Discovery and characterization of a novel carlavirus in Ligularia jaluensis plants  

作　　者：Shifang Fei Jiaping Yu Yali Zhou Yi Xie Li Xie Shuai Fu Jianxiang Wu 

机构地区：[1]Hainan Institute of Zhejiang University,Sanya,572025,China [2]State Key Laboratory of Rice Biology,Key Laboratory of Biology of Crop Pathogens and Insects of Zhejiang Province,Institute of Biotechnology,Zhejiang University,Hangzhou,310058,China [3]Research Center for Life Sciences Computing,Zhejiang Lab,Hangzhou,311100,China [4]Analysis Center of Agrobiology and Environmental Sciences,Zhejiang University,Hangzhou,310058,China

出　　处：《Virologica Sinica》2025年第1期71-79,共9页中国病毒学(英文版)

基　　金：financially supported by the Hainan Province Science and Technology Special Fund(No.ZDYF2022XDNY240);the National Key Research and Development Program of China(2022YFD1401200).

摘　　要：Ligularia jaluensis is an important medicinal and ornamental plant in China.However,the viruses capable of infecting Ligularia jaluensis remains unknown.Here,we identified a novel carlavirus,tentatively named ligularia jaluensis carlavirus(LJCV),as well as a known iris severe mosaic virus(ISMV),in L.jaluensis plants displaying chlorosis and yellow ring spot symptoms,using RNA-seq analysis.The LJCV genome consists of an 8497 nt positive-sense,single-stranded RNA[excluding the poly(A)tail],and contains six open reading frames(ORFs).Phylogenetic analyses based on the fulllength genome and RNA-dependent RNA polymerase(RdRp)amino acid(aa)sequences revealed that LJCV clusters within an evolutionary branch alongside known viruses in the Carlavirus genus.The RdRp protein encoded by ORF1 of LJCV shared 45.38%–67.41%identity with the corresponding proteins of eight closely related carlaviruses.ORFs 2–4 constitute the triple gene block(TGB),with TGBp1 and TGBp3 localized in the endoplasmic reticulum(ER),while TGBp2 is localized at plasmodesmata(PD)and facilitates viral intercellular movement,as demonstrated by its ability to complement the potato virus X with movement-deficient mutant(PVX-Δp25-GFP).Additionally,ORF6 encodes a cysteine-rich protein(CRP)that is localized in the chloroplast and functions as a viral pathogenicity factor,inducing severe viral symptoms in the heterologous PVX expression system.Furthermore,we successfully constructed an infectious cDNA clone of LJCV,and found that it can infect Nicotiana benthamiana plants through mechanical inoculation or agrobacterium-mediated infiltration of the LJCV infectious clone.These findings enhance our understanding of the characteristics and host range of carlaviruses,as well as the viruses capable of infecting L.jaluensis.

关 键 词：Ligularia jaluensis Novel virus CARLAVIRUS Viral infectious clone Movement protein Pathogenicity factor 

分 类 号：S432.1[农业科学—植物病理学]