Figure 5.

CESA1 phosphorylation is modified to regulate root growth under Pi-deficient conditions. For A) and B), roots were grown in a hydroponics system for 14 d in sufficient Pi (1 mM) and transferred to Pi-sufficient (1 mM) or Pi-deficient (20 µM) media for 48 h before experiments. A) and B) Summed peak area of unphosphorylated A) and phosphorylated B) peptide containing S688 phosphosite. At least 30 plants were pooled in a single biological replicate for each treatment, and 3 biological replicates were applied. Data are presented as means ± Se. C) Representative images of 8-d-old seedlings grown on Pi-sufficient and Pi-deficient media. Scale bar = 1 cm. D) Primary root length reduction ratio of plants grown under Pi-deficient conditions as compared with plants grown under Pi-sufficient conditions. E) Primary root length of 8-d-old plants grown under Pi-sufficient and Pi-deficient conditions. For D) and E), the boxes represent the IQR, with medians marked. Whiskers extend 1.5 times IQR, and dots indicate individual data points, n > 15. F) Cellulose quantification in the 8-d-old roots of plants grown under Pi-sufficient and Pi-deficient conditions. S688S and S688E lines are in the cesa1 (−/−) background. Data are presented as means ± Se, n = 3. Asterisks denote statistical significance (*P < 0.05, **P < 0.01, ***P < 0.001, and ****P < 0.0001) according to Student's t test. The graphics and statistical analysis were generated using the ggpubR package in R.