Autophagy pathway induced by a plant virus facilitates viral spread and transmission by its insect vector

PLoS Pathogens

Qian Chen¹  Qianzhuo Mao²  Hongyan Chen²  Manman Li²  Dongsheng Jia²  Wei Wu²  Taiyun Wei²  Yong Chen² 

[1] Fujian Key Laboratory for Monitoring and Integrated Management of Crop Pests, Institute of Plant Protection, Fujian Academy of Agricultural Sciences, Fuzhou, Fujian, PR China;Fujian Province Key Laboratory of Plant Virology, Institute of Plant Virology, Fujian Agriculture and Forestry University, Fuzhou, Fujian, PR China

关键词: Autophagic cell death;    Insect vectors;    Viral transmission;    infection;    Rice;    Vector-borne diseases;    Gastrointestinal tract;    Virions;    Immunofluorescence microscopy;   

DOI  :  10.1371/journal.ppat.1006727

学科分类：生物科学（综合）

来源: Public Library of Science

【 摘 要 】

Many viral pathogens are persistently transmitted by insect vectors and cause agricultural or health problems. Generally, an insect vector can use autophagy as an intrinsic antiviral defense mechanism against viral infection. Whether viruses can evolve to exploit autophagy to promote their transmission by insect vectors is still unknown. Here, we show that the autophagic process is triggered by the persistent replication of a plant reovirus, rice gall dwarf virus (RGDV) in cultured leafhopper vector cells and in intact insects, as demonstrated by the appearance of obvious virus-containing double-membrane autophagosomes, conversion of ATG8-I to ATG8-II and increased level of autophagic flux. Such virus-containing autophagosomes seem able to mediate nonlytic viral release from cultured cells or facilitate viral spread in the leafhopper intestine. Applying the autophagy inhibitor 3-methyladenine or silencing the expression of Atg5 significantly decrease viral spread in vitro and in vivo, whereas applying the autophagy inducer rapamycin or silencing the expression of Torc1 facilitate such viral spread. Furthermore, we find that activation of autophagy facilitates efficient viral transmission, whereas inhibiting autophagy blocks viral transmission by its insect vector. Together, these results indicate a plant virus can induce the formation of autophagosomes for carrying virions, thus facilitating viral spread and transmission by its insect vector. We believe that such a role for virus-induced autophagy is common for vector-borne persistent viruses during their transmission by insect vectors.

【 授权许可】

CC BY