Fig. 2
Impact of ANN5 expression on mature pollen grain size. (a) Scanning electron micrographs of the pollen grains from wild-type Arabidopsis (Col-0), ANN5-RNAi_15, ANN5-RNAi_13, and ANN5-OE_2. Scale bars = 10 μm. (b) Relative expression of ANN5 in mature pollen grains of wild-type Arabidopsis (Col-0), ANN5-RNAi_15, ANN5-RNAi_13, and ANN5-OE_2. Values above each column are expressed as percentage of the ANN5 expression in comparison to the wild-type (100%). (c) Mean length of mature pollen grains from wild-type Arabidopsis (Col-0), ANN5-RNAi_15, ANN5-RNAi_13, and ANN5-OE_2. n = 50. Asterisks indicate significant difference compared with values for wild-type pollen (one-way ANOVA, Dunnett post hoc test, *p < 0.05; **p < 0.01; ***p < 0.001). Bars represent SD. (d) and (e) Ultrastructure of viable and collapsing pollen grains from Arabidopsis genotypes with altered ANN5 expression. (d) Transmission electron micrographs showing ultrastructural details of viable mature pollen grains, whereas (e) depicts aborted pollen grains isolated during anthesis from wild-type Arabidopsis Col-0, ANN5-RNAi_15, ANN5-RNAi_13, and ANN5-OE_2. See also Additional file 1: Figures S3 and S4. Nu: nucleus, black arrow: plastid. Scale bars = 5 μm