An abscisic acid-related reduced transpiration promotes gradual embolism repair when grapevines are rehydrated after drought
An abscisic acid-related reduced transpiration promotes gradual embolism repair when grapevines are rehydrated after drought
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DOI：
10.1111/j.1469-8137.2008.02592.x
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发表时间：
2008-01-01
期刊：
影响因子：
9.4
通讯作者：
Schubert, Andrea
中科院分区：
文献类型：
--
作者：
Lovisolo, Claudio;Perrone, Irene;Schubert, Andrea
对于正在经历脱水和补液循环的植物来说，栓塞恢复的机制是有争议的。本研究对葡萄藤（Vitis vinifera）施加水分胁迫，观察其复水化过程中栓塞恢复、叶片水势（Psi）、蒸腾(E)和脱落酸（ABA）浓度的变化过程。正如预期的那样，叶片Psi和E在水分胁迫下降低，而木质部栓塞和叶片ABA浓度升高。复水后，Psi（叶片）在5 h内恢复，而E在48 h后才完全恢复。复水当天和次日，恢复叶片的ABA含量均高于干旱对照，表明干旱期间根系积累的ABA被输送到复水叶片中。在恢复植株中，叶柄、芽和根的木质部栓塞在补液后24小时内减少。提出了一个基于三点的模型来描述补液后植物的恢复：在Psi（叶片）几乎完全恢复之后，栓塞修复逐渐发生在茎中，并进一步发生在根和叶柄中；当所有植物器官都发生栓塞形成和修复时，水力导度在白天蒸发器时间内恢复；即使水分关系恢复，再水合叶片中的ABA残留信号也会阻碍气孔打开，这表明ABA诱导的蒸腾控制促进了再水合葡萄的栓塞逐渐修复。
Proposed mechanisms of embolism recovery are controversial for plants that are transpiring while undergoing cycles of dehydration and rehydration.Here, water stress was imposed on grapevines (Vitis vinifera), and the course of embolism recovery, leaf water potential (Psi(leaf)), transpiration (E) and abscisic acid (ABA) concentration followed during the rehydration process.As expected, Psi(leaf) and E decreased upon water stress, whereas xylem embolism and leaf ABA concentration increased. Upon rehydration, Psi(leaf) recovered in 5 h, whereas E fully recovered only after an additional 48 h. The ABA content of recovering leaves was higher than in droughted controls, both on the day of rewatering and the day after, suggesting that ABA accumulated in roots during drought was delivered to the rehydrated leaves. In recovering plants, xylem embolism in petioles, shoots, and roots decreased during the 24 h following rehydration.A model is proposed to describe plant recovery after rehydration based on three main points: embolism repair occurs progressively in shoots and further in roots and in petioles, following an almost full recovery of Psi(leaf); hydraulic conductance recovers during diurnal transpiring hours, when formation and repair of embolisms occurs in all plant organs; an ABA residual signal in rehydrated leaves hinders stomatal opening even when water relations have recovered, suggesting that an ABA-induced transpiration control promotes gradual embolism repair in rehydrated grapevines.