caa a22 4500 477100430 CHVBK 20180405111539.0 cr unu---uuuuu 170330e19961001xx s 000 0 eng 10.1007/BF00208310 doi (NATIONALLICENCE)springer-10.1007/BF00208310 A pyrenoid-based carbon-concentrating mechanism is present in terrestrial bryophytes of the class Anthocerotae [Elektronische Daten] [Elizabeth Smith, Howard Griffiths] It has been widely accepted that carbon assimilation in bryophytes is exclusively based on the conventional C3 photosynthetic pathway. The occurrence of biochemical CO2-concentrating mechanisms (C4 or Crassulacean acid metabolism), which have developed in plants in the last 20-100 million years, has been discounted for bryophytes from studies of the carbon isotope composition (δ13C) of organic material. In contrast cyanobacteria and many algae show active accumulation of dissolved inorganic carbon via biophysical CO2-concentrating mechanisms which are also found in the photobiont partners in certain lichens. The presence of a pyrenoid, a granular particle within the chloroplast, has been linked with CO2-concentrating mechanism activity in green algae and lichens and we now show that such a mechanism is categorically associated with the occurrence of a pyrenoid in bryophytes belonging to the class of Anthocerotae. These observations have significant evolutionary implications for the development of terrestrial photosynthesis during the colonisation of the land, raising the intriguing question of why the pyrenoid-based CO2-concentrating mechanism did not persist in the terrestrial environment. Springer-Verlag, 1996 Anthoceros nationallicence Carbon concentration nationallicence Carbon isotope discrimination nationallicence Photosynthesis nationallicence CCM : carbon-concentrating mechanism nationallicence DIG : dissolved inorganic carbon (CO2+HCO 3 - +CO 2 - ) nationallicence DW : dry weight nationallicence K0.5 : external concentration of CO2 at which half-maximal rates of CO2 assimilation are reached nationallicence Rubisco : ribulose-l,5-bisphosphate carboxylase-oxygenase nationallicence Δ : carbon isotope discrimination (%) nationallicence δ13C : carbon isotope ratio (%) nationallicence Smith Elizabeth Department of Agricultural and Environmental Science, University of Newcastle upon Tyne, NE1 7RU, Newcastle upon Tyne, UK aut Griffiths Howard Department of Agricultural and Environmental Science, University of Newcastle upon Tyne, NE1 7RU, Newcastle upon Tyne, UK aut Planta Springer-Verlag 200/2(1996-10-01), 203-212 0032-0935 200:2<203 1996 200 425 https://doi.org/10.1007/BF00208310 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00208310 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Smith Elizabeth Department of Agricultural and Environmental Science, University of Newcastle upon Tyne, NE1 7RU, Newcastle upon Tyne, UK aut NATIONALLICENCE 700 1- Griffiths Howard Department of Agricultural and Environmental Science, University of Newcastle upon Tyne, NE1 7RU, Newcastle upon Tyne, UK aut NATIONALLICENCE 773 0- Planta Springer-Verlag 200/2(1996-10-01), 203-212 0032-0935 200:2<203 1996 200 425 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer