title: HvEXPB7, a novel β-expansin gene revealed by the root hair transcriptome of Tibetan wild barley, improves root hair growth under drought stress.
abstract: Tibetan wild barley is a treasure trove of useful genes for crop improvement including abiotic stress tolerance, like drought. Root hair of single-celled structures plays an important role in water and nutrition uptake. Polyethylene-glycol-induced drought stress hydroponic/petri-dish experiments were performed, where root hair morphology and transcriptional characteristics of two contrasting Tibetan wild barley genotypes (drought-tolerant XZ5 and drought-sensitive XZ54) and drought-tolerant cv. Tadmor were compared. Drought-induced root hair growth was only observed in XZ5. Thirty-six drought tolerance-associated genes were identified in XZ5, including 16 genes specifically highly expressed in XZ5 but not Tadmor under drought. The full length cDNA of a novel β-expansin gene (HvEXPB7), being the unique root hair development related gene in the identified genes, was cloned. The sequence comparison indicated that HvEXPB7 carried both DPBB_1 and Pollon_allerg_1 domains. HvEXPB7 is predominantly expressed in roots. Subcellular localization verified that HvEXPB7 is located in the plasma membrane. Barley stripe mosaic virus induced gene silencing (BSMV-VIGS) of HvEXPB7 led to severely suppressed root hairs both under control and drought conditions, and significantly reduced K uptake. These findings highlight and confer the significance of HvEXPB7 in root hair growth under drought stress in XZ5, and provide a novel insight into the genetic basis for drought tolerance in Tibetan wild barley.
authors.affiliation: Department of Agronomy, College of Agriculture and Biotechnology, Zijingang Campus, Zhejiang University, Hangzhou 310058, PR China.
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: He
authors.affiliation: Department of Agronomy, College of Agriculture and Biotechnology, Zijingang Campus, Zhejiang University, Hangzhou 310058, PR China.
authors.forename: Jianbin
authors.initials: J
authors.lastname: Zeng
authors.affiliation: Department of Agronomy, College of Agriculture and Biotechnology, Zijingang Campus, Zhejiang University, Hangzhou 310058, PR China.
authors.forename: Fangbin
authors.initials: F
authors.lastname: Cao
authors.affiliation: Department of Agronomy, College of Agriculture and Biotechnology, Zijingang Campus, Zhejiang University, Hangzhou 310058, PR China.
authors.forename: Imrul Mosaddek
authors.initials: IM
authors.lastname: Ahmed
authors.affiliation: Department of Agronomy, College of Agriculture and Biotechnology, Zijingang Campus, Zhejiang University, Hangzhou 310058, PR China.
authors.forename: Guoping
authors.initials: G
authors.lastname: Zhang
authors.affiliation: Department of Molecular Biology and Genetics, University of Aarhus, Fosøgsvej 1, DK-4200 Slagelse, Denmark.
authors.forename: Eva
authors.initials: E
authors.lastname: Vincze
authors.affiliation: Department of Agronomy, College of Agriculture and Biotechnology, Zijingang Campus, Zhejiang University, Hangzhou 310058, PR China wufeibo@zju.edu.cn.
authors.forename: Feibo
authors.initials: F
authors.lastname: Wu
mesh_terms: D000595:Amino Acid Sequence; D003001:Cloning, Molecular; D055864:Droughts; D018506:Gene Expression Regulation, Plant; D020868:Gene Silencing; D017343:Genes, Plant; D005838:Genotype; D001467:Hordeum / Q000235:genetics* / Q000502:physiology; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000235:genetics*; D018517:Plant Roots; D060888:Real-Time Polymerase Chain Reaction; D013312:Stress, Physiological / Q000235:genetics; D018609:Tibet; D059467:Transcriptome
chemical_list: D010940:Plant Proteins; C095825:expansin protein, plant
keywords: BSMV-VIGS; RNA-Seq; Tibetan wild barley; drought; root hair; β-expansin gene (HvEXPB7).