CO2浓度倍增对几种植物叶片的叶绿素蛋白质复合物的影响

研究了CO_2浓度倍增对大豆(Glycine max L.,C_3植物)、黄瓜(Cucumis sativus L.,C_3植物)、谷子(Setaria italica (L.) Beauv.,一种不很典型的C_4植物)和玉米(Zea mays L.,C_4植物)叶片的叶绿素蛋白质复合物的影响。实验植物盆栽于聚乙烯薄膜(或玻璃)的开顶式培养室中。播种后对照室的CO_2浓度立即保持在大气浓度(350±10)×10~(-6)中,CO_2浓度倍增处理室则保持在(700±10)×10~(-6)下。研究结果表明,对于大豆、黄瓜和谷子,CO_2浓度倍增均使其PSⅡ捕光叶绿素a/b-蛋白质复合物(LHCⅡ)的聚合体态的量增多,单体态的量减少。但C_4植物玉米对CO_2浓度倍增没有这样的反应。作者认为在大豆等植物中,LHCⅡ的上述状态变化可能是植物的光合机构对长期高CO_2浓度的一种适应效应,这样能提高光合作用中光能的吸收、传递和转换的效率,并支持高效的光合碳素同化作用。

EFFECT OF DOUBLED CO_2 CONCENTRATION ON LEAF CHLOROPHYLL-PROTEIN COMPLEXES IN SEVERAL PLANTS

The effect of doubled CO2 on the chlorophyll-protein complexes of the leaves of soybean (GLycine max L. , C3 plants), cucumber ( Cucumis sativus L. , C3 plant), millet ( Setaria italica (L.) Beauv. , not a very typical C4 plant) and corn (Zea mays L. , C4 plant) was studied. Experimental plants were pot-cultured in polyethylene membrane (or glass) open top cultured chambers. After sowing, CO2 was kept immediately either at ambient ((350 10)x10-6) concentration for the control or at doubled CO2 ((700 10)x10-6) concentration for the treatment chambers. The chlorophyll-protein complexes of the thylakoid membrane of the plants were resolved by disk SDS-PAGE. The results showed that after doubled CO2 treatment, either in the soybean and cucumber, or in the millet, the quantity of polymer state of PS II light-harvesting chlorophyll a/b-protein complex (LHCII ) had increased as the monomer state of LHCII decreased. But such response to doubled CO2 was not found in corn, the C4 plant. The change of the state of LHCII in soybean etc . might be an adaptive effect of plant photosynthetic mechanism to the long term elevated CO2. Thus it could increase the efficiency of the absorption, transfer and conversion of light energy in plant photosynthe- sis, and support the high efficiency of photosynthetic carbon assimilation.