Genes affecting novel seed constituents inLimnanthes albaBenth: transcriptome analysis of developing embryos and a new genetic map of meadowfoam

Abstract

The seed oil of meadowfoam, a new crop in the Limnanthaceae family, is highly enriched in very long chain fatty acids that are desaturated at the Δ5 position. The unusual oil is desirable for cosmetics and innovative industrial applications and the seed meal remaining after oil extraction contains glucolimnanthin, a methoxylated benzylglucosinolate whose degradation products are herbicidal and anti-microbial. Here we describe EST analysis of the developing seed transcriptome that identified major genes involved in biosynthesis and assembly of the seed oil and in glucosinolate metabolic pathways. mRNAs encoding acyl-CoA Δ5 desaturase were notably abundant. The library was searched for simple sequence repeats (SSRs) and single nucleotide polymorphisms (SNPs). Fifty-four new SSR markers and eight candidate gene markers were developed and combined with previously developed SSRs to construct a new genetic map for Limnanthes alba. Mapped genes in the lipid biosynthetic pathway encode 3-ketoacyl-CoA synthase (KCS), Δ5 desaturase (Δ5DS), lysophosphatidylacyl-acyl transferase (LPAT), and acyl-CoA diacylglycerol acyl transferase (DGAT). Mapped genes in glucosinolate biosynthetic and degradation pathways encode CYP79A, myrosinase (TGG), and epithiospecifier modifier protein (ESM). The resources developed in this study will further the domestication and improvement of meadowfoam as an oilseed crop.

Ancient Biosyntheses in an Oil Crop: Glucosinolate Profiles in Limnanthes alba and Its Relatives (Limnanthaceae, Brassicales)

“…One batch included our extensive general collection of reference dGSLs 30,31 and the NMR-verified d31 and d45; all batches included all relevant reference samples from our general collection for the particular experiment (such as all listed references in attempts to identify observed isomers). The multiple batches used, and the fact that the most informative MS 2 was not always being from the center of the peak due to the algorithm behind MS 2 selection, means that t R values of the same analyte may vary somewhat (0−0.2 min) in illustrated spectra and chromatograms. Peak identification by comparison with authentic standards consistently included both t R and MS 2 comparisons.…”

“…(meadowfoam) has been developed as a niche oil crop because the seed oil is attractive for the cosmetic industry. 1,2 This "meadowfoam seed oil" is rich in triglycerides based on Δ5 mono-unsaturated long-chain fatty acids. 1,2 The protein-rich (25%) press cake is high in glucosinolates (GSLs).…”

“…1,2 This "meadowfoam seed oil" is rich in triglycerides based on Δ5 mono-unsaturated long-chain fatty acids. 1,2 The protein-rich (25%) press cake is high in glucosinolates (GSLs). At high levels relevant for livestock feed, GSLs are antinutritional compounds lowering the value of the press cake.…”

“…14 Earlier research 16 had also established significant levels of a hydrolysis product of 2-hydroxy-2-methylpropylGSL (31) in L. alba seeds, but this GSL has not been reported from analyses carried out during breeding of L. alba. 2,14 Lack of mentioning of 31 could either mean that the GSL had been lost during breeding or escaped Other Limnanthes species (Figure 2) are valued as ornamental plants (particularly L. douglasii, the poached egg flower) and for lipid biochemical research. 17 Apart from their agronomic and horticultural significance, the eight Limnanthaceae species are also of interest for their rather basal placement in the phylogenetic tree of GSL-containing plants.…”

Two- and Three-Dimensional Spectrofluorimetric Qualitative Analysis of Selected Vegetable Oils for Biomedical Applications

“…Concerning the oil composition, Limnanthes alba is the richest known source of ∆5-unsaturated very long chain fatty acids (VLCFAs) amounting to 87-98 wt.% [23], including mainly monounsaturated fatty acids, namely gondoic acid (C20:1, ω-9) and erucic acid (C22:1, ω-9), but also vitamins A and E, both having antioxidant properties [24][25][26]. Therefore, meadowfoam seed oil is especially used in cosmetic formulations [27]. The content in high amounts of long chain fatty acids (C20-22) ensures the oil a high lubricity and a good penetration rate onto the skin.…”