Activation of violaxanthin cycle in darkness is a common response to different abiotic stresses: a case study in Pelvetia canaliculata.
Activation of violaxanthin cycle in darkness is a common response to different abiotic stresses: a case study in Pelvetia canaliculata.
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DOI：
10.1186/1471-2229-11-181
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发表时间：
2011-12-26
影响因子：
5.3
通讯作者：
García-Plazaola JI
中科院分区：
文献类型：
--
作者：
Fernández-Marín B;Míguez F;Becerril JM;García-Plazaola JI
在紫黄质（V）循环中，当强光或光与其他胁迫物组合导致光系统的过度激发时，V被脱环氧化为玉米黄质（Z）。然而，植物在黑暗中也会受到胁迫，最近的报道表明，脱水会在没有光的情况下引发V-脱环氧化。在这项研究中，我们使用了高度耐胁迫的棕色Pelvetia canaliculata作为模式生物，由于其缺乏叶黄素和其非光化学猝灭独立于transthylakoid-ΔpH，研究非生物胁迫诱导的黑暗中V循环的触发。我们发现，除了干燥，其他因素，如浸泡，缺氧和高温也诱导V-脱环氧化在黑暗中。一旦处理停止，这个过程是可逆的（除了热，它会造成致命的伤害）。无论施加的压力，所产生的脱环氧化叶黄素与Fv/Fm的减少，这表明在光合效率的下调的共同功能。还研究了质体醌池的氧化还原状态和V-循环酶在黑暗中对V-脱环氧化的差异活性的影响。目前的研究结果表明，紫黄质脱环氧酶（VDE）和玉米黄质环氧酶（ZE）有一个基本的组成活动，即使在黑暗中，被ZE抑制胁迫下。这种抑制导致Z积累。这项研究表明，V-循环活动是由几个非生物胁迫触发的，即使它们发生在绝对没有光的情况下，导致Fv/Fm下降。这一发现提供了新的见解的V-循环的调节机制和其生理生态作用的理解。
In the violaxanthin (V) cycle, V is de-epoxidized to zeaxanthin (Z) when strong light or light combined with other stressors lead to an overexcitation of photosystems. However, plants can also suffer stress in darkness and recent reports have shown that dehydration triggers V-de-epoxidation in the absence of light. In this study, we used the highly stress-tolerant brown alga Pelvetia canaliculata as a model organism, due to its lack of lutein and its non-photochemical quenching independent of the transthylakoidal-ΔpH, to study the triggering of the V-cycle in darkness induced by abiotic stressors. We have shown that besides desiccation, other factors such as immersion, anoxia and high temperature also induced V-de-epoxidation in darkness. This process was reversible once the treatments had ceased (with the exception of heat, which caused lethal damage). Irrespective of the stressor applied, the resulting de-epoxidised xanthophylls correlated with a decrease in Fv/Fm, suggesting a common function in the down-regulation of photosynthetical efficiency. The implication of the redox-state of the plastoquinone-pool and of the differential activity of V-cycle enzymes on V-de-epoxidation in darkness was also examined. Current results suggest that both violaxanthin de-epoxidase (VDE) and zeaxanthin-epoxidase (ZE) have a basal constitutive activity even in darkness, being ZE inhibited under stress. This inhibition leads to Z accumulation. This study demonstrates that V-cycle activity is triggered by several abiotic stressors even when they occur in an absolute absence of light, leading to a decrease in Fv/Fm. This finding provides new insights into an understanding of the regulation mechanism of the V-cycle and of its ecophysiological roles.
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DOI：
10.1046/j.1432-1033.2003.03766.x
发表时间：
2003-09-01
期刊：
EUROPEAN JOURNAL OF BIOCHEMISTRY
影响因子：
--
作者：
Josse, EM;Alcaraz, JP;Kuntz, M
通讯作者：
Kuntz, M
影响因子：
2.8
作者：
Holzwarth, Alfred R.;Miloslavina, Yuliya;Jahns, Peter
通讯作者：
Jahns, Peter
影响因子：
3.4
作者：
Kostecka-Gugala, A;Latowski, D;Strzalka, K
通讯作者：
Strzalka, K
影响因子：
2.9
作者：
Mueller, Marc G.;Lambrev, Petar;Holzwarth, Alfred R.
通讯作者：
Holzwarth, Alfred R.
影响因子：
7.3
作者：
Ebbert, V;Adams, WW;Demmig-Adams, B
通讯作者：
Demmig-Adams, B