Banks said having the spikemoss genome revealed that the transition from mosses to plants with vascular systems didn't involve as many genes as going from a vascular plant that doesn't produce flowers to one that does. "We have a much better idea with Selaginella which genes evolved only in angiosperms. Plants need vascular tissues to be tall, to transport nutrients from roots to leaves," she said. "That's fairly complicated, but it turns out that process just didn't need that many genes compared to inventing flowers."
To help vascular tissues to stay upright, plants rely on lignin, a polymer biofuels researchers are targeting for investigation because its rigid structure is challenging to break down, impeding their use as potential bioenergy feedstocks. Banks' colleague Clint Chapple, a coauthor on the paper and a Purdue colleague, has been using the Selaginella genome to study the pathways by which three different types of lignin are synthesized in plants.
"What we learned is that Selaginella not only invented the S type of lignin independently, maybe even earlier, than angiosperms but that they go about doing it through a related but different chemical route," Chapple said. He described a recent project [funded by the National Science Foundation] in which enzymes from the lignin-synthesizing pathway in Selaginella were used to modify the canonical lignin-producing pathway in Arabidopsis to produce the polymer. Having the genome sequence offers strategic research opportunities, he said. "We've known for some time that if you alter the lignin building blocks you can improve biomass for agricultural and industrial uses."
Banks also noted that the Selaginella research community has grown up around the availability of the genome, which was made publicly available through the DOE JGI's plant portal
|Contact: David Gilbert|
DOE/Joint Genome Institute