tailieunhanh - Báo cáo y học: " Molecular characterization of two distinct monopartite begomoviruses infecting tomato in india"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành y học dành cho các bạn tham khảo đề tài: Molecular characterization of two distinct monopartite begomoviruses infecting tomato in india | Pandey et al. Virology Journal 2010 7 337 http content 7 1 337 VIROLOGY JOURNAL RESEARCH Open Access Molecular characterization of two distinct monopartite begomoviruses infecting tomato in india Prerna Pandey1 Subhra Mukhopadhya2 Afsar R Naqvi3 Sunil K Mukherjee2 Gyan S Shekhawat1 Nirupam R Choudhury2 Abstract Background Tomato leaf curl viruses which are the members of the genus Begomovirus have emerged as devastating pathogens worldwide causing huge economic losses and threatening production of crops like cassava cotton grain legumes and vegetables. Even though the ToLCV isolates from Northern India have been shown to possess bipartite genome designated as DNA A and DNA B those from Australia Taiwan and Southern India have a single genomic component DNA A . We describe here the genetic diversity of two isolates of monopartite Tomato leaf curl virus infecting tomato in two extreme regions North and South of Indian subcontinent. Results The rolling circle amplification RCA products obtained from symptomatic samples were digested cloned and sequenced. The complete DNA sequence of two Tomato leaf curl virus isolates identified as ToLCV-CTM India New Delhi 2005 and ToLCVK3 K5 India Kerala 2008 are reported here. These isolates had the characteristic features of Begomovirus genome organization with six conserved open reading frames ORFs . The ToLCV-K3 and ToLCV-K5 isolates may be the strains of the same virus since they show sequence homology of 97 over their entire genome. This according to the guidelines established by the ICTV Geminiviridae Study-Group is higher than threshold 92 for delineation of different viral variants and hence single average value has been assigned for all their analyses presented here. The ToLCV-CTM and ToLCV-K3 K5 viruses were found to be monopartite as neither DNA-B component nor betasatellite associated with begomovirus species were detected. The complete nucleotide sequence of DNA-A genome of CTM exhibited highest .