title: Identification of the dehydrin gene family from grapevine species and analysis of their responsiveness to various forms of abiotic and biotic stress.
abstract: BACKGROUND
  Dehydrins (DHNs) protect plant cells from desiccation damage during environmental stress, and also participate in host resistance to various pathogens. In this study, we aimed to identify and characterize the DHN gene families from Vitis vinifera and wild V. yeshanensis, which is tolerant to both drought and cold, and moderately resistant to powdery mildew.
  
  
  RESULTS
  Four DHN genes were identified in both V. vinifera and V. yeshanensis, which shared a high sequence identity between the two species but little homology between the genes themselves. These genes were designated DHN1, DHN2, DHN3 and DHN4. All four of the DHN proteins were highly hydrophilic and were predicted to be intrinsically disordered, but they differed in their isoelectric points, kinase selectivities and number of functional motifs. Also, the expression profiles of each gene differed appreciably from one another. Grapevine DHN1 was not expressed in vegetative tissues under normal growth conditions, but was induced by drought, cold, heat, embryogenesis, as well as the application of abscisic acid (ABA), salicylic acid (SA), and methyl jasmonate (MeJA). It was expressed earlier in V. yeshanensis under drought conditions than in V. vinifera, and also exhibited a second round of up-regulation in V. yeshanensis following inoculation with Erysiphe necator, which was not apparent in V. vinifera. Like DHN1, DHN2 was induced by cold, heat, embryogenesis and ABA; however, it exhibited no responsiveness to drought, E. necator infection, SA or MeJA, and was also expressed constitutively in vegetative tissues under normal growth conditions. Conversely, DHN3 was only expressed during seed development at extremely low levels, and DHN4 was expressed specifically during late embryogenesis. Neither DHN3 nor DHN4 exhibited responsiveness to any of the treatments carried out in this study. Interestingly, the presence of particular cis-elements within the promoter regions of each gene was positively correlated with their expression profiles.
  
  
  CONCLUSIONS
  The grapevine DHN family comprises four divergent members. While it is likely that their functions overlap to some extent, it seems that DHN1 provides the main stress-responsive function. In addition, our results suggest a close relationship between expression patterns, physicochemical properties, and cis-regulatory elements in the promoter regions of the DHN genes.
authors.affiliation: College of Horticulture, Northwest A&F University, Yangling, Shaanxi 712100, China.
authors.forename: Yazhou
authors.initials: Y
authors.lastname: Yang
authors.forename: Mingyang
authors.initials: M
authors.lastname: He
authors.forename: Ziguo
authors.initials: Z
authors.lastname: Zhu
authors.forename: Shuxiu
authors.initials: S
authors.lastname: Li
authors.forename: Yan
authors.initials: Y
authors.lastname: Xu
authors.forename: Chaohong
authors.initials: C
authors.lastname: Zhang
authors.forename: Stacy D
authors.initials: SD
authors.lastname: Singer
authors.forename: Yuejin
authors.initials: Y
authors.lastname: Wang
mesh_terms: D000040:Abscisic Acid / Q000494:pharmacology; D000085:Acetates / Q000494:pharmacology; D000595:Amino Acid Sequence; D001203:Ascomycota / Q000472:pathogenicity; D032461:Chromosomes, Plant / Q000235:genetics; D003080:Cold Temperature; D003517:Cyclopentanes / Q000494:pharmacology; D055864:Droughts; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D008969:Molecular Sequence Data; D054883:Oxylipins / Q000494:pharmacology; D010802:Phylogeny; D010935:Plant Diseases / Q000382:microbiology; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D012045:Regulatory Sequences, Nucleic Acid; D020156:Salicylic Acid / Q000494:pharmacology; D012639:Seeds / Q000187:drug effects / Q000235:genetics; D016415:Sequence Alignment; D013312:Stress, Physiological; D059467:Transcriptome; D027843:Vitis / Q000187:drug effects / Q000235:genetics* / Q000382:microbiology
chemical_list: D000085:Acetates; D003517:Cyclopentanes; D054883:Oxylipins; D010940:Plant Proteins; C070556:dehydrin proteins, plant; D000040:Abscisic Acid; C072239:methyl jasmonate; D020156:Salicylic Acid