Figure 3.

Pollen tube growth in exo70a2 and the wild type. A, Distribution of pollen tube lengths 20 h after imbibition in vitro (related to Fig. 2A). More than 100 pollen tubes were evaluated for wild-type and heterozygous plants, and 50 pollen tubes for the exo70a2 mutant. Pollen was collected from five different plants for each genotype, with three biological replicates. B, Aniline blue staining for visualization of callose in pollen tubes in representative self-pollinated pistils from a wild-type and a homozygous exo70a2 plant. Dashed lines indicate the longest pollen tubes. C, Quantification of the maximal pollen tube length based on aniline blue staining. At least 30 pistils of each genotype were evaluated, with two biological replicates. Error bars represent the mean ± sd. Asterisks indicate statistical difference using Student’s t test (P < 0.001).