Abstract
Conjugation of phytohormones with glucose is a means of modulating their activities, which can be rapidly reversed by the action of β-glucosidases. Evaluation of previously characterized recombinant rice β-glucosidases found that nearly all could hydrolyze abscisic acid glucose ester (ABA-GE). Os4BGlu12 and Os4BGlu13, which are known to act on other phytohormones, had the highest activity. We expressed Os4BGlu12, Os4BGlu13 and other members of a highly similar rice chromosome 4 gene cluster (Os4BGlu9, Os4BGlu10 and Os4BGlu11) in transgenic Arabidopsis. Extracts of transgenic lines expressing each of the five genes had higher β-glucosidase activities on ABA-GE and gibberellin A4 glucose ester (GA4-GE). The β-glucosidase expression lines exhibited longer root and shoot lengths than control plants in response to salt and drought stress. Fusions of each of these proteins with green fluorescent protein localized near the plasma membrane and in the apoplast in tobacco leaf epithelial cells. The action of these extracellular β-glucosidases on multiple phytohormones suggests they may modulate the interactions between these phytohormones.
Highlights
Introduction βGlucosidases (EC. 3.2.1.21, β-D-glucopyranosidases) are enzymes that hydrolyze glycosidic linkages to release glucose from the non-reducing termini of oligosaccharides and aryl and alkyl glucosides [1]. β-Glucosidases have been found in wide range of living organisms, from bacteria and archaea to multicellular eukaryotes, including mammals and plants
glycoside hydrolase family 1 (GH1) enzymes recombinantly expressed in Escherichia coli for Abscisic acid (ABA)-gibberellin A4 glucose ester (GE) hydrolysis. Most of these enzymes hydrolyze abscisic acid glucose ester (ABA-GE), we found that Os4BGlu12 and Os4BGlu13 hydrolyzed ABA-GE better than the other rice β-glucosidases tested
Generation of Transgenic Arabidopsis Plants Expressing Rice β-Glucosidases were transformed into Arabidopsis thaliana Col-0 and selected to obtain homozygous transThe pH7FWG2 lines expression vectors containing the Os4BGlu9, genic
Summary
To identify which enzymes may hydrolyze ABA-GE, several GH1 β-glucosidases ex2.1. Rice Os4BGlu, Os4BGlu, Os4BGlu, Os3BGlu, Os7BGlu, Os9BGlu and ABA-GE, barley βII several showedGH1 activity with ABATo identify which enzymes may hydrolyze β-glucosidases expressed inin. Been shown Os7BGlu, to hydrolyze other phytohormone [19,20,21,22], GE, albeit low in some cases, as shown in. Os4BGlu, which showed the highest hydrolysis activity with ABA-GE. 4, suggesting a repetitive gene duplication tempts to express Os4BGlu, Os4BGlu and Os4BGlu in E. coli failed to produce active (Figure 1). Express Os4BGlu, Os4BGlu and Os4BGlu in E. coli failed to produce active enzymes (data not shown), so their activities could not be explored in the same manner
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
