Cathrin, P.B., Department of Entomology, Agricultural Research Organization, The Volcani Center, Bet Dagan, Israel
Ghanim, M., Department of Entomology, Agricultural Research Organization, The Volcani Center, Bet Dagan, Israel

Tomato yellow leaf curl virus (TYLCV) is the most damaging and threatening virus for tomato production worldwide. It causes tomato yellow leaf curl disease (TYLCD), is phloem-limited, and is exclusively transmitted by the whitefly Bemisia tabaci in a persistent circulative non-propagative manner. In this mode of transmission, the virus is acquired from the phloem of the infected plant and is taken up through the food canal in the whitefly's stylet. It then passes through the esophagus, circulates in the looped midgut, and is mostly absorbed into the insect's hemolymph via the filter chamber. The virus circulates in the hemolymph and becomes internalized in the primary salivary glands cells; it is then emptied into the salivary duct within the stylet and injected into the phloem of a new plant host where it starts another round of infection. The parameters for acquisition, retention and transmission of TYLCV by the whitefly have been established for several virus isolates around the world. While begomoviruses are believed not to replicate in B. tabaci, TYLCV is an exception; it has been shown to carry out some transcriptional activity, and it influences the whitefly's fertility and fecundity. TYLCV has been further shown to be transovarially transmitted between whitefly generations and to be transmitted between whitefly individuals during sexual intercourse. Recent projects employing RNAseq analysis and transcriptome profiling have shown that TYLCV induces changes in the whitefly's gene expression. © 2014 Elsevier Inc. All rights reserved.