Hornwort pyrenoids, carbon-concentrating structures, evolved and were lost at least five times during the last 100 million years.

ABSTRACT: Ribulose-1,5-biphosphate-carboxylase-oxygenase (RuBisCO) has a crucial role in carbon fixation but a slow catalytic rate, a problem overcome in some plant lineages by physiological and anatomical traits that elevate carbon concentrations around the enzyme. Such carbon-concentrating mechanisms are hypothesized to have evolved during periods of low atmospheric CO(2). Hornworts, the sister to vascular plants, have a carbon-concentrating mechanism that relies on pyrenoids, proteinaceous bodies mostly consisting of RuBisCO. We generated a phylogeny based on mitochondrial and plastid sequences for 36% of the approximately 200 hornwort species to infer the history of gains and losses of pyrenoids in this clade; we also used fossils and multiple dating approaches to generate a chronogram for the h

SUBMITTER: Villarreal JC 

PROVIDER: S-EPMC3503201 | biostudies-literature | 2012 Nov

REPOSITORIES: biostudies-literature