Functions of CsGPA1 on the hypocotyl elongation and root growth of cucumbers

Yan Yan,Wenna Zhang,Lihong Gao,Chaoxing He,Xianchang Yu,Yansu Li

doi:10.1038/s41598-018-33782-4

Abstract

G proteins regulate shoot, root, and epidermis development, as well as biotic stress tolerance in plants; however, most studies have examined model plants and less attention has been paid to the function of G proteins in horticultural plants. Here, we identified a G protein, CsGPA1, from cucumber and studied its function in seedling development of cucumbers. CsGPA1 is a peptide of 392 amino acids with a predicted molecular mass of 44.6 kDa. Spatiotemporal expression analysis found that endogenous CsGPA1 was highly expressed in roots and young leaves. Immunohistochemical assay revealed that functional CsGPA1 was present in the plasma membranes of the epidermis and cortex, and in the cytosol of the endodermis, parenchyma, and vasculature of root meristematic cells. In comparison with wild-type seedlings, CsGPA1-overexpressing transgenic lines exhibited enhanced seed germination and earlier seedling development including hypocotyl elongation and root growth. In contrast, RNAi silencing of the CsGPA1 gene inhibited seedling growth and development. Further study showed that CsGPA1 controled hypocotyl elongation and root growth via promoting cell size and the meristem of hypocotyl and root tip cells of cucumber plants. Our study expands the roles of G proteins in plants and helps to elucidate the mechanism by which cucumber regulates early seedling development.

Highlights

Heterotrimeric G proteins form a family of GTP-binding proteins and function as signaling molecules that are activated after binding to GTP1
The first clade consisted of all genes, except for PsGPA1 and ZmGPA1, and showed that CsGPA1 possessed around 70% evolutionally homology with Arabidopsis, Solanum, Glycine max, Cucumis sativus, Zea mays, Oryza sativa, and other species (Fig. 1a)
We found that the CsGPA1 gene was homologous to the GPA1 gene in other plant species

Summary

Introduction

Heterotrimeric G proteins form a family of GTP-binding proteins and function as signaling molecules that are activated after binding to GTP1. The Gα subunit is an important component of the heterotrimeric G-protein complex and is associated with the Ca2+/CaM signature, regulation of monomeric GTPases, phospholipase C- and D-mediated signaling, and the relay into secondary signaling pathways, which in turn lead to changes in the activity of specific proteins[3,4]. It plays important roles in the diverse process of plant growth and development. We identified a G-protein from cucumber and investigated its function in seedling growth and development

Methods

Results

Conclusion