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

Zha Sang; Chunbao Yang; Hongjun Yuan; Yulin Wang; Dunzhu Jabu; Qijun Xu

doi:10.6026/97320630015845

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

Bioinformation. 2019 Dec 31;15(12):845-852. doi: 10.6026/97320630015845. eCollection 2019.

Authors

Zha Sang^{1

2}, Chunbao Yang^{1

2}, Hongjun Yuan^{1

2}, Yulin Wang^{1

2}, Dunzhu Jabu^{1

2}, Qijun Xu^{1

2}

Affiliations

¹ State Key Laboratory of Hulless Barley and Yak Germplasm Resources and Genetic Improvement, Lhasa 850002, China.
² Institute of Agricultural Research, Tibet Academy of Agricultural and Animal Husbandry Sciences, Lhasa 850002, China.

Abstract

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.

Keywords: Tibetan hulless barley; glycerolipids; low nitrogen stress; metabolome; polyphenols.