ZmGRAS46 Negatively Regulates Flowering Time in Arabidopsis thaliana

Abstract

Flowering is an essential process in plant development, and there are six major flowering pathways: the photoperiodic pathway, gibberellin pathway, vernalization pathway, age pathway, autonomous pathway, and temperature pathway. In this study, we screened the transcriptome sequencing of early flowering mutants from the laboratory for the significantly differentially expressed ZmGRAS46, which belongs to the DELLA subfamily of the GRAS family. DELLA is involved in the gibberellin pathway to regulate plant flowering. However, it is not clear whether ZmGRAS46 is involved in the gibberellin pathway which regulates plant flowering; therefore, in this experiment, we investigated the regulatory role of this gene in Arabidopsis flowering by overexpressing ZmGRAS46. It was found that overexpression of ZmGRAS46 in Arabidopsis promotes the formation of rosette leaves and flower buds and delays flowering time in Arabidopsis, and experiments have shown that ZmGRAS46 represses the expression of FLOWERING LOCUS T (FT), SUPPRESSOR OF CONSTANS1 (SOC1), CONSTANS (CO), and LEAFY (LFY). Our results indicated the possibility that ZmGRAS46 represses flowering through the CO-FT-SOC1-mediated photoperiodic flowering pathway. The delayed flowering phenotype of overexpressing ZmGRAS46 Arabidopsis could be rescued by applying GA3. The experimental results indicate that ZmGRAS46 depends on the GA3 pathway to regulate flowering in Arabidopsis.