title: Effect of light and auxin transport inhibitors on endoreduplication in hypocotyl and cotyledon.
abstract: Enhancement of endoreduplication in dark-grown hypocotyl is a common feature in dicotyledonous polysomatic plants, and TIBA-mediated inhibition of the endoreduplication is partially due to abnormal actin organization. Many higher plant species use endoreduplication during cell differentiation. However, the mechanisms underlying this process have remained elusive. In this study, we examined endoreduplication in hypocotyls and cotyledons in response to light in some dicotyledonous plant species. Enhancement of endoreduplication was found in the dark-grown hypocotyls of all the polysomatic species analyzed across five different families, indicating that this process is a common feature in dicotyledonous plants having polysomatic tissues. Conversely, endoreduplication was enhanced in the light-grown cotyledons in four of the five species analyzed. We also analyzed the effect of a polar auxin transport inhibitor, 2,3,5-triiodobenzoic acid (TIBA) on endoreduplication in hypocotyl and cotyledon tissues of radish (Raphanus sativus L. var. longipinnatus Bailey). TIBA was found to inhibit and promote endoreduplication in hypocotyls and cotyledons, respectively, suggesting that the endoreduplication mechanism differs in these organs. To gain insight into the effect of TIBA, radish and spinach (Spinacia oleracea L.) seedlings were treated with a vesicle-trafficking inhibitor, brefeldin A, and an actin polymerization inhibitor, cytochalasin D. Both of the inhibitors partially inhibited endoreduplication of the dark-grown hypocotyl tissues, suggesting that the prominent inhibition of endoreduplication by TIBA might be attributed to its multifaceted role.
authors.affiliation: Graduate School of Life and Environmental Sciences, Osaka Prefecture University, 1-1 Gakuen, Nakaku, Sakai, Osaka, 599-8531, Japan.
authors.forename: Riko
authors.initials: R
authors.lastname: Tanaka
authors.affiliation: Graduate School of Life and Environmental Sciences, Osaka Prefecture University, 1-1 Gakuen, Nakaku, Sakai, Osaka, 599-8531, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Amijima
authors.affiliation: Graduate School of Life and Environmental Sciences, Osaka Prefecture University, 1-1 Gakuen, Nakaku, Sakai, Osaka, 599-8531, Japan.
authors.forename: Yuji
authors.initials: Y
authors.lastname: Iwata
authors.affiliation: Graduate School of Life and Environmental Sciences, Osaka Prefecture University, 1-1 Gakuen, Nakaku, Sakai, Osaka, 599-8531, Japan.
authors.forename: Nozomu
authors.initials: N
authors.lastname: Koizumi
authors.affiliation: Graduate School of Life and Environmental Sciences, Osaka Prefecture University, 1-1 Gakuen, Nakaku, Sakai, Osaka, 599-8531, Japan. mishiba@plant.osakafu-u.ac.jp.
authors.forename: Kei-Ichiro
authors.identifier: http://orcid.org/0000-0002-3827-1020
authors.initials: KI
authors.lastname: Mishiba
mesh_terms: D001692:Biological Transport / Q000187:drug effects / Q000528:radiation effects; D020126:Brefeldin A / Q000494:pharmacology; D018548:Cotyledon / Q000187:drug effects / Q000235:genetics* / Q000528:radiation effects; D015638:Cytochalasin D / Q000494:pharmacology; D062951:Endoreduplication / Q000187:drug effects* / Q000528:radiation effects*; D005449:Fluorenes / Q000494:pharmacology; D018546:Hypocotyl / Q000187:drug effects / Q000235:genetics* / Q000254:growth & development / Q000528:radiation effects; D007210:Indoleacetic Acids / Q000378:metabolism*; D058610:Isobutyrates / Q000494:pharmacology; D008027:Light; D010797:Phthalimides; D011003:Ploidies; D031224:Raphanus / Q000187:drug effects / Q000378:metabolism / Q000528:radiation effects; D018724:Spinacia oleracea / Q000187:drug effects / Q000378:metabolism / Q000528:radiation effects; D014283:Triiodobenzoic Acids / Q000494:pharmacology
chemical_list: D005449:Fluorenes; D007210:Indoleacetic Acids; D058610:Isobutyrates; D010797:Phthalimides; D014283:Triiodobenzoic Acids; D020126:Brefeldin A; D015638:Cytochalasin D; C002687:alpha-naphthylphthalamic acid; C052968:2,3,5-triiodobenzoic acid
keywords: BFA; Cotyledon; Cytochalasin D; Endoreduplication; Hypocotyl; TIBA