Molecular characterization of Tobacco leaf curl Pusa virus, a new monopartite Begomovirus associated with tobacco leaf curl disease in India Manoj K. Singh • K. Singh • Q. M. R. Haq • B. Mandal • A. Varma Received: 21 March 2011 / Accepted: 23 May 2011 Ó Springer Science+Business Media, LLC 2011 Abstract Leaf curl disease of tobacco (TbLCD) is endemic in India. A monopartite Begomovirus, a betasat- ellite and an alphasatellite were found associated with the disease in Pusa, Bihar. The DNA-A of the Begomovirus associated with TbLCD in Pusa, Bihar was found to comprise of 2707 nt with a typical Old World begomovi- rus-like genome organization. The full-length sequence of DNA-A [HQ180391] showed that the Pusa isolate is a newly described member of the genus Begomovirus, as it had \ 89% sequence homology with DNA-A of all the known begomoviruses. The isolate is tentatively named as Tobacco leaf curl Pusa virus [India:Pusa:2010]. The beta- satellite (HQ180395) associated with TbLCD in Pusa was identified as a variant of Tomato leaf curl Bangladesh betasatellite [IN:Raj:03], with which it shared 90.4% sequence identity. The alphasatellite (HQ180392) asso- ciated with the disease had highest 87% nucleotide sequence identity with Tomato leaf curl alphasatellite. The Begomovirus, betasatellite, and alphasatellite associated with TbLCD in Pusa, Bihar, India were found to be recombinants of extant begomoviruses, betasatellites and alphasatellites spreading in the Indian sub-continent and South-East Asia. Keywords Tobacco  Begomovirus  Tobacco leaf curl disease  Betasatellite  Alphasatellite  Tobacco leaf curl Pusa virus Introduction The whitefly transmitted begomoviruses cause devastating plant diseases of dicot plants, particularly in the tropics and subtropics [1, 2]. The genome of begomoviruses mostly consists of two ssDNA components, designated as DNA-A and DNA-B. Some begomoviruses have a monopartite genome consisting of a single ssDNA, designated as DNA- A[3]. The genomic components of monoprtite begom- oviruses like, Ageratum yellow vein virus, Bhindi yellow vein virus, Cotton leaf curl Multan virus, and Tomato leaf curl China virus resemble the DNA-A of the bipartite be- gomoviruses, and require co-infection by cognate betasat- ellite for disease induction [4–8]. Tobacco leaf curl disease (TbLCD) has been known for nearly a century. It was first observed in the Netherlands [9]. In India, TbLCD is known to cause serious losses in tobacco production for over 75 years [10, 11]. Based on symptomatology, four distinct viruses were expected to be associated with the disease in India [10]. Antigenically, the begomoviruses associated with TbLCD in India were found to be more variable than those causing diseases in other crops [12]. So far 11 distinct monopartite begomoviruses have been identified to cause leaf curl or leaf curl-like diseases of tobacco in various parts of the world [2]; these include, Tobacco leaf curl Thailand virus [13], Tobacco mottle leaf curl virus [14], Tobacco leaf curl Kochi virus (NC_004641), Tobacco leaf curl Korea virus (HM164550), and Tobacco leaf curl Indonesia virus [15]. A bipartite Begomovirus, Tobacco yellow crinkle virus, has also been M. K. Singh  B. Mandal  A. Varma (&) Advanced Centre for Plant Virology, Division of Plant Pathology, Indian Agricultural Research Institute, New Delhi 110012, India e-mail: av.acpv@gmail.com K. Singh Indian Agricultural Research Institute Regional Station, Pusa, Bihar, India M. K. Singh  Q. M. R. Haq Department of Biosciences, Jamia Millia Islamia, New Delhi 110025, India 123 Virus Genes DOI 10.1007/s11262-011-0631-7