Effects of Overexpression on Solanesol Content, Plant Growth, Photosynthesis, and Metabolome of .

solanesyl diphosphate synthase 1 (NtSPS1) is the key enzyme in solanesol biosynthesis. However, changes in the solanesol content, plant growth, photosynthesis, and metabolome of tobacco plants after overexpression (OE) have not been previously reported. In the present study, these parameters, as well as photosynthetic gas exchange, chlorophyll content, and chlorophyll fluorescence parameters, were compared between OE and wild type (WT) lines of tobacco. As expected, OE significantly increased solanesol content in tobacco leaves. Although OE significantly increased leaf growth, photosynthesis, and chlorophyll content, the chlorophyll fluorescence parameters in the leaves of the OE lines were only slightly higher than those in the WT leaves. Furthermore, OE resulted in 64 differential metabolites, including 30 up-regulated and 34 down-regulated metabolites, between the OE and WT leaves. Pathway enrichment analysis of these differential metabolites identified differentially enriched pathways between the OE and WT leaves, e.g., carbon fixation in photosynthetic organisms. The maximum carboxylation rate of RuBisCO and the maximum rate of RuBP regeneration were also elevated in the OE line. To our knowledge, this is the first study to confirm the role of in solanesol biosynthesis and its possible functional mechanisms in tobacco.