The lncRNA and the transcription factor WRKY42 target common cell wall EXTENSIN encoding genes to trigger root hair cell elongation.

Plant long noncoding RNAs (lncRNAs) are key chromatin dynamics regulators, directing the transcriptional programs driving a wide variety of developmental outputs. Recently, we uncovered how the lncRNA () directly recognizes the locus encoding the root hair (RH) master regulator () modulating its transcriptional activation and leading to low temperature-induced RH elongation. We further demonstrated that interacts with the transcription factor WRKY42 in a novel ribonucleoprotein complex shaping epigenetic environment and integrating signals governing RH growth and development. In this work, we expand this model showing that is able to bind and positively control the expression of several cell wall EXTENSIN (EXT) encoding genes, including , a key regulator for RH growth. Interestingly, emerged as a novel common target of and WRKY42. Furthermore, we showed that the ROS homeostasis-related gene is deregulated upon overexpression, likely through the RHD6-RSL4 pathway, and that is required for low temperature-dependent enhancement of RH growth. Collectively, our results uncover an intricate regulatory network involving the /WRKY42 hub in the control of master and effector genes during RH development.