蚜虫是如何适应不同寄主的？ z-bo 2020-10-16 280

　　The green peach aphid (Myzuspersicae) is one of the top ten pests in the world and can destroy more than 100 plants in more than 40 families. It is a typical ubiquitous pest and an important agricultural pest. In the long-term co-evolution, blue peach afid formed different host biotypes to adapt to different host plants. Tobacco-grown green peach relatives usually feed on tobacco plants, but after eating tobacco, the growth and development of green peach relatives in other hosts (such as cabbage and cabbage) slows down significantly. However, the mystery of Afido's adaptability to different hosts remains unclear.

　　FengGe and YuchengSun teams, researchers from the Institute of Zoology, Chinese Academy of Sciences and the Center of Excellence for Biological Interactions of the Chinese Academy of Sciences published their research papers in the international journal "Current Biology". We have found that tobacco from the immune system can identify Myzuspersicae that is not suitable for tobacco. Adhesin B (CathB) is a plant immune stimulating (inducing) protein secreted by saliva, which can activate tobacco's resistance to tobacco. This discourages continued feeding and growth of green peaches in tobacco. Because Green Peach Afid consumes tobacco for a long time, it can avoid reducing the secretion of salivary protein CathB and stimulating the anti-toxicity of tobacco, and it can adapt to the juice of tobacco plants and eat it smoothly. Based on the comprehensive analysis of the transcriptome and salivary protein profile, this study screened the CathB gene, which is differentially expressed in the salivary glands of various host biotypes in Myzuspersicae. Cath B3 protein. The expression of Myzus persicae CathB3 in plants may inhibit the feeding of Afido phloem, but it will not promote its growth and development. On the contrary, blocking the expression of CathB3 in Afido and reducing its secretion in saliva may benefit Afido's phloem feeding and damage. Biochemical experiments show that the propeptide domain of Myzus persicae Cath B3 interacts with tobacco EDR1-like (Raf-like, MAPKKK) protein, and EDR1-like protein is expressed in plants. This further indicates that Afido saliva protein CathB3 activates the reactive oxygen pathway of vascular bundles by stabilizing EDR1, thereby inhibiting Afido's feeding. Peach afid adapted to tobacco reduces the expression and secretion of CathB3 in the salivary glands, and avoids the activation of plant resistance. As a result, its feeding and growth are not affected. This study clarifies the biochemical basis of the transmission and activation of the peach aphid salivary protein CathB3, which recognizes tobacco signals from the immune system, and reveals the molecular mechanism of the adaptability of various affinities to different hosts and affinities. Occurrence provides new ideas and a basis for the development of endogenous crop tolerance regulation.