Effect of heat stress on wild type and A7a knockout mutant Arabidopsis thaliana plants

Rise in temperature causes heat stress which is a major global risk that limits plant growth, metabolism and productivity. Plants possess various strategies and have numerous mechanisms at various levels like morphological, biochemical, physiological levels to withstand high temperature conditions. At molecular level, in Arabidopsis thaliana class A HSFs specifically AtHsfA1b, AtHsfA1d, AtHsfA7a act as activators of transcription reported to have a positive feedback during heat stress which helps in thermo-tolerance. Hence, this study was carried out to understand the role of transcription factor HsfA7a gene for the ability of sustaining heat stress by A. thaliana. Two ecotypes of A. thaliana, Col-0 (wild Columbia type) and HsfA7a knockout mutant were used for the study. Various morphological, biochemical and physiological parameters were analysed to evaluate the performance of the plants under stress. For treatment, 38 °C temperature (heat stress) for 24 h followed by a recovery of 24 h was used which were compared with plants grown under normal conditions. Consequently, it was found that heat stress and recovery both had significant effects on both the ecotypes whereas wild type was found to perform better under heat stress compared to the mutant. Thus, it can be concluded that HsfA7a gene is playing a key role in thermo-tolerance in A. thaliana, similar to other class A HSFs.