Partitioning of absorbed light energy differed between the sun-exposed side and the shaded side of apple fruits under high light conditions
Partitioning of absorbed light energy differed between the sun-exposed side and the shaded side of apple fruits under high light conditions
复制标题
高光条件下苹果果实阳面和阴面吸收光能的分配存在差异
DOI：
10.1016/j.plaphy.2012.07.016
复制
发表时间：
2012-11-01
影响因子：
6.5
通讯作者：
Ma, Fengwang
中科院分区：
文献类型：
--
作者：
Chen, Changsheng;Zhang, Di;Ma, Fengwang
以不同发育阶段的苹果果皮为材料，定量比较了日照果皮和遮荫果皮在光化学和不同热耗散过程中吸收的光能比例。在果实发育过程中，强光条件下，日照果皮的光化学吸收比例不超过7%，遮荫果皮不超过5%。在强光下，通过光依赖热耗散吸收的光能比例较高，而通过结构性热耗散吸收的光能比例较低。光照下果皮的光热耗散主要依赖于叶黄素循环，且光照下果皮的叶黄素循环池大小显著大于遮荫果皮。遮荫果皮中的光相关热耗散取决于叶黄素循环和失活反应中心的存在。在强光条件下，遮荫果皮中Q(A)还原反应中心和Q(B)还原反应中心密度的下降速度均快于日照果皮。在果实发育过程中，与光抑制有关的热耗散在日照下先增加后保持不变，而在遮荫下减少。我们得出结论，在强光下，果皮释放过剩能量的优势顺序为：首先是叶黄素循环，然后是与光抑制有关的热耗散，然后是失活反应中心，最后是结构性热耗散。(C)2012年爱思唯尔·马森公司。版权所有。
Fractions of absorbed light energy consumed via photochemistry and different thermal dissipation processes was quantified and compared between the sun-exposed peel and the shaded peel of apple fruits at different developmental stages. During fruit development, the fraction of absorbed light consumed via photochemistry was no more than 7% in the sun-exposed peel and no more than 5% in the shaded peel under high light conditions. Under high light, the fraction of absorbed light energy consumed via light dependent thermal dissipation was higher whereas that via constitutive thermal dissipation was lower in the sun-exposed peel. The light dependent thermal dissipation in the sun-exposed peel mainly depended on the xanthophyll cycle, and the xanthophyll cycle pool size was significantly larger in the sun-exposed peel than in the shaded peel. The light dependent thermal dissipation in the shaded peel was dependent on both the xanthophyll cycle and the presence of inactivated reaction centers. Under high light conditions, the densities of both Q(A)-reducing reaction centers and Q(B)-reducing reaction centers decreased faster in the shaded peel than in the sun-exposed peel. The thermal dissipation related to photoinhibition increased and then kept unchanged in the sun-exposed peel but decreased in the shaded peel during fruit development. We conclude that under high light intensities, fruit peel looses the excess energy in order of predominance: first by the xanthophyll cycle, then the thermal dissipation related to photoinhibition, next through inactivated reaction centers, and finally by constitutive thermal dissipation. (c) 2012 Elsevier Masson SAS. All rights reserved.