title: Involvement of ethylene-responsive microRNAs and their targets in increased latex yield in the rubber tree in response to ethylene treatment.
abstract: The rubber tree is an economically important plant that produces natural rubber for various industrial uses. The application of ethylene contributes to increased latex production in rubber trees; however, the molecular biology behind the effects of ethylene on latex yield remains to be elucidated. Recently, the intersection between microRNA (miRNA) regulation and phytohormone responses has been revealed. Insight into the regulation of miRNAs and their target genes should help to determine the functional importance of miRNAs as well as the role of miRNAs in signaling under ethylene stimulation in the rubber tree. In this study, hbr-miR159 and hbr-miR166 were down-regulated in bark under ethylene treatment. The ethylene also down-regulated ATHB15-like (Class III Homeodomain Leucine Zipper, HD-ZIP III) which have been extensively implicated in the regulation of primary and secondary vascular tissue pattern formation. The strong negative-regulation of ARF6/ARF8 caused by hbr-miR167 involved in an attenuation of vascular development and may gradually lead to bark dryness syndrome in the long term ethylene treatment. The negative correlation of hbr-miR172 and its target REF3 in the inner soft bark under ethylene treatment results in dramatic increases in latex yield in the ethylene-sensitive clone of the rubber tree. The overall results suggested that the differential expression of HD-ZIP III, miR167/ARF6, ARF8, and miR172/REF3 and related genes may play possible roles in the response to ethylene treatment, resulting in longer latex flow and increased latex yield.
authors.affiliation: Department of Biotechnology, Faculty of Science, Mahidol University, Bangkok, Thailand.
authors.forename: Porawee
authors.initials: P
authors.lastname: Pramoolkit
authors.affiliation: Department of Biotechnology, Faculty of Science, Mahidol University, Bangkok, Thailand.
authors.forename: Manassawe
authors.initials: M
authors.lastname: Lertpanyasampatha
authors.affiliation: Department of Plant Science, Faculty of Science, Mahidol University, Bangkok, Thailand; Rubber Technology Research Centre, Faculty of Science, Mahidol University, Thailand.
authors.forename: Unchera
authors.initials: U
authors.lastname: Viboonjun
authors.affiliation: Department of Plant Science, Faculty of Science, Mahidol University, Bangkok, Thailand; Rubber Technology Research Centre, Faculty of Science, Mahidol University, Thailand.
authors.forename: Panida
authors.initials: P
authors.lastname: Kongsawadworakul
authors.affiliation: Department of Plant Science, Faculty of Science, Mahidol University, Bangkok, Thailand; Institut de Recherche pour le Développement (IRD), Montpellier, France.
authors.forename: Hervé
authors.initials: H
authors.lastname: Chrestin
authors.affiliation: Department of Biotechnology, Faculty of Science, Mahidol University, Bangkok, Thailand; Rubber Technology Research Centre, Faculty of Science, Mahidol University, Thailand. Electronic address: scjnr@mahidol.ac.th.
authors.forename: Jarunya
authors.initials: J
authors.lastname: Narangajavana
mesh_terms: D005030:Ethylenes / Q000494:pharmacology*; D018506:Gene Expression Regulation, Plant / Q000187:drug effects / Q000235:genetics; D028482:Hevea / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism*; D035683:MicroRNAs / Q000235:genetics*; D010937:Plant Growth Regulators / Q000378:metabolism*
chemical_list: D005030:Ethylenes; D035683:MicroRNAs; D010937:Plant Growth Regulators; C036216:ethylene
keywords: Ethylene; Latex yield; MicroRNAs; Rubber tree