Figure 1.

iMet of SIB1 undergoes NTA. Transgenic sib1 plants harboring pSIB1::SIB1-GFP were grown on Murashige and Skoog medium under continuous light conditions. Five-day-old plants initially grown on normal medium were transferred to SA-containing Murashige and Skoog medium (1 mm SA). The samples were harvested before (0 h) and after a 6-h SA treatment. A, IP-immunoblot assay shows multiple bands of SIB1-GFP proteins. SIB1-GFP proteins were identified by anti-GFP (αGFP) antibody. Seedlings of the sib1 mutant and a transgenic line expressing a GFP-tagged small subunit of Rubisco (GFP) were used as controls for the IP assay. B, iMet of SIB1 was acetylated in all detected Nt peptides by IP-MS analysis. C, MS spectrum of Nt peptide ¹MESSSSTFLTTTSLDKK¹⁷ showing acetylation on iMet.