Nutrient homeostasis and salt stress tolerance

Abstract

Soil salinity is an unavoidable constraint in crop production globally. Soil salinization is often caused by improper soil management and/or crop production practices, which has made highly productive lands barren/unusable. Plant species have evolved several mechanisms to cope with salinity stress. Nutrient homeostasis is among the different mechanisms employed by plant species to withstand elevated salt levels in the root zone. Nutrients are the mediators of metabolism, so their cytoplasmic levels need to be effusively controlled both under stressful and benign environments. Several studies report the homeostasis of a single ion, i.e., sodium, potassium, or chloride. However, limited studies are available reporting the role of nutrient homeostasis (all nutrients together) under salinity stress. This chapter describes the role of nutrient homeostasis and ion channels and transporters in salt stress tolerance of plant species. The ion efflux at plasma membrane and vacuolar compartmentation in response to salinity stress has been described in detail. The impaired uptake of the nutrients is an obvious effect of salinity, mainly disturbing the sodium and potassium uptake. Much of the research has been done to test the role of different nutrients on salinity alleviation, and silicon is found to alleviate the negative effects of salinity. The nutrient homeostasis starts from ion sensing, uptake, transport, and activation of defense mechanisms as well as regulation of genes or gene networks to alleviate/withstand the adverse effects of salinity. Thus, the ion sensing, uptake, transport, and gene defense activation in response to salinity stress have also been described comprehensively.