Fig. 3.

Phenotypes of Populus trichocarpa ptrcesa4, ptrcesa7a/b, and ptrcesa8a/b mutants (CesA, cellulose synthase). (a) Morphology of multiple ptrcesa mutant and wild‐type (WT) trees grown for 3 months in a glasshouse. (b‐d) Light microscopic analysis of stems (b), petioles (c) and roots (d) from 3‐month‐old ptrcesa mutant and WT trees. Sections were stained with toluidine blue. Stem cross‐sections are from the 10^th internode; petiole cross‐sections are from the 8^th leaf below the apical bud. Bars: (a) 5 cm; (b) 20 μm; (c–d) 100 μm.