Thermal stress imposes detrimental impacts on the growth and developmental processes of organisms universally. Throughout evolutionary history, a suite of defense mechanisms has emerged, enabling survival under stressful high-temperature environments, with many of these adaptive strategies exhibiting conservation across different biological Kingdoms. By examining heat stress tolerance in Arabidopsis thaliana, a model dicotyledonous plant, we aim to uncover these evolutionarily conserved defense mechanisms. Our research is driven by the aspiration to unravel novel pathways that govern thermotolerance, which may hold profound implications for enhancing resilience in diverse species.
Tracking heat stress granule dynamics across a wide temperature range
Heat stress granules (HSGs) represent a class of membraneless organelles that emerge as a cellular defense against thermal stress, playing a critical role in the preservation of proteins and mRNA integrity under conditions of elevated temperature. Yet, the processes governing their assembly and disassembly remain poorly delineated, and their responsiveness to nuanced temperature changes is largely unexplored. In pursuit of advancing our understanding of HSG dynamics in vivo, we have forged a partnership with experts in mechanical engineering to create a cost-effective, high-performance heating apparatus tailored for use with confocal microscopy. This innovative device rivals top-tier commercial alternatives, offering rapid and accurate temperature modulation—capable of adjusting temperatures at a rate of 0.3°C per second with a precision of 0.2°C. Armed with this technologically advanced tool, our research is directed toward an in-depth characterization of the behavior and composition of HSGs under a spectrum of thermal conditions.
Gene mining for essential regulators of heat stress responses in Arabidopsis thaliana
Various plant species possess divergent thermal tolerance zones. Within a single species, the physiological response to heat stress can vary substantially across a spectrum of temperatures. This implies that disparate heat stimuli—characterized by intensity, duration, and frequency—can elicit distinct responses in plants, each mediated by unique molecular actors. To probe the intricacies of heat stress responses across varying thermal regimes, we engineered a robust heat-responsive luciferase reporter system in Arabidopsis thaliana. Through intensive genetic screens, our objective is to pinpoint factors that are consistently activated and govern the plant’s heat stress response across a broad array of thermal exposures, as well as to identify those factors that are selectively triggered under specific thermal stress conditions.
Qiu Laboratory at Ole Miss 