Identification And Biological Characteristics Of The Thladiantha Dubia Mosaic Virus

The epidemic and outbreak of Plant viruses seriously threaten food production and human food security.The research has focused primarily on the transmission and damage of plant viruses in cultivated crops.Since the 20th century,wild plants have attracted interest since non-crop plant may share virus and vector populations with crops,due to the consistency of some genes.As a result,some strange phenomena often occur in agricultural production.For example,some non-seed-borne plant viral diseases also occur and spread when crops are introduced to new cultivation areas.This indicates that some viruses are hidden in wild plants as trans-host to cause crop diseases.Perennial wild plants are more susceptible to viruses in many years,as intermediate hosts for virus transmission,enabling viruses to overcome hot summer and cold winter in the regain.While studies have shown that viruses in crops can be transmitted to wild plants and stored in wild plants,whether viruses can be transferred from wild plants to cultivated crops is somewhat less well known.In this study,more than 200 perennial wild plants with typical virus-like symptoms were collected.Potyvirus,the largest number of plant viruses,was used as the detection object.the existence of Potyvirus virus and new member of Potyvirus virus were detected by degenerate primers.In this study,a new member of Potyvirus virus was found.The biological characteristics,genome sequence and structure,virus detection methods and the survey of the virus in cultivated crops were studied.The conclusions of this study are as follows:1.In this study,Potyvirus in perennial herbs was detected by degenerate primers.A novel Potyvirus,tentatively named Thladiantha dubia mosaic virus(ThDMV),was isolated from Thladiantha dubia Bunge(Cucurbitaceae).Flexuous,filamentous particles with a size of approximately 650 nm were observed under by electron microscopy.This virus has a narrow host range.The CP gene sequence be obtained by degenerate primers(NIb2F/3R)and 3'-RACE Amplification,and The CP gene sequence be obtained by degenerate primers(NIb2F/3R)and 3'-RACE amplification,with the closest Potyvirus,papaya leaf distortion mosaic virus(PLDMV),at 79%.Sequencing and morphological data were consistent with the typical characteristics of Potyvirus virus.2.Thladiantha dubia mosaic virus is a member of Potyvirus,Single-stranded and sense sequence RNA.The genome had one open reading frame,encoding eleven mature proteins.The ThDMV genome sequence shows homology to a previously reported PLDMV from Hainan Island(GenBank accession number:KT633944.1),with 74%and 79%identity at the nt and aa levels,respectively.3.The prokaryotic expression vector of pET28(a)-CP was constructed.Protein was induced by IPTG to express,and purified,used to immunize rabbits for the preparation of antisera with high titer at 1:32000 by indirect ELISA.The antiserum prepared in this research had high titer and specificity and could be used in the detection of ThDMV.4.ThDMV was detected in the tubers,stems,leaves and flowers of Thladiantha dubia by PCR.83%tubers carried the virus.20%seeds carried the virus.The experimental results show that ThDMV could be transmitted by aphids.5.Cultivated crop survey results for ThDMV from four different vegetable plots indicated that the samples of cultivated potato were positive.Potato Samples survey results for ThDMV in five different major potato-producing areas in Heilongjiang Province indicated that 37.5%samples carried the virus.The viral genome of ThDMV(GenBank accession number:MK396781)from Youjin-885 was amplified.The similarity between the virus and ThDMV from T.dubia was 92.6%(nt)and 96.8%(aa).