LingWang, JingyiXue, JingYan, MengLiu, YujingTang, YuejinWang, ChaohongZhang.Expression and functional analysis of VviABCG14 from Vitis vinifera suggest the role in cytokinin transport and the interaction with VviABCG7

Expression and functional analysis of VviABCG14 from Vitis vinifera suggest the role in cytokinin transport and the interaction with VviABCG7

LingWang, JingyiXue, JingYan, MengLiu, YujingTang, YuejinWang, ChaohongZhang

Plant Physiology and Biochemistry

DOI: 10.1016/j.plaphy.2020.05.011

Abstract

Cytokinins are important hormones involved in many aspects of plant growth and development. However, there remain many knowledge gaps with regard to their metabolism and transport mechanisms. Here, we characterise a half-size ATP binding cassette G (ABCG) transporter gene, also called white-brown complex transporter, VviABCG14, from grapevine (Vitis vinifera L. cv. Pinot noir). Quantitative real-time PCR analysis shows the expression of VviABCG14 gene is significantly increased after grape berries are treated with exogenous N-(2-chloro-4-pyridyl)-N′-phenylurea (CPPU) and trans-zeatin (tZ). Significant differences in phenotype were observed between overexpressing VviABCG14 transgenic and wild-type Arabidopsis lines grown for 12 days. The fresh weight of transgenic Arabidopsis was greater than of wild-type plants, and root lengths were greater. After growing in soil for 26 days, the vegetative growth of transgenic lines significantly greater than the wild-type and the bolting rate was lower. Hormone content analysis indicates the levels of tZ in the shoots of overexpressing transgenes are higher than in wild-types. Using the split-ubiquitin yeast membrane system and bimolecular fluorescence complementation assay we show VviABCG14 and VviABCG7 transporter can form a heterodimer. Meanwhile, VviABCG7 is also significantly induced by exogenous CPPU and tZ in grape berries. Altogether, our results suggest VviABCG14 may affect the phenotype of Arabidopsis by transporting cytokinins and VviABCG14 interacts with VviABCG7 to form a heterodimer.