Antioxidants and xanthophyll cycle-dependent energy dissipation in Cucurbita pepo L. and Vinca major L. acclimated to four growth PPFDs in the field
Antioxidants and xanthophyll cycle-dependent energy dissipation in Cucurbita pepo L. and Vinca major L. acclimated to four growth PPFDs in the field
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DOI：
10.1093/jxb/49.328.1869
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发表时间：
1998-11
影响因子：
6.9
通讯作者：
B. Logan;B. Demmig-Adams;W. W. Adams-W.;S. Grace
中科院分区：
文献类型：
--
作者：
B. Logan;B. Demmig-Adams;W. W. Adams-W.;S. Grace
Cucurbita pepo L. 和 Vinca Major L. 的叶子在光合光子通量密度 (PPFD) 范围内从深遮荫到田间全日照下发育，以光化学、叶黄素循环依赖性能量耗散和抗氧化剂的适应为特征。叶色素成分的主要适应反应是叶黄素循环池大小随着生长 PPFD 的增加而增加。在这两个物种中，中午的估计热能耗散率随着 PPFD 的增加而增加，并且中午每叶绿素中玉米黄质和蒽黄质的水平与所有生长 PPFD 条件下的非光化学荧光猝灭水平密切相关。然而，在充足的阳光照射下，与南瓜相比，V.major 的叶黄素循环依赖性能量耗散水平似乎要高得多，而估计的光化学速率则表现出相反的趋势。在这两种植物中，抗坏血酸过氧化物酶和超氧化物歧化酶的叶子活性以及抗坏血酸含量随着 PPFD 生长的增加而增加。 V. Major 的活性/含量在 100% 全日照下更高，并且从中等生长 PPFD 到 100% 全日光的增加更强烈。这些适应模式与叶黄素循环依赖性能量耗散所表现出的模式相似。在还原型谷胱甘肽的多重作用的背景下讨论了谷胱甘肽还原酶的适应模式。过氧化氢酶以与其清除通过光呼吸和/或线粒体呼吸产生的H 2 O 2 的作用一致的方式适应。叶α-生育酚没有表现出依赖于PPFD的生长趋势。
The acclimation of photochemistry, xanthophyll cycle-dependent energy dissipation, and antioxidants was characterized in leaves of Cucurbita pepo L. and Vinca major L. that developed under photosynthetic photon flux densities (PPFDs) ranging from deep shade to full sunlight in the field. The predominant acclimatory response of leaf pigment composition was an increase in the xanthophyll cycle pool size with increasing growth PPFD. In both species, the estimated rate of thermal energy dissipation at midday increased with increasing PPFD and midday levels of zeaxanthin and antheraxanthin per chlorophyll were closely correlated with the levels of non-photochemical fluorescence quenching under all growth PPFD regimes. However, at full sunlight there appeared to be considerably higher levels of xanthophyll cycle-dependent energy dissipation in V. major compared with pumpkin while estimated rates of photochemistry exhibited the reverse trend. Leaf activities of the antioxidant enzymes ascorbate peroxidase and superoxide dismutase, as well as ascorbate content, increased with increasing growth PPFD in both plant species. Activities/contents were higher under 100% full sunlight and increased more strongly from intermediate growth PPFDs to 100% full sunlight in V. major than in C. pepo. These patterns of acclimation are similar to those exhibited by xanthophyll cycle-dependent energy dissipation. The patterns of acclimation of glutathione reductase are discussed in the context of the multiple roles for reduced glutathione. Catalase acclimated in a manner consistent with its role in scavenging H 2 O 2 generated via photorespiration and/or mitochondrial respiration. Leaf α-tocopherol did not exhibit growth PPFD-dependent trends.