盐碱土壤转Bt基因棉花外源蛋白表达量时空变化对抗虫性影响的研究

During the growing period of cotton, temporal and spatial variation of foreign protein expression directly affects insect resistance of Bt-cotton, and then affects the resistance ability of cotton to insects and external adversity stress, and ultimately affects growth of cotton as well as yield and quality. Due to more and more soil is planted with food crop as well as salinization and secondary salinization of soli is increasingly severe, Bt-cotton is massively planted in saline-alkali soil. Under this circumstance, in order to ensure the bumper harvest of cotton in saline-alkali soil, it is the urgent need and one of the key factors to find out temporal and spatial variation rule of foreign protein expression of Bt-cotton and its relationship with insect resistance in saline-alkali soil, take saline-alkali-resistant cultivation techniques and enhance the resistance ability of cotton to the external adversity to improve yield and quality of cotton.Therefore, the Project, on the basis of dynamic salt state of the soil and temporal and spatial variation of foreign expression as well as analysis of biochemical substances and the related enzyme activity at the same time, takes Bt-cotton as experimental material and its parental non-transgene cotton as the comparing material to study and explain physiological and biochemical mechanisms of influence that temporal and spatial variation of foreign protein expression of cotton exerted on insect resistance, and analyze the production practice under insect-resistant nonuniformity and dynamic space-time condition, which provides a theoretical guidance for taking cultivation regulation technology to enhance the resistance ability of Bt-cotton to insects and external adversity stress during the growing period in saline-alkali soil.

棉花生长期外源蛋白表达量时空变化直接影响Bt棉抗虫性变化，进而影响棉花抵御害虫及外界逆境胁迫能力，最终影响棉花生长发育及产量品质形成。在粮棉争地矛盾日益突出，土壤盐渍化和次生盐渍化不断加剧的背景下，基于Bt棉向盐碱地大面积转移种植趋势，明确盐碱土壤Bt棉外源蛋白表达量时空变化规律及其与抗虫性的关系，采取耐盐碱栽培调控措施，增强棉花自身抵御外界逆境能力，提高棉花产量和品质是确保盐碱地棉花丰产丰收的迫切需要和关键因素之一。本项目以转Bt基因棉花为试验材料，以其亲本非转基因棉花为对照，从土壤盐分水平动态、外源蛋白表达量时空变化入手，辅以分析生化物质及相关酶活性，研究并阐明盐碱土壤转Bt基因棉花外源蛋白表达量时空变化对抗虫性影响的生理生态机制，解析盐碱地Bt棉抗虫不均匀和时空动态生产实践现象，为增强盐碱地Bt棉对害虫及外界逆境胁迫抵御能力采取适度栽培调控措施提供理论依据。

我国是盐碱地面积最大的国家之一，棉花是我国重要的经济作物，也是一种中等耐盐碱作物。为保障我国粮食生产和棉花生产安全，棉花生产向盐碱旱地转移种植。本课题在大田盐碱条件下监测了土壤盐分水平的动态变化；明确了在土壤盐分胁迫条件下，转基因抗虫棉花叶片中外源杀虫蛋白表达量受到抑制，在某种程度上不利于棉田转基因抗虫棉对靶标害虫抗虫性的发挥；测定了盐分胁迫条件下棉花叶片中可溶性蛋白含量、K+浓度下降，棉酚含量和Na+浓度上升，SOD、CAT、POD和APX等相关活性在一定盐分胁迫条件下发生变化；初步了解棉铃虫幼虫取食盐分胁迫后的转基因棉花叶片其取食行为、取食量和排泄等方面无显著变化，棉铃虫幼虫相对生长率、食物近似消化率、毛转化率和净转化率等有所下降；室内封闭条件下转基因棉花上棉铃虫成虫产卵数量在低、中和高浓度NaCl溶液胁迫下先升高后下降；棉铃虫幼虫中肠保护酶（过氧化氢酶、超氧化物歧化酶和过氧化物酶）和解毒酶（碱性磷酸酶、谷胱甘肽过氧化物酶、羧酸酯酶）等在不同胁迫时间变化有差异。上述研究结果，可为盐碱地种植转基因抗虫棉田的害虫防治提供借鉴。项目资助发表中文核心论文2篇，SCI 论文2篇；获得实用新型专利2项。项目投入直接经费20万元，全部执行完。