Data from: Comparative transcriptome and lipidome analyses reveal molecular chilling responses in chilling-tolerant sorghums

Chilling temperatures (0 to 15°C) are a major constraint for temperate cultivation of tropical-origin crops, including the cereal crop sorghum (Sorghum bicolor [L.] Moench). Northern Chinese sorghums have adapted to early-season chilling, but molecular mechanisms of chilling tolerance are unknown. We used RNA sequencing of seedlings to compare the chilling-responsive transcriptomes of a chilling-tolerant Chinese accession with a chilling-sensitive US reference line, and mass spectrometry to compare chilling-responsive lipidomes of four chilling-tolerant Chinese accessions with two US reference lines. Comparative transcriptomics revealed chilling-induced up-regulation of cold-response regulator C-repeat binding factor (CBF) transcription factor and genes involved in reactive oxygen detoxification, jasmonic acid (JA) biosynthesis, and lipid remodeling phospholipase Dα1 (PLDα1) gene in the chilling-tolerant Chinese line. Lipidomics revealed conserved chilling-induced increases in lipid unsaturation, as well as lipid remodeling of photosynthetic membranes that is specific to chilling-tolerant Chinese accessions. Our results point to CBF-mediated transcriptional regulation, galactolipid and phospholipid remodeling, and JA as potential molecular mechanisms underlying chilling adaptation in Chinese sorghums. These molecular systems underlying chilling response could be targeted in molecular breeding for chilling tolerance.

低温胁迫（0~15℃）是热带起源作物进行温带种植的主要限制因素之一，其中包括谷类作物高粱（Sorghum bicolor [L.] Moench）。中国北方高粱已适应生育早期的低温环境，但当前对其耐低温的分子调控机制仍未明确。本研究通过对幼苗开展RNA测序（RNA sequencing），对比了1份耐低温中国高粱种质与1份低温敏感型美国参考品系的低温响应转录组；同时借助质谱技术，对比了4份耐低温中国高粱种质与2份美国参考品系的低温响应脂质组。比较转录组学分析显示，在该耐低温中国高粱品系中，低温诱导了冷响应调控因子C-重复结合因子（C-repeat binding factor, CBF）转录因子、活性氧解毒相关基因、茉莉酸（jasmonic acid, JA）生物合成基因，以及参与脂质重塑的磷脂酶Dα1（phospholipase Dα1, PLDα1）基因的上调表达。脂质组学分析发现，低温诱导的脂质不饱和程度升高在所有供试材料中均具有保守性，而光合膜的脂质重塑则是中国耐低温高粱种质所特有的响应模式。本研究结果表明，CBF介导的转录调控、半乳糖脂与磷脂重塑，以及茉莉酸信号通路，是中国北方高粱适应低温环境的潜在分子机制。上述低温响应分子调控系统，可作为耐低温高粱分子育种的潜在靶向靶点。