Fig. 8

TCTP- and ECHIDNA-deficient pollen tubes consistently fail to target ovules. a The SIV ovule-targeting assay. Pollen tube targeting competence was assessed using a single pollen genotype or in a one-to-one genotype competition assay. b ech-/- pollen grains showed reduced but adequate pollen tube germination in vitro as well as semi-in vivo but showed significantly reduced ovule-targeting competence semi-in vivo. c Quantification of pollen tube ovule-targeting competence semi-in vivo of ech-/- plants in a single genotype or mixed genotype competition assay. n is the number of pistil explants assessed, asterisks denote significant differences assessed with Student’s t-test (p < 0.01). d Aniline blue stain of wild-type and ech-/- pollinated wild-type pistils 18 h after pollination (HAP) showing near complete lack of ovule targeting in ech-/- pollinated pistils (red arrow) compared with wild type-pollinated pistils (yellow arrows), verifying the semi-in vivo observations in c. e Frequency of ovule targeting by pollen tubes in aniline blue-stained pistils. All score variances (asterisk) are statistically significant (Student’s t-test, p < 0.01). Error bars represent standard deviation (stdv). f Blue dot assay by GUS-staining of ms1 pistils pollinated with wild-type pollen grains homozygous or heterozygous for Lat52-GUS and Lat52-GUS;tctp-1/+ 18 HAP. Red arrows point to tctp-1 mutant pollen tubes targeting ovules at the bottom of the pistil, suggesting tctp-1 pollen tube growth is not greatly impaired. Insets: variable mistargeting phenotypes observed in tctp-1/+ pollinated pistils. g Counts of “blue dots” revealed ovule targeting was greatly impaired in tctp-deficient pollen tubes