Fig. 7. Cells defective in cru1 fail to grow inside the plant. (A) Disease symptoms on the leaf blades of young maize plants 14 days post inoculation with the strains are indicated. Wild-type infection produced the characteristic symptoms of disease (antocyanin streaking and tumor production); however, cru1 cell infections do not induce symptoms further to chlorosis. Notice the chlorotic area near the infection point (arrow). (B) Clorazole Black E staining of symptomatic leafs after 1 week of inoculation. Notice the proliferation of wild-type cells and the absence of such growth in mutant cells. Bars, 15 µm.