Investigating and manipulating lignin biosynthesis in the postgenomic era

Enormous progress has been made over the last decade in understanding and manipulating the pathway for lignin biosynthesis in plants. The roles of most of the genes on the pathway have now investigated by reverse genetic approaches in a variety of species, including trees, and field trails underpinning commercial exploitation have taken place. Despite this, many basic aspects of the lignin pathway are still very poorly understood. Little is known about the cell biology of the process, for example, and much has still to be learned about how the pathway is controlled and regulated at transcriptional and biochemical levels. The advent of post-genomic technologies such as transcript and metabolite profiling offer new opportunities for probing the lignin pathway and its inter-relationship with other pathways and developmental processes in plants. This review describes recent advances in understanding lignification while highlighting the areas where significant further work is needed.