Infectious clone construction of jasmine virus C and motif analysis of CP

Abstract:

[Objective] The full-length cDNA infectious clone of jasmine virus C (JaVC),from Fujian Province was constructed.Coat protein (CP) genes of JaVC isolates from 9 provinces/autonomous regions in China were cloned and the motif difference was analyzed.Thereby,the distribution and transmission of JaVC in jasmine producing areas in China were investigated.[Methods] Total RNA of jasmine leaves which tested positive for JaVC was extracted and then reverse-transcribed to cDNA.The cDNA was then used as template for amplification to obtain the full-length genome sequence of JaVC,followed by the construction of full-length cDNA clone pXT-JaVC-FJ and the CP-fused red fluorescent protein mCherry clone pXT-JaVC CP-mCherry.Both of them were then transformed into Agrobacterium tumefaciens for Nicotiana benthamiana infiltration and verified through RT-PCR and confocal laser scanning electron microscopy.Samples collected from eight other provinces/autonomous regions of China positive for JaVC were then used for cloning and sequencing of the 3'end containing CP.Field investigation was conducted to identify the occurrence and transmission vector of JaVC.[Results] pXT-JaVC-FJ induced systemic infection on N.benthamiana by agro-infiltration,which demonstrated that it was biologically active.CPs of all isolates encoded 296 amino acids.The CP of isolate from Taiwan of China shared 82.27%–91.36% nucleotide sequences and 92.23%–96.82% amino acid sequences with those of isolates from the 9 provinces/autonomous regions.It showed the highest similarity to that from Guangdong and Yunnan Province at nucleotide level and amino acid level,respectively.The CP from different isolates mainly showed difference at aa 32‒35 and six motif arrangements of SEHA,GENA,REGT,SENA,GGDA,and GGNA were identified.Field investigation suggested that JaVC was widely distributed on jasmine plants and could be detected in thrips.[Conclusion]An infectious clone of JaVC-FJ is developed,which lays a foundation for the study of gene function and pathogenic mechanism of JaVC.The analysis of occurrence and variation of JaVC in indifferent jasmine producing areas in China is helpful for the prevention and control of JaVC diseases.