DSSS - Understanding the temporal dynamics of temperature stress responses in plants

To better adapt to their environment and align key metabolic and physiological activities, the circadian clock helps organisms partition specific responses to the most optimal times of the day. In plants, gene expression dynamics in response to environmental stimuli are highly dependent on the time of day, a process referred to as circadian gating. However, the key regulators involved, the regulatory mechanisms, and the functional relevance of circadian gating remain poorly understood in plants. This talk will discuss work in our lab to dissect the molecular mechanisms modulated by time of day in response to heat stress. Using transcriptomic analysis, we have determined that the clock gates the response to heat stress for both cycling and non-cycling genes across multiple levels of gene regulation in Arabidopsis. Furthermore, a notable subset of genes is regulated posttranscriptionally, suggesting that the clock may regulate the fate of these mRNAs to fine-tune translation. In crops, such as Sorghum, we observe that the clock also gates temperature responses, and aspects of this regulation depend on the genotype sensitivity. In rice, spatial responses to heat stress are also modulated by the clock. We have identified candidate genes from Arabidopsis, sorghum, and rice for genetic manipulation via cis-element modifications to investigate the functional relevance of clock-controlled stress gating. Our long-term goal is to be able to precisely enhance or engineer time of day specific gene expression responses for beneficial physiological outcomes.