Green Genes

The finished sequences of the flowering plants Arabidopsis, rice, poplar, and grape; the moss Physcomitrella, and the algae Chlamydomonas have begun to allow us to understand how plant genomes share common ground with the genomes of other organisms and how they differ. In this special section, along with an online collection (www.sciencemag.org/plantgenomes), we see how current knowledge of plant genomes lends insights to investigations from biochemistry to ecosystems. Taking a comparative view of plant genomes, DellaPenna and Last (p. 479) consider how metabolic pathways are encoded in the genomes and are derived from a complex evolutionary history. Leitch and Leitch (p. 481) discuss why polyploidy is so common in plants and its evolutionary and ecological consequences. Gaut and Ross-Ibarra (p. 484) examine the evolutionary constraints on a plant's genome, with a particular focus on how genomes enlarge or shrink without changing their number of chromosomes. Tang et al. (p. 486) look at the consequences of these changes over time and how to uncover genomic changes through the examination of synteny and collinearity. Zhang (p. 489) examines the genomic landscape of epigenetics in plants. In an ecological context, Whitham et al. (p. 492) explore how the genome of a single keystone species affects interactions across communities and ecosystems. Benfey and Mitchell-Olds (p. 495) examine gene regulation from a systems network perspective and consider how natural variation and environmental inputs affect the phenotype of an individual.

Two teams have deciphered the grape's genetic code, but whether GM wine will be accepted is a lingering question, says Travis (p. 475). Kintisch explores how plant genomics can advance biofuel agriculture (p. 478). Finally, Kaiser describes how some researchers bent on using GM plants to make human proteins and other pharmaceutical products are moving indoors to allay safety concerns (p. 473).

In addition to these overviews, see the associated Editorial by Fedoroff and the Science Careers article by Williams, as well as reports by Field and Osbourn (p. 543), Baerenfaller et al. (www.sciencemag.org/cgi/content/full/1157956/DC1), and Dinneny et al. (www.sciencemag.org/cgi/content/full/1153795/DC1). Given what has been learned so far from a variety of plant genomes, we eagerly look ahead to a growing field.