Guard cell‐specific upregulation of sucrose synthase 3 reveals that the role of sucrose in stomatal function is primarily energetic

• DOI: 10.1111/nph.13704
• Publication Date: 2015-10-15T11:53:15Z
• Authors: Danilo M. Daloso; Thomas C. R. Will...; Werner C. Antunes; Daniela P. Pinheiro; Caroline Müller; Marcelo E. Loureiro; Alisdair R. Fernie
• Keywords: 0106 biological sciences; 0301 basic medicine; Carbon Isotopes; Light; Carboxylic Acids; Plant Development; Plant Transpiration; Plants, Genetically Modified; 16. Peace & justice; Adaptation, Physiological; 01 natural sciences; Droughts; Plant Leaves; Kinetics; 03 medical and health sciences; Phenotype; Glucosyltransferases; Organ Specificity; Plant Stomata; Metabolome; Metabolomics; Gases; Promoter Regions, Genetic; Plant Proteins; Solanum tuberosum

Summary Isoform 3 of sucrose synthase ( SUS3 ) is highly expressed in guard cells; however, the precise function SUS this cell type remains to be elucidated. Here, we characterized transgenic Nicotiana tabacum plants overexpressing under control stomatal‐specific KST 1 promoter, and investigated changes metabolism during dark light transition. Guard cell‐specific overexpression led increased activity, stomatal aperture, conductance, transpiration rate, net photosynthetic rate growth. Although only minor were observed metabolite profile whole leaves, an fructose level decreased organic acid levels ratio cells lines. Furthermore, content was lower light‐induced opening. In a complementary approach, incubated cell‐enriched epidermal fragments 13 C‐Na HCO followed redistribution label transitions; revealed labeling metabolites of, or associated with, tricarboxylic cycle. The results suggest that breakdown mechanism provide substrate for provision acids respiration, imply manipulation may represent effective strategy plant growth improvement.