Biologists have discovered that a fundamental building block in the cells of flowering plants evolved independently, yet almost identically, on a separate branch of the evolutionary tree--in an ancient plant group called lycophytes that originated at least 420 million years ago.
Researchers believe that flowering plants evolved from gymnosperms, the group that includes conifers, ginkgos and related plants. This group split from lycophytes hundreds of millions of years before flowering plants appeared.
The building block, called syringyl lignin, is a critical part of the plants' scaffolding and water-transport systems. It apparently emerged separately in the two plant groups, much like flight arose separately in both bats and birds.
Purdue University researcher Clint Chapple and graduate students Jing-Ke Weng and Jake Stout, along with post-doctoral research associate Xu Li, conducted the study with the support of the National Science Foundation, publishing their findings in the May 20, 2008, Proceedings of the National Academy of Sciences.
"We're excited about this work not only because it may provide another tool with which we can manipulate lignin deposition in plants used for biofuel production, but because it demonstrates that basic research on plants not used in agriculture can provide important fundamental findings that are of practical benefit," said Chapple.
The plant studied--Selaginella moellendorffii, an ornamental plant sold at nurseries as spike moss--came from Purdue colleague Jody Banks. While not a co-author on the paper, Banks helped kick-start the study of the Selaginella genome with NSF support in 2002, and is now scientific coordinator for the plant's genome-sequencing effort conducted by the Department of Energy Joint Genome Institute in Walnut Creek, Calif.
"Because Selaginella is a relict of an ancient vascular plant lineage, its genome sequence will provide the plant commun
|Contact: Josh Chamot|
National Science Foundation