Fatty Acid Profile and Unigene-Derived Simple Sequence Repeat Markers in Tung Tree (Vernicia fordii)

Abstract

Tung tree (Vernicia fordii) provides the sole source of tung oil widely used in industry. Lack of fatty acid composition and molecular markers hinders biochemical, genetic and breeding research. The objectives of this study were to determine fatty acid profiles and develop unigene-derived simple sequence repeat (SSR) markers in tung tree. Fatty acid profiles of 41 accessions showed that the ratio of α-eleostearic acid was increasing continuously with a parallel trend to the amount of tung oil accumulation while the ratios of other fatty acids were decreasing in different stages of the seeds and that α-eleostearic acid (18∶3) consisted of 77% of the total fatty acids in tung oil. Transcriptome sequencing identified 81,805 unigenes from tung cDNA library constructed using seed mRNA and discovered 6,366 SSRs in 5,404 unigenes. The di- and tri-nucleotide microsatellites accounted for 92% of the SSRs with AG/CT and AAG/CTT being the most abundant SSR motifs. Fifteen polymorphic genic-SSR markers were developed from 98 unigene loci tested in 41 cultivated tung accessions by agarose gel and capillary electrophoresis. Genbank database search identified 10 of them putatively coding for functional proteins. Quantitative PCR demonstrated that all 15 polymorphic SSR-associated unigenes were expressed in tung seeds and some of them were highly correlated with oil composition in the seeds. Dendrogram revealed that most of the 41 accessions were clustered according to the geographic region. These new polymorphic genic-SSR markers will facilitate future studies on genetic diversity, molecular fingerprinting, comparative genomics and genetic mapping in tung tree. The lipid profiles in the seeds of 41 tung accessions will be valuable for biochemical and breeding studies.

An investigation into the curing of urushi and tung oil films by thermoanalytical and mass spectrometric techniques

“…In particular, αeleostearic acid ((9Z,11E,13E)-octadeca-9,11,13-trienoic acid) accounts for ca. 80 % of the fatty acids 6 . Tung oil thus belongs to the group of drying oils that polymerise under exposure to air and light 7 .…”

“…The evolved gaseous compounds were directly transferred to the mass spectrometer, where they were ionised and analysed as a function of time.2.5. GC-MS.Standard solutions of lauric acid (5,216 μg/g), suberic acid (5,474 μg/g), myristic acid (3,889 μg/g), azelaic acid (3,844 μg/g), sebacic acid (4,128 μg/g), palmitic acid (4,530 μg/g), oleic acid (6,279 μg/g), and stearic acid(6,198 μg/g) were made in acetone. Different volumes of the standard solutions were used to obtain calibration curves, with which the concentration of the fatty acids in the samples was then calculated.…”

Genome-Wide Analysis of Oleosin Gene Family in 22 Tree Species: An Accelerator for Metabolic Engineering of BioFuel Crops and Agrigenomics Industrial Applications?

“…Plant TAGs are both for human consumption and for industrial applications (Cahoon et al, 2007;Dyer et al, 2008) including biofuel production (Carvalho et al, 2008;Chen et al, 2010b;Tai and Stephanopoulos, 2013;Winichayakul et al, 2013). Many trees contain up to 50%-80% of oil in the seeds and fruits (Cao et al, 2013;Chen et al, 2008;Zeng et al, 2014;Zhang et al, 2014). The amounts of TAGs are influenced by OLEs, generally low-molecular-mass hydrophobic proteins covering the oil bodies/droplets (Dyer et al, 2008;Huang, 1992).…”

“…Plant TAGs are rich source of edible oils for human consumption and special oils for industrial applications (Cahoon et al, 2007;Dyer et al, 2008) and biofuels (Carvalho et al, 2008;Chen et al, 2010b;Tai and Stephanopoulos, 2013;Winichayakul et al, 2013). Trees contribute to enormous plant oil reserves because fruits and kernels of many trees contain up to 50%-80% of oil (Cao et al, 2013;Chen et al, 2008;Zeng et al, 2014;Zhang et al, 2014).…”

The Tung Tree (Vernicia Fordii) Genome Provides A Resource for Understanding Genome Evolution and Oil Improvement

“…As the major component in tung oil, α-ESA has three conjugated double bonds (9 cis, 11 trans, 13 trans), and thus is easily oxidized. Due to its excellent characteristics, tung oil has been widely used as a drying ingredient in paints, varnishes, coating and finishes since ancient times [2]. Tung oil also can be used for synthesizing thermosetting polymers and resins with superior properties [3, 4], and has been proposed as a potential source of biodiesel [5–7].…”