title: Genome-wide identification and characterization of WRKY transcriptional factor family in apple and analysis of their responses to waterlogging and drought stress.
abstract: As one of the largest transcriptional factor families in plants, WRKY genes play significant roles in various biotic and abiotic stress responses. Although the WRKY gene family has been characterized in a few plant species, the details remain largely unknown in the apple (Malus domestica Borkh.). In this study, we identified a total of 127 MdWRKYs from the apple genome, which were divided into four subgroups according to the WRKY domains and zinc finger motif. Most of them were mapped onto the apple's 17 chromosomes and were expressed in more than one tissue, including shoot tips, mature leaves, fruit and apple calli. We then contrasted WRKY expression patterns between calli grown in solid medium (control) and liquid medium (representing waterlogging stress) and found that 34 WRKY genes were differentially expressed between the two growing conditions. Finally, we determined the expression patterns of 10 selected WRKY genes in an apple rootstock, G41, in response to waterlogging and drought stress, which identified candidate genes involved in responses to water stress for functional analysis. Our data provide interesting candidate MdWRKYs for future functional analysis and demonstrate that apple callus is a useful system for characterizing gene expression and function in apple.
authors.affiliation: Department of Horticulture, Cornell University, 134A Plant Science, Ithaca, NY 14853, USA.
authors.forename: Dong
authors.initials: D
authors.lastname: Meng
authors.affiliation: Department of Horticulture, Cornell University, 134A Plant Science, Ithaca, NY 14853, USA; College of Horticulture Science and Engineering, Shandong Agricultural University, Taian 271018, Shandong, China.
authors.forename: Yuanyuan
authors.initials: Y
authors.lastname: Li
authors.affiliation: Boyce Thompson Institute for Plant Research, Ithaca, NY 14853, USA.
authors.forename: Yang
authors.initials: Y
authors.lastname: Bai
authors.affiliation: Department of Horticulture, Cornell University, 134A Plant Science, Ithaca, NY 14853, USA; College of Horticulture, Northwest A&F University, Yangling, Shaanxi, 712100, China.
authors.forename: Mingjun
authors.initials: M
authors.lastname: Li
authors.affiliation: Department of Horticulture, Cornell University, 134A Plant Science, Ithaca, NY 14853, USA. Electronic address: LC89@Cornell.edu.
authors.forename: Lailiang
authors.initials: L
authors.lastname: Cheng
mesh_terms: D000595:Amino Acid Sequence; D032461:Chromosomes, Plant / Q000235:genetics; D003470:Culture Media; D003681:Dehydration; D055864:Droughts; D005638:Fruit / Q000235:genetics / Q000502:physiology; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D018745:Genome, Plant / Q000235:genetics*; D027845:Malus / Q000235:genetics* / Q000502:physiology; D005810:Multigene Family; D010802:Phylogeny; D018515:Plant Leaves / Q000235:genetics / Q000502:physiology; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D018520:Plant Shoots / Q000235:genetics / Q000502:physiology; D016415:Sequence Alignment; D017423:Sequence Analysis, RNA; D013312:Stress, Physiological; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism
chemical_list: D003470:Culture Media; D010940:Plant Proteins; D014157:Transcription Factors
keywords: Apple; Drought stress; Transcriptional factor; WRKY; Water stress