Eggplant mild leaf mottle virus (EMLMV), a new putative member of the genus Ipomovirus that harbors an HC-Pro gene Aviv Dombrovsky • Rumakanta Sapkota • Oded Lachman • Yehezkel Antignus Received: 8 September 2011 / Accepted: 31 October 2011 / Published online: 16 November 2011 Ó Springer Science+Business Media, LLC 2011 Abstract Since 2003, a new viral disease of eggplant (Solanum melongena L.) has been spreading in fields in the Jordan and Arava Valleys, Israel. The symptoms of this disease include mild leaf mottling and varying degrees of fruit distortion. This disease can be transmitted by mechanical sap inoculation, as well as by the whitefly Bemisia tabaci (Homoptera, Aleyrodidae) and has been tentatively named eggplant mild leaf mottle virus (EM- LMV). Our study aimed to determine the complete sequence and genome organization of EMLMV. The extracted viral RNA was subjected to SOLiD next-gener- ation sequence analysis and used as a template for reverse transcription synthesis, which was followed by ds-cDNA synthesis or PCR amplification. The ssRNA genome of EMLMV includes 9,280 nucleotides, excluding a 3 0 ter- minal poly-adenylated tail. The genome includes a putative single, large open reading frame (ORF) that encodes a polyprotein of 3,011 amino acids, a short overlapping ORF of PIPO protein comprised of 71 amino acids and 5 0 and 3 0 non-coding regions of 108 and 136 nucleotides, respec- tively. The deduced amino acid sequence of the EMLMV polyprotein is relatively close to that of sweet potato mild mottle virus (SPMMV), with 37% shared sequence iden- tity. Among the four ipomoviruses, only SPMMV and the putative genus member EMLMV contain a helper com- ponent-proteinase (HC-Pro) gene. Like SPMMV-HC-Pro, EMLMV-HC-Pro also contains the highly conserved PTK domain that is thought to be involved in the aphid-assisted transmission of potyviruses. Keywords Potyviridae Á Whitefly Á Bemisia tabaci Á Next-generation sequencing (NGS) Introduction In a previous study [1, 2], we reported on a new viral disease of eggplant that has been discovered in Israel. The symptoms of this disease include mild leaf mottling and varying degrees of fruit distortion. The viral disease- causing agent was assigned to the Potyviridae based on its particle morphology and the presence of pinwheel cyto- plasmic inclusion bodies and high levels of shared sequence identity with the nuclear inclusion B-coat protein genes (NIb-CP) of tomato mild mottle virus (TomMMoV) [3], an unassigned aphid-borne member of the Potyviridae family [4]. Unlike TomMMoV, which is transmitted by the aphid Myzus persicae [4], EMLMV is transmitted only by the whitefly Bemisia tabaci (Homoptera, Aleyrodidae) [1, 2]. Based on these results, the viral disease-causing agent of this eggplant disease was assigned to the family Poty- viridae and tentatively named EMLMV [1, 2]. Potyviridae is the second largest family of plant viruses and includes 170 members [according to the 2009 report of the International Committee on Taxonomy of Viruses (ICTV), (http://www.ictvonline.org/virusTaxonomy.asp? bhcp=1)]. This family is composed of seven genera: Bram- byvirus (one species), Bymovirus (six species), Ipomovirus (four species), Macluravirus (six species), Potyvirus (143 species), Rymovirus (three species) and Tritimovirus (four species), as well as three unassigned species including Sugarcane streak mosaic virus SCSMV. Recently, Electronic supplementary material The online version of this article (doi:10.1007/s11262-011-0686-5) contains supplementary material, which is available to authorized users. A. Dombrovsky (&) Á R. Sapkota Á O. Lachman Á Y. Antignus Department of Plant Pathology, ARO, The Volcani Center, Bet Dagan 50250, Israel e-mail: aviv@volcani.agri.gov.il 123 Virus Genes (2012) 44:329–337 DOI 10.1007/s11262-011-0686-5