Exogenous Strigolactones alleviate KCl stress by regulating photosynthesis, ROS migration and ion transport in Malus hupehensis Rehd.
Exogenous Strigolactones alleviate KCl stress by regulating photosynthesis, ROS migration and ion transport in Malus hupehensis Rehd.
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DOI：
10.1016/j.plaphy.2020.12.015
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发表时间：
2020-12
期刊：
影响因子：
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通讯作者：
Xiaodong Zheng;Yuqi Li;X. Xi;Changqing Ma;Zhijuan Sun;Xueqing Yang;Xiangyang Li;Yike Tian
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文献类型：
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作者：
Xiaodong Zheng;Yuqi Li;X. Xi;Changqing Ma;Zhijuan Sun;Xueqing Yang;Xiangyang Li;Yike Tian
近年来，苹果园大量施用钾肥，导致KCl胁迫加剧。独脚金内酯（SL）是一种新型植物激素，参与植物对NaCl和干旱胁迫的耐受。但其机制及外源SL对苹果幼苗KCl胁迫的影响尚不清楚。在KCl胁迫下，测定了叶片光合参数、活性氧含量、渗透调节物质含量和矿质元素含量等生理指标。此外，还对KCl胁迫下苹果幼苗叶片中响应KCl的基因和SL信号转导基因的表达进行了检测和分析。外源SL增强了过氧化物酶和过氧化氢酶的活性，从而消除了KCl胁迫诱导的活性氧的产生，促进了脯氨酸的积累，维持了渗透平衡。外源SL将K+排出细胞质，将K+分隔到液泡中，增加细胞质中Na+、Mg2+、Fe2+、Mn2+的含量，维持KCl胁迫下的离子稳态。
AimsIn recent years, the application of large amounts of potash fertilizer in apple orchards leads to worsening KCl stress. Strigolactone (SL), as a novel phytohormone, reportedly participates in plant tolerance to NaCl and drought stresses. However, the underlying mechanism and the effects of exogenous SL on the KCl stress of apple seedlings remain unclear.MethodsWe sprayed different concentrations of exogenous SL onMalus hupehensisRehd. under KCl stress and measured the physiological indexes like, photosynthetic parameter, content of ROS, osmolytes and mineral element. In addition, the expressions of KCl-responding genes and SL-signaling genes were also detected and analyzed.ResultsApplication of exogenous SL protected the chlorophyll and maintained the photosynthetic rate of apple seedlings under KCl stress. Exogenous SL strengthened the enzyme activities of peroxidase and catalase, thereby eliminating reactive oxygen species production induced by KCl stress, promoting the accumulation of proline, and maintaining osmotic balance. Exogenous SL expelled K+outside of the cytoplasm and compartmentalized K+into the vacuole, increased the contents of Na+, Mg2+, Fe2+, and Mn2+in the cytoplasm to maintain the ion homeostasis under KCl stress.ConclusionsExogenous SL can regulate photosynthesis, ROS migration and ion transport in apple seedlings to alleviate KCl stress.