|Shatters, Robert - Bob|
|Weathersbee Iii, Albert|
Submitted to: Bemisia International Workshop Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 10/6/2006
Publication Date: 12/3/2006
Citation: Shatters, R.G., McKenzie, C.L., Boykin, L.M., Sinisterra, X., Weathersbee Iii, A.A., Brown, J.K., Gazit, S., Czosnek, H. 2006. A knottin-like putative antimicrobial gene family in the Whitefly Bemisia tabaci B: cloning and transcript regulation. Bemisia International Workshop Proceedings. Interpretive Summary:
Technical Abstract: The whitefly, Bemisia tabaci, is a worldwide plant pest and the vector of agriculturally important plant pathogenic begomoviruses. Of two vectored begomoviruses, Tomato yellow leaf curl virus (TYLCV) is transcriptionally active in B. tabaci and Tomato mottle virus (ToMoV)is not. Comparative analyses of 7093 EST sequences from cDNA libraries from either aviruliferous or ToMoV or TYLCV viruliferous whiteflies revealed four clones of a knottin-like gene family (btk-1, -2, -3, and -4). Two of these, btk-1 and btk-3, were more abundant in cDNA libraries from viruliferous whiteflies. Time course, virus uptake/acquisition experiments showed physical manipulation of whiteflies induced a transient increase in btk-1and btk-3 transcripts that was influenced by the presence of ToMoV. The Btk proteins range from 59 to 65 amino acids, and contain a secretory signal sequence and a conserved spatial representation (in peptide sequence and predicted 3-D protein-folding model) of six cysteine residues. These characteristics were identical to those for plant and insect knottin-family antifungal/toxin proteins. Begomovirus and physical stress influence on transcript abundance and sequence similarities with other knottin proteins suggest that btk protein family belongs to the knottin antimicrobial family and are part of the insect innate immune system.