Proteome Dynamics of the Developing Açaí Berry Pericarp (Euterpe oleracea Mart.)

Quantitative proteome analysis of four developmental
stages of
pericarp tissues of the açaí berry (Euterpe
oleracea Mart.) was performed by the isobaric labeling
of peptides with iTRAQ 4-plex, hydrophilic interaction liquid chromatography
pre-fractionation of labeled peptides, and high-performance mass spectrometry
analysis. This analysis resulted in the identification of 4286 proteins,
of which 476 presented differential abundance between the stages.
The differential abundance of these proteins was seen to be coordinated
with the metabolic demands during cell division, lignification, and
cell expansion at developmental stages 1 and 2 as well as phenolic
acid accumulation and metabolic changes in the fruit maturation at
developmental stages 3 and 4. The distinct accumulation of anthocyanins
observed in the pericarp at developmental stage 4 was correlated with
the increase in abundance of some key biosynthetic enzymes, such as
leucoanthocyanidin dioxygenase, anthocyanidin O-3-glycosyltransferase,
and UDP-glycosyltransferase. Here, evidence is also provided for the
presence in the açaí berry of secondary metabolites
not previously described in açaí, such as pterostilbene,
matairesinol, and furaneol. Together, these results will pave the
way for studies aimed at the genetic improvement of the nutritional
properties of this important fruit crop.