Expression of Anti-microbial Genes in Transgenic Grapevines for Enhanced Disease Resistance

Grapevines are susceptible to numerous diseases harming both plants and profits. Transgenic grapevines that resist disease would provide better disease control as well as economic benefits from the reduction in spray applications. Our overall goal has been to research and develop methods to create transgenic selections of elite cultivars with improved resistance to diseases. The transgenic strategy is especially appropriate for clonally-propagated crops, such as grapevines, where the wine industry is rooted in traditional European grapes with strong name recognition and very high disease susceptibility. During the past year, we screened six different antimicrobial peptides, which are small proteins known to be inhibitory to a range of bacteria and fungi, to determine which might best provide resistance to bunch rot (Botrytis) and crown gall (Agrobacterium vitis). These same peptides are also being tested for their effects on germinationof powdery mildew conidia. Based on the incoming results from peptide screening, development of new gene constructs is underway. These constructs will be inserted into Chardonnay and the resulting vines will be tested for improvements in disease resistance.