High Temperature Sensing Mechanisms and Their Downstream Pathways in Plants

Plants, as sessile organisms, possess excellent strategies to acclimate to fluctuating temperature changes. Numerous studies have uncovered many pathways, not limited to the network of HEAT SHOCK TRANSCRIPTION FACTORS (HSFs) and HEAT SHOCK PROTEINS (HSPs), that are involved in the adaptation of growth to warm temperature or protection of cells against heat stress. It is relatively easy to imagine that response of plants to high temperatures might be initiated by the mechanisms which may sense temperature changes. Indeed, several candidates of warm temperature or heat stress sensors have been identified in the last decade. Although these sensors are localized in different organelles, their functions might be integrated via multiple signaling molecules such as Ca2+, reactive oxygen species (ROS), nitric oxide (NO) and plant hormones. In addition, mode of coordination between different signals could be modulated depending on temperature, timing, types of organs and growth stages. In this chapter, the roles of multiple warm temperatures and heat stress sensors will be addressed. Furthermore, the coordination between various signals that might function downstream of these sensors will be also discussed.