Figure 7.

Phenotypes of nas mutants to Ni treatment. A, Growth assay showing 17-d-old seedlings grown on 60 μm Ni and control Hoagland agar medium. Note the short root phenotypes of Ni-treated plants and the severe white-yellow leaf chlorosis phenotype of nas4x-1 mutants compared with the wild type on Ni. B, Distribution of leaf chlorosis phenotypes among multiple nas mutant lines grown for 17 d on 60 μm Ni and control Hoagland agar medium (n = 10–35). Three leaf phenotypic classes were defined: light green leaf appearance of mildly affected plants, intermediate intercostal leaf chlorosis of Ni-sensitive plants, and the most severe white-yellow leaf chlorosis of severely Ni-affected plants. The number of plants belonging to each phenotypic class was calculated in percentage. [See online article for color version of this figure.]