Aluminium (Al) is a highly abundant metal in the earth?s crust, mostly in nontoxic forms. Its solubilization to toxic forms occurs in acid soils, a major worldwide problem. Soluble Al (mainly Al3+) shows phytotoxicity, which rapidly inhibits root elongation at the micromolar level, subsequently affecting the uptake of water and nutrients. Efflux of Al and internal Al detoxification are two mechanisms involve in response to Al toxicity. Al-induced secretion of citrate mediated by OsFRDL2 and OsFRDL4 cause chelation of Al outside of cell hence prevent Al entrance (Yokosho et al., 2016). A rapid Al-induced upregulation of OsMGT1 contributes to increased Mg concentration in the cytosol, thereby detoxifying Al (Chen et al., 2012). Al resistance transcription factor 1 (ART1) regulates genes implicated in Al tolerance (Yamaji et al., 2009). WRKY22 promotes Al?induced increases in OsFRDL4 expression, thus enhancing Al?induced citrate secretion and Al tolerance in rice (Li et al., 2018). OsART2 regulates different genes implicated in Al tolerance, indicating a supplementary pathway leading to Al tolerance in rice (Che et al., 2018). OsALS1 is responsible for internal detoxification of Al by sequestering Al into the vacuoles (Huang et al., 2011). OsCDT3 as a chelator plays a role in preventing Al into the cells (Xia et al., 2013).
