title: Roles of JnRAP2.6-like from the transition zone of black walnut in hormone signaling.
abstract: An EST sequence, designated JnRAP2-like, was isolated from tissue at the heartwood/sapwood transition zone (TZ) in black walnut (Juglans nigra L). The deduced amino acid sequence of JnRAP2-like protein consists of a single AP2-containing domain with significant similarity to conserved AP2/ERF DNA-binding domains in other species. Based on multiple sequence alignment, JnRAP2-like appears to be an ortholog of RAP2.6L (At5g13330), which encodes an ethylene response element binding protein in Arabidopsis thaliana. Real-time PCR revealed that the JnRAP2-like was expressed most abundantly in TZ of trees harvested in fall when compared with other xylem tissues harvested in the fall or summer. Independent transgenic lines over-expressing JnRAP2-like in Arabidopsis developed dramatic ethylene-related phenotypes when treated with 50 µM methyl jasmonate (MeJA). Taken together, these results indicated that JnRAP2-like may participate in the integration of ethylene and jasmonate signals in the xylem and other tissues. Given the role of ethylene in heartwood formation, it is possible JnRAP2-like expression in the transition zone is part of the signal transduction pathway leading to heartwood formation in black walnut.
authors.affiliation: Department of Forestry and Natural Resources, Hardwood Tree Improvement and Regeneration Center (HTIRC), Purdue University, West Lafayette, Indiana, United States of America.
authors.forename: Zhonglian
authors.initials: Z
authors.lastname: Huang
authors.forename: Peng
authors.initials: P
authors.lastname: Zhao
authors.forename: Jose
authors.initials: J
authors.lastname: Medina
authors.forename: Richard
authors.initials: R
authors.lastname: Meilan
authors.forename: Keith
authors.initials: K
authors.lastname: Woeste
mesh_terms: D000040:Abscisic Acid / Q000378:metabolism / Q000494:pharmacology; D000085:Acetates / Q000378:metabolism / Q000494:pharmacology; D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism; D003001:Cloning, Molecular; D003517:Cyclopentanes / Q000378:metabolism / Q000494:pharmacology; D005030:Ethylenes / Q000378:metabolism / Q000494:pharmacology; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D023061:Gene Order; D031324:Juglans / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism*; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D054883:Oxylipins / Q000378:metabolism / Q000494:pharmacology; D010641:Phenotype; D010802:Phylogeny; D010937:Plant Growth Regulators / Q000378:metabolism* / Q000494:pharmacology; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics*; D030821:Plants, Genetically Modified; D016415:Sequence Alignment; D015398:Signal Transduction; D014157:Transcription Factors / Q000737:chemistry / Q000235:genetics*; D014158:Transcription, Genetic; D014934:Wood / Q000235:genetics*
chemical_list: D000085:Acetates; D003517:Cyclopentanes; D005030:Ethylenes; D054883:Oxylipins; D010937:Plant Growth Regulators; D010940:Plant Proteins; D014157:Transcription Factors; D000040:Abscisic Acid; C072239:methyl jasmonate; C036216:ethylene