Alleviation of drought-induced oxidative stress in maize (Zea mays L.) plants by dual application of 24-epibrassinolide and spermine
Alleviation of drought-induced oxidative stress in maize (Zea mays L.) plants by dual application of 24-epibrassinolide and spermine
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DOI：
10.1016/j.envexpbot.2015.01.006
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发表时间：
2015-05
影响因子：
5.7
通讯作者：
N. B. Talaat;B. Shawky;A. Ibrahim
中科院分区：
文献类型：
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作者：
N. B. Talaat;B. Shawky;A. Ibrahim
双施[24-表油菜素内酯（EBL）和精胺（Spm）]对缺水植物抗氧化机制的影响尚未得到关注。本研究为首次研究干旱条件下EBL、Spm及其双重施用对植物清除ROS的抗氧化防御机制的影响。这种方法被评估为可能的抗旱机制，以及这些应用如何保护植物免受氧化胁迫。为了实现这一目标，两个玉米杂交种（吉萨10号和吉萨129号）分别在水分充足和缺水的条件下（田间容量的75%和50%）施用和不施用EBL和/或Spm。在温室条件下，将籽粒播种在含有粘土壤土（砂37%，粉28%，粘土35%）土壤（Inceptisols； FAO）的塑料盆中。水分缺乏显著降低了杂交吉萨10号的生长、产量和膜稳定性指数。然而，后续双施处理（25 mg l - 1Spm + 0.1 mg l - 1EBL）可以解毒干旱胁迫，并显著改善上述参数，特别是在杂交吉萨129中。干旱胁迫显著增加了h2o2和o2自由基dot -含量，并引起脂质氧化应激。然而，在双重施用的胁迫植株中，它们显著降低。此外，双重应用减轻了干旱对电解液泄漏的不利影响。超氧化物歧化酶、过氧化氢酶、抗坏血酸过氧化物酶和谷胱甘肽还原酶的活性以及抗坏血酸、谷胱甘肽、脯氨酸和甘氨酸甜菜碱的水平在干旱处理和叶面施用的反应中增加。双施显著缓解了干旱对单脱氢抗坏血酸还原酶和脱氢抗坏血酸还原酶活性的抑制，以及对AsA/DHA和GSH/GSSG比值的抑制。总的来说，双重施用通过提高抗氧化酶活性和改善抗坏血酸和谷胱甘肽的氧化还原状态来增强活性氧的清除能力，从而提高了植物的抗旱性，减少了活性氧的积累。
Dual application [24-epibrassinolide (EBL) and spermine (Spm)] influence on the antioxidant machinery in water-stressed plants has received no attention. The present study, as a first investigation, was conducted with an aim to investigate the effects of EBL, Spm and their dual application on the ROS scavenging antioxidant defense machinery in plants subjected to drought conditions. This approach was assessed as possible mechanisms of drought tolerance and how these applications protect plants against oxidative stress. To achieve this goal, two maize hybrids (Giza 10 and Giza 129) were subjected to well-watered conditions and water-stressed conditions (75% and 50% of field capacity) with and without EBL and/or Spm foliar application. The grains were sown in plastic pots containing clay-loam (sand 37%, silt 28%, clay 35%) soil (Inceptisols; FAO), under greenhouse condition. Water deficiency significantly reduced growth, productivity, and membrane stability index, particularly in hybrid Giza 10. However, the follow-up treatment with the dual application (25 mg l−1Spm + 0.1 mg l−1EBL) detoxified the stress generated by drought and significantly improved the above parameters, particularly in hybrid Giza 129. Drought stress significantly increased H2O2and O2radical dot−contents and caused oxidative stress to lipids assessed by the increase in MDA content. However, they were significantly decreased in stressed plants treated with the dual application. Moreover, dual application alleviated the detrimental effects of drought on the electrolyte leakage. Activities of superoxide dismutase, catalase, ascorbate peroxidase, and glutathione reductase and levels of ascorbate, glutathione, proline, and glycinebetaine were increased in response to drought treatments as well as foliar applications. Dual application significantly alleviated drought-induced inhibition in the activities of monodehydroascorbate reductase and dehydroascorbate reductase as well as in the ratios of AsA/DHA and GSH/GSSG. Overall, dual application improved the plant drought tolerance and decreased the accumulation of ROS by enhancing their scavenging through elevation of antioxidant enzymes activity and improving the redox state of ascorbate and glutathione.