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ARS Home » Pacific West Area » Davis, California » Crops Pathology and Genetics Research » Research » Research Project #431947

Research Project: Development of Versatile Phytophthora-Resistant Almond and Walnut Rootstocks Using Host-Induced Gene Silencing

Location: Crops Pathology and Genetics Research

Project Number: 2032-22000-016-009-R
Project Type: Reimbursable Cooperative Agreement

Start Date: Oct 1, 2016
End Date: Jun 30, 2019

Development of disease resistant walnut and almond rootstocks using host-induced gene silencing: 1)Select multiple candidate gene fragments for suppression of infection by Phytophthora. 2)Test multiple candidate gene fragments for transient gene silencing activity in plant. 3) Test stable walnut host-induced gene silencing (HIGS) lines for resistance to Phytophthora. 4) Develop and test a transformation system for stable HIGS in peach x almond hybrid rootstocks.

Several recent reports showed host-induced gene silencing (HIGS)- a plant expressing a part of a pathogen's gene that can silence corresponding gene activity in the pathogen- is able to effectively suppress infection. Although this method is significantly faster to develop resistant lines than conventional breeding, it is known that only a small fraction of genes in the genome of the pathogen, when expressed in the plant cell, confers resistance. At present, there is no efficient means for the pre-selection of effective target genes. Instead of transforming plants, we propose to use plants infected with virus that expresses pathogen's genes, a technique called virus-induced gene silencing (VIGS), for prescreening of hundreds of gene targets. The candidate genes, which confer strong resistance, will then be used to develop resistant almond and walnut HIGS lines.