Figure 3.

Leaf surface hydrophobicity and trichome density. A, Images of droplets on wild-type and sitiens leaf surfaces illustrating the differences in surface tension. B, Hydrophobicity determined by measuring the contact angle of a 10-μL droplet of distilled water on the leaf surface by the sessile drop method. Mean contact angles were averages of at least 10 measurements. Fourth leaves of 5-week-old plants (seventh leaf stage) were used. Error bars indicate se. A Student’s t test indicated that differences between the wild type and sitiens were statistically significant, indicated by the star (P < 0.001). C, Number of trichomes per 10 mm². Error bars indicate se. A Mann-Whitney test revealed a significant difference between the wild type and sitiens, indicated by the star (P < 0.001). D, Representative photographs of leaf sections illustrating differences in trichome density between the wild type (top) and sitiens (bottom). [See online article for color version of this figure.]