| Title |
Investigators | Department | Objectives | Approach Keywords | Progress Reports | Impact Statements | Publications | |
Project * COL00743 | |
| Title | The Functional and Evolutionary Genomics of Drought Adaptation Networks in Arabidopsis thaliana |
| Investigator(s) | McKay, JK; |
| Department | Bioagricultural Sciences and Pest Mgmt. |
| Objectives | To characterize natural genetic variation in gene expression induced by drought treatments that simulate ecologically and agriculturally relevant stress levels and patterns. To evaluate the role of constitutive versus induced gene expression in differences in drought adaptation among physiologically distinct accessions. To map expression level polymorphisms (eQTL) for candidate drought adaptation genes in existing RI mapping populations. To develop genome-wide nearly-isogenic lines (NILs) for the new Tsu x Kas mapping population. To train students, future teachers, and postdoctoral researchers in experimental and statistical aspects of quantitative genetics and evolutionary biology. |
| Approach | A. thaliana provides a unique opportunity to explore adaptive evolutionary responses to drought as (i) A. thaliana has an extensive geographical distribution and has experienced a wide-range of climatic selective regimes for thousands of generations, (ii) short-term dehydration and recovery responses in A. thaliana are often large and well documented with respect to gene expression, (iii) the molecular tools are available for the rapid localization and characterization of QTL, and (iv) abundant marker and DNA sequence data provide a framework for molecular evolutionary inference. Our study will provide a paradigm for the study of natural allelic variation by addressing the following key points: This research will determine environmental and genetic effects on constitutive and drought-induced gene expression among A. thaliana accessions that differ in drought adaptation. Contrasts of expression profiles with drought performance will benchmark gene function and provide candidate drought adaptation genes and identify mechanisms of dehydration avoidance and tolerance. We will explore the genetic basis of variation in transcript abundance for candidate drought adaptation genes. These studies will estimate: the number of loci underlying variation, the distribution and action of their allelic effects, patterns of gene-gene and gene-environment interaction, and identify novel mechanisms of constitutive and drought-induced gene expression. We will create a set of genome-wide nearly-isogenic lines for the Tsu x Kas RI mapping population. This will greatly extend the usefulness of this mapping population and will facilitate additional genome-wide physiological, genetic, and expression level studies of natural variation. We will characterize the diversity of both promoter and coding regions of candidate loci to reveal the evolutionary processes underlying drought adaptation at the molecular level. These studies will link functional variation with natural selective regimes and evolutionary processes. |
| Keywords | acclimation, adaptation, Arabidopsis thaliana, carbon isotope ratio, correlated traits, drought avoidance, drought escape, drought tolerance, quantitative trait locus, stomatal conductance, transpiration, water use efficiency |
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