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Accueil du site → Doctorat → Israel → Candidate genes associated with drought resistance in wild emmer wheat Triticum dicoccoides and wild barley Hordeum spontaneum

Haifa University (2011)

Candidate genes associated with drought resistance in wild emmer wheat Triticum dicoccoides and wild barley Hordeum spontaneum

Krugman, Tamar

Titre : Candidate genes associated with drought resistance in wild emmer wheat Triticum dicoccoides and wild barley Hordeum spontaneum

Auteur : Krugman, Tamar

Université de soutenance : Haifa University

Objectives and experimental approach (partiel)
Drought tolerance is a complex trait as it encompasses a wide range of characteristics involving multiple genetic, physiological, cellular and biochemical strategies in the plant. Dissecting drought tolerance to the level of a single gene or group of genes amenable to genetic engineering is difficult. Therefore, a major challenge in the use of functional genomics to enhance the development of drought tolerance is to define the system and focus on key traits. The main objectives of the present study were to use functional genomics approaches to explore adaptive mechanisms that have been evolved in wild barley and wild emmer wheat to cope with drought stress, and to discover potential candidate genes that may be involved in drought resistance responses. The approach applied in the current study relies primarily on the hypothesis that genes that are differentially regulated in response to drought may be further regarded as potential sources for drought resistance candidates. Therefore, the implementation of this approach required first to apply a thoughtful selection of wild barley and wild wheat ecotypes with differences in their drought resistance that will be used for comparison of gene expression in response to drought stress (from "Phenotype to Genotype Approach"). Our working hypothesis was that such a comparison of gene expression will enable us to identify candidate genes that are related to drought resistance and not only to the response to drought stress per-se. Furthermore, a wide range of experimental approaches were applied, extending from exploration of the expression pattern of a single gene family, associated with drought stress (e.g., Dehydrin genes), to whole genome transcriptome and metabolome analyses. Various plant tissues and developmental stages were studied, from young leaves and roots at the seedling stage to flag leaves at terminal drought applied during anthesis and grain filling period. Following are the specific objectives of the current study and the experimental approaches used to achieve each of the goals : 1. Characterization of gene expression patterns of the dehydrin gene family in wild barley genotypes contrasting in their response to drought stress. The dehydrins belong to a known drought responsive family. The goal of this study was to use expression analyses in order to identify association between specific members of the dehydrin gene family and resistance to drought. 2. Identification of novel candidate genes for drought resistance in wild barley using cDNA-AFLP technology. This technology can be used to screen for differences in gene expression of thousands of genes. The aim of the study was to use cDNA-AFLP to identify unique genes associated with drought resistance within wild barley gene pool. 3. Identification of adaptive complexes of genes associated with drought resistance mechanisms in wild emmer wheat by transcriptome analysis. Whole genome analysis was based on Affymetrix wheat Gene Chip microarray technology that enabled us to compare the expression profiling of 55,052 transcripts, simultaneously. Therefore, our goal was to use this advanced microarray technology for the discovery of novel candidate genes for drought resistance within the gene pool of wild emmer wheat

Grade : Doctor of Philosophy (PhD) 2011

Mots Clés : Gene mapping. — Genetic engineering. — Wheat — Biotechnology

Présentation

Page publiée le 11 janvier 2012, mise à jour le 24 novembre 2018