Summary

The biotechnological lignin-reduction endeavors thus far reported have, in general, afforded plants apparently unsuitable for large-scale cultivation, resulting from compromised vasculature and perhaps higher susceptibility to pathogen attacks as well. Similarly, lignin represents a challenge in the processing of plant biomass (e.g., corn, switchgrass, or miscanthus) for biofuel/bioethanol generation using current fermentation techniques. Therefore, novel approaches must be developed if the so-called lignin challenge is to be circumvented for these purposes. Here, we have suggested some new areas of such exploration aiming at tackling these issues through the application of a newly elucidated metabolic process sharing the same lignin biochemical precursors, that is, the biosynthesis of liquid allyl and propenyl phenols. In the past year, the pertinent enzymes, genes, and specific biochemical precursors in this process have been isolated and described, thus lending themselves to exploitation through bioengineering. Further research in these areas will eventually determine the actual (economic) potential of the allyl and propenyl phenols as biofuels, intermediate chemicals for polymer synthesis, and/or specialty chemicals. Success in the research envisaged here could potentially lead to the development of a multibillion dollar per year industry within the United States alone. The challenge will be to identify a viable balance between acceptable structural and defensive properties of cultivated plants and their uses as sources of economically valuable products.