Global climate change has generated significant fluctuations of ambient growth temperature, which can profoundly influence diverse developmental, physiological, and morphological responses, including modulations in plant growth, flowering, immunity, and yield. Understanding how plants adjust their developmental programs in response to temperature variations is central to sustain crop productivity. Research in my laboratory will use combined genetic, molecular, cellular, biochemical, and genomic approaches to determine how plants sense and respond to changes in ambient temperature.
Daytime temperature is sensed by Phytochrome B through HEMERA
Elevations in ambient temperature are perceived by plants in the dark under short-day (SD) conditions but in the light under long-day (LD) and continuous light conditions, leading to augmented hypocotyl growth at distinct times. However, the molecular mechanisms underlying these differential regulations are not fully understood. Phytochrome B (PHYB), the well-known red/far-red photoreceptor, also functions as an ambient temperature sensor and controls thermosensory hypocotyl growth mainly through PIF4-mediated transcriptional regulation of growth-related genes, particularly those involved in auxin biosynthesis and signaling. My postdoctoral research proposed that PHYB plays distinct roles in thermoresponsive growth under LD and SD conditions. While PHYB mediates nighttime temperature responses in SD conditions by controlling PIF4 transcription through the Evening Complex, we discovered that it controls daytime thermo-induced hypocotyl elongation in LD conditions by regulating the activity and stability of PIF4 through a key PHYB signaling component named HEMERA (HMR).
In my current research, I aim to understand the interplay among PHYB, HMR, and PIF4, three key components of thermomorphogenesis, with the focus on: (1) the modulation of PIF4 stability in response to ambient temperature fluctuation; (2) the transcriptional control of thermo-induced PIF4 target genes; (3) integration of local and systemic signals during thermosensory growth; and (4) interplay between different photoreceptors in thermomorphogenetic responses under natural light conditions.