Begomovirus coat protein interacts with a small heat-shock protein of its transmission vector (Bemisia tabaci)

Tomato yellow leaf curl Sardinia virus (TYLCSV) is transmitted from plant to plant by the whitefly Bemisia tabaci in a persistent-circulative manner. The coat protein (CP) plays an important role in this transmission cycle. In this study, the CP was used to screen a Bemisia tabaci cDNA library using the yeast two-hybrid system, in a search for interacting partners. A member of the small heat-shock protein family (termed BtHSP16) was identified and its interaction with the CP was verified by an in vitro pull-down assay. The binding domain was located at the variable N-terminal part of the CP, while full-length BtHSP16 is required for the interaction. The putative role for this interaction in the transmission cycle by the whitefly is discussed.