| Title: | A salivary effector enables whitefly to feed on host plants by eliciting salicylic acid-signaling pathway |
| Author(s): | Xu HX; Qian LX; Wang XW; Shao RX; Hong Y; Liu SS; Wang XW; |
| Address: | "Ministry of Agriculture Key Lab of Molecular Biology of Crop Pathogens and Insects, Institute of Insect Sciences, Zhejiang University, 310058 Hangzhou, China. Ministry of Agriculture Key Lab of Molecular Biology of Crop Pathogens and Insects, Institute of Insect Sciences, Zhejiang University, 310058 Hangzhou, China xwwang@zju.edu.cn" |
| ISSN/ISBN: | 1091-6490 (Electronic) 0027-8424 (Print) 0027-8424 (Linking) |
| Abstract: | "Phloem-feeding insects feed on plant phloem using their stylets. While ingesting phloem sap, these insects secrete saliva to circumvent plant defenses. Previous studies have shown that, to facilitate their feeding, many phloem-feeding insects can elicit the salicylic acid- (SA-) signaling pathway and thus suppress effective jasmonic acid defenses. However, the molecular basis for the regulation of the plant's defense by phloem-feeding insects remains largely unknown. Here, we show that Bt56, a whitefly-secreted low molecular weight salivary protein, is highly expressed in the whitefly primary salivary gland and is delivered into host plants during feeding. Overexpression of the Bt56 gene in planta promotes susceptibility of tobacco to the whitefly and elicits the SA-signaling pathway. In contrast, silencing the whitefly Bt56 gene significantly decreases whitefly performance on host plants and interrupts whitefly phloem feeding with whiteflies losing the ability to activate the SA pathway. Protein-protein interaction assays show that the Bt56 protein directly interacts with a tobacco KNOTTED 1-like homeobox transcription factor that decreases whitefly performance and suppresses whitefly-induced SA accumulation. The Bt56 orthologous genes are highly conserved but differentially expressed in different species of whiteflies. In conclusion, Bt56 is a key salivary effector that promotes whitefly performance by eliciting salicylic acid-signaling pathway" |
| Keywords: | Animals Hemiptera/*metabolism Herbivory/*physiology Homeodomain Proteins/metabolism Plant Proteins/metabolism Salicylic Acid/*metabolism Saliva/*metabolism Signal Transduction/*physiology KNOTTED 1-like homeobox protein SA elicitor feeding behaviors phloe; |
| Notes: | "MedlineXu, Hong-Xing Qian, Li-Xin Wang, Xing-Wei Shao, Ruo-Xuan Hong, Yue Liu, Shu-Sheng Wang, Xiao-Wei eng Research Support, Non-U.S. Gov't 2018/12/26 Proc Natl Acad Sci U S A. 2019 Jan 8; 116(2):490-495. doi: 10.1073/pnas.1714990116. Epub 2018 Dec 24" |
