Insights into the metabolic responses of two contrasting Tibetan hulless barley genotypes under low nitrogen stress.
Kata kunci
Abstrak
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.