Identification and promoter analysis of a GA-stimulated transcript 1 gene from Jatropha curcas

Abstract

Members of Gibberellic acid-stimulated Arabidopsis (GASA) gene family play roles in plant growth and development, particularly in flower induction and seed development. However, there is still relatively limited knowledge of GASA genes in Jatropha curcas. Herein, we identified a GASA family gene from Jatropha curcas, namely JcGAST1, which encodes a protein containing a conserved GASA domain. Sequence alignment showed that JcGASAT1 protein shares 76% sequence identity and 80% sequence similarity with SlGAST1. JcGAST1had higher expression and protein levels in the male flowers than in the female flowers. Overexpression of JcGAST1 in tobacco promotes plant growth but inhibits pistil development. JcGAST1 expression was upregulated by GA and downregulated by MeJA. Promoter analysis indicated that the pyrimidine box and CGTCA motif were the GA-and MeJA-responsive elements of the JcGAST1 promoter. Using a Y1H screen, six transcription factors were found to interact with the pyrimidine box, and three transcription factors were found to interact with theCGTCA motif. Overall, the results of this study improve our understanding of the JcGAST1 gene and provide useful information for further studies.