Geminiviral C2 proteins inhibit active autophagy to facilitate virus infection by impairing the interaction of ATG7 and ATG8

作     者：Buwei Cao Linhao Ge Mingzhen Zhang Fangfang Li Xueping Zhou Buwei Cao;Linhao Ge;Mingzhen Zhang;Fangfang Li;Xueping Zhou

作者机构：State Key Laboratory for Biology of Plant Diseases and Insect PestsInstitute of Plant ProtectionChinese Academy of Agricultural SciencesBeijing 100193China State Key Laboratory of Rice BiologyInstitute of BiotechnologyZhejiang UniversityHangzhou 310058China 

出 版 物：《Journal of Integrative Plant Biology》 (植物学报（英文版）)

年 卷 期：2023年第65卷第5期

页      面：1328-1343页

核心收录：

学科分类：0710[理学-生物学] 09[农学] 0904[农学-植物保护] 090401[农学-植物病理学] 

基　　金：support from the National Natural Science Foundation of China(31930089)to X.Z. the National Key Research and Development Program of China(2021YFD1400400)to F.L. 

主　　题：autophagy C2 counterdefense geminivirus plant defense the ATG7–ATG8 interaction 

摘      要：Autophagy is a conserved intracellular degradation process that plays an active role in plant response to virus infections.Here we report that geminiviruses counteract activated autophagymediated antiviral defense in plant cells through the C2 proteins they encode.We found that,in Nicotiana benthamiana plants,tomato leaf curl Yunnan virus(TLCYnV)infection upregulated the transcription levels of autophagy-related genes(ATGs).Overexpression of NbATG5,NbATG7,or NbATG8a in N.benthamiana plants decreased TLCYnV accumulation and attenuated viral symptoms.Interestingly,transgenic overexpression of NbATG7 promoted the growth of N.benthamiana plants and enhanced plant resistance to TLCYnV.We further revealed that the C2 protein encoded by TLCYnV directly interacted with the ubiquitinactivating domain of ATG7.This interaction competitively disrupted the ATG7–ATG8 binding in N.benthamiana and Solanum lycopersicum plants,thereby inhibiting autophagy activity.Furthermore,we uncovered that the C2-mediated autophagy inhibition mechanism was conserved in three other geminiviruses.In summary,we discovered a novel counter-defensive strategy employed by geminiviruses that enlists their C2 proteins as disrupters of ATG7–ATG8 interactions to defeat antiviral autophagy.