National Institute of Agrobiological Sciences

Riken Corporation

Incorporated Administrative Agency, National Agriculture and Bio-Oriented Research Organization

National Agriculture and Bio-Oriented Research Organization

Bio-Oriented Technology Research Advancement Institution

Hiroshi Takatsuji

Shoji Sugano

Shingo Goto

Hirohiko Hirochika

Minami Matsui

Masaki Mori

Nagao Hayashi

Masaki Shimono

Chang-Jie Jiang

Hisatoshi Kaku

Hironori Kaminaka

Ken-ichi Kubo

Kenji Oda

Meenu Kapoor

Sanjay Kapoor

Akira Kobayashi

The present invention relates to plants that have been transformed so as to have both disease resistance and acceptable agronomic traits. More specifically, the present invention relates to transgenic plants that have acquired disease resistance through expression in the plants of a polynucleotide encoding the transcription factor WRKY45 in an infection-responsive manner, and methods for generating the transgenic plants.

Disease resistant plant expressing WRKY45 under control of infection-responsive promoter

The present inventors isolated many promoters having various expression characteristics from monocots, connected the OsWRKY45 gene downstream of these promoters, and then re-introduced them into a monocot (rice plant), and thereby strived to produce a rice line having both complex disease resistance and excellent agronomic traits. As a result, the present inventors succeeded in producing transgenic plants having both disease resistance and good agronomic traits by expressing OsWRKY45 using upstream sequences of the EF1&#x3b1; or OsUbi7 gene as promoters.

Complex disease resistant monocot having optimized agronomic characteristics

A three-step screening of selection for resistance against pathogenic bacteria infection, selection for resistance against pathogenic fungi infection, and selection for sensitivity to salicylic acid was carried out onlines highly expressing rice full-length cDNA (rice-FOXlines) which were prepared by using a FOX hunting system. As a result, oneline (line K15424) selected in all of the three types of screening was successfully selected. Line K15424 carries a rice full-length cDNA. Rice overexpressing AK070024 was produced, and resistance against rice bacterial leaf blight was assayed using the T1 generation. As a result, it was confirmed that AK070024-overexpressing rice is resistant against bacterial leaf blight and blast.

Rice gene capable of imparting wide-spectrum disease resistance

The present inventors analyzed genes involved in plant disease resistance. As a result, they discovered the transcription factor gene OsWRKY45, which is induced in leaf blades of rice plants by activating the systemic acquired resistance (SAR) that plants inherently have, i.e., by treating rice plants with benzothiadiazole (hereafter may be abbreviated as BTH), which is an agent thought to induce disease resistance in plants. It was further discovered that rice blast disease resistance and rice bacterial leaf blight resistance were markedly improved by reintroducing the gene into rice plants and constitutively expressing it.

Improving disease resistance in plants by introducing transcription factor gene

To investigate the function of ZPT2-3, petunia transformants overexpressing the ZPT2-3 gene under the control of the CamV 35S promoter were generated to investigate the presence or absence of tolerance against desiccation stress treatment. Surprisingly, petunia plant transformants showed significant tolerance against desiccation as compared to the wild type plants. In addition, neither growth abnormality nor morphological abnormality was observed in petunia plants, and thus overexpression of the ZPT2-3 gene was revealed to have no adverse effects on plant growth.

Use of zinc finger transcription factor zpt2-3 to generate plants with increased desiccation tolerance

An objective of the present invention is to genetically improve plant crossing properties as to effectively prevent recombinant genes in transgenic plants from spreading into the environment. A TFIIIA-type zinc-finger transcription factor gene ZPT2-10 was introduced into. As a result, some of the transformants (i.e., transgene-dependent incompatibility (TDI) strain plants) were found to have a useful crossing property. Specifically, the plants were fertile and produced normal seeds when self propagated or mated with another specified transformant comprising the same recombinant gene, but were infertile (transgene dependent incompatibility) when mated with another transformant strain that does not have the TDI property or with a wild-type plant. It may be possible to utilize plants having such a crossing property to prevent transgenic plants from spreading into the environment.

Modification of plant crossing properties via gene transfer

Genomic DNA containing the promoter region of the pMADS3 gene was isolated, ligated to a reporter gene, and then introduced into petunia plants via an-mediated method. Surprisingly, the resultant plants became double-flowered by conversion of stamens into petaloid structures.

Flower morphology of plants by targeting mads-box gene

A novel promoter is provided which has an expression activity specific to any pistil tissue. The promoter has any one of the DNA sequence from position 1 to 2595 of SEQ ID NO. 1, the DNA sequence from position 1 to 2322 of SEQ ID NO. 2, and the DNA sequence from position 1 to 2012 of SEQ ID NO. 3, and a part thereof. A method for producing a plant having a modified trait by introducing a heterogenous gene operatively linked to the promoter into a plant, and a plant having a modified trait produced by the method are further provided.

Promoter having specific activity to pistil tissue and use of the same

A method is provided for producing a male sterile plant of the family Solanaceae by utilizing a plant expression cassette including a nucleic acid which is DNA encoding zinc finger transcription factors (ZPT2-5) derived fromand a promoter operatively linked to the nucleic acid.

Growing community of inventors

Ibaraki, Japan

Hiroshi Takatsuji