R-loops act as a master regulatory switch modulating transcription of cold-responsive genes in rice

Cold is a major naturally occurring stress that usually causes complex symptoms and severe yield loss in plants. R-loops can function in a series of biological processes, including normal development and stress responses, in plants. However, how R-loops function in cold responses is still largely unknown in plants, especially in cold sensitive rice. Herein, we conducted DRIP-seq in combination with other newly generated omics data (RNA-seq, DNase-seq, ChIP-seq and MNase-seq) in rice with or without cold treatment. We found that cold treatment caused R-loop dynamics across the genome, indicating that R-loops are cold sensitive non-B DNA structures. Moreover, cold biased R-loops had high GC content and novel motifs the binding of distinct TFs as compared to CK biased R-loops, indicative of occurrence of differential biological implications of R-loop dynamics in response to cold stress. More importantly, we for the first time to provide evidence showing that, in addition to the direct involvement of R-loops in the regulation of cold-responsive gene transcription, R-loops can indirectly modulate transcription of subsets of cold-responsive genes through R-loop overlapping TF-centered or cis-regulatory element related regulatory networks and lncRNAs in rice. Thus, our study for the first time provides evidence showing functions of R-loop dynamics in rice cold responses. It also provides some potential R-loop loci for genetic and epigenetic manipulation towards breeding of enhanced cold tolerance rice varieties. we conducted DRIP-seq in combination with other newly generated omics data (RNA-seq, DNase-seq, ChIP-seq) in rice with or without cold treatment.