Al-induced, 51-kilodalton, membrane-bound proteins are associated with resistance to Al in a segregating population of wheat

• Published in: Plant physiology (Bethesda) 1997-05, Vol.114 (1), p.363-372
• Main Authors: Taylor, G.J. (University of Alberta, Edmonton, Alberta, Canada.), Basu, A, Basu, U, Slaski, J.J, Zhang, G, Good, A
• Format: Article
• Language: English
• Subjects: Adenosine triphosphatases; Agronomy. Soil science and plant productions; ALUMINIO; ALUMINIUM; Aluminum; ANALISIS CUANTITATIVO; ANALYSE QUANTITATIVE; AZUFRE; Biological and medical sciences; CALLOSE; CELL MEMBRANES; CELL STRUCTURE; CHEMICAL COMPOSITION; CITOPLASMA; COMPOSICION QUIMICA; COMPOSITION CHIMIQUE; CULTIVARS; CYTOPLASM; CYTOPLASME; CYTOPLASMIC ORGANELLES; CYTOSOL; DOSAGE EFFECTS; Economic plant physiology; ESTRUCTURA CELULAR; FITOTOXICIDAD; Fundamental and applied biological sciences. Psychology; GENETIC VARIATION; GENOTIPOS; GENOTYPE; GENOTYPES; Intracellular membranes; ISOTOPE RADIOACTIF; MEMBRANAS CELULARES; MEMBRANE CELLULAIRE; MICROSOMES; Mineral nutrition; MITOCHONDRIA; MITOCHONDRIE; MITOCONDRIA; Nutrition. Photosynthesis. Respiration. Metabolism; ORGANITE CELLULAIRE; ORGANULOS CITOPLASMICOS; PHYTOTOXICITE; PHYTOTOXICITY; Plant physiology and development; Plant roots; Plants; PLASMA MEMBRANES; POLISACARIDOS; POLYHOLOSIDE; POLYSACCHARIDES; PROTEIN SYNTHESIS; PROTEINAS; PROTEINE; PROTEINS; PURIFICACION; PURIFICATION; QUANTITATIVE ANALYSIS; RADIOACTIVE TRACERS; RADIOISOTOPES; RADIOISOTOPOS; Root tips; Seedlings; Segregation; SINTESIS DE PROTEINAS; SOUFRE; STRESS RESPONSE; STRUCTURE CELLULAIRE; SULPHUR; SYNTHESE PROTEIQUE; TONOPLAST; TRITICUM AESTIVUM; VARIACION GENETICA; VARIATION GENETIQUE; VARIEDADES; VARIETE; VARIETIES; Water and solutes. Absorption, translocation and permeability; Whole Plant, Environmental, and Stress Physiology
• ISSN: 0032-0889; 1532-2548
• DOI: 10.1104/pp.114.1.363

Incorporation of 35S into protein is reduced by exposure to Al in wheat (Triticum aestivum), but the effects are genotype-specific. Exposure to 10 to 75 micromolars Al had little effect on 35S incorporation into total protein, nuclear and mitochondrial protein, microsomal protein, and cytosolic protein in the Al-resistant cultivar PT741. In contrast, 10 micromolars 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-bound proteins accumulated in root tips of PT741 under conditions of Al stress. We now report that the 51-kD band is labeled with 35S after 24 h of exposure to 75 micromolars 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 F2 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 micromolars 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 H+-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