Results
Title

Functional characterization of a new pathogen induced xylanase inhibitor (RIXI) from rice.

Authors

Hou, Chun-Xiao; Zhan, Yi-Hua; Jiang, De-An; Weng, Xiao-Yan

Abstract

Rice xylanase inhibitor RIXI is a XIP-type inhibitor that belongs to the glycoside hydrolase family 18 (GH18), which includes plant class III chitinases (EC 3.2.1.14) known as PR-8 proteins. The aim of this study was to elucidate whether RIXI had any effect on rice endoxylanase and its role(s) in plant defence. RIXI encoding sequence was cloned from rice ( Oryza sativa cv. Nipponbare), and was expressed in Escherichia coli. The activity of recombinant RIXI was investigated - among the tested xylanases, the GH11 xylanase from Aspergillus niger was the most inhibited, while rice endogenous xylanase OSX was least inhibited. Semi-quantitative real-time polymerase chain reaction (PCR) and quantitative real-time PCR showed that the xylanase inhibitor gene RIXI was up-regulated in rice seedlings infected by Magnaporthe grisea. The increased RIXI expression was also accompanied by significantly elevated expression of pathogenesis-related protein gene ( PR-1) and class III chitinase gene ( Cht-3). This suggested that RIXI might be involved in environmental responses such as defense against phytopathogens.

Subjects

XYLANASE genetics; POLYMERASE chain reaction; PLANT defenses; RICE; CHITINASE genetics

Publication

European Journal of Plant Pathology, 2014, Vol 138, Issue 2, p405

ISSN

0929-1873

Publication type

Academic Journal

DOI

10.1007/s10658-013-0342-0