在这项工作中，研究组在拟南芥中引入了一个新的自然CO2固定循环，即甲基辅酶a -甘油（McG）循环，它与CBB循环形成了一个双循环CO2固定系统。这个循环可以通过磷酸烯醇丙酮酸羧化酶固定一个额外的碳，并将光呼吸产物乙醇酸转化为乙酰辅酶a。具有McG循环的植物在其光系统中显示出更高的蛋白质丰度和更高的光系统II效率。McG植物在大气CO2下的CO2固定率增加了一倍，脂质产量增加，生长明显增强，种子产量增加了两倍。
据介绍，通过卡尔文-本森-巴萨姆（CBB）循环进行的碳固定占大气中二氧化碳（CO2）吸收的大部分。CBB循环产生C3碳水化合物，但在产生乙酰辅酶A (CoA) （C2）方面效率低下，后者是合成脂质的普遍前体。
附：英文原文
Title: Dual-cycle CO2 fixation enhances growth and lipid synthesis in Arabidopsis thaliana
Author: Kuan-Jen Lu, Chia-Wei Hsu, Wann-Neng Jane, Mien-Hao Peng, Ya-Wen Chou, Pin-Hsuan Huang, Kuo-Chen Yeh, Shu-Hsing Wu, James C. Liao
Issue&Volume: 2025-09-11
Abstract: Carbon fixation through the Calvin-Benson-Bassham (CBB) cycle accounts for the majority of carbon dioxide (CO2) uptake from the atmosphere. The CBB cycle generates C3 carbohydrates but is inefficient at producing acetyl–coenzyme A (CoA) (C2), which is the universal precursor for synthesizing lipids. In this work, we introduced in Arabidopsis thaliana a new-to-nature CO2 fixing cycle, malyl-CoA-glycerate (McG) cycle, which together with the CBB cycle forms a dual-cycle CO2 fixation system. This cycle can fix one additional carbon by phosphoenolpyruvate carboxylase and convert the photorespiration product, glycolate, to acetyl-CoA. Plants with the McG cycle show enhanced protein abundance in their photosystems and enhanced photosystem II efficiency. McG plants had doubled CO2 fixation rates under atmospheric CO2, increased lipid production, pronounced growth enhancement, and tripled the seed yield.
DOI: adp3528
Source: https://www.science.org/doi/10.1126/science.adp3528