title: Genome-Wide Identification of MicroRNAs in Leaves and the Developing Head of Four Durum Genotypes during Water Deficit Stress.
abstract: MicroRNAs (miRNAs) are small non-coding RNAs that play critical roles in plant development and abiotic stress responses. The miRNA transcriptome (miRNAome) under water deficit stress has been investigated in many plant species, but is poorly characterised in durum wheat (Triticum turgidum L. ssp. durum). Water stress during early reproductive stages can result in significant yield loss in durum wheat and this study describes genotypic differences in the miRNAome between water deficit tolerant and sensitive durum genotypes. Small RNA libraries (96 in total) were constructed from flag leaf and developing head tissues of four durum genotypes, with or without water stress to identify differentially abundant miRNAs. Illumina sequencing detected 110 conserved miRNAs and 159 novel candidate miRNA hairpins with 66 conserved miRNAs and five novel miRNA hairpins differentially abundant under water deficit stress. Ten miRNAs (seven conserved, three novel) were validated through qPCR. Several conserved and novel miRNAs showed unambiguous inverted regulatory profiles between the durum genotypes. Several miRNAs also showed differential abundance between two tissue types regardless of treatment. Predicted mRNA targets (130) of four novel durum miRNAs were characterised using Gene Ontology (GO) which revealed functions common to stress responses and plant development. Negative correlation was observed between several target genes and the corresponding miRNA under water stress. For the first time, we present a comprehensive study of the durum miRNAome under water deficit stress. The identification of differentially abundant miRNAs provides molecular evidence that miRNAs are potential determinants of water stress tolerance in durum wheat. GO analysis of predicted targets contributes to the understanding of genotypic physiological responses leading to stress tolerance capacity. Further functional analysis of specific stress responsive miRNAs and their interaction with targets is ongoing and will assist in developing future durum wheat varieties with enhanced water deficit stress tolerance.
authors.affiliation: School of Agriculture, Food and Wine, Waite Research Institute, University of Adelaide, Glen Osmond, South Australia, Australia.
authors.forename: Haipei
authors.initials: H
authors.lastname: Liu
authors.affiliation: School of Agriculture, Food and Wine, Waite Research Institute, University of Adelaide, Glen Osmond, South Australia, Australia.|School of Biological Sciences, University of Adelaide, Adelaide, South Australia, Australia.|The University of Adelaide-Shanghai Jiao Tong University Joint International Centre for Agriculture & Health, School of Agriculture, Food and Wine, Waite Research Institute, University of Adelaide, Adelaide, South Australia, Australia.
authors.forename: Iain R
authors.initials: IR
authors.lastname: Searle
authors.affiliation: Australian Centre for Plant Functional Genomics, School of Agriculture, Food and Wine, University of Adelaide, Adelaide, South Australia, Australia.
authors.forename: Nathan S
authors.initials: NS
authors.lastname: Watson-Haigh
authors.affiliation: Australian Centre for Plant Functional Genomics, School of Agriculture, Food and Wine, University of Adelaide, Adelaide, South Australia, Australia.
authors.forename: Ute
authors.initials: U
authors.lastname: Baumann
authors.affiliation: School of Agriculture, Food and Wine, Waite Research Institute, University of Adelaide, Glen Osmond, South Australia, Australia.
authors.forename: Diane E
authors.initials: DE
authors.lastname: Mather
authors.affiliation: School of Agriculture, Food and Wine, Waite Research Institute, University of Adelaide, Glen Osmond, South Australia, Australia.
authors.forename: Amanda J
authors.initials: AJ
authors.lastname: Able
authors.affiliation: School of Agriculture, Food and Wine, Waite Research Institute, University of Adelaide, Glen Osmond, South Australia, Australia.
authors.forename: Jason A
authors.initials: JA
authors.lastname: Able
mesh_terms: D055864:Droughts; D018506:Gene Expression Regulation, Plant; D035683:MicroRNAs / Q000235:genetics*; D018515:Plant Leaves / Q000235:genetics* / Q000502:physiology; D018749:RNA, Plant / Q000235:genetics*; D013312:Stress, Physiological; D014908:Triticum / Q000235:genetics* / Q000502:physiology; D014867:Water / Q000378:metabolism
chemical_list: D035683:MicroRNAs; D018749:RNA, Plant; D014867:Water