【作者】 王文芳；

【导师】 陈信波；

【作者基本信息】 湖南农业大学 ， 生物化学与分子生物学， 2009， 硕士

【摘要】 水稻（Oryza sativa）是世界上非常重要的粮食作物之一。但是由于全球环境的变化,水稻产量和品质受到了严重的威胁,这就使如何获得优良水稻品种变得十分迫切。因此,研究水稻中起重要调控作用的基因,用于水稻的遗传改良,具有广阔的应用前景和农业发展意义。本研究进行了水稻OsCesA4和OsSCP基因的功能鉴定,取得了以下研究结果:1.对水稻OsCesA4基因进行了生物信息学分析。通过OsCesA4基因启动子驱动的GUS基因表达分析,发现OsCesA4基因在根、茎、叶、鞘和穗中均有表达。OsCesA4基因的表达对NaCl和高温比较敏感,对PEG、ABA和低温不敏感。OsCesA4基因的纯合缺失突变体植株矮小,生长周期延长,生育力下降,叶尖枯萎,茎、叶、鞘和穗出现脆性,并表现出茎和叶的细胞学变化;OsCesA4突变体光合速率和气孔导度显著下降,胞间CO₂浓度和蒸腾速率无显著性差异;OsCesA4突变体叶片的叶绿素a、叶绿素b、类胡萝卜素和总叶绿素含量与野生型日本晴无显著性差异;OsCesA4突变体的幼苗、叶的硅质含量显著性升高。构建了OsCesA4的RNAi载体,并转入了农杆菌。2.对水稻OsSCP基因进行了生物信息学分析。构建了OsSCP基因的启动子载体,并转入农杆菌。通过RT-PCR发现OsSCP基因在根、茎、叶、鞘和穗中均有表达,在叶和鞘中表达高,穗中最低。水稻OsSCP纯合缺失突变体对水稻正常的生长发育、生殖和光合作用无明显影响。水稻OsSCP基因对NaCl、高温、干旱逆境和ABA比较敏感的,对PEG和低温不敏感。更多还原

【Abstract】 Rice （Oryza sativa） is a very important food crop in the world. However, due to changes in the global environment, rice yield and quality are threated seriouly, which makes the creation of stress resistant rice varieties becoming very urgent. Therefore, research on important rice regulating gene for the genetic improvement of rice has broad application prospects. Functional Characterization of Rice OsCesA4 and OsSCP genes were done in this work and the following results wre obtained:1. The OsCesA4 gene expressions in root, stem, leaf, sheath and spike was observed from the OsCesA4 gene promoter driving GUS expression. OsCesA4 gene was sensitive to NaCl and high temperature stresses, but not sensitive to PEG, ABA and low temperature stresses. The null mutation of OsCesA4 gene resulted in decrease in plant height, longer growth cycle, declined fertility, tip wilt; brittle of stems, leaves, sheath and panicle as well as stem and leaf cytological changes. The photosynthetic rate and Stomatal conductance were also significantly decreased and but the intercellular CO₂ concentration and transpiration rate were not significantly different in photosynthesis. But the chlorophyll a, chlorophyll b, carotenoids and total chlorophyll content had no significant difference. The silica content in the seedlings and leaves of the mutants were increased significantly. The OsCesA4 gene RNAi vector was construced and transferred into Agrobacterium.2. The OsSCP gene expressions in root, stem, leaf, sheath and spike was analyzed by RT-PCR. The expressions were high in leaves and sheaths. The lowest expression was in spike. The OsSCP gene null mutation did not make many changes in growth and development, fertility and reproduction and photosynthesis. The OsSCP gene was found more sensitive to NaCl, high temperature, drought and ABA, but not sensitive to PEG and low temperature.更多还原