RECOVERY FROM PHOTOINHIBITION IN PEAS (PISUM-SATIVUM L) ACCLIMATED TO VARYING GROWTH IRRADIANCES - ROLE OF D1 PROTEIN-TURNOVER
RECOVERY FROM PHOTOINHIBITION IN PEAS (PISUM-SATIVUM L) ACCLIMATED TO VARYING GROWTH IRRADIANCES - ROLE OF D1 PROTEIN-TURNOVER
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DOI：
10.1104/pp.104.3.1033
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发表时间：
1994-03-01
期刊：
影响因子：
7.4
通讯作者：
ANDERSON, JM
中科院分区：
文献类型：
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作者：
ARO, EM;MCCAFFERY, S;ANDERSON, JM
以豌豆叶片为试材，研究了不同光强驯化处理后，光系统II(PSII)光化学效率的恢复和D1蛋白代谢的变化。所有适应不同光照强度的豌豆都能够从光抑制中恢复，至少部分地，在远高于其生长光强的光照强度下。然而，豌豆叶片在强光照下从光抑制中恢复的能力严格依赖于叶片的光适应，即生长过程中光照度越高，豌豆叶片在中高光下从光抑制中恢复的能力越强。在我们的实验条件下，主要监测了依赖于D1蛋白周转的恢复，因为在叶绿体编码的蛋白质合成抑制剂林可霉素的存在下，仅发生了可以忽略的恢复。在黑暗中，PSII光化学效率没有恢复，受损的D1蛋白也没有发生明显的降解。但在弱光条件下，适应不同光照强度的豌豆均表现出较好的PS II恢复能力，并伴随着D1蛋白的快速降解。在光恢复条件下，光抑制叶片中D1蛋白的降解速度是非光抑制叶片的3~4倍，光恢复条件下，光抑制叶片的降解速率为S(-1)。在400mU·m~(-2)S(~(-1))的中光下，弱光抑制的豌豆不能进一步提高D1蛋白的降解速率，也不可能恢复PSⅡ的功能。另一方面，即使在中光和强光条件下，光抑制的叶片也能够提高D1蛋白的降解速率，确保至少部分恢复PSII的功能。我们得出结论，光抑制叶片在不同光照条件下恢复PSII功能的能力与恢复条件下叶片降解受损的D1蛋白的能力直接相关。
D1 protein turnover and restoration of the photochemical efficiency of photosystem II (PSII) after photoinhibition of pea leaves (Pisum sativum L. cv Greenfeast) acclimated to different light intensities were investigated. All peas acclimated to different light intensities were able to recover from photoinhibition,, at least partially, at light intensities far above their growth light irradiance. However, the capacity of pea leaves to recover from photoinhibition under increasing-high irradiances was strictly dependent on the light acclimation of the leaves; i.e. the higher the irradiance during growth, the better the capacity of pea leaves to recover from photoinhibition at moderate and high light. In our experimental conditions, mainly D1 protein turnover-dependent recovery was monitored, since in the presence of an inhibitor of chloroplast-encoded protein synthesis, lincomycin, only negligible recovery took place. In darkness, neither the restoration of PSII photochemical efficiency nor any notable degradation of damaged D1 protein took place. In low light, however, good recovery of PSII occurred in all peas acclimated to different light intensities and was accompanied by fast degradation of the D1 protein. The rate of degradation of the D1 protein was estimated to be 3 to 4 times faster in photoinhibited leaves than in nonphotoinhibited leaves under the recovery conditions of 50 mu mol of photons m(-2) s(-1). In moderate light of 400 mu mol of photons m(-2) s(-1), the photoinhibited low-light peas were not able to increase further the rate of D1 protein degradation above that observed in nonphotoinhibited leaves, nor was the restoration of PSII function possible. On the other hand, photoinhibited high-light leaves were able to increase the rate of D1 protein degradation above that of nonphotoinhibited leaves even in moderate and high light, ensuring at least partial restoration of PSII function. We conclude that the capacity of photoinhibited leaves to restore PSII function at different irradiances was directly related to the capacity of the leaves to degrade damaged D1 protein under the recovery conditions.