Proteomic changes associated with the development of açaí (Euterpe oleracea Mart.) seeds

Abstract

Açaí palm (Euterpe oleracea Mart.) seeds are a rich source of mannans, which can be used to generate bioethanol or be converted to high‐value D‐mannose, in addition to being a source of polyphenols with beneficial health properties. Here, we present a quantitative proteome dataset of açaí seeds at four stages of development (S1, S2, S3, and S4 stages), in which 2465 high confidence proteins were identified and 524 of them show statistically different abundance profiles during development. Several enzymes involved in the biosynthesis of nucleotide‐sugars were quantified, especially those dedicated to the formation of GDP‐mannose, which showed an increase in abundance between stages S1 and S3. Our data suggest that linear mannans found abundantly in endosperm cell walls are initially deposited as galactomannans, and during development lose the galactosyl groups. Two isoforms of alpha‐galactosidase enzymes showed significantly increased abundances in the S3 and S4 stages. Additionally, we quantified the enzymes participating in the central pathway of flavonoid biosynthesis responsible for the formation of catechin and epicatechin, which are subunits of procyanidins, the main class of polyphenols in the açaí seeds. These proteins showed the same pattern of deposition, in which higher abundances were seen in the S1 and S2 stages.

Comparative proteomics of round and wrinkled pea (Pisum sativum L.) during seed development period

“…The early seed growth stages, such as 4DAA for E3 (n = 2770), 7DAA for E1 (n = 2852), and 12DAA for E4 (n = 2637), had the highest protein detection, and the least at maturity (1198 for E3, 1396 for E1, and 1467 for E4) (Figure 2). Neto and co-workers [22] also reported a fewer number of proteins in late seed development of acai palm seed, due to the presence of high abundance proteins and the difficulty of extracting proteins from the thick and lignified tissues. Proteins that were shared among all the time-points ranged in number from 895 for E3 to 1089 for E4 (about 22-26% of the detected protein groups).…”

Phenolic Profile and Antioxidant Properties in Extracts of Developing Açaí (Euterpe oleracea Mart.) Seeds

“…To investigate this, we analyzed the abundance of these critical PC biosynthetic enzymes at each seed developmental stage, to evaluate if the changes in the PC starter unit composition throughout seed development could correlate to the availability of these enzymes. This analysis was based on publicly available quantitative proteomics data published by our group in a recent study of açaí seeds at these same developmental stages . A scheme including what is known about PC biosynthesis is shown in Figure .…”

“…The quantitative data of the enzymes dihydroflavonol 4-reductase (DFR), leucoanthocyanidin dioxygenase (LDOX), anthocyanidin reductase (ANR), and isoflavone reductase-like (IFRL) were retrieved from the proteomic analysis of developing açaí seeds deposited in ProteomeXchange/PRIDE, under access code PXD003453 and previously published data . Their abundance values during the development of açaí seeds had their means compared by Tukey’s HSD test (FDR ≤ 0.05) and used to construct the graphs in GraphPad Prism 7.0.…”

“…This analysis was based on publicly available quantitative proteomics data published by our group in a recent study of acai ́seeds at these same developmental stages. 28 A scheme including what is known about PC biosynthesis is shown in Figure 3. Generally, the dihydroflavonol 4-reductase (DFR) (EC 1.1.1.219) converts (+)-dihydroflavonols to yield 2,3-trans-leucocyanidin, which is transformed (non-enzymatically) to p-quinone methiode to provide (+)-catechin as extension units while also being a substrate for leucoanthocyanidin reductase (LAR) (EC:1.17.1.3) and anthocyanidin synthase (ANS) (EC 1.14.20.4), which catalyzes the formation of (+)-catechin, as a starter unit, and flav-3-en-3,4-diol, respectively.…”

Acquiring thin histological sections of açaí (Euterpe oleracea Mart.) seeds for molecular mapping by mass spectrometry imaging

“…However, there is a very small amount of information about the localization of primary compounds in açaí seeds. A previous study has quantitatively analyzed the proteome dynamics and morphological aspects of the açaí pericarp and seed during the developmental stages 17,18 . Also, a recent histochemical study provided the presence of phenolic compounds and carbohydrates in the açaí seed coat and endosperm, respectivelly 19 .…”