Figure 1.

(A–B) Association of CesAs and microtubules in cc1 cc2 mutants. (A) Spinning disc confocal microscopy of a hypocotyl cell of a 4-day-old etiolated cc1 cc2 seedling expressing YFP-CesA6 (YFP-C6) and mCHERRY-TUA5 (mCh-TUA5). Seedlings were germinated and grown for 2 days on MS plates, and were then transferred to plates containing 100 mM NaCl. After 2 days growth on the salt-containing media the dual-labeled line were imaged by spinning disc confocal microscopy.¹¹ In single frame images (left panel) the majority of YFP-CesA6 foci co-localize with microtubules. The overlapping signal of YFP-CesA6 and mCh-TUA5 in time averages (150 frames, 5 sec interval) indicating that CESAs move along trajectories of cortical MTs in cc1 cc2 double mutants. Bar = 5 µm. (B) Quantification of co-occurrence of YFP-CesA6 and mCh-TUA5 signals in time average images as those in (A). Both markers show identical values for co-localization in cc1 cc2 and wild-type (p-value = 0.4, Welch's unpaired t-test). (C–D) Genetic interaction of cc1 cc2 with pom2-4 or prc1-1. (C) Five-day-old Col-0, cc1, cc2, cc1 cc2, pom2-4 and cc1 cc2 pom2-4 seedlings grown on MS media (left panel). Bar = 1 mm. Five-week-old Col-0, cc1, cc2, cc1 cc2, pom2-4 and cc1 cc2 pom2-4 plants grown on soil (right panel). Note the reduced hypocotyl length and growth of cc1 cc2 pom2-4 compared to pom2-4, respectively. Bar = 2 cm (D) Five-day-old col-0, cc1, cc2, cc1 cc2, prc1-1 and cc1 cc2 prc1-1 seedlings grown on MS media (left panel). Bar = 1 mm. Five-week-old col-0, cc1, cc2, cc1 cc2, prc1-1 and cc1 cc2 prc1-1 plants grown on soil. Note the reduced hypocotyl elongation and rosette size of cc1 cc2 prc1-1 in comparison to prc1-1, respectively. Bar = 2 cm. (E) Quantification of hypocotyl length of genotypes from C and D; n=30 seedlings. **p ≤ 0.001. Student's t test, error bars are SD.