Table1_The grain yield regulator NOG1 plays a dual role in latitudinal adaptation and cold tolerance during rice domestication.XLSX

Rice originated in tropical and subtropical regions and is distributed worldwide. Low temperature is one of the most critical abiotic stresses affecting grain yield and geographical distribution of rice. It is vital to elucidate the molecular mechanism of chilling tolerance in rice for ensuring cereals production. Previously we isolated the domestication-related gene NOG1 which affects rice grain number and yield. In this study, we specified that rice varieties harboring high-yielding NOG1 allele are more distributed in low-latitude regions. Additionally, we observed NOG1 influences the chilling tolerance of rice. Through genome-wide transcriptional analysis after cold treatment at 10°C, there were 717 differentially expressed genes (DEGs) in nog1 near-isogenic lines compared with the control Guichao 2, including 432 up-regulated DEGs and 284 down-regulated DEGs. Gene ontology annotations and KEGG enrichment analysis of DEGs showed that various biological processes and signaling pathways were related to cold stress, such as lipid metabolism and genetic information processing. These results provide new insights into the mechanism of chilling tolerance in rice and the molecular basis of environmental adaptation during rice domestication.

水稻起源于热带与亚热带区域，目前在全球范围内广泛分布。低温是影响水稻籽粒产量与地理分布的最关键非生物胁迫因素之一。解析水稻耐冷的分子机制，对保障粮食安全生产至关重要。此前本课题组已克隆得到与水稻驯化相关的基因NOG1，该基因可调控水稻的穗粒数与籽粒产量。本研究明确，携带高产型NOG1等位基因（allele）的水稻品种，在低纬度区域的分布更为广泛。此外，本研究发现NOG1可对水稻的耐冷性产生调控作用。通过对10℃低温处理后的水稻样本开展全基因组转录组分析，本研究发现：与对照品种桂朝2号（Guichao 2）相比，nog1近等基因系中共鉴定出717个差异表达基因（differentially expressed genes, DEGs），其中上调表达基因432个，下调表达基因284个。对上述DEGs进行基因本体（Gene Ontology, GO）注释与京都基因与基因组百科全书（KEGG）富集分析后发现，多个生物学过程与信号通路均参与低温胁迫响应，例如脂质代谢与遗传信息加工。本研究结果为解析水稻耐冷机制以及水稻驯化过程中环境适应的分子基础提供了全新的研究视角。