State Key Laboratory of Hulless Barley and Yak Germplasm Resources and Genetic Improvement, Lhasa, 850002, China; Agricultural Research Institute, Tibet Academy of Agricultural and Animal Husbandry Sciences, Lhasa, 850002, China.
State Key Laboratory of Hulless Barley and Yak Germplasm Resources and Genetic Improvement, Lhasa, 850002, China; Agricultural Research Institute, Tibet Academy of Agricultural and Animal Husbandry Sciences, Lhasa, 850002, China.
Phytochemistry. 2020 Jun;174:112346. doi: 10.1016/j.phytochem.2020.112346. Epub 2020 Mar 28.
Plants cultivated on the Qinghai-Tibetan Plateau grow in an extremely cold environment and thus are exposed to cold stress. To assess the metabolic processes during cold exposure of Tibetan hulless barley (Hordeum distichon L.), metabolic analyses were conducted on one tolerant (XiLa) and one sensitive (ZangQing) cultivar exposed to six temperatures (24 °C, 12 °C, 5 °C, 0 °C, -5 °C, -8 °C) for 24 h. In total, 770 metabolites were identified, including amino acids and derivatives, carbohydrates, flavonoids, lipids, nucleotides and derivatives, and phenolamides. In principal component analysis, the samples were clearly grouped according to the cultivar, suggesting that the two cultivars have differential responses to cold stress. In cold-grown plants, eight metabolites, including monoacylglycerol (MAG, 18:2), MAG (18:3), deoxyadenosine, 6-methylmercaptopurine, and coniferin, were significantly altered in XiLa, but not in ZangQing when compared to the levels in control plants, and thus, these compounds can be considered as potential biomarkers of exposure to cold stress in hulless barley. Furthermore, differentially altered metabolites between seedlings exposed to -8 °C and those maintained at 24 °C were significantly enriched in glutathione metabolism. The findings of this study will be useful for the development of cultivars with cold stress tolerance.
在青藏高原上种植的植物生长在极寒的环境中，因此会受到寒冷胁迫的影响。为了评估西藏青稞（Hordeum distichon L.）在寒冷暴露下的代谢过程，对两个品种（西拉和藏青）进行了代谢分析，这两个品种分别在 24°C、12°C、5°C、0°C、-5°C和-8°C 下暴露 24 小时。总共鉴定出 770 种代谢物，包括氨基酸及其衍生物、碳水化合物、类黄酮、脂类、核苷酸及其衍生物和酚酰胺。在主成分分析中，根据品种清楚地将样品分组，表明两个品种对寒冷胁迫有不同的反应。在冷生植物中，与对照植株相比，西拉中有 8 种代谢物（包括单酰基甘油（MAG，18:2）、MAG（18:3）、脱氧腺苷、6-甲基巯基嘌呤和松柏苷）发生了显著变化，但藏青中没有，因此，这些化合物可以被认为是青稞暴露于寒冷胁迫的潜在生物标志物。此外，在 -8°C 下暴露的幼苗和在 24°C 下保持的幼苗之间差异改变的代谢物在谷胱甘肽代谢中显著富集。本研究的结果将有助于培育具有抗寒胁迫能力的品种。
