Plant cell walls comprise a complex of mostly cellulose, hemicellulose, and lignin. The composition and interaction among these three constituents dictate in large part the amenability of plant feedstocks for conversion to simple sugars and then to biofuels. One mechanism regulating cell wall biosynthesis is the activity of transcription factors that control higher order events of growth and differentiation; the likely direct regulation of processive and non- processive glycosyltransferases as well as the phenylpropanoid metabolic grid. We measured interactions among the promoters of Arabidopsis cell wall genes and a nearly comprehensive transcription factor library using a high throughput yeast one-hybrid assay. In addition to several NAC and numerous MYB transcription factors some of which have been implicated in cell wall regulation, we measured interactions among twenty-three other families and cell wall promoters. While most (85%) bind just one, some bind multiple promoters. Interestingly, cellulose, hemicellulose, and lignin cis-regulatory regions share several interactors. A loss-of-function mutant of one such gene exhibits significantly more vascular bundles, which make up an appreciable proportion of overall plant biomass. With further screens for protein-DNA interactions, we will resolve either interlocking or independent networks leading to synthesis of cellulose, hemicellulose, and lignin. Ultimately, we hope to determine the effects of regulator perturbation on amenability to deconstruction and cell wall properties.