Abstract
Acacia mangium, a leguminous tree, shows tolerance to aluminum (Al) and can vigorously grow in acid soils in wild conditions. Previously (at the 50th annual meeting), we detected low-pH responsible genes using differential display reverse transcription PCR (DDRT-PCR) analysis and semi-quantitative PT-PCR analysis in cell suspensions of A. mangium that were induced from hypocotyls. Full-length cDNA cloning of those low-pH responsible genes are now in progress.
In addition to proton (H+) toxicity, Al stress is the most significant factor that limits plant growth in acid soils. So the effects of Al on cell growth of A. mangium and gene expression patterns of the low-pH responsible genes under Al stress were examined. Our results indicated that several genes showed differential expression patterns between low-pH stress and Al stress.
Furthermore, degenerate PCR approaches using primers designed from known Al tolerance rerated genes such as aluminum activated malate transporter (ALMT) and aluminum activated citrate transporter (AACT) allowed us to detect the homologous genes of A. mangium. We also report the results of expression analysis of these genes.
