Figure 4.

Overexpressing PtrNAC Genes Affects the Size and Number of Vessels in Xylem Tissue of P. trichocarpa.

(A) Stem cross sections of wild-type and OE-PtrNAC transgenic plants with the 10th internode. Bars = 200 µm.

(B) to (D) Statistical analysis of mean lumen area of individual vessels (µm²) (B), number of vessels per cross-sectional area (mm²) (C), and area of vessels (µm²) per cross-sectional area (mm²) (D) using vessel cells from (A). Error bars represent 1 se of three independent replicates with at least 200 vessel cells for each genotype in each replicate, and asterisks indicate significant differences between the transgenics harboring each gene construct and wild-type plants (*, P < 0.05 and **, P < 0.01, Student’s t test).

(E) Scanning electron micrographs of wild-type and OE-PtrNAC006 transgenic plants with the 10th internode imaged at ×500, ×1000, and ×2000 magnification. Bars = 20 µm.