New features of triacylglycerol biosynthetic pathways of peanut seeds in early developmental stages

Abstract

The peanut (Arachis hypogaea L.) is one of the three most important oil crops in the world due to its high average oil content (50 %). To reveal the biosynthetic pathways of seed oil in the early developmental stages of peanut pods with the goal of improving the oil quality, we presented a method combining deep sequencing analysis of the peanut pod transcriptome and quantitative real-time PCR (RT-PCR) verification of seed oil-related genes. From the sequencing data, approximately 1500 lipid metabolism-associated Unigenes were identified. The RT-PCR results quantified the different expression patterns of these triacylglycerol (TAG) synthesis-related genes in the early developmental stages of peanut pods. Based on these results and analysis, we proposed a novel construct of the metabolic pathways involved in the biosynthesis of TAG, including the Kennedy pathway, acyl-CoA-independent pathway and proposed monoacylglycerol pathway. It showed that the biosynthetic pathways of TAG in the early developmental stages of peanut pods were much more complicated than a simple, unidirectional, linear pathway.

Arachis hypogaea gene expression atlas for fastigiata subspecies of cultivated groundnut to accelerate functional and translational genomics applications

“…The temporal expression patterns of some important genes involved in oil biosynthesis showed that the oil bodies' stability-related oleosin was expressed strongly at seed_25; in contrast, other TAG and FA synthesis-related genes were ª 2020 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd., 18, 2187-2200 expressed at relatively higher level at seed_05 and seed_15 samples As indicated by Yu et al (2015) in their study, our results also indicated that seed first accumulates high levels of the enzymes for oil biosynthesis in the early stage of seed development as compared to the late stage (seed_25). Contrastingly, the biosynthetic rate of proteins (oleosin) for the oil bodies' stability was at high point in the latter stage (seed_25) when the accumulation of seed oil was high.…”

“…In this study, we analysed all of the seed oil-related genes. Global expression data of potential lipid metabolic pathways including the classical Kennedy pathway (GPAT, LPAAT, PAP, DGAT), acyl-CoA-independent pathway (CPT, PDCT, PAP, PLC, PDAT) and FA biosynthesis (ACCase, KAS, SAD, FatA, FatB, LACS) were used to develop a more comprehensive and precise biosynthetic pathway for TAG biosynthesis in groundnut seeds (Yin et al, 2013;Yu et al, 2015). The temporal expression patterns of some important genes involved in oil biosynthesis showed that the oil bodies' stability-related oleosin was expressed strongly at seed_25; in contrast, other TAG and FA synthesis-related genes were ª 2020 The Authors.…”

Seed-Specific Expression of AtLEC1 Increased Oil Content and Altered Fatty Acid Composition in Seeds of Peanut (Arachis hypogaea L.)

“…Finally, acyl chains are added at the sn1-3 sites of the G3P backbone by a series of acyltransferases and form the TAG ( Ohlrogge and Browse, 1995 ; Voelker and Kinney, 2001 ; Sasaki and Nagano, 2004 ). In recent years, several studies have indicated that TAG biosynthesis pathways include the acyl-CoA-dependent Kennedy pathway, the acyl-CoA-independent pathway, and a novel monoacylglycerol pathway ( Yu et al, 2015 ). Thus, the FA composition and content in TAG not only rely on the components of the acyl-CoA pool, but are also involved in the network of acyl fluxes ( Chen et al, 2015 ; Yu et al, 2015 ; Bates, 2016 ; Woodfield et al, 2017 ).…”

Transcriptome comparative analysis of two Camellia species reveals lipid metabolism during mature seed natural drying

“…We identified the presence of oleosins and caleosins proteins in camellia seed, and involved in 4 oleosin unigenes (CL734Contig1, CL422Contig1, CL32127Contig1 and CL25464Contig1) with expression over 1000 RPKM in average (Table 7, S4). So oleosin is the most abundant structural protein in camellia oil bodies like other oilseed crops (Hyun et al 2013;Yu et al 2015;Parthibane et al 2012).…”