High Salinity Induces Different Oxidative Stress and Antioxidant Responses in Maize Seedlings Organs.
High Salinity Induces Different Oxidative Stress and Antioxidant Responses in Maize Seedlings Organs.
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DOI：
10.3389/fpls.2016.00276
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发表时间：
2016
影响因子：
5.6
通讯作者：
Abuelsoud W
中科院分区：
文献类型：
--
作者：
AbdElgawad H;Zinta G;Hegab MM;Pandey R;Asard H;Abuelsoud W
盐度对植物生长产生负面影响，并在世界范围内造成显著的作物产量损失。玉米是受高盐影响的重要经济作物。在这项研究中，玉米幼苗进行75 mM和150 mM的NaCl，模拟高土壤盐度。播种3周后收获根、成熟叶（基生叶对1、2）和幼叶（远生叶对3、4）。在盐胁迫下，根的生物量减少最多，其次是成熟叶和幼叶。伴随着生长减少的模式，根积累的Na+水平最高，其次是成熟和年轻的叶片。高盐诱导氧化胁迫的根和成熟的叶片，但在较小程度上在年轻的叶片。仅在150 mM NaCl下，嫩叶的电解质渗漏（EL）、丙二醛（MDA）和过氧化氢（H2 O2）浓度才显示出增加。根和成熟叶的总抗氧化能力（TAC）和多酚含量随着盐浓度的增加而增加，而幼叶的变化不大。盐胁迫下，还原型抗坏血酸（ASC）和谷胱甘肽（GSH）含量增加根，而总生育酚水平增加，特别是在地上部组织。同样，氧化还原变化的氧化还原对（ASC/总抗坏血酸和GSH/总谷胱甘肽）的比例估计显示显着减少的根。酶抗氧化剂，过氧化氢酶（CAT，EC 1.11.1.6）和脱氢抗坏血酸还原酶（达尔，EC 1.8.5.1）的活性，增加在所有器官的盐处理的植物，而超氧化物歧化酶（SOD，EC 1.15.1.1），抗坏血酸过氧化物酶（APX，EC 1.11.1.11），谷胱甘肽-S-转移酶（GST，EC 2.5.1.18）和谷胱甘肽还原酶（GR，EC 1.6.4.2）增加，特别是在根。总的来说，这些结果表明，Na+主要在根中保留和解毒，并且在成熟和年轻的叶片中观察到较少的胁迫影响。这项研究还表明，ROS在从根到叶的系统信号传导中可能发挥作用，使叶片能够激活其防御机制，以更好地抵御盐胁迫。
Salinity negatively affects plant growth and causes significant crop yield losses world-wide. Maize is an economically important cereal crop affected by high salinity. In this study, maize seedlings were subjected to 75 mM and 150 mM NaCl, to emulate high soil salinity. Roots, mature leaves (basal leaf-pair 1,2) and young leaves (distal leaf-pair 3,4) were harvested after 3 weeks of sowing. Roots showed the highest reduction in biomass, followed by mature and young leaves in the salt-stressed plants. Concomitant with the pattern of growth reduction, roots accumulated the highest levels of Na+ followed by mature and young leaves. High salinity induced oxidative stress in the roots and mature leaves, but to a lesser extent in younger leaves. The younger leaves showed increased electrolyte leakage (EL), malondialdehyde (MDA), and hydrogen peroxide (H2O2) concentrations only at 150 mM NaCl. Total antioxidant capacity (TAC) and polyphenol content increased with the increase in salinity levels in roots and mature leaves, but showed no changes in the young leaves. Under salinity stress, reduced ascorbate (ASC) and glutathione (GSH) content increased in roots, while total tocopherol levels increased specifically in the shoot tissues. Similarly, redox changes estimated by the ratio of redox couples (ASC/total ascorbate and GSH/total glutathione) showed significant decreases in the roots. Activities of enzymatic antioxidants, catalase (CAT, EC 1.11.1.6) and dehydroascorbate reductase (DHAR, EC 1.8.5.1), increased in all organs of salt-treated plants, while superoxide dismutase (SOD, EC 1.15.1.1), ascorbate peroxidase (APX, EC 1.11.1.11), glutathione-s-transferase (GST, EC 2.5.1.18) and glutathione reductase (GR, EC 1.6.4.2) increased specifically in the roots. Overall, these results suggest that Na+ is retained and detoxified mainly in roots, and less stress impact is observed in mature and younger leaves. This study also indicates a possible role of ROS in the systemic signaling from roots to leaves, allowing leaves to activate their defense mechanisms for better protection against salt stress.