Sequence and characterization of two Arabidopsis thaliana cDNAs isolated by functional complementation of a yeast gln3 gdh1 mutant

We have isolated two Arabidopsis thaliana cDNAs by complementation of a yeast gln3 gdh1 strain that is affected in the regulation of nitrogen metabolism. The two clones (RGA1 and RGA2) are homologous to each other and to the SCARECROW (SCR) gene that is involved in regulating an asymmetric cell division in plants. RGA1, RGA2 and SCR share several structural features and may define a new family of genes. RGA1 and RGA2 have been mapped, respectively, to chromosome II and I, and their expression in plant is constitutive.