SgRVE6, a LHY-CCA1-Like Transcription Factor From Fine-Stem Stylo, Upregulates NB-LRR Gene Expression and Enhances Cold Tolerance in Tobacco

• Main Authors: Shu Chen, Huai-An Huang, Jian-Hui Chen, Cheng-Cheng Fu, Peng-Lin Zhan, Shan-Wen Ke, Xiang-Qian Zhang, Tian-Xiu Zhong, Xin-Ming Xie
• Format: Article
• Language: English
• Published: Frontiers Media S.A. 2020-08-01
• Series: Frontiers in Plant Science
• Subjects: RVE transcription factor; cold tolerance; circadian clock; fine-stem stylo; nucleotide binding domain leucine-rich repeats
• Online Access: https://www.frontiersin.org/article/10.3389/fpls.2020.01276/full

Stylosanthes species are economically important tropical and subtropical forage legumes which are generally vulnerable to chilling and frost. Fine-stem stylo (S. guianensis var. intermedia) has the most superior cold tolerance among all stylo species. A REVEILLE (RVE) gene, SgRVE6, was cloned from fine-stem stylo. Bioinformatic analysis suggests that SgRVE6 encodes a transcription factor of 292 amino acid residues, which belongs to the LATE ELONGATED HYPOCOTYL/CIRCADIAN CLOCK ASSOCIATED 1-LIKE (LCL) subgroup of RVE family and contains a SHAQKYF-class MYB domain and a LCL domain. SgRVE6 is universally expressed in root, stem and leaf tissues of fine-stem stylo and is rapidly up-regulated in all tested tissues under cold stress. Over-expressing SgRVE6 affects expression of 21 circadian clock genes, up-regulates expression of 6 nucleotide binding domain leucine-rich repeats (NB-LRR) encoding genes associated with tobacco cold tolerance, improves physiological responses to low temperature, and endows the transgenic tobaccos with higher tolerance to cold stress. This is the first time a study investigates the biological function of RVE6 in cold responses of plant species.