title: Tomato leaf curl Java virus V2 protein is a determinant of virulence, hypersensitive response and suppression of posttranscriptional gene silencing.
abstract: We previously identified the Tomato leaf curl Java virus-A (ToLCJV-A[ID]) from Southeast Asia as a new member of the emerging group of monopartite begomoviruses that require a betasatellite component for symptom induction. In this study, the role of V2 in viral pathogenesis and posttranscriptional gene silencing (PTGS) was studied. Our results showed V2 of ToLCJV-A[ID] elicits a reaction resembling the hypersensitive response (HR) associated with the induction of necrosis and a systemic burst of H(2)O(2) production when expressed from a potato virus X vector in Nicotiana species and tomato. Transient expression of ToLCJV-A[ID] V2 after agroinfiltration of Nicotiana benthamiana and tomato also triggered HR-like cell death, demonstrating that ToLCJV-A[ID] V2 is a target of host defense responses. Deletion of 58 amino acids (aa) from the N-terminus did not affect the HR, suggesting that this region has no role in the HR, while deletion of 58 aa from the C-terminus of V2 abolished both the HR response and V2 silencing suppressor activity, suggesting that these sequences are required for the HR-like response and suppression of PTGS. This finding demonstrated that ToLCJV-A[ID] V2 is a pathogenicity determinant that elicits an HR-like response.
authors.affiliation: Department of Life Science, Graduate School of Agricultural Science, Tohoku University, 1-1 Tsutsumidori-Amamiyamachi, Aoba-ku, Sendai 981-8555, Japan. neprads@gmail.com
authors.forename: Pradeep
authors.initials: P
authors.lastname: Sharma
authors.forename: Masato
authors.initials: M
authors.lastname: Ikegami
mesh_terms: D053839:Begomovirus / Q000472:pathogenicity*; D006861:Hydrogen Peroxide / Q000378:metabolism; D018551:Solanum lycopersicum / Q000821:virology*; D017863:Potexvirus / Q000235:genetics; D034622:RNA Interference; D014764:Viral Proteins / Q000737:chemistry / Q000502:physiology*; D014774:Virulence
chemical_list: D014764:Viral Proteins; D006861:Hydrogen Peroxide