Identification of the responsible genes that govern Na and Cl accumulation in leaves of rice under salinity stress

2021 Fiscal Year Final Research Report

• Project/Area Number: 18K05572
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 39010:Science in plant genetics and breeding-related
• Research Institution: Shinshu University
• Principal Investigator: Horie Tomoaki 信州大学, 学術研究院繊維学系, 教授 (90591181)
• Co-Investigator(Kenkyū-buntansha): 石川 亮 神戸大学, 農学研究科, 准教授 (70467687)
• Project Period (FY): 2018-04-01 – 2022-03-31
• Keywords: 耐塩性 / イネ / 遺伝資源

Outline of Final Research Achievements

We searched for genetic loci that govern leaf Na accumulation in rice under salt stress using backcross recombinant inbred lines derived from cultivated rice and wild rice (composed of 159 lines). A quantitative trait locus for Na accumulation was deduced to exist in Chromosome 1 and 5, respectively. However, the responsible genes have not yet been isolated. On the other hand, chromosome segment substitution lines (CSSLs) derived from cultivated rice and salt tolerant rice (composed of 44 lines) were used to search for important loci controlling Cl accumulation in rice under salt stress. Several unexpected problems have hindered the progression of research for Cl. Trial and error has, however, led to the assumption that root Cl accumulation could be an important index to consider salt tolerance of rice. Based on the root-based anion analysis using CSSLs, at least one genetic locus that significantly influences on the level of root Cl accumulation was identified.

Free Research Field

植物分子生理学

Academic Significance and Societal Importance of the Research Achievements

NaやClの高蓄積を伴う土壌の塩類集積は、アジアやアフリカでの稲作と米収量に深刻な悪影響を及ぼし始めている。栽培イネは、穀類で最も塩ストレスに脆弱であり、耐塩性に優れた栽培品種を作出することが急務である。本研究では、塩ストレス環境下における主たる毒性要素であるNaやClの、イネ体内での分配や蓄積に大きな影響を及ぼすと予想される遺伝子座領域を発見することができた。今後、それらの責任遺伝子の構造や機能を同定することで有用知見を蓄積させ、耐塩性のイネ栽培品種の育種を加速させることができるかもしれない。本研究の成果は、その礎となり得るものである。