N. benthamiana Plastoglobule Proteome

ABSTRACT: Plant chloroplasts contain ubiquitous lipid droplets known as plastoglobules which are characterized by a galactolipid monolayer surrounding a neutral lipid core. Plastoglobules are implicated in plant development and stress tolerance and harbor a set of approximately 30 proteins that presumably drive plastoglobule function. Due to the monolayer structure of plastoglobules, these proteins must associate peripherally. However, targeting determinants have not been identified among any plastoglobule protein, and the protein-membrane interaction mechanisms that establish the plastoglobule proteome remain unclear. We demonstrate that plastoglobule-localized Fibrillins harbor an amphipathic helix at the lip of their β-barrel structure that is necessary for proper plastoglobule association. This project sought to test the impacts of heterologous ectopic targeting of the Arabidopsis thaliana Fibrillin 1a on the tobacco (N. benthamiana) plastoglobule proteome. AtFBN1a, and a deletion-variants removing the amphipathic helix were transiently transformed into tobacco leaf tissue. Isolated plastoglobules were subjected to bottom-up shotgun proteomics analysis with label-free quantification. Isolated plastoglobules from tobacco transiently transformed with GFP alone, driven to the chloroplast stroma by the Rubisco chloroplast transit peptide, were also analyzed as a negative control. The quantitative N. benthamiana plastoglobule proteome from the negative control plants was established, representing the baseline tobacco plastoglobule proteome. This revealed a proteome rich in Fibrillins, representing approximately 66% of the total protein mass, as well as many ABC1 kinases, and lipid metabolic enzymes, similar to the proteome of Arabidopsis. In the presence of ectopic AtFBN proteins, certain proteins were found to be reduced or increased in abundance, pointing to candidate proteins that are either outcompeted from the plastoglobule surface by AtFBN1a or recruited to the plastoglobule by AtFBN1a.

INSTRUMENT(S):

ORGANISM(S): Nicotiana Tabacum (common Tobacco) Arabidopsis Thaliana (mouse-ear Cress)

SUBMITTER: Peter Lundquist  

LAB HEAD: Peter K Lundquist

PROVIDER: PXD045458 | Pride | 2026-05-13

REPOSITORIES: Pride