Overexpression of PvGF14c from Phyllostachys violascens Delays Flowering Time in Transgenic Arabidopsis.

Bingjuan Li,Guohui Xiao,Zhengyi Wang,Xinchun Lin,Xiaoqin Guo,Bizeng Mao,Kaisheng Luo

doi:10.3389/fpls.2018.00105

Abstract

14-3-3 Proteins are a family of highly conserved regulatory molecules expressed in all eukaryotic cells and regulate a diverse set of biological responses in plants. However, their functions in flowering of Phyllostachys violascens are poorly understood. In this study, four non-𝜀 Pv14-3-3 genes from P. violascens were identified and named PvGF14b, PvGF14c, PvGF14e, and PvGF14f. qRT-PCR analyses revealed that PvGF14b and PvGF14e exhibited widely expressed in all tested bamboo tissues. PvGF14b was highest expression in root and lowest in immature leaf. Whereas PvGF14c and PvGF14f showed tissue-specific expression. PvGF14c was mainly expressed in immature and mature leaves. PvGF14f was highest expression in mature leaves. These four genes were not significantly differentially expressed in mature leaf before bamboo flowering and during flower development. PvGF14b and PvGF14c were not induced by circadian rhythm. PvGF14c displayed subcellular localization in the cytoplasm and PvFT in nucleus and cytoplasm. Yeast two-hybrid screening and bimolecular fluorescence complementation confirmed the interaction between PvGF14c and PvFT. The overexpression of PvGF14b, PvGF14c, and PvGF14e significantly delayed flowering time in transgenic Arabidopsis under long-day condition. These findings suggested that at least three PvGF14 genes are involved in flowering and may act as a negative regulator of flowering by interacting with PvFT in bamboo.

Highlights

In higher plants, flowering transition time is a major factor affecting the adaptability of plants to their environment
Four primers for cloning Pv14-3-3s were designed according to four candidate genes of P. heterocycla, and four Pv14-3-3s genes from P. violascens were cloned and named PvGF14b, PvGF14c, PvGF14e, and PvGF14f, respectively
To understand the genetic relationships of Pv14-3-3s in plants, we performed a phylogenetic analysis of Arabidopsis, O. sativa, P. violascens, and P. heterocycla (Table 4)

Summary

Introduction

In higher plants, flowering transition time is a major factor affecting the adaptability of plants to their environment. Flowering time in higher plants are controlled by complex signaling pathways, such as photoperiod, autonomous flowering, vernalization, and gibberellin pathways, which are independent yet interconnected with one another, eventually forming a complex network (Johanson et al, 2000; Kim et al, 2009). PvGF14c Overexpression Delays Flowering Time and CONSTANS (CO) genes, which regulate plant flowering time by integrating different flowering signals. FT binds to 14-3-3 protein, and interacts with transcription factor, FLOWERING LOCUS D (FD), thereby promoting the flowering of plants (Taoka et al, 2011). Overexpression of OsGF14c, an isoform of the rice 14-3-3 gene family, delayed strongly flowering time (Purwestri et al, 2009)

Methods

Results

Conclusion