Interaction Between Phloem Sap Feeding Insects and Plant Phloem Sieve Element Defense Response

几大类植物食性昆虫，如蚜虫(3000种)和粉虱(1500种)是专门以韧皮部汁液为食的昆虫。营养物质通过韧皮部汁液运输到整个植物，由于韧皮部汁液的关键重要性，植物通过封闭受损的筛分分子(运输汁液的特定韧皮部细胞)的冗余系统来保护自己免受汁液的损失。为了成功地以韧皮部汁液为食，这些昆虫必须绕过这些密封机制。这个项目的目标是确定他们如何实现这一点。韧皮部对昆虫取食的反应将通过各种显微镜技术进行观察。韧皮部反应对昆虫的影响和昆虫的反作用将通过电生理技术进行监测，这种技术有点类似于EKG，它实时揭示昆虫的口器渗透了哪些植物组织和细胞，以及它们在这些组织和细胞中的行为(如流口水、摄食、口器运动)。对昆虫和植物的反应和反反应以及它们对昆虫和植物的影响将在正常(自然)取食期间和在操纵韧皮部封闭机制的实验中确定。该项目的目标是从机械上确定昆虫如何绕过韧皮部密封反应。这些结果不仅对了解植物和这些非常成功的专业食草动物之间的共同进化具有重要意义，而且还因为这些昆虫包括一些世界上最严重的农业害虫。因此，这些结果可能对揭示可用于开发作物对这些害虫的抗性的机制有价值。该项目还将为该领域的博士后学生提供研究经验，弥合植物生理学和昆虫学之间的差距。结果也将被纳入PI部门的课程作业中。

Several large groups of plant-feeding insects such as aphids (3000 species) and whiteflies (1500 species) are specialized feeders on phloem sap. Nutrients are transported throughout the plant in phloem sap, and because of its critical importance, plants protect themselves from loss of sap by redundant systems that seal off damaged sieve elements (the specific phloem cells that transport the sap). In order to successfully feed on phloem sap, these insects must circumvent these sealing mechanisms. This project's goal is to determine how they accomplish this. Phloem responses to insect feeding will be observed by various microscopy techniques. The effect of the phloem response on the insect and the insect's counter-responses will be monitored by an electrophysiological technique, somewhat similar to an EKG, that reveals in real time what plant tissues and cells the insects have penetrated with their mouthparts and their behaviors (such as salivation, ingestion, mouthpart movement) within those tissues and cells. The responses and counter-responses and their effects on both the insects and plants will be determined during normal (natural) feeding and in experiments where the phloem sealing mechanism will be manipulated. The goal of the project is to determine mechanistically how insects circumvent the phloem sealing response. These results will be important not only for understanding the co-evolution between plants and these highly successful specialized herbivores, but also because these insects include some of the world's worst agricultural pests. The results might thus be valuable for revealing mechanisms that could be exploited for developing crop resistance to these pests. This project also will provide a research experience for a postdoctoral student in this field which bridges the gap between plant physiology and entomology. Results also will be incorporated into coursework in the PI's department.