Identification and analysis of differentially expressed genes associated with aluminum response in two soybean cultivars by cdna-rapd

Identification of aluminum (Al) responsive genes is of great importance in illuminating the molecular mechanism of plant Al response. In this present study, we preliminarily identified several genes that possibly involved in Al-response by cDNA based random amplified polymorphic DNA (cDNA-RAPD) method from Al tolerant/sensitive soybean cultivars exposed to 0 or 50 microM Al3+ solutions for two days. Totally one hundred random primers were used to identify the differentially expressed genes; however, only two primers generated eight stable PCR products. The eight gene fragments were cloned and sequenced, then compared with NCBI gene bank. We subsequently verified the expression profiles of these eight genes by real time quantitative PCR (RT-qPCR) and found that two genes were significantly up-regulated after Al treatment for 24, 48 and 72h. One gene, encoding nucleotide-diphospho-sugar transferase which is essential for polysaccharide synthesis and another gene, encoding polygalacturonase inhibiting protein which exerts its role in terms of inhibiting polysaccharide hydrolysis, suggesting the possibility that they might cooperate in response to Al stress through the modification of cell wall components. These findings provided valuable candidate genes for further study on the molecular mechanisms in plant Al tolerance. (author)