Judith K Brown

Tang, Y.F., Du, Z.G., He, Z.F., Brown, J.K., and She, X.M. 2014. Identification and molecular characterization of two begomoviruses from Pouzol. zeylanica (L.) Benn. exhibiting yellow mosaic symptoms in adjacent regions of China and Vietnam. Arch. Virol. 159:2799-2803.

Quintela, E.; A. Abreu, J. Lima, G. Mascarin, and J.K. Brown. 2016. First report on natural reproduction of Bemisia tabaci (Hemiptera: Aleyrodidae) in maize fields (Zea mays L.) in Brazil. Pest Mgmt. Sci. DOI: 10.1002/ps.4259.

PMID: 23015709;PMCID: PMC3503126;Abstract:

The whitefly Bemisia tabaci (Gennadius) is a major cosmopolitan pest capable of feeding on hundreds of plant species and transmits several major plant viruses. The most important and widespread viruses vectored by B. tabaci are in the genus Begomovirus, an unusual group of plant viruses owing to their small, single-stranded DNA genome and geminate particle morphology. B. tabaci transmits begomoviruses in a persistent circulative nonpropagative manner. Evidence suggests that the whitefly vector encounters deleterious effects following Tomato yellow leaf curl virus (TYLCV) ingestion and retention. However, little is known about the molecular and cellular basis underlying these coevolved begomovirus-whitefly interactions. To elucidate these interactions, we undertook a study using B. tabaci microarrays to specifically describe the responses of the transcriptomes of whole insects and dissected midguts following TYLCV acquisition and retention. Microarray, real-time PCR, and Western blot analyses indicated that B. tabaci heat shock protein 70 (HSP70) specifically responded to the presence of the monopartite TYLCV and the bipartite Squash leaf curl virus. Immunocapture PCR, protein coimmunoprecipitation, and virus overlay protein binding assays showed in vitro interaction between TYLCV and HSP70. Fluorescence in situ hybridization and immunolocalization showed colocalization of TYLCV and the bipartite Watermelon chlorotic stunt virus virions and HSP70 within midgut epithelial cells. Finally, membrane feeding of whiteflies with anti-HSP70 antibodies and TYLCV virions showed an increase in TYLCV transmission, suggesting an inhibitory role for HSP70 in virus transmission, a role that might be related to protection against begomoviruses while translocating in the whitefly. © 2012, American Society for Microbiology.

PMID: 15703848;Abstract:

Two distinct viral genotypes were identified in the same tomato plant collected from Gezira, Sudan and are provisionally designated Tomato leaf curl Sudan virus (ToLCSDV-Gez) and Tomato yellow leaf curl virus-Sudan (TYLCV-SD). A third genotype was identified in tomato samples collected in Shambat, Sudan (ToLCSDV-Sha). The ToLCSDV-Gez and ToLCSDV-Sha isolates were ∼90% identical, TYLCV-SD from Gezira shared ∼93% identity with TYLCV-Mld. Recombination analyses identified two fragments in the ToLCSDV-Gez and TYLCV-SD genomes, providing evidence that these two genomes had undergone intermolecular recombination. A half unit size (737 nt) single-stranded satellite DNA was associated with ToLCSDV-Gez and TYLCV-SD. © Springer-Verlag 2005.