Differences in gene expression in whitefly associated with CYSDV-infected and virus-free melon, and comparison with expression in whiteflies fed on ToCV- and TYLCV-infected tomato

Authors: Kaur, Navneet; CHEN, WENBO - Boyce Thompson Institute; FEI, ZHANGJUN - Boyce Thompson Institute; Wintermantel, William - Bill

Submitted to: BMC Genomics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/26/2019
Publication Date: 8/15/2019
Citation: Kaur, N., Chen, W., Fei, Z., Wintermantel, W.M. 2019. Differences in gene expression in whitefly associated with CYSDV-infected and virus-free melon, and comparison with expression in whiteflies fed on ToCV- and TYLCV-infected tomato. BMC Genomics. 20:654. https://doi.org/10.1186/s12864-019-5999-0.
DOI: https://doi.org/10.1186/s12864-019-5999-0

Interpretive Summary: Cucurbit yellow stunting disorder virus (CYSDV) is transmitted in a by the whitefly, Bemisia tabaci, and is efficiently transmitted by two of the most widely prevalent B. tabaci variants, known as MEAM1 and MED. We analyzed gene expression of the whitefly Bemisia tabaci MEAM1 after 24 h, 72 h, and 7-days of feeding on CYSDV infected melon or healthy melon, using RNA-Sequencing. We also compared gene expression with whiteflies fed in a comparable manner on Tomato chlorosis virus (ToCV) and Tomato yellow leaf curl virus (TYLCV), which are closely related and distantly related to CYSDV, respectively, in order to identify common gene expression changes among whiteflies among different viruses and hosts that may be important for virus transmission. Among 275 differentially expressed genes (DEGs) identified in CYSDV-whiteflies, 3 were uniquely expressed at 24h, 221 at 72 h, and 51 at 7 days of whitefly feeding. Fifty-nine common DEGs were found between whiteflies fed on the CYSDV-infected melon and those fed on ToCV-infected tomato. Activity of eight common DEGs in the three host systems were elevated in CYSDV-whiteflies and TYLCV-whiteflies, while reduced in ToCV-whiteflies. Dynamic gene expression changes occurred in whiteflies after 72 h with decreased gene expression changes at 7-days with CYSDV acquisition. Commonalities of gene expression changes among CYSDV-whiteflies, ToCV-whiteflies and TYLCV-whiteflies suggest the possibility of common requirements for virus acquisition and transmission by whiteflies, even for viruses that are transmitted in very different manners, and could possibly lead commons means of reducing transmission of these viruses to different host plant species.

Technical Abstract: Cucurbit yellow stunting disorder virus (CYSDV; genus Crinivirus, family Closteroviridae) is transmitted in a semipersistent manner by the whitefly, Bemisia tabaci, and is efficiently transmitted by both of the widely prevalent B. tabaci cryptic species, MEAM1 and MED. In this study, we analyzed transcriptomes of B. tabaci, MEAM1, at 24h, 72h and 7 days of feeding on melon plants infected with CYSDV, using RNA-Seq technology. We also compared transcriptome profiles with whiteflies fed on Tomato chlorosis virus (ToCV; genus Crinvirus) and Tomato yellow leaf curl virus (TYLCV, genus Begomovirus, family Geminiviridae) to find common gene expression changes among viruliferous whiteflies feeding on different host plants infected with distinct (TYLCV) and related (ToCV) viruses. A total of 275 differentially expressed genes (DEGs) were identified in the whiteflies fed on CYSDV-infected plants compared with those fed on virus-free plants, with only 3 DEGs after a 24h acquisition access period (AAP), 221 DEGs after a 72 h AAP, and 51 DEGs after a 7 day AAP. A total of 59 common DEGs were found between CYSDV-whiteflies and ToCV-whiteflies, which included 20 orphan genes and 6 lysosomal genes. A comparison of DEGs across the three different virus-host systems revealed 14 common DEGs, among which, surprisingly, eight showed similar up-regulation in CYSDV-whiteflies and TYLCV-whiteflies, while down-regulation was observed in ToCV-whiteflies. Dynamic gene expression changes occurred in whiteflies after 72 h with decreased gene expression changes at 7 days with CYSDV acquisition. Commonalities of gene expression changes among whiteflies fed on CYSDV-infected melon, ToCV- and TYLCV-infected tomato suggest the possibility of common requirements for virus acquisition and transmission by whiteflies, even for viruses with distinctly different modes of transmission.