Robison Tanner A, Oh Zhen Guo, Lafferty Declan, Xu Xia, Villarreal Juan Carlos A, Gunn Laura H, Li Fay-Wei
Boyce Thompson Institute, Ithaca, NY, USA.
Plant Biology Section, Cornell University, Ithaca, NY, USA.
Nat Plants. 2025 Jan;11(1):63-73. doi: 10.1038/s41477-024-01871-0. Epub 2025 Jan 3.
Pyrenoid-based CO-concentrating mechanisms (pCCMs) turbocharge photosynthesis by saturating CO around Rubisco. Hornworts are the only land plants with a pCCM. Owing to their closer relationship to crops, hornworts could offer greater translational potential than the green alga Chlamydomonas, the traditional model for studying pCCMs. Here we report a thorough investigation of a hornwort pCCM using the emerging model Anthoceros agrestis. The pyrenoids in A. agrestis exhibit liquid-like properties similar to those in Chlamydomonas, but they differ by lacking starch sheaths and being enclosed by multiple thylakoids. We found that the core pCCM components in Chlamydomonas, including BST, LCIB and CAH3, are conserved in A. agrestis and probably have similar functions on the basis of their subcellular localizations. The underlying chassis for concentrating CO might therefore be shared between hornworts and Chlamydomonas, and ancestral to land plants. Our study presents a spatial model for a pCCM in a land plant, paving the way for future biochemical and genetic investigations.
基于蛋白核的二氧化碳浓缩机制（pCCM）通过使 Rubisco 周围的二氧化碳饱和来增强光合作用。角苔是唯一具有 pCCM 的陆地植物。由于角苔与农作物的关系更为密切，与研究 pCCM 的传统模式绿藻衣藻相比，角苔可能具有更大的转化潜力。在此，我们报告了一项利用新兴模式植物野生角苔对角苔 pCCM 进行的全面研究。野生角苔中的蛋白核表现出与衣藻中类似的液体样特性，但不同之处在于它们缺乏淀粉鞘且被多个类囊体包围。我们发现，衣藻中 pCCM 的核心成分，包括 BST、LCIB 和 CAH3，在野生角苔中是保守的，并且基于它们的亚细胞定位可能具有相似的功能。因此，浓缩二氧化碳的潜在机制可能在角苔和衣藻之间是共享的，并且是陆地植物的祖先所具有的。我们的研究提出了一种陆地植物中 pCCM 的空间模型，为未来的生化和遗传研究铺平了道路。
