Comparative Transcriptomics Analysis of Brassica napus L. during Seed Maturation Reveals Dynamic Changes in Gene Expression between Embryos and Seed Coats and Distinct Expression Profiles of Acyl-CoA-Binding Proteins for Lipid Accumulation

Abstract

Production of vegetable oils is a vital agricultural resource and oilseed rape (Brassica napus) is the third most important oil crop globally. Although the regulation of lipid biosynthesis in oilseeds is still not fully defined, the acyl-CoA-binding proteins (ACBPs) have been reported to be involved in such metabolism, including oil accumulation, in several plant species. In this study, progressive changes in gene expression in embryos and seed coats at different stages of seed development were comprehensively investigated by transcriptomic analyses in B. napus, revealing dynamic changes in the expression of genes involved in lipid biosynthesis. We show that genes encoding BnACBP proteins show distinct changes in expression at different developmental stages of seed development and show markedly different expression between embryos and seed coats. Both isoforms of the ankyrin-repeat BnACBP2 increased during the oil accumulation period of embryo development. By contrast, the expression of the three most abundant isoforms of the small molecular mass BnACBP6 in embryos showed progressive reduction, despite having the highest overall expression level. In seed coats, BnACBP3, BnACBP4 and BnACBP5 expression remained constant during development, whereas the two major isoforms of BnACBP6 increased, contrasting with the data from embryos. We conclude that genes related to fatty acid and triacylglycerol biosynthesis showing dynamic expression changes may regulate the lipid distribution in embryos and seed coats of B. napus and that BnACBP2 and BnACBP6 are potentially important for oil accumulation.

De novo transcriptome assembly for the five major organs of Zanthoxylum armatum and the identification of genes involved in terpenoid compound and fatty acid metabolism

“…In a previous study, genes related to fatty acid biosynthesis were grouped into two categories and detected in the early or later stages of seed development in tree peony [49]. Similarly, the coordinated regulation of multiple genes has been shown to promote the high accumulation of longchain unsaturated fatty acids in the seeds of tea oil camellia [50], and consistent results have been obtained in Brassica napus [51,52], Glycine max [53], and Linum usitatissimum [54]. Above all, the present results indicated that 40 days after fertilization could be a key point at which the first few steps of fatty acid biosynthesis are promoted in Z. armatum, and the subsequent reactions could be catalysed and completed in the stage occurring 62 days after fertilization, especially for long-chain fatty acid biosynthesis.…”

RICE ACYL-COA-BINDING PROTEIN6 Affects Acyl-CoA Homeostasis and Growth in Rice

“…Thus far, the functions of plant ACBPs have been widely elucidated in the eudicots, such as Arabidopsis and Brassica napus , although there have been many reports on the characterization of ACBP family members from other plant species, such as Oryza sativa , Agave americana , Vernicia fordii , Vitis vinifera , Helianthus annuus , Gossypium hirsutum , Jatropha curcas , and Elaeis guineensis (Du et al 2016 ; Raboanatahiry et al 2018 ; Liao et al 2019 ; Amiruddin et al 2020 ). Other than Arabidopsis and Brassica napus , the functions of ACBPs from other plant species have been mostly investigated using transgenic Arabidopsis (Takato et al 2013 ; Meng et al 2014 ; Panthapulakkal Narayanan et al 2019 ).…”

Big data from small tissues: extraction of high-quality RNA for different plant tissue types during oilseedBrassicaspp. seed development for RNA-Sequencing

“…Removing these contaminants is a critical step, as RNA with high purity and integrity is critical for gene expression analyses. Although there are several methods available for seed RNA extraction (Kanai et al, 2017;Pereira et al, 2017;Mornkham et al, 2013;Suzuki et al, 2004); fewer protocols are available for the extraction of good quality RNA from specific seed tissue types, especially for the seed coat (Jiang et al, 2019;Liao et al, 2019;Hong et al, 2017;Kour et al, 2014).…”