Figure 2
SlSBPase mRNA abundance, SBPase activity and protein levels in different tissues and during leaf development in tomato plants.
All measurements were done on 20-leaf tomato plants. (a,d) SlSBPase mRNA abundance was measured by quantitative real-time PCR using total RNA separately isolated from different organs (fully expanded leaves, one-week old fruits, stems, roots) and leaves at different developmental stages including post-maturation leaves (leaf no. 5 from base), mature fully expanded leaves (leaf no. 9, 13), new fully expanded leaves (leaf no. 17) and young expanding leaves (leaf no. 20) and in tomato plants. (b,e) Protein levels. 25 μg protein samples from different tissues were separated by SDS-PAGE. SBPase protein was stained by coomassie blue and was subjected to western blot analysis with an anti-SBPase polyclonal antibody. (c,f) SBPase activity. The same tissues for SlSBPase mRNA analysis were sampled for SBPase activity assay. (g) CO2 assimilation rate in leaves at the different developmental stages. (h) CO2 assimilation rate as a function of SBPase activity. The results are the means ± SDs (n = 4).
