Data Sheet 1_Metabolomic and lipidomic changes in heat-stressed chickpea seeds.pdf

Extreme climate induced heat stress during the reproductive phase significantly reduces yield and seed quality in chickpea, a vital cool-season pulse crop. While chickpea plants deploy various biochemical and molecular mechanisms, including the production of protective compounds and heat shock proteins to cope with heat stress, the metabolomic and lipidomic bases of heat tolerance remain poorly understood. This study used untargeted metabolomics and lipidomics to identify key metabolites, lipids, and potential biomarkers in seeds of a heat-tolerant (PI518255) and a heat-sensitive (PI598080) chickpea genotypes exposed to heat stress (35 °C day/20 °C night) under controlled environments. Results from volcano plot analysis revealed that 65 metabolites and 131 lipids were upregulated, while 17 metabolites and 195 lipids were downregulated under heat stress. Heatmap analysis showed that the heat-tolerant genotype had elevated metabolites (Naringenin, Astilbin,1-O-Cinnamoyl-(6-arabinosylglucose), Hesperetin 7-glucoside, luteolin, and neoandrographolide) and lipids [dimethylphosphatidylethanolamine (dMePE), phosphatidylinositol phosphates (PIP), phosphatidylethanolamine (PE), phosphatidylcholines (PC), phosphatidylglycerol (PG), phosphatidylinositol (PI), diacylglycerol monogalactoside (DGMG) (36:5), monogalactosyldiacylglycerol (MGDG), phosphatidic acid (PA), phosphatidylmonomethylethanolamine (PMe), Biotinyl Phosphatidylethanolamine (BiotinylPE), (O-acyl)-omega-hydroxy fatty acids (OAHFAs)], which may serve as diagnostic biomarkers for heat tolerance. Pathway enrichment analysis (KEGG) identified several heat stress-responsive metabolic pathways, including the pentose phosphate pathway, pyruvate metabolism, citrate (TCA) cycle, glyoxylate and dicarboxylate metabolism, starch and sucrose metabolism, glycolysis/gluconeogenesis, and cysteine and methionine metabolism. Lipid metabolic pathways involving MGDG, glycerophosphocholine, PI, PA, PC, phosphatidylcholines, lysophosphatidylcholine (LPC), lysophosphatidylglycerol (LPG), glycerophosphoinositol, and phosphoglyceric acid were also significantly affected. Future research employing targeted metabolomics and lipidomics profiling could elucidate candidate markers to enhance seed yield and quality, and support breeding programs to develop heat- and climate- resilient chickpea cultivars.

极端气候引发的生殖期热胁迫，会显著降低重要冷季豆科作物鹰嘴豆的产量与种子品质。尽管鹰嘴豆植株可调动多种生化与分子机制应对热胁迫，包括合成保护性化合物与热休克蛋白，但目前学界对其耐热性的代谢组学与脂质组学基础仍知之甚少。本研究采用非靶向代谢组学（untargeted metabolomics）与脂质组学（lipidomics）技术，在可控环境下对受热胁迫（昼温35℃/夜温20℃）的耐热型（PI518255）与热敏感型（PI598080）鹰嘴豆基因型的种子进行分析，以鉴定关键代谢物、脂质与潜在生物标志物。火山图分析结果显示，在热胁迫条件下，共有65种代谢物与131种脂质表达上调，17种代谢物与195种脂质表达下调。热图分析显示，耐热型鹰嘴豆基因型中富集的代谢物包括柚皮素（Naringenin）、落新妇苷（Astilbin）、1-O-肉桂酰基-(6-阿拉伯糖基葡萄糖)（1-O-Cinnamoyl-(6-arabinosylglucose)）、橙皮素-7-葡萄糖苷（Hesperetin 7-glucoside）、木犀草素（Luteolin）与新穿心莲内酯（Neoandrographolide）；富集的脂质则包括二甲基磷脂酰乙醇胺（dimethylphosphatidylethanolamine，dMePE）、磷脂酰肌醇磷酸酯（phosphatidylinositol phosphates，PIP）、磷脂酰乙醇胺（phosphatidylethanolamine，PE）、磷脂酰胆碱（phosphatidylcholines，PC）、磷脂酰甘油（phosphatidylglycerol，PG）、磷脂酰肌醇（phosphatidylinositol，PI）、二酰甘油单半乳糖苷（diacylglycerol monogalactoside，DGMG）(36:5)、单半乳糖基二酰甘油（monogalactosyldiacylglycerol，MGDG）、磷脂酸（phosphatidic acid，PA）、单甲基磷脂酰乙醇胺（phosphatidylmonomethylethanolamine，PMe）、生物素酰磷脂酰乙醇胺（Biotinyl Phosphatidylethanolamine，BiotinylPE）以及(O-酰基)-ω-羟基脂肪酸（(O-acyl)-omega-hydroxy fatty acids，OAHFAs），上述物质或可作为耐热性诊断生物标志物。基于京都基因与基因组百科全书（KEGG）的通路富集分析，鉴定出多条响应热胁迫的代谢通路，包括磷酸戊糖途径、丙酮酸代谢、柠檬酸（三羧酸，TCA）循环、乙醛酸与二羧酸代谢、淀粉与蔗糖代谢、糖酵解/糖异生以及半胱氨酸与蛋氨酸代谢。涉及单半乳糖基二酰甘油（MGDG）、甘油磷酸胆碱、磷脂酰肌醇（PI）、磷脂酸（PA）、磷脂酰胆碱（PC）、溶血磷脂酰胆碱（lysophosphatidylcholine，LPC）、溶血磷脂酰甘油（lysophosphatidylglycerol，LPG）、甘油磷酸肌醇以及磷酸甘油酸的脂质代谢通路也受到显著影响。未来可采用靶向代谢组学（targeted metabolomics）与脂质组学分析开展相关研究，以明确候选生物标志物，进而提升鹰嘴豆种子产量与品质，并为培育耐热、耐气候胁迫的鹰嘴豆栽培品种提供育种支撑。