Table 1.
Description of genes targeted in this study
| Name | Genea | Description | Typeb | Sugar Releaseb | Yieldb | Rametsc |
|---|---|---|---|---|---|---|
| CAD | Potri.009G095800 | Cinnamyl alcohol dehydrogenase, catalyzes the formation of coniferyl or coumaryl alcohol from their respective aldehydes [58] | KD | + | + | 12(C), 12(T) |
| DUF231 | Potri.009G072800 | Domain of unknown function, a member of the Trichome Birefringence-Like (TBL) gene family, possibly responsible for O-acetylation of hemicelluloses [49] | OE | + | + | 12(C), 12(T) |
| DUF266 | Potri.011G009500 | Domain of unknown function, possibly acting as a glycosyltransferase [53] | OE | + | + | 12(C), 5(C), 5(T) |
| EPSPS | Potri.002G146400 | 5-enolpyruvylshikimate-3-phosphate synthase, key enzyme in biosynthesis of aromatic amino acids [59] | OE | + | = | 12(C), 12(T) |
| EXT1;EXT2 |
Potri.001G020100
Potri.005G190100 |
Extensin, a basic hydroxyproline-rich glycoprotein localized to the cell wall [60] | KD | + | + | 12(C), 12(T); EXT2: 12(T) |
| GAUT12 | Potri.001G416800 | Galacturonosyltransferase targeted to Golgi and involved in xylan and homogalacturonan biosynthesis [61] | KD | + | + | 12(C), 12(C), 12(T) |
| HB3 | Potri.011G098300 | Transcription factor belonging to the HDZIPIII family, with high expression in xylem tissue [62] | KD | + | + | 12(C), 14(T) |
| IQD10 | Potri.001G375700 | Calmodulin-binding protein with IQ amino acid-rich region with high expression in tension wood [63] | KD | + | + | 11(C), 13(T) |
| P4HA1 | Potri.017G075300 | Prolyl 4-hydroxylase alpha subunit, hydroxylation of proline residues, potentially in hydroxyproline-rich glycoproteins in the cell wall [64] | OE | + | = | 12(C), 12(T) |
| PFD2 | Potri.008G153900 | Probable Prefoldin 2 protein. A heterohexameric chaperon protein that binds to actin, tubulin, and other proteins, possibly affecting the cortical spindle [55] | OE | + | + | 12(C), 13(T) |
| RWA2 | Potri.010G148500 | Reduced wall acetylation 2, catalyzes O-acetylation of cell wall polysaccharides [50] | OE | + | + | 13(C), 12(T) |
| SHMT | Potri.001G320400 | Serine hydroxymethyltransferase, reversible conversion of Ser and tetrahydrofolate to Gly and 5,10-methylene tetrahydrofolate, providing a major 1-carbon source for the cell [65] | OE | + | + | 12(C), 12(T) |
| VND6 | Potri.015G127400 | Vascular-related NAC-domain Protein 6, transcription factors involved in xylem vessel differentiation [66] | OE | - | - | 12(C), 13(T) |
KD knockdown of gene expression using RNAi, OE overexpression of target gene using a constitutive promoter (UBIQUITIN3)
aGene model name based on phytozome [67] version 3.0 of the Populus trichocarpa genome
bSugar release [14] and yield refer to performance relative to controls in greenhouse trials prior to the field trial
cThe number of replicates (ramets) included in the statistical analyses for TOP (T) and comparator (C) lines. For DUF266 and GAUT12 there were two comparator lines, which are listed separately