Genetic composition and phenotype of nas4x-1 mutant plants. A, Location of T-DNA insertions in nas alleles: nas1-1 (GABI_223A09), nas2-1 (SAIL_156C08), nas2-2 (SALK_066962), nas3-1 (GABI_010A10), and nas4-1 (SALK_135507). Arrows indicate the positions of primers used for genotyping by PCR. B, Morphological appearance of plants on soil; from left to right, Col-0 (wild type), nas4x-1 (vegetative stage), nas4x-1 (reproductive stage). C, Transmission light microscopic images of wild-type and nas4x-1 rosette leaves. Note that nas4x-1 rosette leaf veins are darker green than the intercostal leaf areas. D, Morphological appearance of nas4x-2 (vegetative stage).