Rice (Oryza sativa L.) is a chilling-sensitive staple crop that originated in subtropical regions of Asia. Introduction of the chilling tolerance trait enables the expansion of rice cultivation to temperate regions. Here we report the cloning and characterization of HAN1, a quantitative trait locus (QTL) that confers chilling tolerance on temperate japonica rice. HAN1 encodes an oxidase that catalyzes the conversion of biologically active jasmonoyl-L-isoleucine (JA-Ile) to the inactive form 12-hydroxy-JA-Ile (12OH-JA-Ile) and fine-tunes the JA-mediated chilling response. Natural variants in HAN1 diverged between indica and japonica rice during domestication. A specific allele from temperate japonica rice, which gained a putative MYB cis-element in the promoter of HAN1 during the divergence of the two japonica ecotypes, enhances the chilling tolerance of temperate japonica rice and allows it to adapt to a temperate climate. The results of this study extend our understanding of the northward expansion of rice cultivation and provide a target gene for the improvement of chilling tolerance in rice.
水稻是原產(chǎn)于亞洲亞熱帶地區(qū)的一種對(duì)寒冷敏感的主糧作物。引進(jìn)耐冷特性，使水稻向溫帶地區(qū)擴(kuò)展種植。在這里，我們報(bào)道了一個(gè)數(shù)量性狀基因座（QTL）的克隆和特性描述，該基因座在溫帶水稻上具有耐冷性。HAN1編碼一種氧化酶，能催化有生物活性的茉莉酰-L-異亮氨酸（JA-Ile）轉(zhuǎn)化為非活性形式12羥基-茉莉酰-L-異亮氨酸（12OH-JA-Ile），并微調(diào)JA介導(dǎo)的冷凍反應(yīng)。馴化過程中，HAN1在秈稻和粳稻之間的自然變異有差異。來自溫帶粳稻的一個(gè)特異等位基因，在兩種粳稻生態(tài)型的分化過程中，在啟動(dòng)子中獲得一個(gè)預(yù)測(cè)的MYB順式作用元素，增強(qiáng)了溫帶水稻的耐冷性，并使其適應(yīng)溫帶氣候。本研究的結(jié)果拓展了我們對(duì)水稻向北擴(kuò)散的認(rèn)識(shí)，為提高水稻的耐冷性提供了一個(gè)目標(biāo)基因。