新華社東京8月5日電 水稻種植需要大量水,，所以干旱天氣是個大敵,。日本研究人員日前通過基因改良開發(fā)出一種耐旱水稻,，這種水稻的根部能夠深深扎入土壤中吸收水分,，因此在干旱條件下也能生長。
日本農(nóng)業(yè)生物資源研究所宇賀優(yōu)作率領(lǐng)的研究小組介紹說,，水稻的根是橫向伸展的,，所以在土壤中扎根很淺，而旱稻的根則扎得很深,。他們經(jīng)過研究發(fā)現(xiàn),，旱稻擁有一種DRO1基因。這種基因感知重力后,，可以使旱稻根部向下伸展,。
研究小組在新一期《自然－遺傳學》雜志上發(fā)表論文說,，他們對一種名為IR64的水稻（屬于秈稻）進行了基因研究，發(fā)現(xiàn)其DRO1基因有部分缺損,。通過雜交,，研究人員為IR64重新植入DRO1基因。結(jié)果發(fā)現(xiàn)其扎根深度達到以前的2倍以上,。在IR64水稻幾乎會絕收的嚴重干旱環(huán)境下,，植入DRO1基因后，收獲量能夠達到通常水平的30％左右,。
研究人員說,，全球容易受干旱影響的水稻田面積達到2300萬公頃。這一抗旱水稻新品種有助于對抗干旱對水稻種植區(qū)的影響,。此外,，玉米等其他作物也有類似基因，所以此次的研究成果也有望促進開發(fā)出其他作物的耐旱新品種,。（生物谷 Bioon.com）
生物谷推薦的英文摘要
Nature Genetics doi:10.1038/ng.2725
Control of root system architecture by DEEPER ROOTING 1 increases rice yield under drought conditions
Yusaku Uga, Kazuhiko Sugimoto, Satoshi Ogawa, Jagadish Rane, Manabu Ishitani, Naho Hara, Yuka Kitomi, Yoshiaki Inukai, Kazuko Ono, Noriko Kanno, Haruhiko Inoue, Hinako Takehisa, Ritsuko Motoyama, Yoshiaki Nagamura, Jianzhong Wu, Takashi Matsumoto, Toshiyuki Takai, Kazutoshi Okuno & Masahiro Yano
The genetic improvement of drought resistance is essential for stable and adequate crop production in drought-prone areas1. Here we demonstrate that alteration of root system architecture improves drought avoidance through the cloning and characterization of DEEPER ROOTING 1 (DRO1), a rice quantitative trait locus controlling root growth angle. DRO1 is negatively regulated by auxin and is involved in cell elongation in the root tip that causes asymmetric root growth and downward bending of the root in response to gravity. Higher expression of DRO1 increases the root growth angle, whereby roots grow in a more downward direction. Introducing DRO1 into a shallow-rooting rice cultivar by backcrossing enabled the resulting line to avoid drought by increasing deep rooting, which maintained high yield performance under drought conditions relative to the recipient cultivar. Our experiments suggest that control of root system architecture will contribute to drought avoidance in crops.
