Genome-wide analysis of bHLH57 and functional identification of the involvement of BcbHLH57 in abiotic stress in wucai (Brassica campestris L.)

Abstract

Wucai (Brassica campestris L. ssp. chinensis var. rosularis Tsen), a variety of Brassica cabbage in the Cruciferous family, is a kind of cold-tolerant vegetable widely cultivated in the Jianghuai River Basin of China. To breed new varieties of resistance to stress, it is necessary to study the tolerance of Resistance to different stresses. Transcriptomic data showed that exogenous application of 2, 4-epbrassinolide (EBR) significantly increased bHLH genes in wucai at low temperature, and bHLH57 was up regulated significantly. BHLH (Basic helix-loop-helix) TFs (transcription factor) is a superfamily of TFs with complex functions and related to various plant life activities. In this study, a total of 239 bHLH genes were identified, and their amino acid physicochemical properties, chromosome location, gene structure, phylogeny and cis-acting elements were analyzed by bioinformatics. Phylogenetic analysis showed that bHLH gene families in Chinese cabbage and Arabidopsis were divided into six groups, and the distribution of bHLH genes in Chinese cabbage was uneven. Cis-acting elements analysis showed that the promoter region of bHLH family genes in Chinese cabbage had more responsive elements related to light, hormone and abiotic stress. The BcbHLH57 overexpressing Arabidopsis thaliana lines were subjected to different stress treatments, and the seed germination rate, root growth, survival rate and various plant physiological indexes were determined. The results showed that the transgenic lines were more tolerant to salt, heat and drought stress. In this study, the response of BcbHLH57 gene to salt, heat and drought stress was reported for the first time, which provided a basis for further research on the function of BcbHLH57 in abiotic stress.

Genome wide Association Analysis of Flowering Time in <i>Brassica campestris</i>

“…found that 2 insertions/deletions (76-bp) in BnFLC-C2 promoter region of Brassica napus were closely related to flowering time. Zhang (2018) found that the point mutation of BcFLC1 gene in WuCai (Brassica campestris L.) could affect its interaction with SVP gene, further affecting the expression of downstream FT and SOC1 genes, resulting in the late bolting phenotype of WuCai (Brassica campestris L.). Cheng (2017) et al summarized 6 pathways regulating flowering time in Arabidopsis thaliana, and pointed out that FCA, FLD, FLK, FPA, FVE, FY and LD were involved in the autonomous flowering pathway, in which the flowering suppressor gene FLC played an important role in the autonomous flowering pathway.…”