植物光合速率对光强从饱和到有限转变响应方式的物种依赖性  

Species-dependence of the Pattern of Plant Photosynthetic Rate Response to Light Intensity Transition from Saturating to Limiting One

作　　者：陈悦[1] 许大全[1] 

机构地区：[1]中国科学院上海生命科学研究院植物生理生态研究所,上海200032

出　　处：《植物生理与分子生物学学报》2007年第6期538-546,共9页Journal Of Plant Physiology and Molecular Biology

基　　金：国家重点基础研究发展规划(九七三)项目(No.2005CB121106)资助。

摘　　要：在考察过的57种植物中,有32种的光合速率对光强转换的响应曲线为V型,25种的响应曲线为L型。这种响应类型对物种的依赖性即物种差异,与植物科属分类无关,而与碳同化途径的不同有关,可能还与物种起源时的光环境有关。虽然在饱和光下2类植物体内电子传递速率与羧化速率的比值差异不大,但是在有限光下响应曲线为V型的植物该比值远高于响应曲线为L型的植物。这个差别可以部分地用前者具有较大的捕光天线并且在饱和光下部分天线从反应中心复合体可逆脱离来解释。By observing the photosynthetic responses of leaves to changes in light intensity and CO2 concentration it was found that among the more than 50 plant species examined 32 species and 25 species showed respectively the V pattern and L pattern of the photosynthetic response to light intensity transition from saturating to limiting one （Figs.1 and 2 and Table 1）. The pattern of photosynthetic response to light intensity transition is species-dependent but not leaf developmental stage-dependent （Fig.3）. The species-dependence was not related to classification in taxonomy because the photosynthetic response might display the two different patterns （V and L） in plants of the same family, for example, rice and wheat （Gramineae）, soybean and peanut （Leguminosae）. It seemed to be related to the pathway of photosynthetic carbon assimilation because all of the C4 plants examined （maize, green bristlegrass and thorny amaranth） displayed the L pattern. It might be related to light environment where the plants originated. The V pattern of photosynthetic response to light intensity transition was often observed in some plants grown in shade habitats, for example, sweet viburnum and Japan fatsia, while the L pattern was frequently observed in those plants grown in sunny habitats, for example, ginkgo and cotton. Furthermore, the ratio of electron transport rate to carboxylation rate in vivo measured at limiting light was far higher in the V pattern plants （mostly higher than 10） than in the L pattern plants （mostly lower than 5）, but the ratio measured at saturating light had no significant difference between the two kinds of plants （Table 2）. These resuits can be explained in part by that the V pattern plant species have larger light-harvesting complex （LHCII） and at saturating light the reversible dissociation of some LHCIIs from PSII reaction center complex occurs. The pattern of photosynthetic response to light intensity transition and the ratio of electron transport rate to carboxylati

关 键 词：光系统Ⅱ捕光复合体(LHCⅡ) 净光合速率 光 系统Ⅱ(PSⅡ) 可逆脱离 物种依赖性 

分 类 号：Q945[生物学—植物学]