Photosystem II thermostability in situ: Environmentally induced acclimation and genotype-specific reactions in Triticum aestivum L
Photosystem II thermostability in situ: Environmentally induced acclimation and genotype-specific reactions in Triticum aestivum L
复制标题
DOI：
10.1016/j.plaphy.2012.05.012
复制
发表时间：
2012-08-01
影响因子：
6.5
通讯作者：
Allakhverdiev, Suleyman I.
中科院分区：
文献类型：
--
作者：
Brestic, Marian;Zivcak, Marek;Allakhverdiev, Suleyman I.
研究了30个大田冬小麦（Triticum aestivum L.）基因型使用提示叶绿素a荧光动力学之前和之后的黑暗热处理。温度的逐渐升高导致叶绿素荧光诱导曲线上300 us处出现K带，表明PSII供体侧受损（即使在38 ℃下进行热处理）。在超过44 ℃的温度阈值时，观察到通常用作PSII热稳定性标准的基础荧光的增加。此外，在3.5 ℃下观察到K带出现的驯化转变（临界温度增加），但F-0急剧增加的驯化转变仅为1.1 ℃。采用40 ℃的黑暗热处理，在两个月内完成每周定期观察的单一温度方法表明，驯化效果不是渐进的，而是立即发生的，并且与超过30 ℃的每日最高温度增加有关。与未驯化的样品相比，驯化的热处理样品对PSII的供体侧的影响较小，活性Q（（S）超过棒）的较高分数减少了反应中心，并导致PSII单元之间的连接性降低得多。在未处理的植物的触角大小的减少，增加PSII连接和受体侧的变化发生作为热驯化的结果。增强PSII的热稳定性持续了几个星期，无论天气条件。基因型比较确定了三组不同的初始PSII热稳定性或驯化能力，这些分组显然与基因型的起源。(C)2012年Elsevier Masson SAS。All rights reserved.
Photosystem II (PSII) thermostability and acclimation effects on PSII photochemical efficiency were analyzed in thirty field grown winter wheat (Triticum aestivum L.) genotypes using prompt chlorophyll a fluorescence kinetics before and after dark heat treatment. A gradual increase in temperature caused the appearance of K-bands at 300 us on the chlorophyll fluorescence induction curve, indicating the impairment of the PSII donor side (even by heat treatment at 38 degrees C). An increase in basal fluorescence, commonly used as a criterion of PSII thermostability, was observed beyond a temperature threshold of 44 degrees C. Moreover, an acclimation shift (increase of critical temperature) was observed at the 3.5 degrees C identified for K-band appearance, but only by 1.1 degrees C for a steep increase in F-0. The single temperature approach with regular weekly observations completed within two months using dark heat treatment at 40 degrees C demonstrated that the acclimation effect is not gradual, but occurs immediately and is associated with an increase of daily temperature maxima over 30 degrees C. The acclimated heat treated samples had less effect on the donor side of PSII, the higher fraction of active Q((S) over bar) reducing reaction centers and causing a much lower decrease of connectivity among PSII units compared to non-acclimated samples. In the non-treated plants the reduction of antennae size, increase of PSII connectivity and changes in the acceptor side occurred as a result of heat acclimation. The enhancement of PSII thermostability persisted over several weeks regardless of weather conditions. The genotype comparison identified three groups that differed either in initial PSII thermostability or in acclimation capacity; these groupings were clearly associated with the origin of the genotypes. (C) 2012 Elsevier Masson SAS. All rights reserved.