Begomoviruses associated with okra yellow vein mosaic disease (OYVMD): diversity, transmission mechanism, and management strategies.

Abstract

Okra yellow vein mosaic disease (OYVMD) is a major constraint to okra production globally. It is caused by several distinct begomoviruses, including okra yellow vein mosaic virus (OYVMV), that are transmitted by the whitefly. This study synthesizes current knowledge on the complex interactions between whiteflies, begomoviruses, and okra plants that enable viral spread and cause OYVMD. The acquisition and transmission cycle involves specific processes including virion ingestion during phloem-feeding, endocytosis and passage across insect tissues, secretion in saliva, and inoculation into plants. Molecular compatibilities between vector coat proteins, midgut proteins, and plant factors modulate virus replication and movement through barrier tissues. Abiotic stresses and host traits also impact whitefly behavior and virus epidemiology. Begomoviruses such as OYVMV have spread globally wherever whitefly vectors and susceptible okra varieties occur. Integrated management of the tripartite pathosystem that incorporates host resistance, cultural tactics, and biological control is required to mitigate the transmission of begomoviruses and OYVMD impact. Finally, resolving vector-virus interactions and developing interference strategies will help contribute to strengthening okra germplasm resistance which can support sustainable food production.