14-3-3 gene of Zostera japonica ZjGRF1 participates in gibberellin signaling pathway.

Abstract

Zostera japonica is a unique seagrass species in Asia with important ecological value. Gibberellin (GA) is a plant hormone crucial in the regulation of plant growth and development, including seed longevity, seed germination, anti-aging, hypocotyl elongation, leaf development, reproductive organ development, and abiotic stress responses. However, the role of 14-3-3 gene of Z. japonica in GA signaling pathway remains unclear. Herein, gibberellin content and expression of GA synthesis genes were lower in Arabidopsis overexpressing ZjGRF1, 14-3-3 gene of Z. japonica, than in wild type (WT). Moreover, the expression level of GA receptors was lower in transgenic ZjGRF1 Arabidopsis than in WT. The expression level of GA response gene expansin8 (EXP8) was lower in transgenic ZjGRF1 Arabidopsis than in WT. In contrast, the expression levels of PACLOBUTRAZOL RESISTANT1 (PRE1), PRE5 and SCARECROW-LIKE 3 (SCL3) were higher in the transgenic ZjGRF1 Arabidopsis than in WT. Transgenic ZjGRF1 Arabidopsis has decreased sensitivity to paclobutrazol, an inhibitor of GA synthesis. The expression level of flowering regulatory genes was lower in transgenic ZjGRF1 Arabidopsis than in WT. This is the first study to report the function of 14-3-3 gene family in seagrass. These findings can be used in future studies on the regulation role of 14-3-3 gene on plant development.