Mutations in <i>KTN1</i> leading to enhanced conical cell phenotypes of <i>an-t1</i>.

(A) Schematic representation of the KTN1 gene, showing the nature and position of the ktn1 mutant alleles. Arrows indicate nucleotide substitutions, and the triangle indicates T-DNA insertion. (B) KTN1 expression activity throughout petal development stages 7 to 14 was monitored by pKTN1:GUS transgene expression. Scale bar = 1 mm. (C and D) Confocal (C) and scanning electron microscope (D) images of conical cells of WT, an-t1, an-t1 ktn1-7, and ktn1-7 from stage 14 mature petals. Scale bars represent 10 μm. (E and F) Quantification of cone height (E) and cone angle (F) of conical cell phenotypes. For the quantification of cone height, ns indicates no significant difference (Mann–Whitney U test, P > 0.05) between the data sets compared with WT Col-0 (P = 0.2633, P = 0.11099, P = 0.31530, respectively). For the quantification of cone angle, asterisks indicate a significant difference (Mann–Whitney U test, **P an-t1 vs WT, P = 0.00359; for an-t1 ktn1-7 vs WT, P = 0.00129; for ktn1-7 vs WT, P = 0.0017; for an-t1 ktn1-7 vs an-t1, P = 0.00223; for an-t1 ktn1-7 vs ktn1-7, P = 0.0022). Values are given as the mean ± SD of more than 300 cells from 20 petals.