Rice breeding strategy with the use of active transposable elements

Research Project

Project/Area Number	26252002
Research Category	Grant-in-Aid for Scientific Research (A)
Allocation Type	Single-year Grants
Section	一般
Research Field	Science in genetics and breeding
Research Institution	Kyoto University
Principal Investigator	OKUMOTO Yutaka 京都大学, 農学研究科, 教授 (90152438)
Co-Investigator(Kenkyū-buntansha)	寺石政義京都大学, 農学研究科, 講師 (80378819) 吉川貴徳京都大学, 農学研究科, 助教 (00721606) 築山拓司近畿大学, 農学部, 准教授 (00423004) 齊藤大樹京都大学, 農学研究科, 助教 (10536238) 小出陽平京都大学, 学内共同利用施設等, 助教 (70712008)
Project Period (FY)	2014-04-01 – 2019-03-31
Project Status	Completed (Fiscal Year 2018)
Budget Amount *help	¥40,430,000 (Direct Cost: ¥31,100,000、Indirect Cost: ¥9,330,000) Fiscal Year 2018: ¥6,500,000 (Direct Cost: ¥5,000,000、Indirect Cost: ¥1,500,000) Fiscal Year 2017: ¥6,110,000 (Direct Cost: ¥4,700,000、Indirect Cost: ¥1,410,000) Fiscal Year 2016: ¥6,500,000 (Direct Cost: ¥5,000,000、Indirect Cost: ¥1,500,000) Fiscal Year 2015: ¥6,110,000 (Direct Cost: ¥4,700,000、Indirect Cost: ¥1,410,000) Fiscal Year 2014: ¥15,210,000 (Direct Cost: ¥11,700,000、Indirect Cost: ¥3,510,000)
Keywords	イネ / 転移因子 / mPing / ストレス耐性 / ゲノム / MITE / 生育強勢 / Rurm1 / 遺伝子 / 植物 / 進化 / 育種学 / ゲノム改変 / ゲノムショック
Outline of Final Research Achievements	Non-autonomous transposable element mPing is actively transposing in the genome of rice variety Gimbozu. To reveal the usage of mPing as a tool to develop novel breeding strategy, we analyzed the novel traits closely related to the mPing transposition. At first, several stress tolerant plants could be selected from Gimbozu population. In addition, a novel mPing insertion specifically observed in a tolerant line causes the activation of the downstream gene under the stress condition. Secondary, slender-glume mutant line (IM294) derived from Gimbozu is frequently reverted to a normal-glume plant as the result of excision of mPing inserted at the Rurm1 gene. Among the reverse mutants, a few plants (VGI: Vigorously growing IM294) which exceptionally exhibited the vigorous growth are segregating. All the VGI plants harbor large number of newly inserted mPing. Induction of tentative heterozygosity caused by the newly inserted mPing elements may trigger the vigorous growth.
Academic Significance and Societal Importance of the Research Achievements	進化の過程で転移因子は遺伝子発現や転写産物の構造改変に深く関与してきた。本研究の結果、銀坊主集団内にはmPing新規挿入によってストレス条件下での発現が改変された遺伝子が多数分離していること、mPing新規挿入を利用したストレス耐性の育種素材の開発が可能であることが明らかになった。また、生育強勢個体ではmPingの新規挿入数が極めて多いことから、ゲノム内にmPing挿入ヘテロの箇所が増大することにより生じている一種のヘテロシス現象である可能性が認められた。mPing転移は自然突然変異であるため、mPing新規挿入は栽培や利用上の制約を受けない遺伝子発現の制御のための有用なツールとなり得る。