Auxin production in diploid microsporocytes is necessary and sufficient for early stages of pollen development
Fig 5
Localized auxin production in tapetum did not rescue the pollen defects in yuc2yuc6 mutants.
(A) The green color indicates the expression pattern of the A9 promoter. Msp, Microsporocytes; Mp, microspores; Bc, Bicellular pollen; Tc, Tricellular pollen. The A9 promoter cloned from Arabidopsis is used to drive YUC2-GFP expression specifically in tapetum cells from stages 6 to 9 [61, 62]. (B) Morphology of adult shoots (Bars = 2cm). (C) Alexander staining (Bars = 100 μm) and DAPI staining (Bars = 10 μm) of ProA9:YUC2-GFP (yuc2yuc6) anthers and pollens. Note that the sterility phenotype and pollen defects were not rescued in ProA9:YUC2-GFP (yuc2yuc6) transgenic plants. TS, Tricellular Stage; BS, Bicellular Stage; US; Unicellular Stage. (D) In situ hybridization of GFP in ProA9:YUC2-GFP (yuc2yuc6) transgenic plants (Bars = 20 μm). (E) Fluorescence images (Bars = 100 μm) of the YUC2-GFP fusion protein in anthers from yuc2yuc6 transformed with ProA9:YUC2-GFP. In ProA9: YUC2-GFP anther, GFP is significantly expressed in tapetum cell of microsporocyte stage and early microspore stage.