Reduced Carbon Dioxide by Overexpressing Transgene in Arabidopsis and Rice: Implications in Carbon Neutrality through Genetically Engineered Plants.

With the increasing challenges of climate change caused by global warming, the effective reduction of carbon dioxide (CO) becomes an urgent environmental issue for the sustainable development of human society. Previous reports indicated increased biomass in genetically engineered (GE) Arabidopsis and rice overexpressing the 5-enolpyruvylshikimate-3-phosphate synthase () gene, suggesting the possibility of consuming more carbon by GE plants. However, whether overexpressing the gene in GE plants consumes more CO remains a question. To address this question, we measured expression of the gene, intercellular CO concentration, photosynthetic ratios, and gene expression (RNA-seq and RT-qPCR) in GE (overexpression) and non-GE (normal expression) Arabidopsis and rice plants. Results showed substantially increased expression accompanied with CO consumption in the GE Arabidopsis and rice plants. Furthermore, overexpressing the gene affected carbon-fixation related biological pathways. We also confirmed significant upregulation of four key carbon-fixation associated genes, in addition to increased photosynthetic ratios, in all GE plants. Our finding of significantly enhanced carbon fixation in GE plants overexpressing the transgene provides a novel strategy to reduce global CO for carbon neutrality by genetic engineering of plant species, in addition to increased plant production by enhanced photosynthesis.