A peptidoglycan recognition protein acts in whitefly (Bemisia tabaci) immunity and involves in Begomovirus acquisition

Peptidoglycan recognition proteins (PGRPs) are multifunctional pattern recognition proteins. Here, we report that a PGRP gene, BtPGRP, encodes a PGRP from the whitefly Bemisia tabaci (MEAM1) that binds and kills bacteria in vitro. We analyzed BtPGRP transcriptional profiling, and the distribution of the cognate protein within the midgut. Fungal infection and wasp parasitization induced expression of BtPGRP. Silencing BtPGRP with artificial media amended with dsRNA led to reduced expression of a gene encoding an antimicrobial peptide, B. tabaci c-type lysozyme. Begomovirus infection also led to increased expression of BtPGRP. We propose that BtPGRP has a potential Tomato yellow leaf curl virus (TYLCV) binding site because we detected in vitro interaction between BtPGRP and TYLCV by immunocapture PCR, and recorded the co-localization of TYLCV and BtPGRP in midguts. This work addresses a visible gap in understanding whitefly immunity and provides insight into how the whitefly immunity acts in complex mechanisms of Begomovirus transmission among plants.