Plastoglobules are a biosynthetic platform contributing to carotenoid accumulation during tomato fruit maturation

Chloroplasts and chromoplasts of tomato fruits contain lipid droplets known as plastoglobules (PG). Recent studies have shown that PG act as a metabolic sink to store triacylglycerol (TAG), carotenoids, vitamin E, and K as well as other lipophile compounds. In addition, it has been shown that proteins associated with PG contribute to prenyl lipid metabolic pathways and homeostasis. Proteome studies in Arabidopsis and bell pepper, have demonstrated that PG contains a specific proteome containing around 30 proteins. So far, the tomato PG proteome particularly that of red fruit (chromoplast) has not yet been established. We have investigated the chromoplast PG proteome and metabolome and identified 17 new candidate proteins of chromoplast PG with known PG proteins. Interestingly, most of the carotenoid biosynthetic pathway enzymes such as PSY‐1, PDS, ZDS, CRTISO, and β‐LYC are enriched in chromoplast PG compared with chloroplast PG. In this study, we propose a model of chromoplast PG acting as a carotenoid biosynthesis platform.