Melatonin mediates the regulation of ABA metabolism, free-radical scavenging, and stomatal behaviour in two Malus species under drought stress
Melatonin mediates the regulation of ABA metabolism, free-radical scavenging, and stomatal behaviour in two Malus species under drought stress
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DOI：
10.1093/jxb/eru476
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发表时间：
2015-02-01
影响因子：
6.9
通讯作者：
Ma, Fengwang
中科院分区：
文献类型：
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作者：
Li, Chao;Tan, Dun-Xian;Ma, Fengwang
褪黑激素预处理显著提高了耐旱型和耐旱型海棠的耐旱性。湖北植物其有益效果包括更好地保持叶片水分，减少电解质渗漏，稳定叶绿素含量，并在胁迫条件下提高光合性能。褪黑激素选择性地下调脱落酸（阿坝）合成基因MdNCED3，并上调其分解代谢基因MdCYP 707A1和MdCYP 707A2，从而降低干旱胁迫植物中的阿坝含量。褪黑激素还直接清除H2O2，并增强抗氧化酶的活性，间接解毒H2O2。这两种机制协同作用以改善气孔的功能，即使它们重新打开。植物在干旱条件下可以通过上调褪黑激素合成基因MdTDC1、MdAANAT 2、MdT5H4和MdASMT 1的表达来有效地调节其水分平衡。因此，诱导褪黑激素的产生是植物抵抗这种非生物胁迫的重要机制。
Melatonin pre-treatment significantly increases the tolerance of both drought-tolerant Malus prunifolia and drought-sensitive M. hupehensis plants. Its beneficial effects include better water conservation in leaves, less electrolyte leakage, steady chlorophyll contents, and greater photosynthetic performance under stress conditions. Melatonin selectively down-regulates MdNCED3, an abscisic acid (ABA) synthesis gene, and up-regulates its catabolic genes, MdCYP707A1 and MdCYP707A2, thereby reducing ABA contents in drought-stressed plants. Melatonin also directly scavenges H2O2 and enhances the activities of antioxidant enzymes to detoxify H2O2 indirectly. These two mechanisms work synergistically to improve the functions of stomata, i.e. causing them to re-open. Plants can effectively regulate their water balance under drought conditions by up-regulating the expression of melatonin synthesis genes MdTDC1, MdAANAT2, MdT5H4, and MdASMT1. Therefore, inducing melatonin production is an important mechanism by which plants can counteract the influence of this abiotic stressor.