title: Constitutive expression of a miR319 gene alters plant development and enhances salt and drought tolerance in transgenic creeping bentgrass.
abstract: MicroRNA319 (miR319) is one of the first characterized and conserved microRNA families in plants and has been demonstrated to target TCP (for TEOSINTE BRANCHED/CYCLOIDEA/PROLIFERATING CELL FACTORS [PCF]) genes encoding plant-specific transcription factors. MiR319 expression is regulated by environmental stimuli, suggesting its involvement in plant stress response, although experimental evidence is lacking and the underlying mechanism remains elusive. This study investigates the role that miR319 plays in the plant response to abiotic stress using transgenic creeping bentgrass (Agrostis stolonifera) overexpressing a rice (Oryza sativa) miR319 gene, Osa-miR319a. We found that transgenic plants overexpressing Osa-miR319a displayed morphological changes and exhibited enhanced drought and salt tolerance associated with increased leaf wax content and water retention but reduced sodium uptake. Gene expression analysis indicated that at least four putative miR319 target genes, AsPCF5, AsPCF6, AsPCF8, and AsTCP14, and a homolog of the rice NAC domain gene AsNAC60 were down-regulated in transgenic plants. Our results demonstrate that miR319 controls plant responses to drought and salinity stress. The enhanced abiotic stress tolerance in transgenic plants is related to significant down-regulation of miR319 target genes, implying their potential for use in the development of novel molecular strategies to genetically engineer crop species for enhanced resistance to environmental stress.
authors.affiliation: Department of Genetics and Biochemistry, Clemson University, Clemson, SC 29634, USA.
authors.forename: Man
authors.initials: M
authors.lastname: Zhou
authors.forename: Dayong
authors.initials: D
authors.lastname: Li
authors.forename: Zhigang
authors.initials: Z
authors.lastname: Li
authors.forename: Qian
authors.initials: Q
authors.lastname: Hu
authors.forename: Chunhua
authors.initials: C
authors.lastname: Yang
authors.forename: Lihuang
authors.initials: L
authors.lastname: Zhu
authors.forename: Hong
authors.initials: H
authors.lastname: Luo
mesh_terms: D000222:Adaptation, Physiological / Q000187:drug effects / Q000235:genetics*; D031703:Agrostis / Q000033:anatomy & histology / Q000187:drug effects / Q000235:genetics* / Q000254:growth & development; D001483:Base Sequence; D002462:Cell Membrane / Q000187:drug effects / Q000502:physiology; D055864:Droughts; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects; D018506:Gene Expression Regulation, Plant / Q000187:drug effects*; D017343:Genes, Plant / Q000235:genetics; D058685:Genetic Pleiotropy / Q000187:drug effects; D035683:MicroRNAs / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D009929:Organ Size / Q000187:drug effects / Q000235:genetics; D012275:Oryza / Q000187:drug effects / Q000235:genetics; D010641:Phenotype; D010788:Photosynthesis / Q000187:drug effects / Q000235:genetics; D063245:Plant Development / Q000187:drug effects / Q000235:genetics*; D018515:Plant Leaves / Q000033:anatomy & histology / Q000187:drug effects; D030821:Plants, Genetically Modified; D054712:Salinity; D055049:Salt Tolerance / Q000187:drug effects / Q000235:genetics; D012964:Sodium / Q000378:metabolism; D012965:Sodium Chloride / Q000494:pharmacology*; D013312:Stress, Physiological / Q000187:drug effects / Q000235:genetics; D014867:Water / Q000378:metabolism; D014885:Waxes / Q000378:metabolism
chemical_list: D035683:MicroRNAs; D014885:Waxes; D014867:Water; D012965:Sodium Chloride; D012964:Sodium