Viruses are silent enemies that intrude and take control of the plant cell’s machinery for their own multiplication. Infection by viruses and the resulting damage is still a major challenge in the agriculture sector. Plants have the capability to fight back, but the ability of viruses to mutate at a fast rate helps them to evade the host’s response. Therefore, classical approaches for introgressing resistance genes by breeding have obtained limited success in counteracting the virus menace. Genetic modification (GM)-based strategies have been successful in engineering artificial resistance in plants. Several different approaches based on pathogen-derived resistance, antisense constructs, hairpin RNAs, double-stranded RNA, etc., have been used to enhance plants’ resistance to viruses. Recently, genome editing (GE) strategies mainly involving the CRISPR/Cas-mediated modifications are being used for virus control. In this review, we discuss the developments and advancements in GM- and GE-based methods for tackling viral infection in plants.

Plants, being sessile, are unable to disperse during the stress conditions in their environment. Drought, flood, salinity, heavy metal and high and low temperature are the various abiotic stresses experienced by a plant during its life cycle. Abiotic stresses cause a considerable reduction in crop productivity worldwide by causing physiological, biological, morphological and molecular changes in the plant. Various phytohormones play a role in abiotic stress tolerance. Among all, abscisic acid (ABA) plays a crucial role in stress tolerance, so it is also known as the stress hormone. ABA also regulates stress-related pathways through mitogen-activated protein kinase (MAPK) signaling. Abiotic stress in plants also leads to the production of ROS and NO. These molecules are further seen to crosstalk with ABA to induce stress tolerance in plants. This chapter discusses the roles of ABA during abiotic stress, its MAPK-mediated signaling pathway and the crosstalk of ABA with other phytohormones (jasmonic acid, ethylene, gibberellic acid) and signaling molecules (reactive oxygen species, nitric oxide) during abiotic stress. <!----> <!----> <!----> <!---->

Viruses are silent enemies that intrude and take control of the plant cell's machinery for their own multiplication. Infection by viruses and the resulting damage is still a major challenge in the agriculture sector. Plants have the ability to fight back, but the ability of viruses to counteract and mutate at a fast rate helps them to hide from the host response. Therefore, classical approaches for introgressing resistance genes by breeding have obtained limited success in counteracting the virus menace. Genetic modification (GM) based strategies have been successful in engineering artificial resistance in plants. Several different approaches based on pathogen derived resistance, antisense constructs, hairpin RNA, double stranded RNA etc. have been used to enhance plant resistance to the virus. Recently, genome editing (GE) strategies mainly involving the CRISPR/Cas mediated modifications are being used for virus control. In this review, we discuss the developments and advancements in the GM and GE based methods in tackling virus infection in plants.