Understanding how plants integrate multiple stress signals into coordinated growth and developmental responses is essential for generating high-yielding crops with enhanced tolerance to abiotic and biotic stresses. Increasing crop productivity is particularly urgent given global population growth and the challenges posed by climate change. However, extensive breeding-driven genetic erosion has limited the availability of natural variation, making it increasingly difficult to identify gene targets capable of improving resilience and yield. New mechanistic insights and biotechnological tools are therefore required to uncover regulatory pathways that modulate transcriptional programs and enhance plant fitness.

　　Our previous work revealed strong mechanistic links between nuclear proteostasis systems and chromatin remodelers. These connections form part of environmentally responsive signaling pathways that modify epigenetic landscapes and reprogram transcriptomes to elicit adaptive plant responses. Central to these pathways are CRL4-CDDD E3 ubiquitin ligases, which function as integrators of stress and environmental cues to coordinate developmental and physiological outputs. We demonstrated that CRL4-CDDD complexes shape epigenomic landscapes—such as the genome-wide deposition of H2B monoubiquitination (H2Bub)—in response to light/dark transitions, thereby influencing transcription elongation and RNA polymerase II processivity. CRL4-CDDD function also affects other chromatin marks, including H2BKac, a modification of unknown function in plants whose biological relevance and regulatory enzymes we are currently characterizing. This involves identifying the factors responsible for H2BKac deposition and removal and understanding their physical and functional interactions with CRL4-CDDD E3 ubiquitin ligases. Here, we will present our latest findings in these directions for further discussion.

 

Rubio Lab Website: https://laboratorio380vr.wixsite.com/rubio

東京大学大学院理学系研究科・生物科学専攻・遺伝学研究室