Lab News
Our latest work on the function of photobodies is posted on bioRxiv. Congratulations Jean Ae, De, Jiangman, Keunhwa, and Juan!
Our manuscript "Photobodies enable the phase-separation and counterbalance of opposing phytochrome B actions in PIF5 degradation and stabilization" is now online. This work reveals that phytochrome B condensation enables the co-occurrence and competition of two antagonistic phase-separated signaling actions. Link to the paper: https://doi.org/10.1101/2023.11.12.566724 Abstract: Photoactivation of the plant photoreceptor and thermosensor phytochrome B (PHYB) triggers its condensation into subnuclear photobodies (PBs). However, the function of PBs remains frustratingly elusive. Here, we show that PHYB condensation enables the co-occurrence and competition of two antagonistic phase-separated signaling actions. We found that PHYB recruits PHYTOCHROME-INTERACTING FACTOR5 (PIF5) to PBs and, surprisingly, that PHYB exerts opposing roles in degrading and stabilizing PIF5. Perturbing PB size by overproducing PHYB provoked a biphasic PIF5 response: while a moderate increase in PHYB enhanced PIF5 degradation, further elevating the PHYB level stabilized PIF5 by retaining more of it in enlarged PBs. Our results support a model in which [...]
In collaboration with Xuemei Chen’s lab, we report the function of microRNAs in thermomorphogenesis in Nature Communications! Congratulations to Qing, Lusheng, Tianxiang, Yongjian, and Juan!
In collaboration with Xuemei Chen lab, our new article published today in Nature Communications unveils a previously uncharacterized function of microRNA156 in the plant's phenotypic plasticity in response to environmental temperature and light changes. Read the article here. MicroRNAs (miRNAs) play diverse roles in plant development, but whether and how miRNAs participate in thermomorphogenesis remain ambiguous. Here we show that HYPONASTIC LEAVES1 (HYL1) – a key component of miRNA biogenesis – acts downstream of the thermal regulator PHYTOCHROME INTERACTING FACTOR 4 in the temperature-dependent plasticity of hypocotyl growth in Arabidopsis. A hyl1-2 suppressor screen identified a dominant dicer-like1 allele that rescues hyl1-2’s defects in miRNA biosynthesis and thermoresponsive hypocotyl elongation. Genome-wide miRNA and transcriptome analysis revealed microRNA156 (miR156) and its target SQUAMOSA PROMOTER-BINDING-PROTEIN-LIKE 9 (SPL9) to be critical regulators of thermomorphogenesis. Surprisingly, perturbation of the miR156/SPL9 module disengages seedling responsiveness to warm temperatures by impeding auxin sensitivity. Moreover, miR156-dependent auxin sensitivity [...]