Figure 7.

Anthers from MYB26myb26 heterozygotes and myb26 mutants that are expressing both NST1 and NST2 under the control of the CaMV35S promoter. A to D, Anthers isolated and stained with phloroglucinol HCl to detect lignified thickening from lines overexpressing both NST1 and NST2. A and B, High levels of native secondary thickening are seen in the endothecium (En) layer (arrows) in the MYB26myb26 heterozygote background with both NST1 and NST2 transgenes. C and D, In the myb26 mutant the anthers appear contorted with ectopic thickening in epidermal tissues (arrows shows ectopic thickening in anther epidermis [Ep] and also in the filament); normal secondary thickening is not seen in the endothecium in the myb26 background, regardless of expression of both NST1 and NST2. Scale bar represents 0.1 mm.