Functional characterization of a new ORF βV1 encoded by radish leaf curl betasatellite

Neha Gupta; Kishorekumar Reddy; Prabu Gnanasekaran; Ying Zhai; Supriya Chakraborty; Hanu R Pappu

doi:10.3389/fpls.2022.972386

Functional characterization of a new ORF βV1 encoded by radish leaf curl betasatellite

Front Plant Sci. 2022 Sep 20:13:972386. doi: 10.3389/fpls.2022.972386. eCollection 2022.

Authors

Neha Gupta^{1

2}, Kishorekumar Reddy¹, Prabu Gnanasekaran², Ying Zhai², Supriya Chakraborty¹, Hanu R Pappu²

Affiliations

¹ Molecular Virology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, India.
² Department of Plant Pathology, Washington State University, Pullman, WA, United States.

Abstract

Whitefly-transmitted begomoviruses infect and damage a wide range of food, feed, and fiber crops worldwide. Some of these viruses are associated with betasatellite molecules that are known to enhance viral pathogenesis. In this study, we investigated the function of a novel βV1 protein encoded by radish leaf curl betasatellite (RaLCB) by overexpressing the protein using potato virus X (PVX)-based virus vector in Nicotiana benthamiana. βV1 protein induced lesions on leaves, suggestive of hypersensitive response (HR), indicating cell death. The HR reaction induced by βV1 protein was accompanied by an increased accumulation of reactive oxygen species (ROS), free radicals, and HR-related transcripts. Subcellular localization through confocal microscopy revealed that βV1 protein localizes to the cellular periphery. βV1 was also found to interact with replication enhancer protein (AC3) of helper virus in the nucleus. The current findings suggest that βV1 functions as a protein elicitor and a pathogenicity determinant.

Keywords: begomovirus; hypersensitive response; pathogenesis; radish leaf curl betasatellite; reactive oxygen species; replication enhancer protein; tomato leaf curl New Delhi virus; βV1.