Plant Immunity Is Regulated by Biological, Genetic, and Epigenetic Factors

An immune system is a protective mechanism that shields plants from environmental stresses. This primary function is to maintain optimal circumstances for the growth and development of plant tissues while avoiding harm from biotic and abiotic stress factors. Plants subjected to various stressors initiate stress signaling cascades that affect multiple gene expressions and induce adaptation. These signaling pathways are coordinated by transcription factors, non-coding RNAs, RNA-binding proteins, and protein-protein interaction networks. Several studies have focused on various immune systems, but no study has collected all of them together to illustrate them efficiently. According to this review, stress-responsive genes encode ion and water transporters, enzymes, and transcription factors, making plants more resistant to biological and abiotic challenges. Plants have also evolved anti-pathogen defense systems such as regulatory hormone pathways, reactive oxygen species generation, gene expression, programmed cell death, and cell survival. Plants produce short RNAs in response to a viral attack, which silences the offensive genome and creates complex epigenetic regulatory mechanisms such as histone changes, chromatin remodeling, and DNA methylation to protect plants from pathogens. This review provides an in-depth description of proteins, effectors, and pathways included in plant resistance against environmental stresses and offers details on future trends, such as metabolic pathways and genetic engineering, to improve the protection of plants against stress-induced responses.