Dataset Information

Spatial resolution of an integrated C₄+CAM photosynthetic metabolism.

ABSTRACT: C₄ and CAM photosynthesis have repeatedly evolved in plants over the past 30 million years. Because both repurpose the same set of enzymes but differ in their spatial and temporal deployment, they have long been considered as distinct and incompatible adaptations. Portulaca contains multiple C₄ species that perform CAM when droughted. Spatially explicit analyses of gene expression reveal that C₄ and CAM systems are completely integrated in Portulaca oleracea, with CAM and C₄ carbon fixation occurring in the same cells and CAM-generated metabolites likely incorporated directly into the C₄ cycle. Flux balance analysis corroborates the gene expression findings and predicts an integrated C₄+CAM system under drought. This first spatially explicit description of a C₄+CAM photosynthetic metabolism presents a potential new blueprint for crop improvement.

SUBMITTER: Moreno-Villena JJ

PROVIDER: S-EPMC9355352 | biostudies-literature | 2022 Aug

REPOSITORIES: biostudies-literature

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Spatial resolution of an integrated C4+CAM photosynthetic metabolism.

Moreno-Villena Jose J JJ Zhou Haoran H Gilman Ian S IS Tausta S Lori SL Cheung C Y Maurice CYM Edwards Erika J EJ

Science advances 20220805 31

C4 and CAM photosynthesis have repeatedly evolved in plants over the past 30 million years. Because both repurpose the same set of enzymes but differ in their spatial and temporal deployment, they have long been considered as distinct and incompatible adaptations. Portulaca contains multiple C4 species that perform CAM when droughted. Spatially explicit analyses of gene expression reveal that C4 and CAM systems are completely integrated in Portulaca ole ...[more]

PMID: 35930634

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Project description:Solar greenhouses are important in the vegetable production and widely used for the counter-season production in the world. However, the CO2 consumed by crops for photosynthesis after sunrise is not supplemented and becomes chronically deficient due to the airtight structure of solar greenhouses. Vegetable crops cannot effectively utilize light resources under low-CO2 environment, and this incapability results in reduced photosynthetic efficiency and crop yield. We used cucumber as a model plant and generated several sets of transgenic cucumber plants overexpressing individual genes, including β-carbonic anhydrase 1 (CsβCA1), β-carbonic anhydrase 4 (CsβCA4), and sedoheptulose-1,7-bisphosphatase (CsSBP); fructose-1,6-bisphosphate aldolase (CsFBA), and CsβCA1 co-expressing plants; CsβCA4, CsSBP, and CsFBA co-expressing plants (14SF). The results showed that the overexpression of CsβCA1, CsβCA4, and 14SF exhibited higher photosynthetic and biomass yield in transgenic cucumber plants under low-CO2 environment. Further enhancements in photosynthesis and biomass yield were observed in 14SF transgenic plants under low-CO2 environment. The net photosynthesis biomass yield and photosynthetic rate increased by 49% and 79% compared with those of the WT. However, the transgenic cucumbers of overexpressing CsFBA and CsSBP showed insignificant differences in photosynthesis and biomass yield compared with the WT under low-CO2.environment. Photosynthesis, fluorescence parameters, and enzymatic measurements indicated that CsβCA1, CsβCA4, CsSBP, and CsFBA had cumulative effects in photosynthetic carbon assimilation under low-CO2 environment. Co-expression of this four genes (CsβCA1, CsβCA4, CsSBP, and CsFBA) can increase the carboxylation activity of RuBisCO and promote the regeneration of RuBP. As a result, the 14SF transgenic plants showed a higher net photosynthetic rate and biomass yield even under low-CO2environment.These findings demonstrate the possibility of cultivating crops with high photosynthetic efficiency by manipulating genes involved in the photosynthetic carbon assimilation metabolic pathway.

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Dataset Information

Spatial resolution of an integrated C₄+CAM photosynthetic metabolism.

Publications

Spatial resolution of an integrated C<sub>4</sub>+CAM photosynthetic metabolism.

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