title: 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.
authors.affiliation: Key Laboratory of Cultivation and Protection for Non-Wood Forest Trees, Ministry of Education, Central South University of Forestry and Technology, Changsha, Hunan Province, People's Republic of China; Department of Plant Science and Landscape Architecture, University of Connecticut, Storrs, Connecticut, United States of America.
authors.forename: Lin
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Cultivation and Protection for Non-Wood Forest Trees, Ministry of Education, Central South University of Forestry and Technology, Changsha, Hunan Province, People's Republic of China.
authors.forename: Baoguang
authors.initials: B
authors.lastname: Jia
authors.affiliation: Key Laboratory of Cultivation and Protection for Non-Wood Forest Trees, Ministry of Education, Central South University of Forestry and Technology, Changsha, Hunan Province, People's Republic of China.
authors.forename: Xiaofeng
authors.initials: X
authors.lastname: Tan
authors.affiliation: Department of Plant Science and Landscape Architecture, University of Connecticut, Storrs, Connecticut, United States of America.
authors.forename: Chandra S
authors.initials: CS
authors.lastname: Thammina
authors.affiliation: Key Laboratory of Cultivation and Protection for Non-Wood Forest Trees, Ministry of Education, Central South University of Forestry and Technology, Changsha, Hunan Province, People's Republic of China.
authors.forename: Hongxu
authors.initials: H
authors.lastname: Long
authors.affiliation: Key Laboratory of Cultivation and Protection for Non-Wood Forest Trees, Ministry of Education, Central South University of Forestry and Technology, Changsha, Hunan Province, People's Republic of China.
authors.forename: Min
authors.initials: M
authors.lastname: Liu
authors.affiliation: Key Laboratory of Cultivation and Protection for Non-Wood Forest Trees, Ministry of Education, Central South University of Forestry and Technology, Changsha, Hunan Province, People's Republic of China.
authors.forename: Shanna
authors.initials: S
authors.lastname: Wen
authors.affiliation: U.S. Department of Agriculture, Agricultural Research Service, Southern Regional Research Center, New Orleans, Louisiana, United States of America.
authors.forename: Xianliang
authors.initials: X
authors.lastname: Song
authors.affiliation: U.S. Department of Agriculture, Agricultural Research Service, Southern Regional Research Center, New Orleans, Louisiana, United States of America.
authors.forename: Heping
authors.initials: H
authors.lastname: Cao
mesh_terms: D031284:Aleurites / Q000235:genetics* / Q000378:metabolism; D005227:Fatty Acids / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D018895:Microsatellite Repeats; D010802:Phylogeny; D059467:Transcriptome; D014197:Trees / Q000235:genetics* / Q000378:metabolism
chemical_list: D005227:Fatty Acids