title: Heat shock factor C2a serves as a proactive mechanism for heat protection in developing grains in wheat via an ABA-mediated regulatory pathway.
abstract: High temperature at grain filling can severely reduce wheat yield. Heat shock factors (Hsfs) are central regulators in heat acclimation. This study investigated the role of TaHsfC2a, a member of the monocot-specific HsfC2 subclass, in the regulation of heat protection genes in Triticum aestivum. Three TaHsfC2a homoeologous genes were highly expressed in wheat grains during grain filling and showed only transient up-regulation in the leaves by heat stress but were markedly up-regulated by drought and abscisic acid (ABA) treatment. Overexpression of TaHsfC2a-B in transgenic wheat resulted in up-regulation of a suite of heat protection genes (e.g. TaHSP70d and TaGalSyn). Most TaHsfC2a-B target genes were heat, drought and ABA inducible. Transactivation analysis of two representative targets (TaHSP70d and TaGalSyn) showed that TaHsfC2a-B activated expression of reporters driven by these target promoters. Promoter mutagenesis analyses revealed that heat shock element is responsible for transactivation by TaHsfC2a-B and heat/drought induction. TaHsfC2a-B-overexpressing wheat showed improved thermotolerance but not dehydration tolerance. Most TaHsfC2a-B target genes were co-up-regulated in developing grains with TaHsfC2a genes. These data suggest that TaHsfC2a-B is a transcriptional activator of heat protection genes and serves as a proactive mechanism for heat protection in developing wheat grains via the ABA-mediated regulatory pathway.
authors.affiliation: Linyi University, Middle of Shuangling Road, Linyi, Shandong, 276000, China.|CSIRO Agriculture and Food Flagship, 306 Carmody Road, St Lucia, Queensland, 4067, Australia.
authors.forename: Xiao-Jun
authors.initials: XJ
authors.lastname: Hu
authors.affiliation: CSIRO Agriculture and Food Flagship, 306 Carmody Road, St Lucia, Queensland, 4067, Australia.
authors.forename: Dandan
authors.initials: D
authors.lastname: Chen
authors.affiliation: CSIRO Agriculture and Food Flagship, 306 Carmody Road, St Lucia, Queensland, 4067, Australia.
authors.forename: C
authors.initials: C
authors.lastname: Lynne Mclntyre
authors.affiliation: CSIRO Agriculture and Food Flagship, 306 Carmody Road, St Lucia, Queensland, 4067, Australia.
authors.forename: M
authors.initials: M
authors.lastname: Fernanda Dreccer
authors.affiliation: Center for Agricultural Resources Research, Institute of Genetics and Developmental Biology, Chinese Academy of Science, Shijiazhuang, 050021, China.
authors.forename: Zheng-Bin
authors.initials: ZB
authors.lastname: Zhang
authors.affiliation: CSIRO Agriculture and Food Flagship, 306 Carmody Road, St Lucia, Queensland, 4067, Australia.
authors.forename: Janneke
authors.initials: J
authors.lastname: Drenth
authors.affiliation: CSIRO Agriculture and Food Flagship, 306 Carmody Road, St Lucia, Queensland, 4067, Australia.
authors.forename: Sundaravelpandian
authors.initials: S
authors.lastname: Kalaipandian
authors.affiliation: CSIRO Agriculture and Food Flagship, 306 Carmody Road, St Lucia, Queensland, 4067, Australia.
authors.forename: Hongping
authors.initials: H
authors.lastname: Chang
authors.affiliation: CSIRO Agriculture and Food Flagship, 306 Carmody Road, St Lucia, Queensland, 4067, Australia.
authors.forename: Gang-Ping
authors.identifier: http://orcid.org/0000-0002-1135-1768
authors.initials: GP
authors.lastname: Xue
mesh_terms: D000040:Abscisic Acid / Q000378:metabolism*; D001483:Base Sequence; D055864:Droughts; D056625:Endosperm / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D017930:Genes, Reporter; D049452:Green Fluorescent Proteins / Q000378:metabolism; D006360:Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism*; D018869:Heat-Shock Response / Q000235:genetics; D006358:Hot Temperature; D018384:Oxidative Stress / Q000235:genetics; D018515:Plant Leaves / Q000235:genetics; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D018517:Plant Roots / Q000235:genetics; D030821:Plants, Genetically Modified; D011401:Promoter Regions, Genetic / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012639:Seeds / Q000254:growth & development* / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid; D013214:Starch Synthase / Q000378:metabolism; D013312:Stress, Physiological / Q000235:genetics; D000071436:Thermotolerance / Q000235:genetics; D015533:Transcriptional Activation / Q000235:genetics; D014908:Triticum / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism*; D015854:Up-Regulation / Q000235:genetics
chemical_list: D006360:Heat-Shock Proteins; D010940:Plant Proteins; D012333:RNA, Messenger; D049452:Green Fluorescent Proteins; D000040:Abscisic Acid; D013214:Starch Synthase
keywords: abscisic acid; drought stress; heat stress; transcriptional regulation