铝毒是限制酸性土壤作物生产的主要因子之一。铝诱导植物根系分泌有机酸（柠檬酸、苹果酸和草酸）是较普遍和重要的耐铝机制。目前关于铝诱导柠檬酸和苹果酸分泌到根际的基因已在一些物种中被克隆，而诱导草酸分泌的基因还未在任何物种中被报道。此外，由于铝进入根细胞内的不可避免性，将铝从木质部转运到地上部而在叶片解铝毒的重要性也值得关注。本项目以铝诱导荞麦根系分泌草酸到根际和分泌柠檬酸到木质部为前提，结合转录组和蛋白质组分析，挖掘调控铝诱导荞麦根尖有机酸分泌的关键基因；通过启动子分析和酵母单杂交筛选，明确关键基因的转录表达调控机制；通过转基因功能验证，探索通过改造上游信号途径使植物更好适应酸性土壤的可能性。本项目首次系统的开展铝诱导荞麦有机酸分泌的分子机制，可望对植物耐铝机制作出更新和更全面的阐述，为研究铝胁迫信号转导途径、耐铝基因遗传转化、以及通过生物工程手段提高作物耐铝性提供了科学依据。

Aluminum (Al) toxicity represents one of the major limiting constraints to plant growth and development on acidic soils. Al-induced organic acids secretion (mainly citric acid, malic acid, and oxalic acid) is a widely adopted and very important mechanism by which plants deal with Al toxicity. To date, the genes responsible for Al-induced citric acid secretion and malic acid secretion have been isolated in a number of plant species. However, the gene related to Al-induced oxalic acid secretion has not been identified in any species. In addition, it seems that the entrance of Al into root cell symplast is unavoidable even to those plant species that resist Al toxicity mainly by means of exclusion mechanisms. Thus, it is worth to note regarding how to improve the translocation efficiency of Al from root to shoot, and as a consequence, detoxify Al within leaf vacuoles. It has been demonstrated that roots of buckwheat secret oxalic acid into rhizosphere and citrate into xylem when suffering from Al stress. Based on these findings, in this project, we aim to identify the key genes involved in Al-induced oxalic acid secretion and citric acid secretion through comparative analysis of transcriptomic and proteomic responses of buckwheat root apex to Al stress. By means of promoter cloning and analysis, as well as yeast-one-hybrid screening, we try to clarify the transcriptional regulation of these genes. Transgenic approaches will help us to explore whether high and efficient Al resistance plants could be constructed through modification of upstream signal transduction pathways. For the first time, this project will investigate the molecular mechanism of Al-induced organic acids secretion from buckwheat roots, and will further our understanding of Al tolerance mechanism in higher plants. Furthermore, the achievements of this project will also provide scientific guidance for the fields concerning signal transduction of Al stress, evolution of Al tolerance genes, and improvement of Al tolerance through biotechnology.