Fig. 6.

Wild-type root hair lengths were produced in cut1 and ein2-5 Arabidopsis mutants by addition of exogenous nucleotide sugars required for different pectic polymer biosyntheses. A, QRT-PCR analysis of UER1 transcripts in cut1 and ein2-5 Arabidopsis mutants. B, QRT-PCR analysis of GAE6 transcripts in the mutants. Error bars indicate standard deviations. C, 5 μm UDP-Rha or UDP-GalA applied to the growth medium promoted significant cut1 root hair elongation. Addition of the same amount of UDP-Xyl to the growth medium did not promote root hair elongation compared with the control that received no extra chemical (None). Mean ± S.E. of root hair length (in mm) is shown below each image. ***, significant at p < 0.001 compared with wild-type Ler root hairs. D, 5 μm UDP-Rha or UDP-GalA applied to the growth medium promoted significant ein2-5 root hair elongation. ***, significant at p < 0.001 compared with wild-type Col root hairs. E, wild-type root hair lengths were produced from cut1 and ein2-5 plants when a combination of 5 μm UDP-Rha and 5 μm UDP-GalA (UDP-Rha+UDP-GalA) were added to the growth medium. F, addition of 10 μm UDP-Rha did not support further root hair growth in either mutant. G, addition of 10 μm UDP-GalA did not support further root hair growth in either mutant. Scale bars in C–G, 200 μm. ***, significant at p < 0.001 compared with wild-type root hairs.