The abundance of the Calvin–Benson proteoforms is not affected by growth at CO2-enriched atmosphere in Eucalyptus young plants

Mitigation of climate change is an uttermost necessity and plants play an important role in removing atmospheric CO2. Besides being the primary source for the production of pulp and paper, fast-growing evergreen trees have a huge potential to assimilate and stock massive amounts of atmospheric carbon. Previous proteomics study indicated that growth of Eucalyptus urophylla plants in an ultra-high CO2 atmosphere (i.e. 1,000 ppm) increased the abundance of carbon assimilation enzyme proteins. Here, we used proteomics as a multidimensional technology to understand the metabolic changes that occur in Eucalyptus leaves when young plants were cultivated in a higher than current CO2 levels (i.e. 680 ppm). After 30 days of treatment, plant species that presented the most dissimilar phenotypic responses were E. pellita, E. urophylla and E. grandis grown at 680 ppm of CO2. Proteome investigation indicated the absence of a consistent increase in the abundance of the proteoforms and enzymes involved in carbon assimilation. Large-scale multivariate analysis and gene ontology term enrichment suggested that CO2, at the aforementioned concentration, increased the number of photosystem-related proteins. Unique proteome features were identified in the Eucalyptus species when stimulated by CO2. Our data refutes the previous findings on the increase in the number of carbon assimilation proteins upon CO2 cultivation and provides new insights into a differential metabolic regulation in Eucalyptus plants according to the CO2 levels plants are grown in. Mass spectrometric data are available via ProteomeXchange under the identifier PXD044997.