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Al-Induced, 51-Kilodalton, Membrane-Bound Proteins Are Associated with Resistance to Al in a Segregating Population of Wheat

  • Author(s) / Creator(s)
  • Incorporation of S-35 into protein is reduced by exposure to Al in wheat (Triticum aestivum), but the effects are genotype-specific. Exposure to 10 to 75 mu M Al had little effect on S-35 incorporation into total protein, nuclear and mitochondrial protein, microsomal protein, and cytosolic protein in the Al-resistant cultivar PT741. In contrast, 10 mu M Al reduced incorporation by 21 to 38% in the Al-sensitive cultivar Katepwa, with effects becoming more pronounced (31-62%) as concentrations of Al increased. We previously reported that a pair of 51-kD membrane-hound proteins accumulated in root tips of PT741 under conditions of Al stress. We now report that the 51-kD band is labeled with S-35 after 24 h of exposure to 75 mu M Al. The specific induction of the 51-kD band in PT741 suggested a potential role of one or both of these proteins in mediating resistance to Al. Therefore, we analyzed their expression in single plants from an F-2, population arising from a cross between the PT741 and Katepwa cultivars. Accumulation of 1,3-beta-glucans (callose) in root tips after 24 h of exposure to 100 mu M Al indicated that this population segregated for Al resistance in about a 3:1 ratio. A close correlation between resistance to Al (low callose content of root tips) and accumulation of the 51-kD band was observed, indicating that at least one of these proteins cosegregates with the Al-resistance phenotype. As a first step in identifying a possible function, we have demonstrated that the 51-kD band is most clearly associated with the tonoplast. Whereas Al has been reported to stimulate the activity of the tonoplast HC-ATPase and H+-PPase, antibodies raised against these proteins did not cross-react with the 51-kD band. Efforts are now under way to purify this protein from tonoplast-enriched fractions.

  • Date created
    1997
  • Subjects / Keywords
  • Type of Item
    Article (Published)
  • DOI
    https://doi.org/10.7939/R3HH6C682
  • License
    © 1997 American Society of Plant Biologists. This version of this article is open access and can be downloaded and shared. The original author(s) and source must be cited.
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  • Citation for previous publication
    • Taylor, G.J., Basu, A., Slaski, J.J. Zhang, G. & Good, A. (1997). Al-Induced, 51-Kilodalton, Membrane-Bound Proteins Are Associated with Resistance to Al in a Segregating Population of Wheat. Plant Physiology, 114(1), 363-372.