RESEARCH ARTICLE Genome-wide transcriptom lu n p

Full list of author information is available at the end of the articleAluminum (Al) toxicity is a major limiting factor for crop production on acid soils, which make up over 30% of the world’s arable soils and up to 70 % of the potential arable land [1]. On acidic soils with pH below 5.5, phytotoxic forms of Al (mainly Al3+) are solubilized into the soil solution, which inhibit root growth and there-after limit water and mineral nutrient uptake, resulting ments, some plant species have evolved resistance me-chanisms that enable them to tolerate toxic levels of Al. Al-activated organic acid release from roots is a well-documented mechanism of Al detoxification [3,4]. Organic acids such as malate, citrate and oxalate are able to chelate Al and thereby attenuate Al toxicity. Different plants secrete different organic acids to detoxify Al. For example, wheat (Triticum aestivum), oilseed rape (Brassica napus) and Arabidopsis thaliana secrete malate after exposure to Al stress [5-7], while Al-tolerant cultivars of snapbean (Phaseolus vulgaris), rice bean (Vigna um