普通烟对烟粉虱取食及其与TYLCCNV共侵染的生理生化反应

为明确普通烟遭受烟粉虱Bemisia tabaci取食及与中国番茄黄化曲叶病毒(Tomato yellow leaf curl China virus,TYLCCNV)共侵染时的响应机制,采用常规生理生化指标测定法分析比较MED隐种烟粉虱取食及其与TYLCCNV共侵染处理对普通烟植株中营养组分、防御物质积累及主要氧化酶活性的影响。结果显示,与对照植株相比,烟粉虱取食及其与TYLCCNV共侵染均可导致普通烟植株中可溶性糖和可溶性蛋白含量明显降低,多酚含量显著升高,过氧化氢酶(CAT)活性显著升高,超氧化物歧化酶(SOD)和过氧化物酶(POD)活性呈现先升后降的变化趋势。与烟粉虱取食植株相比,烟粉虱与TYLCCNV共侵染后1 d时普通烟植株中可溶糖含量显著降低了21.05%,3、7和9 d时可溶性蛋白含量分别显著降低了27.40%、26.84%和20.90%;共侵染后的1、3、5和9 d时多酚含量分别显著降低了34.60%、14.30%、3.07%和15.19%;共侵染后的1、3、5和7 d时CAT活性分别提高了3.04倍、1.42倍、1.68倍和1.96倍;共侵染后7 d时POD活性显著降低,共侵染后9 d时SOD活性显著升高。表明普通烟可通过改变其营养组分及积累防御物质或提高氧化酶活性来防御烟粉虱取食及其与TYLCCNV的共侵染,而烟粉虱与TYLCCNV共侵染可诱导植株内产生较单独取食时更少的多酚类防御物质,以提高其在宿主植物上的适应性。

Differential physiological and biochemical responses of tobacco plants to the feeding by tobacco whitefly Bemisia tabaci and the co-infection with Tomato yellow leaf curl China virus

To clarify the response mechanisms of tobacco plants to the co-infection of tobacco whitefly Bemisia tabaci and Tomato yellow leaf curl China virus (TYLCCNV), the nutritional contents, the accumulation of defense substance and the activities of main oxidase in tobacco plants were analyzed and compared after co-infection with Mediterranean biotype (MED) B. tabaci and TYLCCNV by using routine physiological and biochemical index determination methods. The results showed that the soluble sugar and protein contents in tobacco plants decreased obviously, and the polyphenol content increased significantly; the activity of catalase (CAT) increased significantly, and the activities of superoxide dismutase (SOD) and peroxidase (POD) increased firstly and then decreased after co-infection with B. tabaci and TYLCCNV. Compared with feeding by B. tabaci alone, the soluble sugar content decreased significa-ntly by 21.05% at the 1st day after co-infection with B. tabaci and TYLCCNV; the soluble protein content decreased significantly by 27.40%, 26.84% and 20.90%, respectively, at the 3rd, 7th and 9th days after treatment; the polyphenol content decreased significantly by 34.60%, 14.30%, 3.07% and 15.19%, respectively, at the 1st, 3rd, 5th and 9th days after treatment; the activity of CAT increased 3.04, 1.42, 1.68 and 1.96 times at the 1st, 3rd, 5th and 7th days after treatment, respectively; the activity of SOD increased significantly at the 9th day after treatment, and the activity of POD decreased significantly at the 7th day after treatment. The results indicated that tobacco plants could prevent whitefly from feeding and co-infection with TYLCCNV by changing their nutrient components and accumulating defensive substances or increasing oxidase activity. However, B. tabaci infected with TYLCCNV could improve its adaptability to the host plants by inducing fewer polyphenol defensive substances in them.