RIKEN

Graduate School of Science, The University of Tokyo

Kobe University

Niigata University

Teikyo University

Kyoto University of Advanced Sciences

Outline

The RIKEN Center for Sustainable Resource Science (RIKEN) Cell Function Research Team, Senior Researcher Satoshi Iwase, Team Leader Keiko Sugimoto (Professor, Graduate School of Science, The University of Tokyo), Plant Immunity Research Group Member Anupong Laohabisit, Group Leader Ken Shirasu (Professor, Graduate School of Science, The University of Tokyo), Kobe University Associate Professor Yuki Kondo of Graduate School of Science, Kobe University, Associate Professor Momoko Ikeuchi of Faculty of Science, Niigata University, Associate Professor Masashi Asahina of Faculty of Science and Technology, Teikyo University, and Associate Professor Hiroho Fukuda of Faculty of Bio-Environment, Kyoto University of Advanced Sciences have discovered that the transcription factor WIND plays an important role not only in wound callus formation but also in the reformation of ducts and acquisition of resistance against pathogens. The research group discovered that the transcription factor WIND plays an important role not only in the callus formation of wounds but also in the reformation of ducts and acquisition of resistance to pathogens.

The research results are expected to lead to the development of technologies that contribute to the sustainable production of food and biomass by plants, such as increased production using tissue culture technology, improved breeding, more efficient grafting, and the imparting of disease resistance.

When plants are wounded, they initiate various physiological responses such as tissue regeneration and defense responses, but the existence of molecules that integrate and activate these responses was not known.

WIND1, one of the transcription factors WIND, has been shown to promote callus formation and stomatal regeneration induced by injury stress. In this study, the joint research group comprehensively investigated genes whose expression levels are increased by WIND1 using Arabidopsis thaliana. As a result, they found that the expression of not only genes involved in regeneration, but also those involved in duct formation and defense responses were upregulated. In addition, when the functions of WIND1 and other WINDs (WIND2-4) were suppressed, the regrowth of vascular vessels and resistance to pathogens in grafting were weakened, indicating that WIND is in fact a factor that integrally regulates wound repair and defense responses.

Figure: Inhibition of tubular element formation in strains with suppressed or deficient function of the transcription factor WIND.

Left) Using the VISUAL method, phloem cells in cotyledons of WT and WIND1-suppressed plants (WIND1-SRDX) were converted to vascular cells. Green and yellow indicate tubular elements; in WIND1-SRDX, few ectopic tubular elements are formed, and only the original vascular bundle tubular elements (ducts) are stained yellow, indicating fewer tubular elements than in WT. Scale bar is 0.5 mm.

Right) Graph of the rate of differentiation into tubular elements, approximated by the percentage of fluorescent area in the total area of the cotyledon, showing that WIND1-SRDX and loss-of-function mutants (wind1/2/3/4) have suppressed tubular element formation.

The results of this study were published in the online edition of the scientific journal New Phytologist on August 10.

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