Project number		Stand-alone Projects  P21203
Title		Compatible Phylloxera - Grape interaction
Principal investigator		FORNECK Astrid
Approval date		06.10.2008
University / Research institution		Department für Angewandte Pflanzenwissenschaften und Pflanzenbiotechnologie Institut für Garten-, Obst- und Weinbau (IGOW), Universität für Bodenkultur Wien
Scientific field(s)
Keywords		Phylloxera, Grape, Root gals, Starch accummulation, Sugar transport
Homepage		http://www.dapp.boku.ac.at

In the second part of the 18^th century a small aphid, the grapevine louse (Daktulosphaira vitifoliae FITCH) Grape Phylloxera, was introduced to Europe with devastating effects on indogenous European Grapevine cultivars and enormous economic losses. The root system of susceptible cultivars is severely damaged by the formation of gall tissues, called nodosities and tuberosities. Scientists and agronomists have circumvented the problem by grafting V. vinifera cultivars on tolerant rootstocks gained from North American Vitis species. This strategy has been working well for over 100 years, but recently reports show that this tolerance is endangered by appearance of aggressive Phylloxera biotypes. Therefore the need to understand the Phylloxera - plant interaction has dramatically increased. In this proposal we will focus on the processes taking place in grape roots upon Phylloxera feeding with a special interest on nodosity development and on the nutrient supply of the aphid. We will analyse the sugar and starch metabolism of nodosities from two angles: the genes involved in sugar and starch metabolism and their transport mechanisms in developing nodosities. The transcriptional changes in root galls, especially concerning genes involved in sugar and starch metabolism, will be analysed with GeneChip and qPCR analyses. Transport mechanisms of sugars to feeding and storage cells of nodosities will be determined with microscopical, histochemical and molecular biological means. The results will give new insights into Phylloxera - grape interaction, a still not well understood plant - pathogen system, and will provide essential knowledge for the identification of crucial physiological processes for the development of new strategies to fight aggressive Phylloxera biotypes.