Variations of carotenoid pathways in transgenic maize endosperms highlighted by a Label-Free quantitative proteomics approach

b-carotene and astaxanthin that are mainly produced by chemical synthesis constitute typical supplement feed for poultries and fishes. The project CaroMaize (ANR program Plant-KBBE) proposes to use transgenic maize seeds expressing high level of carotenoids, obtained by metabolic engineering of biosynthesis pathway (Zhu et al.) as a raw source for industry and animal feeding. In addition to metabolomics analyses including the characterization of carotenoids profiles, transgenic maize lines are subjected to integrated transcriptomics and proteomics approach. As such, the proteomic profile of endosperm from transgenic plants enriched in b-carotene and astaxanthin was compared to that of a control genotype. A quantitative label-free proteomics analysis of total protein extracts allowed us to establish a first endosperm protein directory, to describe its functional characteristics and to characterize proteins with significant variations between genotypes highlighting putative variations of the carotenoids pathway.