PHD17 acts as a target of miR1320 to negatively control cold tolerance via JA-activated signaling in rice

Abstract

Plant Homeo Domain (PHD) proteins are involved in diverse biological processes during plant growth. However, the regulation of genes on rice cold stress response remains largely unknown. Here, we reported that negatively regulated cold tolerance in rice seedlings as a cleavage target of . expression was greatly induced by cold stress, and was down-regulated by overexpression and up-regulated by knockdown. Through 5′RACE and dual luciferase assays, we found that targeted and cleaved the 3′UTR region of . PHD17 was a nuclear-localized protein and acted as a transcriptional activator in yeast. overexpression reduced cold tolerance of rice seedlings, while knockout of increased cold tolerance, partially via the CBF cold signaling. By combining transcriptomic and physiological analyses, we demonstrated that modulated ROS homeostasis and flavonoid accumulation under cold stress. K-means clustering analysis revealed that differentially expressed genes in transgenic lines were significantly enriched in the jasmonic acid (JA) biosynthesis pathway, and expression of JA biosynthesis and signaling genes was verified to be affected by . Cold stress tests applied with MeJA or IBU (JA synthesis inhibitor) further suggested the involvement of in JA-mediated cold signaling. Taken together, our results suggest that acts downstream of and negatively regulates cold tolerance of rice seedlings through JA-mediated signaling pathway.