Palma F, López-Gómez M, Tejera N A, Lluch C
Departamento de Fisiología Vegetal, Facultad de Ciencias, Universidad de Granada, Campus de Fuentenueva s/n, 18071 Granada, Spain.
Departamento de Fisiología Vegetal, Facultad de Ciencias, Universidad de Granada, Campus de Fuentenueva s/n, 18071 Granada, Spain.
Plant Sci. 2014 Jun;223:16-24. doi: 10.1016/j.plantsci.2014.02.005. Epub 2014 Feb 25.
Legumes are classified as salt-sensitive crops with their productivity particularly affected by salinity. Abcisic acid (ABA) plays an important role in the response to environmental stresses as signal molecule which led us to study its role in the response of nitrogen fixation and antioxidant metabolism in root nodules of Medicago sativa under salt stress conditions. Adult plants inoculated with Sinorhizobium meliloti were treated with 1 μM and 10 μM ABA two days before 200 mM salt addition. Exogenous ABA together with the salt treatment provoked a strong induction of the ABA content in the nodular tissue which alleviated the inhibition induced by salinity in the plant growth and nitrogen fixation. Antioxidant enzymes superoxide dismutase (SOD), catalase (CAT) and glutathione reductase (GR) were induced by ABA pre-treatments under salt stress conditions which together with the reduction of the lipid peroxidation, suggest a role for ABA as signal molecule in the activation of the nodular antioxidant metabolism. Interaction between ABA and polyamines (PAs), described as anti-stress molecules, was studied being detected an induction of the common polyamines spermidine (Spd) and spermine (Spm) levels by ABA under salt stress conditions. In conclusion, ABA pre-treatment improved the nitrogen fixation capacity under salt stress conditions by the induction of the nodular antioxidant defenses which may be mediated by the common PAs Spd and Spm that seems to be involved in the anti-stress response induced by ABA.
豆科植物被归类为对盐敏感的作物，其生产力尤其受到盐度的影响。脱落酸（ABA）作为信号分子在对环境胁迫的响应中发挥着重要作用，这促使我们研究其在盐胁迫条件下对紫花苜蓿根瘤中固氮和抗氧化代谢响应中的作用。在添加200 mM盐前两天，用1 μM和10 μM ABA处理接种了苜蓿中华根瘤菌的成年植株。外源ABA与盐处理一起引发了结节组织中ABA含量的强烈诱导，这减轻了盐度对植物生长和固氮的抑制作用。在盐胁迫条件下，ABA预处理诱导了抗氧化酶超氧化物歧化酶（SOD）、过氧化氢酶（CAT）和谷胱甘肽还原酶（GR），这与脂质过氧化作用的降低一起，表明ABA作为信号分子在结节抗氧化代谢激活中发挥作用。研究了ABA与被描述为抗胁迫分子的多胺（PAs）之间的相互作用，发现在盐胁迫条件下ABA诱导了常见多胺亚精胺（Spd）和精胺（Spm）水平的升高。总之，ABA预处理通过诱导结节抗氧化防御提高了盐胁迫条件下的固氮能力，这可能由常见的PAs Spd和Spm介导，它们似乎参与了ABA诱导的抗胁迫反应。
