【作者】 尹吴；

【导师】 诸葛强；

【作者基本信息】 南京林业大学 ， 生物化学与分子生物学， 2009， 硕士

【摘要】 杨树是我国重要的速生用材树种之一,用途广泛。磷酸烯醇式丙酮酸羧化酶基因（PEPC）是C4植物光合作用途径中的关键基因,利用PEPC基因开展杨树（C3植物）高光效基因工程研究具有重要的意义。本研究以转PEPC基因南林895杨（Populus×euramericana cv.‘Nanlin895’）为材料,将转基因植株与对照（未转基因杨树）在苗期生长、C4光合作用相关酶活性、光合作用相关参数等方面进行了初步的对比分析,为选育高光效转基因杨树新品种提供依据。主要研究结果如下:（1）转基因杨树的PEPCase活性比对照增加显著,最高达38.6%,而其他与C4光合作用相关的酶活性增加不明显;（2）转基因杨树表现出较强的对强光利用能力,其光饱和点比对照提高约10%～20%,饱和点时的光合速率比对照高;且光补偿点低于对照,表明转基因杨树利用弱光的能力较强;（3）转基因杨树CO₂饱和点与CO₂补偿点均较低;其光呼吸比对照减少,有利于光合形成有机物积累;羧化效率也较高,比对照增加最高达62.3%,表明转基因杨树利用CO₂的能力较强;（4）光氧化处理后,转基因杨树的PSⅡ原初光化学效率、PSⅡ实际光化学效率和光化学猝灭下降幅度比对照显著减少;而转基因植株的非光化学猝灭上升幅度比对照显著增加。表明转基因杨树具有较好的热耗散能力与耐光氧化能力。更多还原

【Abstract】 Poplar is one of important timber species with fast-growing in China, and a wide range of uses. Phosphoenol pyruvate carboxylase （PEPC） plays a key role in C4 plant high efficiency photosynthesis. It is of a great significance to carry out poplar （C3 plants） high-efficiency genetic engineering research by use of C4 plants PEPC gene.In this study, Transgenic Poplar with PEPC gene for materials with the control transgenic plants （non-transgenic poplar） in the seedling growth, C4 photosynthesis-related activity, photosynthesis relevant parameters of a preliminary comparative analysis of high efficiency for selection of transgenic poplar provide the basis for new varieties. The main findings are as follows:（1）The enzymes in transgenic poplars related to C4 photosynthesis increased than the control, and PEPC activity increased significantly as high as 38.6 %.（2）Transgenic poplars have strong capacity for using high light intensity, and its light saturation point increased than the control by about 10% to 20%. The photosynthetic rates of transgenic poplars in light saturation point were higher than that of the control, and the light compensation points of transgenic poplars were lower than that of control.Also,the ability of transgenic poplars to use low light were stronger than the control.（3）CO₂ saturation point and CO₂ compensation point of transgenic poplars were lower than the control. The photorespiration of transgenic poplars was lower than that of control, which is favourable to photosynthetic formation and organics accumulation. In addition, the transgenic poplars had higher efficiency of carboxylation, the highest of which was higher than that of the control by 62.3 %, indicating that transgenic poplars have the ability to use more CO₂.（4）Photo-oxidation treatment, transgenic poplars original PSⅡphotochemical efficiency, PSⅡphotochemical efficiency and the actual decrease in photochemical quenching significantly reduced compared to the control; and transgenic plants increased the rate of non-photochemical quenching increased significantly than control.The show that the transgenic poplar with better heat dissipation capability and light oxidation.更多还原