Submitted to: Plant Pathology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 11/3/2009
Publication Date: 3/2/2010
Citation: Dang, P.M., Scully, B.T., Lamb, M.C., Guo, B. 2010. Analysis and RT-PCR identification of viral sequences in peanut (Arachis hypogaea L.) expressed sequence tags from different peanut tissues. Plant Pathology. 9(1):14-22.2010. Interpretive Summary: Peanut is one of the major economically-important legumes and is widely grown in the southern United States. A field survey for peanut viruses conducted in 1983 found peanut mottle virus (PMV), peanut strip virus (PStV), and peanut stunt virus, but did not detect tomato spotted wilt virus (TSWV). These viruses cause economic yield losses, and are sometime a major limiting factor in peanut production. TSWV has become increasingly important in the production of peanut in the southeastern US. In 1997, losses to TSWV in peanut were estimated at $40 million for Georgia alone. The objective of this study was to search viral sequences in peanut plants and develop control strategies. We have sequenced a total of 44,064 clones from peanut cDNA libraries, which were derived from developing peanut seeds at three reproduction stages (R5, R6 and R7) and derived from leaf tissues of peanut in the field from a resistant and a susceptible peanut, Tifrunner (a runner type, resistant to TSWV) and GT-C20 (a Spanish type, susceptible to TSWV). We have analyzed the extent of viral sequences in these data, and detected the sequences of PMV, PStV, TSWV, and Tobamovirus. We also identified peanut plant-sequences with homologues to pea plant-specific Potyvirus VPg-interacting protein (PVIP) and to Arabidopsis thaliana tobamovirus multiplication protein 3 (TOM3). These two host proteins are essential for these virus replications and movement. Biotechnology of silencing or disruption of these genes can control virus infection and multiplication in peanuts.
Technical Abstract: Peanut plants grown in the field have been naturally infected with different viruses resulting in economic yield loss in the southeastern US, such as tomato spotted wilt tospovirus (TSWV) in peanuts. The objectives of this study were to investigate peanut sequences of expressed sequence tags (EST) for viral nucleotide sequences, to identify possible new viruses, and to develop control strategies of potential viral diseases. We have sequenced a total of 44,064 clones from 9 peanut cDNA libraries, derived from developing seeds at three reproduction stages (R5, R6 and R7) and from leaf tissues of a resistant and a susceptible cultivated peanuts, ‘‘Tifrunner’’ (a runner type, resistant to TSWV) and ‘‘GT-C20’’ (a Spanish type, susceptible to TSWV). We investigated the extent of viral sequences in these peanut ESTs and detected the sequences of peanut mottle virus (PMV), peanut strip virus (PStV), tomato spotted wilt virus (TSWV), and Tobamovirus. A total of 942 sequences were identified matching viral sequences in the GenBank to PMV (606), PStV (330), TSWV (6), and Tobamovirus (1). We also identified peanut plant-sequences with homologues to pea (Pisum sativum) plant-specific Potyvirus VPg-interacting protein (PVIP) and to Arabidopsis thaliana tobamovirus multiplication protein 3 (TOM3). These two host proteins are essential for viral multiplication and movement from cell to cell in host plants. These sequences were assembled into contigs, and will be submitted to GenBank. One sequence matched to viral sequence of RNA helicase domain of tobamovirus replicase may indicate that TMV could also infect peanuts, which has not been reported in peanuts. Further study of peanut putative PVIP and TOM3 will lead to develop potential new strategies to control these virus diseases by silencing or disruption of these genes to prevent virus infection and multiplication in host plants.