Compatible solute accumulation and stress-mitigating effects in barley genotypes contrasting in their salt tolerance
Compatible solute accumulation and stress-mitigating effects in barley genotypes contrasting in their salt tolerance
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DOI：
10.1093/jxb/erm284
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发表时间：
2007-01-01
影响因子：
6.9
通讯作者：
Shiabala, Sergey
中科院分区：
文献类型：
--
作者：
Chen, Zhonghua;Cuin, Tracey A.;Shiabala, Sergey
相容性溶质的积累通常被认为是植物在非生物胁迫条件下（包括盐度和氧化胁迫）保护和生存的基本策略。在这项工作中，研究了对比大麦基因型积累/合成相容溶质的能力与其盐度胁迫耐受性之间可能存在的因果关系。发现 H2O2（盐胁迫的组成部分之一）对 K+ 通量（胁迫“严重程度”的衡量标准）的影响以及甘氨酸甜菜碱和脯氨酸对 NaCl 诱导的 K+ 流出的缓解作用在盐敏感大麦基因型中显着较高。同时，在盐敏感品种中发现叶和根脯氨酸和叶甘氨酸甜菜碱的积累量高出两倍。耐盐品种的总氨基酸含量受盐度的影响也较小。在这些研究中，发现钾是细胞质渗透压的主要贡献者，而在盐敏感基因型中，甘氨酸甜菜碱和脯氨酸对细胞渗透压有很大贡献，补偿了细胞质 K+ 的减少。 Na+ 诱导的 K+ 流出（耐盐性指标）与叶甘氨酸甜菜碱和脯氨酸之间观察到显着负相关（r = -0.89 和 -0.94）。这些结果表明，大麦中已知主要相容性溶质的超积累似乎并未在耐盐性中发挥主要作用，而可能是盐敏感性的症状。
The accumulation of compatible solutes is often regarded as a basic strategy for the protection and survival of plants under abiotic stress conditions, including both salinity and oxidative stress. In this work, a possible causal link between the ability of contrasting barley genotypes to accumulate/synthesize compatible solutes and their salinity stress tolerance was investigated. The impact of H2O2 (one of the components of salt stress) on K+ flux (a measure of stress 'severity') and the mitigating effects of glycine betaine and proline on NaCl-induced K+ efflux were found to be significantly higher in salt-sensitive barley genotypes. At the same time, a 2-fold higher accumulation of leaf and root proline and leaf glycine betaine was found in salt-sensitive cultivars. The total amino acid content was also less affected by salinity in salt-tolerant cultivars. In these, potassium was found to be the main contributor to cytoplasmic osmolality, while in salt-sensitive genotypes, glycine betaine and proline contributed substantially to cell osmolality, compensating for reduced cytosolic K+. Significant negative correlations (r = -0.89 and -0.94) were observed between Na+-induced K+ efflux (an indicator of salt tolerance) and leaf glycine betaine and proline. These results indicate that hyperaccumulation of known major compatible solutes in barley does not appear to play a major role in salt-tolerance, but rather, may be a symptom of salt-susceptibility.