>> Role of C4 carbon fixation in Ulva prolifera, the macroalga responsible for the world’s largest green tides

2020-09-21阅:354

题名:Role of C4 carbon fixation in Ulva  prolifera, the macroalga responsible for the world's largest green tides

来源:Nature Communications Biology

发表年代:2020

作者:Dongyan LiuQian MaIvan ValielaDonald M. AndersonJohn K. KeesingKunshan GaoYu ZhenXiyan Sun & Yujue Wang

Abstract Most marine algae preferentially assimilate CO2 via the Calvin-Benson Cycle (C3) and catalyze HCO3− dehydration via carbonic anhydrase (CA) as a CO2-compensatory mechanism, but certain species utilize the Hatch-Slack Cycle (C4) to enhance photosynthesis. The occurrence and importance of the C4  pathway remains uncertain, however. Here, we demonstrate that carbon  fixation in Ulva prolifera, a species responsible for massive green  tides, involves a combination of C3 and C4 pathways, and a CA-supported HCO3− mechanism. Analysis of CA and key C3 and C4 enzymes, and subsequent analysis of δ13C photosynthetic products showed that the species assimilates CO2 predominately via the C3 pathway, uses HCO3− via the CA mechanism at low CO2 levels, and takes advantage of high irradiance using the C4  pathway. This active and multi-faceted carbon acquisition strategy is  advantageous for the formation of massive blooms, as thick floating mats  are subject to intense surface irradiance and CO2 limitation. © 2020, The Author(s).

Role of C4 carbon fixation in Ulva prolifera the macroalga responsible for the world's largest green tides.pdf