外源褪黑素增强黄瓜耐盐性研究

Investigation on exogenous melatonin enhancing salt tolerance of cucumber

盐胁迫是导致植物生长发育受阻和产量品质降低的主要环境因素之一,褪黑素是一种具有多效性的信号分子,在植物生长发育和应对环境压力方面具有重要的调控作用。本试验研究了不同浓度褪黑素(50,150和500μmol/L)对盐胁迫(150 mmol/L NaCl)下黄瓜叶片光合作用和氧化还原稳态的影响。结果表明,NaCl胁迫抑制了黄瓜的光合作用,增加了活性氧(ROS)的积累和膜损伤,褪黑素处理以剂量依赖的方式减轻了NaCl胁迫对黄瓜光合作用和氧化还原状态的影响。褪黑素能够改善植株的光合能力,这与其抑制气孔关闭、改善光能吸收和电子传递的作用紧密相关。此外,褪黑素还可降低氧化应激反应,这归因于氧化还原稳态的改善以及抗氧化酶活性的增强。

Salt stress is one of the main environmental factors that lead to the retardation of plant growth and the decrease of yield and quality.Melatonin is a pleiotropic signal molecule,which plays an important role in plant growth and development and coping with environmental pressure.In this experiment,the effects of different concentrations of melatonin(50,150 and 500μmol/L)on photosynthesis and redox homeostasis in cucumber leaves under salt stress(150 mmol/L NaCl)were investigated.The results showed that NaCl stress inhibited photosynthesis and increased the accumulation of reactive oxygen species(ROS)and membrane damage in cucumber,melatonin treatment alleviated the effects of NaCl stress on the photosynthesis and redox status in cucumber in a dose-dependent manner.Melatonin can improve photosynthetic capacity of plants,which is closely related to its inhibition of stomatal closure,improvement of light energy absorption and electron transfer.In addition,melatonin can also reduce oxidative stress response,which is attributed to the improvement of redox homeostasis and the enhancement of antioxidant enzyme activity.