Extended Data Fig. 1: Overexpression of PtrVCS2 and PtrVCS2-h in P. trichocarpa and cambium phenotype analysis.
a, Relative expression levels of PtrVCS2 in wild-type (WT) and OE-PtrVCS2 transgenic plants, as determined by RT-qPCR. b, Phenotypes of WT and OE-PtrVCS2 transgenics. The inset shows the magnification of an OE-PtrVCS2 #3 transgenic plant. Scale bars, 10 cm. c, Histochemistry and histological analysis of WT, OE-PtrVCS2 #2, and OE-PtrVCS2-h #2 transgenics. d, Number of cambium cell layers in stem vascular tissues of WT and OE-PtrVCS2 #2 transgenics. e, Relative expression levels of PtrVCS2-h in WT and OE-PtrVCS2-h transgenic plants as determined by RT-qPCR. In (a) and (e), data are shown as mean±s.e.m.; n = 3 biological replicates. Asterisks indicate significant difference between the transgenic and WT plants, *P < 0.05, **P < 0.01, ***P < 0.001 (Two-tailed Student’s t-test). f, Phenotypes of WT and OE-PtrVCS2-h #3 transgenics. The inset shows the magnification of an OE-PtrVCS2-h transgenics plant. Scale bars, 10 cm. g, Basal stem of WT and OE-PtrVCS2-h #3 transgenics. Scale bars, 1 mm. h, Histochemistry and histological analysis of WT and OE-PtrVCS2-h #3 transgenics. In (c) and (h), cross-sections of the 5th–8th internodes of P. trichocarpa stems were stained with toluidine blue O. Black brackets mark the cambium cells in one radial cell file. Scale bars, 25 µm. C, cambium; P, phloem, X, xylem. i,j, Number of cambium cell layers in stem vascular tissues of WT and OE-PtrVCS2-h #3 (i) and OE-PtrVCS2-h #2 (j) transgenics. In (d), (i) and (j), the number of cambium cell layers of at least ten radial cell files was counted within one cross-section from each biological replicate. Three biological replicates were analyzed. n = 30 for (i); n for (d) and (j) are shown in the panel. Boxes show the median with the upper and lower quantiles, and the whiskers represent the data range excluding outliers. Two-tailed Student’s t-test: *P < 0.05, **P < 0.01, ***P < 0.001.
