RNA Polymerase III–Dependent BoNR8 and AtR8 lncRNAs Contribute to Hypocotyl Elongation in Response to Light and Abscisic Acid.

This article focuses on the roles of two homologous long non-coding RNAs (lncRNAs), BoNR8 in cabbage and AtR8 in Arabidopsis, in regulating hypocotyl elongation through integration of light and abscisic acid (ABA) signaling pathways. Both lncRNAs, transcribed by RNA polymerase III and sharing 77% sequence identity, exhibit opposite expression responses to light and ABA and differentially affect hypocotyl growth when overexpressed in Arabidopsis. Their regulation influences key light-related genes (PHYB, COP1, HY5, PIF4) and ABA-responsive genes (ABI3, ABI5), with ABI3 identified as a critical integrator of light and ABA signals controlling hypocotyl elongation. The study suggests that BoNR8 and AtR8 modulate hypocotyl development by coordinating these signaling networks, highlighting the importance of lncRNAs in plant morphogenesis and stress responses.