Cloning, expression pattern and stress responses analysis of BnbHLH122 genes in Brassica napus L.

Abstract:

In order to explore the biological function of bHLH transcription factors in Brassica napus L., two full-length cDNA sequences of bHLH122 transcription factor genes were cloned from Brassica napus L. by homologous cloning method and named BnbHLH122-1 (GenBank accession number: MT795160) and BnbHLH122-2 (GenBank accession number: MT795161) respectively. Bioinformatics analysis showed that both BnbHLH122 proteins were unstable hydrophilicity proteins with the bHLH conserved domain, which were closely related to the predicted bHLH122 proteins in Brassica rapa and Brassica oleracea, respectively. The results of subcellular localization and transcriptional activation verification showed that both BnbHLH122 proteins were located in the nucleus and had transcriptional activation activity. Then the qRT-PCR results showed that the BnbHLH122-1 gene is mainly expressed in the roots at the flowering stage, and the BnbHLH122-2 gene is mainly expressed in the roots at the seeding stage and flowers at the flowering stage. Besides, the expression of BnbHLH122 genes was significantly affected by the stresses of high temperature, low temperature, drought, salt, osmosis, Sclerotinia sclerotiorum and the hormone treatments of ABA, SA and MeJA, indicating that BnbHLH122 genes may play important roles in regulation in the progress of maintaining normal growth and development and resisting stresses in Brassica napus L..