Increasing ambient temperature progressively disassembles Arabidopsis phytochrome B from individual photobodies with distinct thermostabilities

• DOI: 10.1038/s41467-020-15526-z
• Publication Date: 2020-04-03T10:06:32Z
• Authors: Joseph Hahm; Keunhwa Kim; Yongjian Qiu; Meng Chen
• Keywords: 0301 basic medicine; Light; Science; Arabidopsis; Article; Plant Epidermis; 03 medical and health sciences; Gene Expression Regulation, Plant; Phytochrome B; Plant Cells; Photoreceptor Cells; 0303 health sciences; Arabidopsis Proteins; Q; Temperature; Plant; Biological Sciences; Cell Nucleus Structures; Hypocotyl; Gene Expression Regulation; Biochemistry and Cell Biology; Cotyledon; Signal Transduction; Transcription Factors

AbstractWarm temperature is postulated to induce plant thermomorphogenesis through a signaling mechanism similar to shade, as both destabilize the active form of the photoreceptor and thermosensor phytochrome B (phyB). At the cellular level, shade antagonizes phyB signaling by triggering phyB disassembly from photobodies. Here we report temperature-dependent photobody localization of fluorescent protein-tagged phyB (phyB-FP) in the epidermal cells of Arabidopsis hypocotyl and cotyledon. Our results demonstrate that warm temperature elicits different photobody dynamics than those by shade. Increases in temperature from 12 °C to 27 °C incrementally reduce photobody number by stimulating phyB-FP disassembly from selective thermo-unstable photobodies. The thermostability of photobodies relies on phyB’s photosensory module. Surprisingly, elevated temperatures inflict opposite effects on phyB’s functions in the hypocotyl and cotyledon despite inducing similar photobody dynamics, indicative of tissue/organ-specific temperature signaling circuitry either downstream of photobody dynamics or independent of phyB. Our results thus provide direct cell biology evidence supporting an early temperature signaling mechanism via dynamic assembly/disassembly of individual photobodies possessing distinct thermostabilities.