Shinozaki Research Collaborative Group
Kazuo SHINOZAKI, Ph.D.
This research group contributes to BioResource Research Center through collection of full-length cDNAs from various plants and Arabidopsis mutant lines and their phenotype analysis.In combination with transcriptome, holmonome, metabolome or proteome analyses, we utilize the resources of the BRC to discover Arabidopsis genes of which functions are linked to quantitative improvements in plants and those with new functions for minimizing the effects of the environmental stresses to achieve maximum productivity.We are also trying to apply the stress related genes for molecular breeding of drought tolerant crops and biomass production.
■Research and Development in 2016-2017
- Exploration and analysis of regulatory and signalingfactors in environmental stress responses
Our research group aims to discover Arabidopsis genes whose functions are linked to quantitative improvements in plants and those with new functions for minimizing the effects of the environmental stresses to achieve maximum productivity.
- To understand molecular mechanisms driving dehydration responses and drought tolerance, we clarified an overview of plant hormone metabolism and signaling in plants under drought stress conditions (Urano et al., in press)(Figure.1).
- Abscisic acid (ABA) is one of the major phytohormones, and it has a pivotal role in plants’ responses to environmental conditions.We screened an Arabidopsis mutant library and identified novel trans-acting factors that are involved in drought stress induction of the NCED3 gene encoding an ABA biosynthetic enzyme.
- We are searching for novel genes contribute different transpiration ratio in two wild ecotypes.
From genetic approaches with the 1,000 F2 population, we discovered a major QTL contributes to the reduced transpiration.We continue to dissect the causal gene(s) for this QTL.stress and ABA signaling, we focused the ABA-mediated SnRK2 protein kinases, and analyzed the substrates of SnRK2 with phosphor-proteomics approach.
- To understand environmental stress response, we analyzed natural variation of resistance to environmental stresses in Arabidopsis accessions distributed by RIKEN BRC.
- Research for the application of the stress genes for molecular breeding of drought tolerant crops
- Development of environmental stress resistance crops: To develop st ress tolerant crops, we are introducing stress-resistant genes into wheat, rice, and soybean varieties and the field evaluation of stress tolerances in collaboration with international institutes such as IRRI, CIAT, CIMMYT, and EMBRAPA.We demonstrated that soybean lines transformed with a galactinol synthesis gene, AtGols2 showed higher yield under irrigated (IRR) and non-irrigated (NIRR) conditions (Honna et al., 2016).We also generated galactinol synthetic gene, GolS2, transgenic upland rice in both Curinga from Colombia and NERICA from Africa, and showed that those transgenic rice enhance dehydration stress resistance and grain yield in the field.
- To elucidate plant growth response to water stresses in detail, we constructed an automatic growth system that control pot soil moisture precisely.
Development of imaging systems utilizing various type of camera is in progress (Figure 2).
- We constructed transgenic plants overexpressing an ABA transporter gene, ABCG25.We demonstrated that the transgenic plants showed activated ABA signaling in stomata and exhibited higher water use efficiency.
Fig. 2 RIPPS (RIKEN Phenotyping System)
Fig. 1 Temporal changes in ABA and JA-Ile levels in WT and ABA biosynthetic mutant (nced3-2) in response to moderate dehydration stress