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HYBRID EVENT
September 08-10, 2025 | Valencia, Spain
GPMB 2025

Unraveling papaya ringspot virus pathogenesis: Psba downregulation and host interactions through structural modeling and docking

Saadia Naseem, Speaker at Plant Biology Conferences
COMSATS University Islamabad, Pakistan
Title : Unraveling papaya ringspot virus pathogenesis: Psba downregulation and host interactions through structural modeling and docking

Abstract:

Papaya ringspot virus from Pakistan (PRSV-PK) is an atypical strain significantly impacting papaya production. To understand its pathogenic mechanisms, we conducted a function- based structural analysis of key viral proteins—coat protein (CP), silencing suppressor helper component proteinase (HC-Pro), and replicase nuclear inclusion b protein (NIb). Using Phyre2, Swiss-Model, and i-TASSER, we modeled their structures, followed by final validation through AlphaFold. Conserved functional motifs were identified, mapped, and analyzed to highlight their roles within the host system. In-silico protein-protein docking was performed to explore interactions between papaya host proteins and PRSV-PK viral proteins. The highest docking scores of PRSV-CP with light harvesting complex (LHC type III chlorophyll a/b) (-1687.9) and Photosystem II (PSII) psbA (- 1568.3) suggest chloroplast impairment leading to characteristic mosaic and chlorosis symptoms. HC-Pro interactions with LHC type III chlorophyll a/b (-1731.1) and psbA (-2058.4) indicate its role in exacerbating symptoms alongside CP. Additionally, PRSV-PK-NIb exhibited a strong binding affinity (-1977.4) with psbA, while significant interactions with ubiquitin S27a (-1860.4) suggest its involvement in hijacking the host translational machinery for viral replication. Furthermore, we confirmed the downregulation of the psbA gene during PRSV-PK infection through gene expression analysis. These findings provide novel insights into host-virus interactions, revealing crucial mechanisms of virus infectivity, host adaptability, and potential host defense responses, laying a foundation for future research into plant-virus interactions.

Biography:

Dr. Saadia Naseem earned her PhD in Biological Sciences from Leibniz University Hannover, Germany, with a prestigious DAAD scholarship. Since 2011, she has been a faculty member at COMSATS University Islamabad and previously served as a Senior Scientist at the Advance National Institutes of Genomics and Biotechnology. Passionate about fostering scientific education and research, she strives to build trust in science, particularly among women in Pakistan. She has secured independent research funding from IFS, HEC Pakistan, and PSF. Her work has been widely recognized through publications in esteemed peer-reviewed journals, contributing to advancements in plant science and molecular biology.

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