GmFT2a and GmFT5a redundantly and differentially regulate flowering through interaction with and upregulation of bZIP transcription factor GmFDL19 in soybean.

Reference Report for AP20210615.2

Title:	GmFT2a and GmFT5a redundantly and differentially regulate flowering through interaction with and upregulation of bZIP transcription factor GmFDL19 in soybean.
Authors:	Nan, H., Cao, D., Zhang, D., Li, Y., Lu, S., Tang, L., Yuan, X., Liu, B., Kong, F.
Source:	Nan et al. 2014 PLoS ONE 9(5):e97669
Abstract:	FLOWERING LOCUS T(FT) is the key flowering integrator in Arabidopsis (Arabidopsis thaliana), and its homologs encode florigens in many plant species regardless of their photoperiodic response. Two FT homologs, GmFT2a and GmFT5a, are involved in photoperiod-regulated flowering and coordinately control flowering in soybean. However, the molecular and genetic understanding of the roles played by GmFT2a and GmFT5a in photoperiod-regulated flowering in soybean is very limited. In this study, we demonstrated that GmFT2a and GmFT5a were able to promote early flowering in soybean by overexpressing these two genes in the soybean cultivar Williams 82 under noninductive long-day (LD) conditions. The soybean homologs of several floral identity genes, such asGmAP1, GmSOC1andGmLFY, were significantly upregulated by GmFT2a and GmFT5a in a redundant and differential pattern. A bZIP transcription factor, GmFDL19, was identified as interacting with both GmFT2a and GmFT5a, and this interaction was confirmed by yeast two-hybridization and bimolecular fluorescence complementation (BiFC). The overexpression ofGmFDL19in soybean caused early flowering, and the transcription levels of the flowering identity genes were also upregulated by GmFDL19, as was consistent with the upregulation of GmFT2a and GmFT5a. The transcription ofGmFDL19was also induced by GmFT2a. The results of the electrophoretic mobility shift assay (EMSA) indicated that GmFDL19 was able to bind with the cis-elements in the promoter ofGmAP1a.Taken together, our results suggest that GmFT2a and GmFT5a redundantly and differentially control photoperiod-regulated flowering in soybean through both physical interaction with and transcriptional upregulation of the bZIP transcription factor GmFDL19, thereby inducing the expression of floral identity genes.

Funded by the USDA-ARS. Developed by the USDA-ARS SoyBase and Legume Clade Database group at the Iowa State University, Ames, IA

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