Genetic, Epigenetic, Genomic and Microbial Approaches to Enhance Salt Tolerance of Plants: A Comprehensive Review

Abstract

Globally, soil salinity has been on the rise owing to various factors that are both human and environmental. The abiotic stress caused by soil salinity has become one of the most damaging abiotic stresses faced by crop plants, resulting in significant yield losses. Salt stress induces physiological and morphological modifications in plants as a result of significant changes in gene expression patterns and signal transduction cascades. In this comprehensive review, with a major focus on recent advances in the field of plant molecular biology, we discuss several approaches to enhance salinity tolerance in plants comprising various classical and advanced genetic and genetic engineering approaches, genomics and genome editing technologies, and plant growth-promoting rhizobacteria (PGPR)-based approaches. Furthermore, based on recent advances in the field of epigenetics, we propose novel approaches to create and exploit heritable genome-wide epigenetic variation in crop plants to enhance salinity tolerance. Specifically, we describe the concepts and the underlying principles of epigenetic recombinant inbred lines (epiRILs) and other epigenetic variants and methods to generate them. The proposed epigenetic approaches also have the potential to create additional genetic variation by modulating meiotic crossover frequency.

Evaluation of metabolites in Iranian Licorice accessions under salinity stress and Azotobacter sp. inoculation

“…Salt-tolerant rhizobacteria can increase the uptake of K ions by inducing the expression of a high-affinity ion transporter (AtHKT1) in plants under salinity, resulting in a higher K + /Na + ratio that promotes salt tolerance. Strains of PGPB directly modify plant growth by solubilizing P and K, while increasing nutrient uptake 63 . Also, there are indications that salt-tolerant Azospirillum restricts the Na + influx into the roots and causes a high K + /Na + ratio in salt-stressed plants.…”

Epigenetic Changes Occurring in Plant Inbreeding

“…When this gene loses its function, there is incorrect gene expression and activation of TE due to the nearly complete absence of methylation of CG [ 36 , 167 ]. The insertion of the wild type of the DDM1 gene into a ddm1 mutant, or of MET1 into a met1 mutant, does not restore the DNA methylation at all loci where it was previously lost [ 168 ]. The inbreeding of met1 or ddm1 mutants contributes to obtaining stable epialleles [ 166 , 169 ].…”

Phenotypic Variability of Wheat and Environmental Share in Soil Salinity Stress [3S] Conditions

“…Over the last few decades, several studies have been carried out to understand plant biology in response to 3S, with a major emphasis on genetic and other hereditary components [9,12,29]. Based on the outcome of these studies, several approaches are being followed, to enhance plants' ability to tolerate salt stress while still maintaining reasonable levels of crop yields [40,41]. This research indicates the importance of studying the correlations between yield components and wheat grain yield in 3S, which is in accordance with Matković Stojšin, et al [42].…”