Expression of Vitis amurensis VaERF20 in Arabidopsis thaliana Improves Resistance to Botrytis cinerea and Pseudomonas syringae pv. Tomato DC3000

Abstract

Ethylene response factor (ERF) transcription factors play important roles in regulating immune responses in plants. In our study, we characterized a member of the ERF transcription factor family, <i>VaERF20</i>, from the Chinese wild <i>Vitis</i> genotype, <i>V. amurensis</i> Rupr "Shuangyou". Phylogenetic analysis indicated that <i>VaERF20</i> belongs to group IXc of the ERF family, in which many members are known to contribute to fighting pathogen infection. Consistent with this, expression of <i>VaERF20</i> was induced by treatment with the necrotrophic fungal pathogen <i>Botrytis cinerea (B. cinerea</i>) in "Shuangyou" and <i>V. vinifera</i> "Red Globe". <i>Arabidopsis thaliana</i> plants over-expressing <i>VaERF20</i> displayed enhanced resistance to <i>B. cinerea</i> and the bacterium <i>Pseudomonas syringae</i> pv. tomato (<i>Pst</i>) DC3000. Patterns of pathogen-induced reactive oxygen species (ROS) accumulation were entirely distinct in <i>B. cinerea</i> and <i>Pst</i>DC3000 inoculated plants. Examples of both salicylic acid (SA) and jasmonic acid/ethylene (JA/ET) responsive defense genes were up-regulated after <i>B. cinerea</i> and <i>Pst</i>DC3000 inoculation of the <i>VaERF20</i>-overexpressing transgenic <i>A. thaliana</i> plants. Evidence of pattern-triggered immunity (PTI), callose accumulation and stomatal defense, together with increased expression of PTI genes, was also greater in the transgenic lines. These data indicate that <i>VaERF20</i> participates in various signal transduction pathways and acts as an inducer of immune responses.