Due to the after-effects of human anthropogenic activities and parallel changes in weather, adverse environmental conditions are progressively prevailing across the globe. As a result, there is a disadvantageous influence on all sessile plants and their related characteristics such as growth, development, chance to survive and ultimately reproduce. So, in order to adapt to such an ever-changing and unstable scenario, plants have developed mechanisms of stress avoidance and/or tolerance. One of the important tolerance mechanisms is ‘expression and regulation of stress-responsive genes’. The reason lies in the nature of expressing genes and their regulatory role in the production of important metabolic proteins such as the chaperones as well as other genes related to downstream signal transduction under stressful conditions. This variety of regulation is observed at mainly three levels such as transcriptional, post-transcriptional and post-translational. Regulation at transcription involves the interplay of elements that are cis or trans-regulatory and chromatin modifications and remodelling. Post-transcriptional regulation occurs at different stages related to mRNA maturation (such as processing, trafficking, translation, turnover and stability). Finally, post-translational regulation occurs via different processes such as phosphorylation, dephosphorylation, adenylation, SUMOylation and ubiquitination at the protein level. All these regulations ensure the appropriate pattern of gene expression to ‘switch on’ the adaptive response. As a result, the current book chapter is an attempt to highlight the stress-responsive gene expression and regulation in plants under stressful conditions.