Grape Phylloxera (Daktulosphaira vitifoliae Fitch) Effectors for Root Gall Induction
Abstract
Abstract Since grape phylloxera (Daktulosphaira vitifoliae; Phylloxeridae) has been introduced into Europe in the second half of the 19th cenutry, it became the most threatening pest for worldwide viticulture. The root form of the monophagous insect initiates the development of root galls (nodosities) on susceptible or partial resistant Vitis spp. It harms the host plant by consuming assimilates, interrupting water and mineral uptake, manipulation of the sink source allocation and creating entrances for secondary infections. Grafting scions onto resistant rootstocks of American Vitis spp. and their hybrids were the main cultural management technique to fight this parasite for more than 150 years. Because of the development of aggressive phylloxera strains establishing larger populations in European vineyards and the effects of biotic and abiotic stresses (in the cause of global warming) multiplied through phylloxerated root tips, phylloxera-based damages in vineyards are increasing. The knowledge on the phylloxera-grapevine interaction is still scarce and covers the plant-based responses only since no resistant rootstocks are available to date. All rootstock are partially resistant and specific effectors, secreted by the parasite, are required to establish a compatible Phylloxera-Vitis interaction. Knowledge about these effectors allows the identification of plant defense pathways required for the induction of solid resistance against phylloxera in grapevine. This study aims to identify and define effector molecules of phylloxera-Vitis interactions, which affect the aggressivity of the parasites. Additionally basic knowledge on gall induction and formation as well as influences of effectors on signaling pathways will be gained on a molecular and cellular basis. Within the project we plan to identify up regulated transcripts in the insects by RNA extraction combined with novel RNAseq technology. Up regulation of transcripts are confirmed using qRT-PCR techniques. Additionally we want to identify and characterize proteins extracted from phylloxera individuals of two strains with differing aggressivity AT1 and DE1 as well as parasitic proteins localized in the host feeding tissues of three Vitis plants (Rootstock Teleki (V. berlandieri x V. riparia) 5C, Rootstock Fercal (B.C. n°1B × Richter 31) and Vitis vinifera L. cv. Riesling), using GE- LC-MS/MS and LC-MS/MS techniques. Using bioinformatic approaches candidate effectors are selected out of proteomic and transcriptomic results. Regulatory influences of the candidate effectors are confirmed by testing the host plant response of Vitis cell cultures. Expression levels of effector-treated and non-treated cells are compared using qRT-PCR technique.
Publikationen
Project staff
Astrid Forneck
Univ.Prof. Dipl.-Ing.sc.agr. Dr.sc.agr. Astrid Forneck
astrid.forneck@boku.ac.at
Tel: +43 1 47654-95811
Project Leader
01.05.2016 - 31.07.2018