title: Ionomic and physiological responses to low nitrogen stress in Tibetan wild and cultivated barley.
abstract: In a previous study, we identified the low-nitrogen (LN) tolerant accessions from the Tibetan wild barley (Hordeum vulgare subsp. spontaneum). In this study, two wild barley genotypes (XZ149, LN-tolerant and XZ56, LN-sensitive) and a barley cultivar ZD9 (H. vulgare) were used to determine the LN tolerant mechanism underlying the wild barley in the ionomic and physiological aspects. XZ149 exhibited higher LN tolerance with highest relative dry weight and N accumulation among three barley genotypes under LN stress. When exposed to LN stress, XZ149 had more N transportation from roots to leaves, and remained relatively higher activities of nitrate reductase (NR, EC.1.7.1.1) and glutamine synthetase (GS, EC.6.3.1.2) in leaves than other two genotypes, ensuring its higher capacity of N assimilation and utilization. The ionome analysis showed that LN stress had a significant effect on tissue ionome and the effect was genotypic and tissue-specific difference. On the whole, XZ149 maintained more stable Mn and Cu contents in roots, and less reduction of root P, K and Ca contents than XZ56 and ZD9 when exposed to LN stress. It may be assumed that more N movement into shoots, greater N assimilating capacity and specific rearrangement of nutrient element levels in tissues under LN stress are attributed to LN tolerance in XZ149.
authors.affiliation: Agronomy Department, Institute of Crop Science, Zhejiang University, Hangzhou, 310058, China.
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Quan
authors.affiliation: Agronomy Department, Institute of Crop Science, Zhejiang University, Hangzhou, 310058, China.
authors.forename: Jianbin
authors.initials: J
authors.lastname: Zeng
authors.affiliation: Agronomy Department, Institute of Crop Science, Zhejiang University, Hangzhou, 310058, China.
authors.forename: Zhigang
authors.initials: Z
authors.lastname: Han
authors.affiliation: Agronomy Department, Institute of Crop Science, Zhejiang University, Hangzhou, 310058, China. Electronic address: zhanggp@zju.edu.cn.
authors.forename: Guoping
authors.initials: G
authors.lastname: Zhang
mesh_terms: D005838:Genotype; D005974:Glutamate-Ammonia Ligase / Q000378:metabolism; D001467:Hordeum / Q000187:drug effects / Q000235:genetics / Q000254:growth & development / Q000502:physiology*; D007477:Ions / Q000378:metabolism; D055432:Metabolomics; D050901:Nitrate Reductase / Q000378:metabolism; D009566:Nitrates / Q000378:metabolism; D009584:Nitrogen / Q000494:pharmacology*; D018517:Plant Roots / Q000187:drug effects / Q000502:physiology; D018520:Plant Shoots / Q000187:drug effects / Q000502:physiology; D025341:Principal Component Analysis; D012995:Solubility; D013312:Stress, Physiological / Q000187:drug effects*
chemical_list: D007477:Ions; D009566:Nitrates; D050901:Nitrate Reductase; D005974:Glutamate-Ammonia Ligase; D009584:Nitrogen
keywords: Glutamine synthetase; Ionome; Nitrate reductase; Nitrogen; Tibetan wild barley