The Pathogenicity Analysis Of Two Begomoviruses And Their Associated Satellite DNA

Geminiviruses are single stranded DNA virus with twinned icosahedral particles,it occurs widely in the world,and it has caused devastating damage on a variety of crops.Since1980 s,a variety of geminiviruses have been found in crops and weeds in Yunnan,Guangdong and Hainan provinces of China,and the recombination of geminiviruses has been found in many plants.In recent years,studies have showed that a lot of monopartite geminiviruses associated with a class of symptom-modulating satellites(known as betasatellites,DNA?),and the betasatellites are essential for inducing typical disease symptoms in the hosts.The DNA? molecules with its helper virus have formed a new type of disease complex.More new viruses or complexes have increased damage to crops,they lead to geminivirus disease epidemic;In this process,geminiviruses can be reassembled to form a new virus and this restructuring resulted in geminiviruses recombinant and disease epidemics continue a vicious cycle,this has caused huge losses to crops in Asia and Africa.In this study,we constructed the infectious clone of Papaya leaf curl China virus(PaLCuCNV)and a newly reported Tomato yellow leaf curl Vietnam betasatellite(TYLCVNB).As Tomato yellow leaf curl virus(TYLCV)and PaLCuCNV are widespread in crops and have caused huge damage,this study is mainly to analyse the pathogenicity of TYLCV and PaLCuCNV associated with TYLCVNB molecule.The infectious clone of TYLCV has been constructed by our laboratory before this study.The main results are as follows.(1)The construct of PaLCuCNV and TYLCVNB infectious clone have completed,and their infectivity were proved by agroinoculation.(2)Symptoms induced by TYLCV co-inoculated with TYLCVNB are serious than TYLCV inoculated alone,and the accumulation level of TYLCV in co-inoculated plants is higher than TYLCV inoculated alone in N.benthamiana.(3)Symptoms induced by PaLCuCNV co-inoculated with TYLCVNB are serious than PaLCuCNV inoculated alone,and the accumulation level of PaLCuCNV in co-inoculatedplants is higher than PaLCuCNV inoculated alone in N.benthamiana.