ABSTRACT
Plants being sessile, maintain an active interaction with their environment, have to face several kinds of stresses in their lifetime, and evolve the tolerance mechanism to survive; hence the enhancement of environmental stress tolerance has been a primary focus for researchers to maintain crop performances and productivity. According to recent studies, several exogenous treatments of plants with chemical compounds can elicit strong stress defense responses. In this chapter, the role of two such chemical compounds, i.e., chloride ions and organic acids in enhancing stress tolerance in plants have been elucidated. Both chloride and organic acids can play paramount roles in increasing stress defense responses. Although previously chloride was considered to be toxic, it is now regarded as a beneficial macronutrient involved in increasing plant growth, photosynthetic efficiency, water, and nitrogen utilization efficiency. Chloride ions can also orchestrate well-concerted defense responses in plants by means of a series of molecular and biochemical pathways contributing to draft and salinity tolerance. Similarly, amendments of organic acids in the soil can be another sustainable tool to protect plants from heavy metals. Organic acid metabolism is fundamental in maintaining several biochemical reactions involved in energy production, amino acid synthesis, in modulating plant’s adaptation towards the environment. Chelating heavy metals with carboxyl 416groups of organic acids can reduce their phyto-availability and help in heavy metal stress tolerance. Since, these chemicals are widely available, ecofriendly, and cost-effective tools for increasing stress tolerance, their roles in the elicitation of plant defense responses must be explored further to open up new perspectives about sustainable agriculture.
