Identification of <i>CkSNAP33</i>, a gene encoding synaptosomal-associated protein from <i>Cynanchum komarovii</i>, that enhances Arabidopsis resistance to <i>Verticillium dahliae</i>
<div><p>SNARE proteins are essential to vesicle trafficking and membrane fusion in eukaryotic cells. In addition, the SNARE-mediated secretory pathway can deliver diverse defense products to infection sites during exocytosis-associated immune responses in plants. In this study, a novel gene (<i>CkSNAP33</i>) encoding a synaptosomal-associated protein was isolated from <i>Cynanchum komarovii</i> and characterized. CkSNAP33 contains Qb- and Qc-SNARE domains in the N- and C-terminal regions, respectively, and shares high sequence identity with AtSNAP33 from <i>Arabidopsis</i>. <i>CkSNAP33</i> expression was induced by H<sub>2</sub>O<sub>2</sub>, salicylic acid (SA), <i>Verticillium dahliae</i>, and wounding. Arabidopsis lines overexpressing CkSNAP33 had longer primary roots and larger seedlings than the wild type (WT). Transgenic Arabidopsis lines showed significantly enhanced resistance to <i>V</i>. <i>dahliae</i>, and displayed reductions in disease index and fungal biomass, and also showed elevated expression of <i>PR1</i> and <i>PR5</i>. The leaves of transgenic plants infected with <i>V</i>. <i>dahliae</i> showed strong callose deposition and cell death that hindered the penetration and spread of the fungus at the infection site. Taken together, these results suggest that <i>CkSNAP33</i> is involved in the defense response against <i>V</i>. <i>dahliae</i> and enhanced disease resistance in Arabidopsis.</p></div
