P-406 - Deciphering the role of transcriptional condensates in thermally regulated plant immunity

As climate change accelerates and extreme weather events become more frequent, plants are increasingly vulnerable to infectious diseases, especially under heat stress. Salicylic acid (SA), a key phytohormone in plant immunity, is notably suppressed at elevated temperatures, weakening plant defense responses. To understand how high temperatures influence SA-related gene regulation, we focus on CBP60g, a key transcription factor involved in temperature-dependent immune responses, and GBPL defense-activated biomolecular condensates (GDACs), which facilitate transcriptional condensate formation. We hypothesize that GDACs are part of temperature-sensitive regulatory hubs, recruiting specific genes and regulatory elements to modulate the transcription of immune-related genes such as CBP60g. To test the hypothesis, we employed CBP60g promoter-specific proximity labeling, GDAC proximity labeling, and chromatin capture sequencing. These approaches allowed us to identify potential transcriptional regulators of CBP60g, characterize temperature-dependent compositional changes in GDAC formation, and uncover alterations in chromatin architecture under heat stress. Our findings provide new insights into the transcriptional regulation of SA-mediated immunity under combined thermal and immune stress, shedding light on how biomolecular condensates promote plant immune responses.