B型烟粉虱危害对烟草叶片光系统Ⅱ的影响

摘要

[目的]研究B型烟粉虱取食危害对烟草光系统Ⅱ的影响,为明确烟粉虱对寄主植物光合作用的影响机制提供依据.[方法]通过测定烟草叶片叶绿素荧光快速诱导曲线,使用JIP-test分析技术进行参数分析,研究B型烟粉虱危害烟草后对烟草的局部虫体叶和系统叶光系统Ⅱ (PSⅡ)的影响.[结果]B型烟粉虱危害烟草后虫体叶和系统叶上的最大光化学效率(φpo)和光化学性能指数(PIABS)与对照相比均明显升高(P＜0.05),表明处理烟草植株的局部叶和系统叶的原初光化学反应受到较大的伤害.B型烟粉虱危害烟草后虫体叶和系统叶PSⅡ反应中心的电子传递均受阻,放氧复合体受到严重破坏.B型烟粉虱危害烟草后系统叶的单位反应中心吸收的能量(ABS/RC)和单位反应中心热耗散掉的能量(DIo/RC)增加,单位反应中心捕获的能量(TRo/RC)下降；B型烟粉虱危害的虫体叶中ABC/RC没有变化,DIo/RC增加,TRo/RC下降.B型烟粉虱危害烟草后虫体叶和系统叶的单位面积反应中心数量(RC/CS)均明显降低(P＜0.05),而光系统PS Ⅱ反应中心的关闭程度(1-qP)却明显升高,分别较各自对照升高了69.83％和142.58％(P＜0.05).[结论] B型烟粉虱的危害严重影响了烟草叶片的光系统Ⅱ(PSⅡ),主要是由于PSⅡ反应中心的失活和关闭以及对PSⅡ电子传递的抑制,电子传递中受抑制的位点包括放氧复合体和QA到Q8间的电子传递过程,同时B型烟粉虱危害影响了烟草叶片光系统的能量流动,且烟粉虱对烟草叶片PSⅡ的影响具有系统传导性.%[ Objective ] The objective of this study is to define the effects of Bemisia tabaci biotype B infestation on the photosystem II (PSII) in tobacco, and to reveal the mechanism of B. tabaci infestation affecting photosynthesis of host plant. [Method! Effects of B. tabaci infestation on the PSII performance in damaged leaves and systemic leaves of tobacco were investigated by measuring chlorophyll fluorescence transients and analyzing the related parameters using HP-test. [Result] B. tabaci infestation significantly increased the maximal photochemical efficiency of primary photochemistry (tppo) and performance index on absorption basis (PIabs) both in local and systemic leaves (P<0.05), indicating that the original photochemical reaction was greatly damaged. Photosynthetic electron transport was inhibited and oxygen-evolving complexes (OEC) were severely damaged. B. tabaci infestation increased the energy absorption per active reaction centers (ABS/RC) and the energy dissipation per active reaction centers (DIo/RC) increase while decreased energy trapping per active reaction centers (TRo/RC) in systemic leaves. In damaged leaves, DIo/RC increased and TRo/RC decreased, however, the ABC/RC was not affected. B. tabaci infestation reduced the density of active reaction centers per excited cross-section (RC/CS) both in damaged and systemic leaves (P<0.05) while increased thernclosure degree of the PS II reaction centers by 69.83% and 142.58% (P<0.05), respectively, in damaged and systemic leaves. [Conclusion] B. tabaci infestation damaged the PSII of tobacco leaves. The reaction centers were damaged and the electron transporting was inhibited. The inhibited points of the electron transporting included the OEC and the electron transporting from QA to QB. Energy flux of PSII was also affected by the B. tabaci infestation. The damage on PSII caused by B. tabaci in tobacco leaves was systematically conductive.