C3植物叶片跨膜电势差(ΔΨ)的光谱测量  

Spectroscopic measurements of the electric potential difference(ΔΨ)of C3 leaves

作　　者：吕辉 王春波 王芬 崔宝禄 宋丽莎 LYU Hui;WANG Chun-bo;WANG Fen;CUI Bao-lu;SONG Li-sha(School of Biological&Agricultural Science,Qiannan Normal University for Nationalities,Duyun 558000,China)

机构地区：[1]黔南民族师范学院生物科学与农学院,都匀558000

出　　处：《生物学杂志》2020年第2期57-60,共4页Journal of Biology

基　　金：国家自然科学基金项目(31660056);贵州省教育厅自然科学基金重点项目(黔教合KY字〔2015〕380);贵州省教育厅青年科技人才成长项目(黔教合KY字〔2018〕436);贵州省植物学重点支持学科开放基金项目(qnsyzw1801&qnsyzw1804)。

摘　　要：C3植物是最重要的光合生物之一,在光照条件下,其类囊体膜上光驱的电子流与基质内质子的跨膜转运相耦合。质子在囊腔内的积累产生了跨膜质子动势(pmf),其驱动ATP合成酶的构象发生转变并合成ATP分子。质子动势的一个重要组分,即跨膜电势差(ΔΨ),是反映原初光合能量转化的一个重要指标量,它会使色素分子(包括叶绿素分子以及胡萝卜素分子等)对光能的最大吸收峰迁至515 nm处。515 nm最大吸收峰的形成除了有ΔΨ的贡献,也有来自“光散射”效应的叠加。因此,对于ΔΨ的实验测量一直是一个难题,并且在国内,关于ΔΨ的实验测量鲜见报道。以烟草叶作为样品,使用双通道可变振幅式叶绿素荧光仪,并搭配最新设计的P515/535模块,测量样本在单周转饱和光(ST)、1 s可见光、60 s可见光的P515光谱信号变化情况。实验结果可为研究C 3作物高光效品种选育提供技术支持。C3 photosynthesis is one of the most important photosynthetic mechanisms,in which light-driven electron transport is coupled to the movement of protons from the chloroplast stroma into the thylakoid lumen.With it,positive-charged protons accumulate in the lumen,and the protons decrease in the stroma,producing the transmembrane proton motive force(pmf),eventually,driving the conformational variation of the transmembrane thylakoid ATPase which converts ADP(adenosine diphosphate)and Pi(inorganic phosphate)into ATP(adenosine triphosphate)which are subsequently used in the ensuing Calvin cycle to make the organic products.Proton motive force contains two components,one is the chemical potential difference caused by the transmembrane osmotic pressure,and another pmf component,i.e.ΔΨ,is an essential indicator of light energy transduction,which triggers a so-called electrochromic shift of the absorption maximum of the pigment(s)to 515 nm.Majorly,carotenoid pigment and chlorophyll b pigment are responsible for the electrochromic shift.This shift is not solely intensified byΔΨ,also overlapped by the absorption change caused from the“light scattering”effect.The interpretation of this signal is complicated,which indeed find the P515 measurement a hard trial for the example ofΔΨprobing,particularly in the long-term temporal range.It has seldom been reported in the published papers domestically for the P515 measurement.In this work,tobacco leaves(Nicotiana tabacum)were measured by Dual-PAM-100 chlorophyll fluorescence photosynthesis analyzer using the novel P515/535 Emitter-Detector module.The results illustrated the P515 curves when single turnover flash was on,when actinic light was lasting for 1 s,and when actinic light was lasting for 1 min followed by another 2 min dark phase interval.Our results could offer a technological foundation for the scientific research of the photosynthetic primary energy transduction.

关 键 词：C3植物 类囊体膜 跨膜电势差(ΔΨ) P515光谱信号 

分 类 号：Q945[生物学—植物学]