Evidence of Drought Stress Memory in the Facultative CAM, Aptenia cordifolia: Possible Role of Phytohormones.
Evidence of Drought Stress Memory in the Facultative CAM, Aptenia cordifolia: Possible Role of Phytohormones.
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DOI：
10.1371/journal.pone.0135391
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发表时间：
2015
期刊：
影响因子：
3.7
通讯作者：
Munné-Bosch S
中科院分区：
文献类型：
--
作者：
Fleta-Soriano E;Pintó-Marijuan M;Munné-Bosch S
虽然植物对干旱胁迫的反应已经在包括CAM植物在内的几种植物中进行了详细的研究，但对胁迫记忆的发生及其可能的调节机制仍然知之甚少。为了更好地了解植物胁迫记忆的发生和可能的调节机制，我们测量了反复干旱的Aptenia cordifolia中植物激素的浓度，以及各种胁迫指标，包括叶片含水量，光合作用和光和抗氧化保护机制。结果表明，植物暴露于干旱胁迫的反应不同，如果以前的挑战与第一次干旱。赤霉素水平下降后，暴露于第一次干旱，并保持较低的双重压力的植物相比，暴露于压力的第一次。与此相反，脱落酸水平较高，在双比单强调植物。这与氢过氧化物水平的变化同时发生，但与丙二醛水平的变化不同时发生，因此表明氧化状态增加，但不会导致双重应激植物的氧化损伤。结果表明：（1）干旱胁迫记忆在双胁迫下发生; cordifolia植物，（ii）赤霉素和脱落酸都可以发挥作用，在植物响应干旱的重复周期，和（iii）脱落酸水平的变化，在双胁迫植物可能有一个积极的影响，通过调节细胞的氧化还原状态的变化，在信号传导中的作用，而不是造成氧化损伤的细胞。
Although plant responses to drought stress have been studied in detail in several plant species, including CAM plants, the occurrence of stress memory and possible mechanisms for its regulation are still very poorly understood. In an attempt to better understand the occurrence and possible mechanisms of regulation of stress memory in plants, we measured the concentrations of phytohormones in Aptenia cordifolia exposed to reiterated drought, together with various stress indicators, including leaf water contents, photosynthesis and mechanisms of photo- and antioxidant protection. Results showed that plants exposed to drought stress responded differently if previously challenged with a first drought. Gibberellin levels decreased upon exposure to the first drought and remained lower in double-stressed plants compared with those exposed to stress for the first time. In contrast, abscisic acid levels were higher in double- than single-stressed plants. This occurred in parallel with alterations in hydroperoxide levels, but not with malondialdehyde levels, thus suggesting an increased oxidation state that did not result in oxidative damage in double-stressed plants. It is concluded that (i) drought stress memory occurs in double-stressed A. cordifolia plants, (ii) both gibberellins and abscisic acid may play a role in plant response to repeated periods of drought, and (iii) changes in abscisic acid levels in double-stressed plants may have a positive effect by modulating changes in the cellular redox state with a role in signalling, rather than cause oxidative damage to the cell.