Trapping of Tomato yellow leaf curl virus (TYLCV) and other plant viruses with a GroEL homologue from the whitefly Bemisia tabaci

Abstract

To avoid destruction in the haemolymph of their vector, many plant circulative viruses interact with GroEL homologues produced by insect endosymbiotic bacteria. We have exploited this phenomenon to devise tools allowing trapping of plant viruses by either GroEL purified from the whitefly Bemisia tabaci or by whitefly GroEL over-expressed in E. coli. PCR tubes or 96-well plates coated with a GroEL preparation were incubated with cleared sap of virus infected plant leaves or insect vectors. GroEL-bound viruses were then identified by PCR or RT-PCR using virus-specific primers or by ELISA with virus specific antibodies. In this way Tomato yellow leaf curl virus (TYLCV) - a whitefly-transmitted geminivirus - was detected in plant sap, in extracts of leaf squashes and in homogenates of individual viruliferous whiteflies. Anti-GroEL antibody prevented TYLCV binding to GroEL. GroEL-bound virus was also detected by ELISA. GroEL was much more potent in binding TYLCV than commercial anti-TYLCV antibodies. In addition to several other geminiviruses, these procedures allowed detecting a variety of RNA viruses such as Cucumber mosaic virus (CMV), Prune dwarf virus (PDV) and Tomato spotted wilt (TSWV), but not Potato virus X and Potato virus Y (PVX and PVY), Grapevine leafroll-associated viruses (GLRV) and Tobacco mosaic virus (TMV). Predictions pertaining to viruses that do, or do not bind to GroEL, and applications in plant virus diagnosis, are presented.

Molecular and Histological Characterization of Primary (Betaproteobacteria) and Secondary (Gammaproteobacteria) Endosymbionts of Three Mealybug Species

“…This predicts that the "Ca. Tremblaya princeps" GroEL homolog is able to bind GLRaV-3 coat protein whereas E. coli GroEL cannot, the latter observation having been confirmed (1). The data suggest a role for "Ca.…”

“…Others (1,30,31,41) have found that (for other insect-transmitted viruses in sucking insects) a specific region of the intact virus (i.e., the assembled viral coat) binds to the endosymbiont GroEL and that mutant viruses do not persist in the insect. For the virus to be specifically transported from the gut to the salivary glands without being degraded there must be some protein specifically binding to the virus.…”

Virion Stability Is Important for the Circulative Transmission of Tomato Yellow Leaf Curl Sardinia Virus by Bemisia tabaci , but Virion Access to Salivary Glands Does Not Guarantee Transmissibility

“…play a role in transmission (69). In whiteflies, prior feeding with anti-GroEL antibodies strongly reduced TYLCV transmission (58), and binding of geminivirus CP to GroEL confirmed the specificity of this interaction (3,57). However, since the CP of NT isolates of AbMV still bound to GroEL (57), its role in transmission appears controversial.…”

Application of molecular antiviral compounds: novel approach for durable resistance against geminiviruses

“…In a study, it was revealed that, these GroEL expressed in the plant phloem trapped the TYLCV particles. Further, it was demonstrated that whitefly derived-GroEL expressing tomato plants have provided moderate resistance to TYLCV [2,3].…”

“…Moreover, due to equal affinity of the antiviral Endosymbiotic bacterial GroEL proteins TYLCV particles will be trapped by GroEL in the plant phloem TYLCV Tomato [2,3] Recombinant antibodies Antibody fragments corresponding to the target viral proteins hinder the necessary viral infection.…”