title: Characterization of Glycolytic Pathway Genes Using RNA-Seq in Developing Kernels of Eucommia ulmoides.
abstract: Eucommia ulmoides Oliver, the only member of the Eucommiaceae family, is a rare and valuable tree used to produce a highly valued traditional Chinese medicine and contains α-linolenic acid (ALA) up to 60% of the total fatty acids in the kernels (embryos). Glycolysis provides both cellular energy and the intermediates for other biosynthetic processes. However, nothing was known about the molecular basis of the glycolytic pathway in E. ulmoides kernels. The purposes of this study were to identify novel genes of E. ulmoides related to glycolytic metabolism and to analyze the expression patterns of selected genes in the kernels. Transcriptome sequencing based on the Illumina platform generated 96,469 unigenes in four cDNA libraries constructed using RNAs from 70 and 160 days after flowering kernels of both low- and high-ALA varieties. We identified and characterized the digital expression of 120 unigenes coding for 24 protein families involved in kernel glycolytic pathway. The expression levels of glycolytic genes were generally higher in younger kernels than in more mature kernels. Importantly, several unigenes from kernels of the high-ALA variety were expressed more than those from the low-ALA variety. The expression of 10 unigenes encoding key enzymes in the glycolytic pathway was validated by qPCR using RNAs from six kernel stages of each variety. The qPCR data were well consistent with their digital expression in transcriptomic analyses. This study identified a comprehensive set of genes for glycolytic metabolism and suggests that several glycolytic genes may play key roles in ALA accumulation in the kernels of E. ulmoides.
authors.affiliation: Paulownia Research and Development Center, State Forestry Administration , Zhengzhou, Henan 450003, China.|Key Laboratory of Cultivation and Protection for Non-Wood Forest Trees, Ministry of Education, Central South University of Forestry and Technology , Changsha, Hunan 410004, China.
authors.forename: Yanzhi
authors.initials: Y
authors.lastname: Feng
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 410004, China.
authors.forename: Lin
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Paulownia Research and Development Center, State Forestry Administration , Zhengzhou, Henan 450003, China.
authors.forename: Jianmin
authors.initials: J
authors.lastname: Fu
authors.affiliation: Paulownia Research and Development Center, State Forestry Administration , Zhengzhou, Henan 450003, China.
authors.forename: Fangdong
authors.initials: F
authors.lastname: Li
authors.affiliation: Paulownia Research and Development Center, State Forestry Administration , Zhengzhou, Henan 450003, China.
authors.forename: Lu
authors.initials: L
authors.lastname: Wang
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 410004, China.
authors.forename: Xiaofeng
authors.initials: X
authors.lastname: Tan
authors.affiliation: Forestry Experiment Center of North China, Chinese Academy of Forestry , Beijing 102300, China.
authors.forename: Wenjuan
authors.initials: W
authors.lastname: Mo
authors.affiliation: Southern Regional Research Center, Agricultural Research Service, U.S. Department of Agriculture , New Orleans, Louisiana 70124, United States.
authors.forename: Heping
authors.initials: H
authors.lastname: Cao
mesh_terms: D031283:Eucommiaceae / Q000235:genetics* / Q000378:metabolism; D020869:Gene Expression Profiling; D006019:Glycolysis; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D018749:RNA, Plant / Q000235:genetics*; D060888:Real-Time Polymerase Chain Reaction; D012639:Seeds / Q000235:genetics / Q000378:metabolism; D017962:alpha-Linolenic Acid / Q000378:metabolism
chemical_list: D010940:Plant Proteins; D018749:RNA, Plant; D017962:alpha-Linolenic Acid
keywords: Eucommia ulmoides; RNA-seq; glycolytic pathway; quantitative real-time PCR (qPCR); transcriptome; unigene; α-linolenic acid