HvAACT1 increases Al3+-tolerance in wheat and barley

Al³⁺-activated release of citrate from the root apices of aluminium-tolerant genotypes of barley is controlled by a MATE gene named HvAACT1 that encodes a citrate transporter. Zhou et al. over-express HvAACT1 in wheat (Triticum aestivum) and barley (Hordeum vulgare) using the maize ubiquitin promoter, and find that increased expression in both species is associated with increased citrate efflux from root apices, and that this enhances Al³⁺ tolerance in both hydroponic solution and in acid soil. Genetically modifying barley and wheat to express the barley gene HvAACT1 gene therefore has potential in helping to alleviate the effects of aluminium toxicity in acid soils.