Strategies for survival and growth of rice plants in response to nitrogen starved conditions

2014 Fiscal Year Final Research Report

• Project Area: Integrated analysis of strategies for plant survival and growth in response to global environmental changes
• Project/Area Number: 22119003
• Research Category: Grant-in-Aid for Scientific Research on Innovative Areas (Research in a proposed research area)
• Allocation Type: Single-year Grants
• Review Section: Biological Sciences
• Research Institution: Tohoku University
• Principal Investigator: YAMAYA Tomoyuki 東北大学, (連合)農学研究科(研究院), 教授 (30144778)
• Co-Investigator(Kenkyū-buntansha): KUSANO Miyako 筑波大学, 生命環境系, 教授 (60415148)
• Co-Investigator(Renkei-kenkyūsha): HAYAKAWA Toshihiko 東北大学, 大学院農学研究科, 准教授 (60261492) ; KOJIMA Soichi 東北大学, 大学院農学研究科, 助教 (30462683)
• Project Period (FY): 2010-04-01 – 2015-03-31
• Keywords: イネ / 窒素飢餓 / 生存戦略 / 環境突破力 / 同化代謝バランス

Outline of Final Research Achievements

Under nitrogen starved conditions, rice plants reduce their active tiller number in vegetative stage and their spikelet number in reproductive stage. However, molecular mechanisms in these responses are largely not known. We have carried out 1) NH4+-signal perception, 2) assimilation and remobilization of nitrogen, 3) metabolic balance between C and N, and 4) modeling of spikelet-ripening to understand molecular mechanisms of response. We obtained clear results, using reverse genetics approaches together with localization works, that glutamine synthetase (GS)1;2 was important in both the primary assimilation of NH4+ and outgrowth of axillary tiller buds, whereas GS1;1 is important in remobilization of N from senescing organs. NADH-glutamate synthase2 was tightly related to the determination of panicle number. These mutants showed metabolic disorder, indicating that N metabolism is important in normal growth and development of rice. Those results were published in several journals.

Free Research Field

植物分子生理学