转TaWK对小麦耐旱性的影响及其生理机制研究
毕业论文关键词：小麦；光合速率；抗氧化能力；耐旱性
The physiological mechanism of improving drought tolerance in TaWK transgenic wheat
Abstract: As one of the main grain crops in China, drought is an important limiting factor restricting the stability of wheat in China. WK protein kinase gene is involved in stress transduction signal transduction pathway and plays an important role in improving plant stress tolerance. In this study, the physiological and biochemical indexes related to drought stress were analyzed by transgenic TaWK wheat strain WK, TaWK-RNAi wheat strain wki and recipient Kenong 199 as experimental materials. The results showed that the WK had higher relative water content, net photosynthetic rate, actual photochemical efficiency and light maximum photochemical efficiency index under the drought stress. Under drought stress, the antioxidant enzyme activities of WK were higher than that of receptor and wki, and the rate and content of O2- and H2O2 were significantly reduced, so as to prevent the injury of reactive oxygen free radicals. The results showed that the TaWK gene could enhance the tolerance of wheat to drought stress by improving the light and performance and antioxidant ability of wheat leaves. The results provide important theoretical guidance for enhancing wheat dryland cultivation.
Key words: Wheat, Photosynthetic rate, Antioxidant capacity, Drought tolerance
目录
摘要1
关键词…1
Abstract 1
Keywords1
1 引言2
2 材料与方法2
2.1 材料2
2.2 试验方法2
2.2.1 转基因小麦株系分子检测2
2.2.2 耐旱性相关指标测定3
2.2.3 数据处理及统计分析3
2.3 结果与分析…3
2.3.1 转基因植株PCR分子检测2.3.2 转TaWK对小麦耐旱性的影响3
2.3.2.1 转TaWK对干旱胁迫下小麦叶片相对含水量的影响4
2.3.2.2 转TaWK对干旱胁迫下小麦叶片光合能力的影响…4
2.3.2.3 转TaWK对干旱胁迫下小麦叶片叶绿素荧光特性相关参数的影响4
2.3.2.4 转TaWK对干旱胁迫下小麦叶片抗氧化系统能力的影响5
2.3.2.5 转TaWK对干旱胁迫下小麦根系形态及抗氧化能力的影响6
3 讨论与结论…8
致谢 …9
参考文献 …10
转TaWK对小麦耐旱性的影响及其生理机制研究
小麦是世界上种植面积和总产最大的粮食作物。中国是世界最早种植小麦的国家之一，小麦产量占我国粮食总产的比重大，在保障粮食安全中占有重要的地位[1]。随着全球气候变化，极端气候发生的频率增加，如低温、干旱、渍水等逆境气候限制着我国乃至世界的作物生产，干旱是影响小麦生长和生产重要的生态因子[2]。干旱胁迫的频发严重的影响了我国冬小麦的生产，尤其在北方麦区。干旱会严重影响植物的正常水分代谢，导致其生长受阻，加快其衰老进程，导致作物减产。根系是植物吸收水分和养分的重要器官，植物的正常生长依靠地上部分的光合作用和地下部分的根系吸收水分及养分统一。在土壤水分亏缺的情况下，根系受到干旱胁迫刺激做出的一系列反应，促使植株做出相应的反应来适应这种逆境。有研究表明，在水分亏缺情况下植物的根系统更加庞大，跟土壤水的接触面积变大[3]。此外，初生根系在小麦前中期生长发育过程中发挥着重要的作用。在正常水分条件下，小麦初生根的一级分枝可达21.1%个/条，而干旱条件下比正常水分条件下增加38.5%，这说明干旱条件有利于小麦初生根上分枝的形成，这无疑对干旱条件下产量的形成具有重要作用[4]。