Advances in Functional Genomics in Investigating Salinity Tolerance in Plants

Abstract

Soil salinity has diverse effects on the morphological, physiological, and biochemical characteristics of plants, which results in reduction in yield. Excessive salt exposure induces morphological and anatomical changes that include a reduction in the dry weight of leaves and roots, root length, root volume, average root diameter, chlorophyll and net photosynthesis, and stomatal conductance. A number of genes were found to be involved in salt tolerance across diverse plant genera. Through functional genomics, transcriptomics, and proteomics approaches the functional significance of some of the major genes has been discovered that play pivotal role in salt tolerance of plants. A number of transgenic approaches have been taken to over-express genes involved in salt-tolerant mechanisms and in addition to that down-regulation of some important genes in transgenic plants also demonstrated salt tolerance. Recently, due to the advancement of genomics, several genomic information are available in public database and furthermore, transcriptomics studies identified several genes directly or indirectly involved in salt tolerance. This chapter specifically describes the over-expression or down-regulation of different candidate genes for mitigating salt tolerance in plants. Along with different functional genomics strategies, how recent researches on microRNA (miRNA) revealed a new field in understanding as well as combating salt stress, have been discussed in this chapter. More recently, another concept has come in the biotechnological research area where a plant genome can be edited in a target-oriented manner. This chapter also summarizes how genome editing is helpful in controlling the detrimental effects of salt stress.