Submitted to: International Symposium on Phosphorus Dynamics in the Soil Plant Continuum
Publication Type: Abstract Only
Publication Acceptance Date: 6/18/2003
Publication Date: N/A
Citation: N/A Interpretive Summary:
Technical Abstract: When grown under low P, white lupin develops proteoid roots: short, lateral, densely clustered rootlets adapted to improve P acquisition. We previously reported the identification of 35 ESTs (expressed sequence tags) differentially expressed in -P proteoid roots, compared to +P and -P normal roots. Here we present the characterization of a gene with strikingly enhanced expression in proteoid roots subjected to P deficiency, nitrogen deficiency, or aluminum toxicity. The deduced amino acid sequence displays homology to MATE (multi drug and toxin extrusion) family proteins from Arabidopsis. Preliminary results of protein immunoblot analysis indicate that the corresponding protein is most abundant in proteoid root membrane fractions. The MATE promoter has been fused to a GUS reporter gene, and we are currently pursuing the analysis of MATE promoter::GUS fusion activity in transgenic alfalfa and Arabidopsis. For functional analysis, the white lupin MATE gene has been expressed in Saccharomyces cerevisiae and is currently being analyzed.