title: Molecular Mechanisms Underlying Hull-Caryopsis Adhesion/Separation Revealed by Comparative Transcriptomic Analysis of Covered/Naked Barley (Hordeum vulgare L.).
abstract: The covered/naked caryopsis trait of barley is an important agronomic trait because it is directly linked to dietary use. The formation of covered/naked caryopsis is controlled by an NUD transcription factor, which is involved in pericarp cuticle development. However, the molecular mechanism underlying this trait remains so far largely unknown. In this study, comparative transcriptomes of grains three weeks after anthesis of Tibetan Hulless barley landrace Dulihuang and covered barley Morex were analyzed using RNA-seq technique. A total of 4031 differentially expressed genes (DEGs) were identified. The Nud gene was overexpressed in Morex, with trace expression in Dulihuang. Among seventeen cuticle related DEGs, sixteen were down regulated and one up regulated in Morex. These results suggest that the Nud gene in covered caryopsis might down regulate cuticle related genes, which may cause a permeable cuticle over pericarp, leading to a hull-caryopsis organ fusion. A functional cuticle covering the pericarp of naked caryopsis might be the result of deletion or low expression level of the Nud gene. The functional cuticle defines a perfect boundary to separate the caryopsis from the hull in naked barley.
authors.affiliation: Key Laboratory of Cold and Arid Regions Stress Physiology and Ecology in Gansu Province, Cold and Arid Regions Environmental and Engineering Institute, Chinese Academy of Sciences, Lanzhou 730000, China. ruijunduan@163.com.|National Key Laboratory Breeding Base for Innovation and Utilization of Plateau Crop Germplasm, Qinghai University, Xining 810016, China. ruijunduan@163.com.
authors.forename: Ruijun
authors.initials: R
authors.lastname: Duan
authors.affiliation: College of Agriculture and Animal Husbandry, Qinghai University, Xining 810016, China. huiyanxqh@163.com.
authors.forename: Huiyan
authors.initials: H
authors.lastname: Xiong
authors.affiliation: Key Laboratory of Cold and Arid Regions Stress Physiology and Ecology in Gansu Province, Cold and Arid Regions Environmental and Engineering Institute, Chinese Academy of Sciences, Lanzhou 730000, China. cabin.wang@gmail.com.
authors.forename: Aidong
authors.initials: A
authors.lastname: Wang
authors.affiliation: Key Laboratory of Cold and Arid Regions Stress Physiology and Ecology in Gansu Province, Cold and Arid Regions Environmental and Engineering Institute, Chinese Academy of Sciences, Lanzhou 730000, China. guoxiong@lzb.ac.cn.
authors.forename: Guoxiong
authors.initials: G
authors.lastname: Chen
mesh_terms: D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D059014:High-Throughput Nucleotide Sequencing; D001467:Hordeum / Q000737:chemistry / Q000235:genetics* / Q000254:growth & development; D010940:Plant Proteins / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012639:Seeds / Q000737:chemistry / Q000235:genetics* / Q000254:growth & development; D059467:Transcriptome / Q000235:genetics*
chemical_list: D010940:Plant Proteins; D012333:RNA, Messenger
keywords: RNA-seq; barley; covered/naked caryopsis; plant cuticle; transcriptome