Wheat TaNPSN SNARE homologues are involved in vesicle-mediated resistance to stripe rust (Puccinia striiformis f. sp. tritici).

Xiaodong Wang,Jorge Dubcovsky,Haitao Chang,Xiaojie Wang,Qingmei Han,Lili Huang,Lin Deng,Hao Feng,Zhensheng Kang

doi:10.1093/jxb/eru241

Abstract

Subcellular localisation of SNAREs (soluble N-ethylmaleimide-sensitive factor attachment protein receptors) and their ability to form SNARE complexes are critical for determining the specificity of vesicle fusion. NPSN11, a Novel Plant SNARE (NPSN) gene, has been reported to be involved in the delivery of cell wall precursors to the newly formed cell plate during cytokinesis. However, functions of NPSN genes in plant–pathogen interactions are largely unknown. In this study, we cloned and characterized three NPSN genes (TaNPSN11, TaNPSN12, and TaNPSN13) and three plant defence-related SNARE homologues (TaSYP132, TaSNAP34, and TaMEMB12). TaSYP132 showed a highly specific interaction with TaNPSN11 in both yeast two-hybrid and bimolecular fluorescence complementation (BiFC) assays. We hypothesize that this interaction may indicate a partnership in vesicle trafficking. Expressions of the three TaNPSNs and TaSYP132 were differentially induced in wheat leaves when challenged by Puccinia striiformis f. sp. tritici (Pst). In virus-induced gene silencing (VIGS) assays, resistance of wheat (Triticum aestivum) cultivar Xingzi9104 to the Pst avirulent race CYR23 was reduced by knocking down TaNPSN11, TaNPSN13 and TaSYP132, but not TaNPSN12, implying diversified functions of these wheat SNARE homologues in prevention of Pst infection and hyphal elongation. Immuno-localization results showed that TaNPSN11 or its structural homologues were mainly distributed in vesicle structures near cell membrane toward Pst hypha. Taken together, our data suggests a role of TaNPSN11 in vesicle-mediated resistance to stripe rust.

Highlights

SNAREs are key components in vesicle trafficking in eukaryotic cells (Heese et al, 2001; Wick et al, 2003)
Recent study shows that SEC11 from Arabidopsis modulates PEN1dependent vesicle traffic by dynamically competing for PEN1 binding with VAMP721 and SNAP33 (Karnik et al, 2013)
Six wheat SNARE homologues with complete ORFs were cloned from cDNA of wheat cultivar Xingzi9104, and designated as TaNPSN11, TaNPSN12, TaNPSN13, TaSYP132, TaSNAP34, and TaMEMB12 (GenBank accession numbers JX104547, JX104548, JX104549, JX104550, JX104551, and JX104552)

Summary

Introduction

SNAREs (soluble N-ethylmaleimide-sensitive factor attachment protein receptors) are key components in vesicle trafficking in eukaryotic cells (Heese et al, 2001; Wick et al, 2003). One helix of the SNARE bundle is formed by one vesicle membrane-anchored SNARE (v-SNARE) and three target membrane-anchored SNAREs (t-SNAREs) through their R-, Qa-, Qb- and Qc-SNARE domains (Antonin et al, 2000; Fukuda et al, 2000). Tobacco (Nicotiana tabacum) NbSYP132 has been implicated in plant resistance against bacterial pathogen by mediating the secretion of pathogenesis-related protein 1 (Kalde et al, 2007). Another Golgi SNARE AtMEMB12 was targeted by miR393b* and involved in the accumulation of PR1 (Zhang et al, 2011). By interacting with potyviral 6K2 integral membrane protein, the Arabidopsis SNARE protein Syp is an essential host factor for successful Turnip mosaic potyvirus infection (Wei et al, 2013)

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