Inhibition of photosynthesis by viral infection:: Effect on PSII structure and function
Inhibition of photosynthesis by viral infection:: Effect on PSII structure and function
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DOI：
10.1034/j.1399-3054.2000.110220.x
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发表时间：
2000-10-01
影响因子：
6.4
通讯作者：
Barón, M
中科院分区：
文献类型：
--
作者：
Rahoutei, J;García-Luque, I;Barón, M
以不同辣椒和辣椒轻斑驳病毒（PMMoV和PaMMoV）株系及其嵌合病毒基因组为材料，研究了病毒感染对本氏烟草（Nicotiana benthamiana Gray）光合作用的影响。在有症状和无症状的叶片病毒感染的植物，光合电子传递光系统II（PSII）减少。在所有分析的情况下，病毒感染影响类囊体膜中的放氧复合物（OEC）的多肽模式。当与健康对照中的水平相比时，24和16 kDa蛋白质的水平均降低至不同程度。这种OEC外源蛋白的损失影响了受感染植物的类囊体膜和叶片的放氧速率。此外，病毒外壳蛋白（CP）被发现与叶绿体和类囊体膜的感染植物。CP积累水平取决于感染后的时间和分析的病毒，但独立的CP本身，因为杂交病毒不表现为它们的亲本病毒与相同的CP，相对于PSII抑制，CP积累率和OEC蛋白水平。在两种类型的叶子中进行的调制叶绿素（Chl）荧光和氧气释放测量表明，与对照植物相比，感染植物PSII电子传递的量子产率减少。电子传递效率的下降主要是由于开放反应中心的分数减少。受感染的植物也表现出减少的效率，激发捕获PSII的光保护热耗散多余的激发能量。
The effect of viral infection on photosynthesis was investigated in Nicotiana benthamiana Gray plants infected with different strains of pepper and paprika mild mottle viruses (PMMoV and PaMMoV) and chimeric viral genomes derived from them. In both symptomatic and asymptomatic leaves of virus-infected plants, photosynthetic electron transport in photosystem II (PSII) was reduced. In all cases analyzed, viral infection affected the polypeptide pattern of the oxygen-evolving complex (OEC) in thylakoid membranes. The levels of both the 24 and 16 kDa proteins were reduced to a differing extent when compared with the levels in healthy control. This loss of the OEC extrinsic proteins affected the oxygen evolution rates of thylakoid membranes and leaves from infected plants. Additionally, viral coat protein (CP) was found associated with the chloroplasts and the thylakoid membranes of the infected plants. The CP accumulation level was dependent upon both the post-infection time and the virus analyzed, but independent of the CP itself since hybrid viruses did not behave as their parental viruses with the same CP, with respect to PSII inhibition, CP accumulation rates and OEC protein levels. Modulated chlorophyll (Chl) fluorescence and oxygen evolution measurements carried out in both types of leaves showed that the quantum yield of PSII electron transport was diminished in infected plants with respect to those of control plants. The decrease in electron transport efficiency was mainly caused by a reduction in the fraction of open reaction centers. The infected plants also showed a reduction in the efficiency of excitation capture in PSII by photoprotective thermal dissipation of excess excitation energy.