Sang Zha, Yang Chunbao, Yuan Hongjun, Wang Yulin, Jabu Dunzhu, Xu Qijun
State Key Laboratory of Hulless Barley and Yak Germplasm Resources and Genetic Improvement, Lhasa 850002, China.
Institute of Agricultural Research, Tibet Academy of Agricultural and Animal Husbandry Sciences, Lhasa 850002, China.
Bioinformation. 2019 Dec 31;15(12):845-852. doi: 10.6026/97320630015845. eCollection 2019.
Nitrogen (N) is an essential macronutrient for plants. However, excessive use of N fertilizer for cultivation is an environmental hazard. A good adaption to N deficiency is known in the Tibetan hulless barley. Therefore, it is of interest to complete the metabolic analysis on LSZQK which is a low nitrogen (low-N) sensitive genotype and Z0284 that is tolerant to low-N. We identified and quantified 750 diverse metabolites in this analysis. The two genotypes show differences in their basal metabolome under normal N condition. Polyphenols and lipids related metabolites were significantly enriched in Z0284 having a basal role prior to exposure to low-N stress. Analysis of the differentially accumulated metabolites (DAM) induced by low-N explain the genotype-specific responses. Fourteen DAMs showed similar patterns of change between low-N and control conditions in both genotypes. This could be the core low-N responsive metabolites regardless of the tolerance level in hulless barley. We also identified 4 DAMs (serotonin, MAG (18:4) isomer 2, tricin 7-O-feruloylhexoside and gluconic acid) shared by both genotypes displaying opposite patterns of regulation under low-N conditions and may play important roles in low-N tolerance. This report provides a theoretical basis for further understanding of the molecular mechanisms of low-N stress tolerance in hulless barley.
氮（N）是植物必需的大量营养素。然而，在种植过程中过量使用氮肥会对环境造成危害。已知西藏青稞对缺氮有良好的适应性。因此，对低氮（low-N）敏感基因型LSZQK和耐低氮的Z0284进行代谢分析很有意义。在该分析中，我们鉴定并定量了750种不同的代谢物。这两个基因型在正常氮条件下的基础代谢组存在差异。在暴露于低氮胁迫之前，与多酚和脂质相关的代谢物在Z0284中显著富集，具有基础作用。对低氮诱导的差异积累代谢物（DAM）的分析解释了基因型特异性反应。在两个基因型中，14种DAM在低氮和对照条件下表现出相似的变化模式。无论青稞的耐受水平如何，这可能是核心的低氮响应代谢物。我们还鉴定出两个基因型共有的4种DAM（血清素、MAG（18:4）异构体2、小麦黄素7-O-阿魏酰己糖苷和葡萄糖酸），它们在低氮条件下表现出相反的调控模式，可能在低氮耐受性中发挥重要作用。本报告为进一步了解青稞耐低氮胁迫的分子机制提供了理论依据。
