The role of orphan ORFs of the passionfruit green spot virus (Cilevirus passiflorae)

• Grant number: 24/23284-9
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: March 01, 2025
• End date: February 28, 2026
• Field of knowledge: Agronomical Sciences - Agronomy - Plant Health
• Principal Investigator: Juliana de Freitas Astúa
• Grantee: Sílvia de Oliveira Dorta
• Host Institution: Instituto Biológico (IB). Agência Paulista de Tecnologia dos Agronegócios (APTA). Secretaria de Agricultura e Abastecimento (São Paulo - Estado). São Paulo , SP, Brazil
• Associated research grant: 19/25078-9 - Genomics and trascriptome of virus-vector-host plant relationship in the pathosytem of Brevipalpus transmitted viruses; systematic and evolution of Brevipalpus mites and their endosymbionts; new strategies to manage citrus Leprosis in the S. Paulo State, AP.TEM

Abstract

PfGSV is the cilevirus with largest natural host range known.Symptoms caused by PfGSV in infected plants are usually large patches of chlorotic blotches or spots, or alternatively, green patches in yellow leaves, contrasting with those caused by other cileviruses (citrus leprosis C, solanum violifolium ringspot), which tend to be smaller chlorotic or necrotic spots. PfGSV genome differs remarkably in relation to other cilevirus- the region between P15 and P61 ORFs, at the 5 end, is hypervariable, presenting orphan ORFs. Some PfGSV isolates possess a 13kDa protein coding ORF, while others, of 11 or 7 kDa, or even without extra ORFs. In the present project it is intended to isolate these ORFs and express them in stable manne in transgenic plants of Arabidopsis thaliana. Observation will be made on possible phenotpe alterations, subcellular localization of the evaluated proteins based on fusion with reporter gene or by immunolocalization of a fused tag, and the effect of accumulation of these proteins on the infection (qualitative and quantitative) with PfGSV,and other cileviruses as CiLV-C.Furthermore, the possible role of these ORFs as viral supressor by gene silencing will be studied, using the model C16 of Nicotiana benthamiana.