BEAR1, a bHLH Transcription Factor, Controls Salt Response Genes to Regulate Rice Salt Response

Transcription factors play important roles in plant abiotic stresses. However, there are a large number of TF functions in rice salt response need to be characterized. Our study identified a new transcription factor, BEAR1, acts as a regulator of rice salt response. We used artificial microRNA to generate BEAR1 knockdown transgenic rice, and CRISPR to generate BEAR1 gene editing mutant lines. Both knockdown lines and mutant lines showed salt sensitive phenotypes, compared to NIP. Transient expression in rice protoplast was used to confirm the subcellular localization of BEAR1. The transcription activity of BEAR1 was detected by yeast system. BEAR1 was induced by salt stress and dominantly expressed in root at seedling stage and spikelet at mature stage. BEAR1 regulating rice salt response by controlling expression levels of many salt-related genes, including salt response marker genes and ion transporter genes. The study revealed that BEAR1 was a regulator of rice salt response.