【作者】 许冬清；

【导师】 张红生；

【作者基本信息】 南京农业大学 ， 作物遗传育种， 2008， 硕士

【摘要】 干旱、高盐和低温等环境胁迫严重影响着植物的生长发育和作物产量。迄今为止,人们已经从各种植物中分离和鉴定了许多胁迫应答相关的基因,这些基因编码的产物直接保护植物细胞免受非生物胁迫的伤害,或者调控其它基因的表达提高植物耐非生物逆境胁迫的能力。水稻是世界上最重要的粮食作物之一,也是单子叶植物分子生物学研究的模式植物。已有研究表明水稻TFⅢA型锌指蛋白基因ZFP252在水稻幼苗中受到高盐和干旱的诱导,本论文通过农杆菌介导法得到了由35S(CaMV)启动子驱动的转正义和反义ZFP252基因水稻植株。半定量RT-PCR和real-time PCR检测发现ZFP252基因在转正义ZFP252基因水稻植株中表达较未转基因植株明显增强,而在转反义ZFP252基因水稻植株中表达受到抑制。并且转基因植株和未转基因植株在表型和农艺性状上没有显著差异。非生物胁迫分析表明,ZFP252的过量表达显著增强了转基因水稻植株的耐盐性和耐旱性。在高盐和干旱处理10天后,转反义ZFP252基因植株和未转基因植株叶片的相对电解质渗透率极显著高于转正义ZFP252基因植株叶片的电解质渗透率。在高盐和干旱胁迫下,转正义ZFP252基因植株幼苗的脯氨酸和可溶性糖含量极显著高于转反义ZFP252基因植株和未转基因植株。Real-time PCR检测发现,在干旱和高盐处理下,OsDREB1A、Oslea3、OsP5CS和OsProT等胁迫相关基因在转正义ZFP252基因水稻植株中的表达水平明显较转反义ZFP252基因植株和未转基因植株中增强。据此推测,在非生物胁迫条件下,水稻TFⅢA型锌指蛋白ZFP252可能通过调控一些胁迫相关基因表达,在水稻幼苗中积累脯氨酸、可溶性糖和LEA蛋白等渗透性物质,保护植物细胞免受胁迫的伤害,提高植物耐非生物逆境胁迫的能力。更多还原

【Abstract】 Plant growth and crop productivity are largely affected by environmental stresses such as drought, high salinity and low temperature. To date, many stress-related genes have been isolated and characterized from various plant species. These genes may encode products either directly protecting plant cells from abotic stresses or regulating expression of other genes to enhance plant tolerance to abiotic stresses.Rice (Oryza sativa L.) is not only one of the most important food crops in the world, but also a model plant for research on molecular biology in monocots. It was previously found that a TFⅢA-type zinc-finger protein gene ZFP252 from rice could be significantly up-regulated in rice seedlings under salt or drought stress.It was generated several sense or antisense ZFP252 transgenic rice plants driven by the cauliflower mosaic virus (CaMV) 35S promoter. The expression level of ZFP252 was significantly higher in sense ZFP252 transgenic plants than that in non-transgenic plants and was hardly detected in antisense ZFP252 transgenic plants by both semi-quantitative RT-PCR and quantitative real-time PCR.There were no significant changes in morphological or agronomic traits among ZFP252 transgenic plants and non-transgenic plants. The stress assays showed that overexpression of ZFP252 in rice significantly enhanced the tolerance of transgenic plants to salt and drought stress. After 10 d of salt or drought treatment, their relative electrolyte leakage from antisense ZFP252 transgenic plants and non-transgenic plants were higher than that from sense ZFP252 transgenic plants.The contents of proline and soluble sugars in sense ZFP252 transgenic lines were much more increased than those in antisense ZFP252 transgenic plants and non-transgenic plants under salt and drought stress. Furthermore, it was found that the transcripts of several stress-related genes including OsDREB1A, Oslea3, OsP5CS and OsProT were accumulated more in sense ZFP252 transgenic plants under stress treatments by quantitative real-time PCR.It was concluded that overexpression of ZFP252 may contribute to accumulate compatible osmolytes, such as free proline, soluble sugars and LEA proteins that function as osmoprotectants, by regulating expression of stress-related genes in rice under salt and drought stress conditions.更多还原