Carbon–calcium inclusions (CCaI) either as calcium oxalate crystals (CaOx) or amorphous calcium carbonate cystoliths are spread among most photosynthetic organisms. They represent dynamic structures with a significant construction cost and their appearance during evolution indicates an ancient origin. Both types of inclusions share some similar functional characteristics providing adaptive advantages such as the regulation of Ca levels, and the release of CO₂ and water molecules upon decomposition. The latter seems to be essential under drought conditions and explains the intense occurrence of these structures in plants thriving in dry climates. It seems, however, that for plants CaOx may represent a more prevalent storage system compared with CaCO₃ due to the multifunctionality of oxalate. This compound participates in a number of important soil biogeochemical processes, creates endosymbiosis with beneficial bacteria and provides tolerance against a combination of abiotic (nutrient deprivation, metal toxicity) and biotic (pathogens, herbivores) stress factors. We suggest a re‐evaluation of the roles of these fascinating plant structures under a new and holistic approach that could enhance our understanding of carbon sequestration at the whole plant level and provide future perspectives.

中文翻译：

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对植物中碳-钙包裹体功能的新见解。

草酸钙晶体（CaOx）或无定形碳酸钙囊藻体的碳钙夹杂物（CCaI）散布在大多数光合生物中。它们代表了具有巨大建造成本的动态结构，并且它们在进化过程中的出现表明了其古老的起源。两种类型的夹杂物都具有一些相似的功能特征，从而提供了适应性优势，例如调节Ca含量，分解时释放CO ₂和水分子。后者在干旱条件下似乎是必不可少的，并解释了这些结构在干燥气候下繁盛的植物中的大量发生。但是，与CaCO ₃相比，对于植物来说，CaOx似乎代表了更普遍的存储系统由于草酸盐的多功能性。该化合物参与许多重要的土壤生物地球化学过程，与有益细菌共生，并对非生物（营养缺乏，金属毒性）和生物（病原体，草食动物）胁迫因子的组合具有耐受性。我们建议以一种全新的整体方法重新评估这些引人入胜的植物结构的作用，这可以加深我们对整个植物碳固存的了解，并提供未来的展望。