MacGregor, Dana , Deak, Karen , Brannon, Paul , Jung, Jee , Malamy, Jocelyn .
A role for fatty acid metabolism in regulating lateral root development in response to environmental conditions.
Environmental conditions exert a profound effect on root system architecture. In Arabidopsis thaliana ecotype Columbia, the formation of lateral roots from lateral root primordia is repressed or significantly delayed under conditions of mild water stress. Using this repressed phenotype, we screened for mutants with aberrant root architectures and isolated Lateral Root Development mutants from a population of 10,000 EMS mutagenized seeds. One of these mutants, lrd2, exhibits a dramatic increase in its total lateral root length (TOT) both on water stress and water plentiful conditions. Moreover, the root systems of lrd2 plants are significantly less affected by the water stress conditions compared with wild type. Further characterization has shown the increase in TOT is due to an increased initiation of lateral root primordia and a significantly higher percent of primordia that develop into lateral roots compared to wild type. To identify the causative gene, we used a map-based cloning approach and sequenced the genes in the identified region. Several genes therein contained missense mutations, including the gene encoding for the long-chain acyl-CoA synthetase LACS2. In support of the hypothesis that the identified mutation in LACS2 causes the lrd phenotype, we have shown that additional alleles of LACS2, including one previously characterized as RNA null (Schnurr et al., 2004), also exhibit the increased lateral root phenotype on our conditions. Our progress in proving causation and defining the function of LACS2 in the regulation of lateral root development will be reported. The identification of LRD2 as LACS2 reveals a role for fatty acid metabolism in the regulation of root system architecture in response to environmental conditions.
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Malamy Lab Website
1 - University of Chicago, Molecular Genetics & Cellular Biology, 1103 E. 57th St., EBC 209 - Malamy, Chicago, IL, 60637, USA
2 - University of Chicago, Committee on Genetics
3 - University of Chicago, Molecular Genetics & Cellular Biology
Presentation Type: Plant Biology Abstract
Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton
Date: Sunday, July 8th, 2007
Time: 8:00 AM