Dear Editor,Oxalic acid,the simplest of all dicarboxylic acids,is widely found in all plant species (Franceschi and Nakata,2005).Two pathways exist for oxalate degradation in plants:degradation via oxalate oxidase and ATP-and CoA-dependent decarboxylation of oxalate through a poorly studied series of enzymatic reactions (Giovanelli and Tobin,1961).Oxalyl-CoA synthetase,the enzyme that initiates the second degradation pathway was recently identified in Arabidopsis thaliana as a protein encoded by ACYL-ACTIVATING ENZYME3 (AAE3).It was shown that AAE3-dependent degradation of oxalate is important for normal seed development and for defense against oxalate-producing fungal pathogens in Arabidopsis (Foster et al.,2012).In addition,it was shown recently that AAE3 also plays a role in seed development in maize and rice (Wang et al.,2011).