Aluminum stress and protein synthesis in near isogenic lines of Triticum aestivum differing in aluminum tolerance

To further understand the genetics and physiology of Al stress, a pair of near isogenic lines of wheat (Triticum aestivum L. em Thell.) and several sister lines differing in Al tolerance were examined for root growth and levels of protein synthesis following Al stress in a hydroponic system. The Al-sensitive recurrent parent (Katepwa) showed marginal root elongation in low Al concentrations. In contrast, the Al-tolerant near isogenic line (Alikat) and Al-tolerant donor (Maringa) had much greater root elongation. All of the genotypes tested showed an increase (approximately 2 fold) in the level of protein synthesis after 3 d in Al, based on incorporation of L-[35S]-Met. This increase in protein synthesis occurred at lower Al concentrations in Katepwa than in Alikat and Maringa and was directed entirely toward the microsomal fraction of the cell. The redistribution of L-[35S]-Met labeled proteins between the cytoplasmic and microsomal fraction was directly correlated (r=0.75) to Al tolerance and root elongation.