Abstract
Chloroplasts, the green plastid-type present in all photosynthetic organisms, are the physical place where photosynthesis and many other metabolic pathways occur. Chloroplasts are essential for plants, not only by performing photosynthesis but also due to the production of important compounds comprising a great variety of secondary metabolites, lipids, and plant hormones. The production of these compounds is highly regulated and coordinated with development in crops that have fruits with specialized plastids called chromoplasts. Study of plastid biology is essential to understand plant physiology and how plastid biogenesis and development impact plant growth. With the introduction of the genetic and genomic technologies to plant research the discovery and functional characterization of chloroplast proteins was boosted. Nowadays, technologies such as transcriptomics and proteomics are routinely used to assign functions to chloroplast proteins. The generation of high-throughput data sets allows a great increase in our knowledge about many chloroplast processes (e.g. pigment synthesis and accumulation, chloroplast to chromoplast transition, protein degradation) but also the possibility to apply these knowledge to genetically modify plants to improve beneficial traits (e.g. biomass, carotenoid content). The aim of this review is to highlight the importance of proteomic approaches for the study of plastid biology and how this technique speeds up the gain of knowledge in this field.