23, 247-250, 1995</text></nplcit>) based on the Agrobacterium gene transport system outlined by <nplcit id="ncit0029" npl-type="b"><text>Hinchee et al. (Plant Cell and Tissue Culture, pp. 231-270, Eds. I. K. Vasil, T. A Thorpe, Kluwer Academic Publisher, 1994</text></nplcit>).
(1) Construction of AtMVR expression vector for plant
The AtMVR gene sequence was excised from pAtMVR using SacI/SacII and subcloned into pBlueScript (STRATAGENE). Subsequently, a fragment containing the AtMVR gene sequence was cleaved with XbaI/SacI and introduced at Xba1/SacI site that is present downstream of the CaMV 35S promoter of pBI121 (manufactured by Clontech). The resulting vector was used below as an AtMVR expression vector for plant.
(2) Production of AtMVR transgenic plant
The AtMVR expression vector for plant produced in the above (1) was introduced into <i>Agrobacterium tumefaciens</i> LBA4404 strain by the electroporation method (Plant Molecular Biology Manual, Second Edition, B. G. Stanton, A. S. Robbert, Kluwer Academic Publishers, 1994). Subsequently, the <i>Agrobacterium tumefaciens</i> having the AtMVR expression vector for plant introduced therein was introduced into wild-type <i>Arabidopsis thaliana</i> ecotype Col-0 by an infiltration method described by <nplcit id="ncit0030" npl-type="s"><text>Clough et al. (The Plant Journal 16: 735-743, 1998</text></nplcit>).
Transformants were screened in a kanamycin-containing medium, and a T3 generation plant (homozygous line having 1 AtMVR gene introduced) was produced by self-pollination.
Next, the amount of the introduced AtMVR gene expressed was examined. Seeds of a transformant produced as described above and a non-transformant were respectively planted in pots containing vermiculite (Asahi Kagaku Kogyo Co., Ltd.) and allowed to grow for approximately one month under a light intensity of 100 µE/m<sup>2</sup>/s at 23°C with a photoperiod condition of 16 hrs photoperiod/8 hrs dark period.
After growing, total RNA was extracted from the transformant and the wild-type <i>Arabidopsis thaliana</i> ecotype Col-0 non-transformant using the RNeasy Plant Mini Kit (QIAGEN). Thereafter, 1 µg of RNA was subjected to reverse transcription using the ProSTAR First Strand RT-PCR Kit (STRATAGEN). PCR was then performed using the following reaction mixture (Table 10) containing Takara EX-Taq (TAKARA BIO) employing 1/50 volume of the synthesized cDNA as a template and using primers for the AtMVR gene (primer 141d1 (SEQ ID NO: 38) and primer 141d2 (SEQ ID NO: 39)). <tables id="tabl0010" num="0010"><table frame="none"><title>[Table 10]</title><tgroup cols="2" colsep="0"><colspec colnum="1" colname="col1" colwidth="56mm" /><colspec colnum="2" colname="col2" colwidth="16mm" /><tbody><row rowsep="0"><entry>PCR reaction mixture:</entry><entry /></row><row rowsep="0"><entry>Template (cDNA):</entry><entry>50 ng</entry></row><row rowsep="0"><entry>10x Ex Taq buffer (TAKARA BIO Inc.):</entry><entry>2 µl</entry></row><row rowsep="0"><entry>dNTPs:</entry><entry>200 µM</entry></row><row rowsep="0"><entry>Each primer:</entry><entry>0.2 µM</entry></row><row><entry>Takara EX-Taq:</entry><entry>1 unit</entry></row><row rowsep="0"><entry>Total volume</entry><entry>20 µl</entry></row></tbody></tgroup></table></tables>
Thirty cycles of 94°C (30 sec)/55°C (30 sec)/72°C (60 sec) were employed as the reaction conditions.
The amplification products were subjected to electrophoresis on agarose gel. <figref idref="f0001">FIG. 1</figref> shows the results of electrophoresis. As can be seen from <figref idref="f0001">FIG. 1</figref>, in comparison to the non-transformant, the produced transformant overexpressed the AtMVR gene.
[Example 4] Evaluation of paraquat resistance of AtMVR gene transformant
Seeds derived from the produced AtMVR gene transformant and non-transformant (wild-type <i>Arabidopsis thaliana</i> ecotype Col-0) were sterilely inoculated in 1/2 MS agar (1%) medium (2.3 g/l of Murashige and Skoog Plant Salt Mixture (Wako Pure Chemical Industries Ltd.), 1.5 mg/l of thiamine hydrochloride, 2.5 mg/l of nicotinic acid, 0.25 mg/l of pyridoxine hydrochloride, 1.5% of sucrose) containing 3 µM of paraquat (methyl viologen (Sigma Chemical Co.)), and cultured for eight days at 22°C under irradiation of light of 60 µmol/m<sup>2</sup>/s (cycle of 16 hrs photoperiod/8 hrs dark period). After culture, the growth of germinated individuals was evaluated. The results are shown in <figref idref="f0002">FIG. 2</figref>, wherein <figref idref="f0002">FIG. 2B</figref> is a photograph showing growth of an AtMVR gene transformant and a non-transformant in a 1/2 MS culture medium without paraquat, and <figref idref="f0002">FIG. 2C</figref> is a photograph showing growth of an AtMVR gene transformant and a non-transformant in a 1/2 MS culture medium with paraquat. <figref idref="f0002">FIG. 2A</figref> is a schematic diagram showing the location of the AtMVR gene transformant and the non-transformant in <figref idref="f0002">FIGS. 2B and 2C</figref>.
As can be seen from <figref idref="f0002">FIG. 2B</figref>, the results showed that in the culture medium without paraquat, the AtMVR gene transformant exhibited the same growth as the non-transformant. Meanwhile, as can be seen from <figref idref="f0002">FIG. 2C</figref>, in a medium containing paraquat the non-transformant developed chlorosis and died, i.e. growth was remarkably inhibited, while in contrast the seedling of the AtMVR gene transformant was able to grow. Thus, it was confirmed that in a medium without paraquat, the AtMVR gene transformant exhibited the same growth as a non-transformant regardless of expression of the AtMVR gene, and also that in a medium with paraquat, the AtMVR gene transformant had clearly greater paraquat resistance than the non-transformant.
Free Text for Sequence Listing
SEQ ID NOS: 31 to 39 are primers.
In SEQ ID NO: 34, n represents a, g, c, or t (location: 1 and 11), s represents g or c (location: 7), and w represents a or t (location: 8 and 13).
In SEQ ID NO: 35, n represents a, g, c, or t (location: 13, 35, 73, 108, 156, 190, 198 and 201).
Industrial Applicability
According to the present invention there are provided methods defined in claims 1 and 2, respectively. A paraquat resistance gene used in the methods according to the present invention is capable of imparting resistance that is specific to paraquat without affecting growth regulation that undergoes control by the generation of active oxygens under various environments.
SEQUENCE LISTING
<ul id="ul0002" list-style="none"><li><110> TOYOTA MOTOR CORPORATION OKAYAMA PREFECTURE</li><li><120> A PARAQUAT RESISTANCE GENE AND A VASCULAR TISSUE- AND TRICHOME-SPECIFIC PROMOTER</li><li><130> PH-2160</li><li><140> <141></li><li><150> <patcit id="pcit0009" dnum="JP2003322051A"><text>JP 2003-322051</text></patcit> <151> 2003-09-12</li><li><160> 41</li><li><170> PatentIn Ver. 2. 1</li><li><210> 1 <211> 855 <212> DNA <213> Arabidopsis thaliana</li><li><400> 1 <img file="EP1514941B1_D0001.tif" /><img file="EP1514941B1_D0002.tif" /></li><li><210> 2 <211> 272 <212> PRT <213> Arabidopsis thaliana</li><li><400> 2 <img file="EP1514941B1_D0003.tif" /><img file="EP1514941B1_D0004.tif" /><img file="EP1514941B1_D0005.tif" /></li><li><210> 4 <211> 822 <212> DNA <213> Arabidopsis thaliana</li><li><400> 4 <img file="EP1514941B1_D0006.tif" /><img file="EP1514941B1_D0007.tif" /></li><li><210> 5 <211> 272 <212> PRT <213> Arabidopsis thaliana</li><li><400> 5 <img file="EP1514941B1_D0008.tif" /><img file="EP1514941B1_D0009.tif" /><img file="EP1514941B1_D0010.tif" /></li><li><210> 6 <211> 792 <212> DNA <213> Arabidopsis thaliana</li><li><400> 6 <img file="EP1514941B1_D0011.tif" /><img file="EP1514941B1_D0012.tif" /></li><li><210> 7 <211> 263 <212> PRT <213> Arabidopsis thaliana</li><li><400> 7 <img file="EP1514941B1_D0013.tif" /><img file="EP1514941B1_D0014.tif" /><img file="EP1514941B1_D0015.tif" /></li><li><210> 8 <211> 984 <212> DNA <213> Arabidopsis thaliana</li><li><400> 8 <img file="EP1514941B1_D0016.tif" /></li><li><210> 9 <211> 327 <212> PRT <213> Arabidopsis thaliana</li><li><400> 9 <img file="EP1514941B1_D0017.tif" /><img file="EP1514941B1_D0018.tif" /><img file="EP1514941B1_D0019.tif" /></li><li><210> 10 <211> 858 <212> DNA <213> Arabidopsis thaliana</li><li><400> 10 <img file="EP1514941B1_D0020.tif" /></li><li><210> 11 <211> 285 <212> PRT <213> Arabidopsis thaliana</li><li><400> 11 <img file="EP1514941B1_D0021.tif" /><img file="EP1514941B1_D0022.tif" /><img file="EP1514941B1_D0023.tif" /></li><li><210> 12 <211> 849 <212> DNA <213> Arabidopsis thaliana</li><li><400> 12 <img file="EP1514941B1_D0024.tif" /></li><li><210> 13 <211> 282 <212> PRT <213> Arabidopsis thaliana</li><li><400> 13 <img file="EP1514941B1_D0025.tif" /><img file="EP1514941B1_D0026.tif" /></li><li><210> 14 <211> 810 <212> DNA <213> Arabidopsis thaliana</li><li><400> 14 <img file="EP1514941B1_D0027.tif" /></li><li><210> 15 <211> 269 <212> PRT <213> Arabidopsis thaliana</li><li><400> 15 <img file="EP1514941B1_D0028.tif" /><img file="EP1514941B1_D0029.tif" /><img file="EP1514941B1_D0030.tif" /></li><li><210> 16 <211> 813 <212> DNA <213> Arabidopsis thaliana</li><li><400> 16 <img file="EP1514941B1_D0031.tif" /><img file="EP1514941B1_D0032.tif" /></li><li><210> 17 <211> 270 <212> PRT <213> Arabidopsis thaliana</li><li><400> 17 <img file="EP1514941B1_D0033.tif" /><img file="EP1514941B1_D0034.tif" /><img file="EP1514941B1_D0035.tif" /></li><li><210> 18 <211> 816 <212> DNA <213> Arabidopsis thaliana</li><li><400> 18 <img file="EP1514941B1_D0036.tif" /></li><li><210> 19 <211> 271 <212> PRT <213> Arabidopsis thaliana</li><li><400> 19 <img file="EP1514941B1_D0037.tif" /><img file="EP1514941B1_D0038.tif" /></li><li><210> 20 <211> 705 <212> DNA <213> Arabidopsis thaliana</li><li><400> 20 <img file="EP1514941B1_D0039.tif" /></li><li><210> 21 <211> 234 <212> PRT <213> Arabidopsis thaliana</li><li><400> 21 <img file="EP1514941B1_D0040.tif" /><img file="EP1514941B1_D0041.tif" /><img file="EP1514941B1_D0042.tif" /></li><li><210> 22 <211> 795 <212> DNA <213> Arabidopsis thaliana</li><li><400> 22 <img file="EP1514941B1_D0043.tif" /></li><li><210> 23 <211> 264 <212> PRT <213> Arabidopsis thaliana</li><li><400> 23 <img file="EP1514941B1_D0044.tif" /><img file="EP1514941B1_D0045.tif" /></li><li><210> 24 <211> 654 <212> DNA <213> Arabidopsis thaliana</li><li><400> 24 <img file="EP1514941B1_D0046.tif" /></li><li><210> 25 <211> 217 <212> PRT <213> Arabidopsis thaliana</li><li><400> 25 <img file="EP1514941B1_D0047.tif" /><img file="EP1514941B1_D0048.tif" /><img file="EP1514941B1_D0049.tif" /></li><li><210> 26 <211> 837 <212> DNA <213> Arabidopsis thaliana</li><li><400> 26 <img file="EP1514941B1_D0050.tif" /></li><li><210> 27 <211> 278 <212> PRT <213> Arabidopsis thaliana</li><li><400> 27 <img file="EP1514941B1_D0051.tif" /><img file="EP1514941B1_D0052.tif" /></li><li><210> 28 <211> 816 <212> DNA <213> Arabidopsis thaliana</li><li><400> 28 <img file="EP1514941B1_D0053.tif" /></li><li><210> 29 <211> 271 <212> PRT <213> Arabidopsis thaliana</li><li><400> 29 <img file="EP1514941B1_D0054.tif" /><img file="EP1514941B1_D0055.tif" /><img file="EP1514941B1_D0056.tif" /></li><li><210> 30 <211> 24 <212> DNA <213></li><li><400> 30 gcggcagcgg cggcaggata tatt 24</li><li><210> 31 <211> 24 <212> DNA <213> Artificial Sequence</li><li><220> <223> Description of Artificial Sequence:primer</li><li><400> 31 tgctttcgcc tataaatacg acgg 24</li><li><210> 32 <211> 23 <212> DNA <213> Artificial Sequence</li><li><220> <223> Description of Artificial Sequence:primer</li><li><400> 32 cgctgcggac atctacattt ttg 23</li><li><210> 33 <211> 22 <212> DNA <213> Artificial Sequence</li><li><220> <223> Description of Artificial Sequence:primer</li><li><400> 33 tcccggacat gaagccattt ac 22</li><li><210> 34 <211> 16 <212> DNA <213> Artificial Sequence</li><li><220> <221> modified base <222> 1 and 11 <223> n represents a, g, c or t</li><li><220> <221> modified base <222> 7 <223> s represents g or c</li><li><220> <221> modified base <222> 8 and 13 <223> w represents a or t</li><li><220> <223> Description of Artificial Sequence:primer</li><li><400> 34 ngtcgaswga nawgaa 16</li><li><210> 35 <211> 278 <212> DNA <213></li><li><220> <221> modified base <222> 13, 35, 73, 108, 156, 190, 198 and 201 <223> n represents a, g, c or t</li><li><400> 35 <img file="EP1514941B1_D0057.tif" /></li><li><210> 36 <211> 20 <212> DNA <213> Artificial Sequence</li><li><220> <223> Description of Artificial Sequence:primer</li><li><400> 36 cttcttcaat catcaccatg 20</li><li><210> 37 <211> 20 <212> DNA <213> Artificial Sequence</li><li><220> <223> Description of Artificial Sequence:primer</li><li><400> 37 tagcttgaac cggcgcaaat 20</li><li><210> 38 <211> 20 <212> DNA <213> Artificial Sequence</li><li><220> <223> Description of Artificial Sequence:primer</li><li><400> 38 gtacgtttta gtaacagtct 20</li><li><210> 39 <211> 20 <212> DNA <213> Artificial Sequence</li><li><220> <223> Description of Artificial Sequence:primer</li><li><400> 39 gattagcagt gactaactcc 20</li></ul>
Contents5
59 sheets
Sheet 1 Sheet 2 Sheet 3 Sheet 4 Sheet 5 Sheet 6 Sheet 7 Sheet 8 Sheet 9 Sheet 10 Sheet 11 Sheet 12 Sheet 13 Sheet 14 Sheet 15 Sheet 16 Sheet 17 Sheet 18 Sheet 19 Sheet 20 Sheet 21 Sheet 22 Sheet 23 Sheet 24 Sheet 25 Sheet 26 Sheet 27 Sheet 28 Sheet 29 Sheet 30 Sheet 31 Sheet 32 Sheet 33 Sheet 34 Sheet 35 Sheet 36 Sheet 37 Sheet 38 Sheet 39 Sheet 40 Sheet 41 Sheet 42 Sheet 43 Sheet 44 Sheet 45 Sheet 46 Sheet 47 Sheet 48 Sheet 49 Sheet 50 Sheet 51 Sheet 52 Sheet 53 Sheet 54 Sheet 55 Sheet 56 Sheet 57 Sheet 58 Sheet 59
4 priority claims, no other members on record
Priority claims4
| Document | Office | Kind | Date |
|---|---|---|---|
| 2003322051 | Japan | A | |
| 2003322051 | Japan | – | |
| 2003322051 | – | – | – |
| JP20030322051 | – | – | – |
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Numbers
- Publication
- 1514941
- Publication, DOCDB
- 1514941
- Publication, EPODOC
- EP1514941
- Application
- 4021478
- Application, DOCDB
- 04021478
- Application, EPODOC
- EP20040021478
Titles3
- German
- Paraquat Resistenz-Gen
- English
- Paraquat resistance gene
- French
- Gène de résistance à la paraquat
Classification
- CPC, 2
- C12N15/8274
- C12N15/8223
- IPC, 9
- A01H5 00
- C12N15 82
- C07K14 415
- C12N1 15
- C12N1 19
- C12N1 21
- C12N5 10
- C12N15 09
- C12Q1 68
Designated states5
- Contracting states, 5
- Germany
- Spain
- France
- United Kingdom
- Italy
