Rice is sensitive to cold and can be grown only in certain climate zones. Human selection of japonica rice has extended its growth zone to regions with lower temperature, while the molecular basis of this adaptation remains unknown. Here, we identify the quantitative trait locus COLD1 that confers chilling tolerance in japonica rice. Overexpression of COLD1jap significantly enhances chilling tolerance, whereas rice lines with deficiency or downregulation of COLD1jap are sensitive to cold. COLD1 encodes a regulator of G-protein signaling that localizes on plasma membrane and endoplasmic reticulum (ER). It interacts with the G-protein α subunit to activate the Ca2+ channel for sensing low temperature and to accelerate G-protein GTPase activity. We further identify that a SNP in COLD1, SNP2, originated from Chinese Oryza rufipogon, is responsible for the ability of COLDjap/ind to confer chilling tolerance, supporting the importance of COLD1 in plant adaptation.
水稻對低溫敏感，只能在特定氣候帶生長。人為選擇使粳稻拓展到溫度較低的生長地區(qū)，然而水稻對低溫適應(yīng)性的分子機(jī)理仍不清楚。本文，我們從粳稻中鑒定了一個耐冷的數(shù)量性狀位點(diǎn)COLD1。過表達(dá)COLD1jap能顯著提高水稻的耐寒性，而缺失或低表達(dá)COLD1jap的水稻株系對冷敏感。COLD1編碼一個G蛋白信號調(diào)節(jié)因子，定位于質(zhì)膜和內(nèi)質(zhì)網(wǎng)。感覺出低溫時，COLD1與G蛋白α亞基RGA互作，激活Ca2+通道，而后增強(qiáng)G蛋白GTP酶活性。我們進(jìn)一步鑒定出COLD1上來自中國普通野生稻的一個SNP位點(diǎn)，SNP2，涉及COLD1jap/ind的耐寒能力，這支持了COLD1在植物適應(yīng)環(huán)境方面的重要性。