RNA interference of an antimicrobial peptide, Btdef, reduces Tomato yellow leaf curl China virus accumulation in the whitefly Bemisia tabaci.
BACKGROUND
The whitefly Bemisia tabaci (Gennadius) is considered one of the main pests for agriculture. One important problem with the whitefly is its notorious status as a vector for plant viruses, primarily begomoviruses. We have previously identified a defensin-like antimicrobial peptide, Btdef, from the whitefly B. tabaci MEAM1. However, the function of Btdef in the immune system of the insect vector and begomovirus transmission has yet to be explored.


RESULTS
To explore the role of Btdef during begomovirus transmission, we firstly investigated the transcriptional response of Btdef following acquisition of Tomato yellow leaf curl China virus (TYLCCNV). The expression of Btdef was up-regulated in the viruliferous whiteflies. After RNA silencing of the Btdef gene in adult whiteflies fed with dsRNA, they were allowed to feed on TYLCCNV-infected plants and then quantified for TYLCCNV DNA titre. Unexpectedly, silencing the Btdef gene reduced both the abundance and expressions of TYLCCNV genes in the whiteflies. In the meantime, the density of the endosymbiont Rickettsia was significantly reduced in dsBtdef-fed whiteflies.


CONCLUSIONS
Our data provide evidence that Btdef is involved in begomovirus infection, possibly through symbiont-mediated alteration of begomovirus-whitefly interactions. These findings indicate that Btdef may be targeted for the development of new technology for the control of whitefly-transmitted begomoviruses. © 2016 Society of Chemical Industry.
Ministry of Agriculture Key Lab of Agricultural Entomology, Institute of Insect Sciences, Zhejiang University, Hangzhou, China.
Zhi-Zhi
ZZ
Wang
Ministry of Agriculture Key Lab of Agricultural Entomology, Institute of Insect Sciences, Zhejiang University, Hangzhou, China.
Xiao-Li
XL
Bing
Ministry of Agriculture Key Lab of Agricultural Entomology, Institute of Insect Sciences, Zhejiang University, Hangzhou, China.
Shu-Sheng
SS
Liu
Ministry of Agriculture Key Lab of Agricultural Entomology, Institute of Insect Sciences, Zhejiang University, Hangzhou, China.
Xue-Xin
XX
Chen
D000818:Animals; D053839:Begomovirus / Q000235:genetics / Q000502:physiology*; D023082:Defensins / Q000235:genetics / Q000378:metabolism*; D006430:Hemiptera / Q000276:immunology* / Q000382:microbiology / Q000821:virology; D019476:Insect Proteins / Q000235:genetics / Q000378:metabolism*; D007303:Insect Vectors / Q000821:virology; D010455:Peptides / Q000235:genetics / Q000378:metabolism*; D010935:Plant Diseases / Q000821:virology*; D010942:Plant Viruses / Q000502:physiology; D034622:RNA Interference; D012281:Rickettsia / Q000502:physiology; D013559:Symbiosis; D014026:Nicotiana / Q000821:virology; D014158:Transcription, Genetic
D023082:Defensins; D019476:Insect Proteins; D010455:Peptides
Begomovirus; TYLCCNV; defensin; symbionts; whitefly