title: Relationship between endogenous indole-3-acetic acid and abscisic acid changes and bark recovery in Eucommia ulmoides Oliv. after girdling.
abstract: Eucommia ulmoides (Eucommiaceae), a traditional Chinese medicinal plant, is often subjected to severe manual peeling of its bark. If the girdled trunk is well protected from desiccation, new bark forms within 1 month. It has been proposed that phytohormones play a key role in this process. Research has been conducted to determine the distribution of endogenous indole-3-acetic acid (IAA) and abscisic acid (ABA) during the bark recovery, using high-performance liquid-chromatography (HPLC) and fluoro-immuno-localization techniques. Results showed that, from 2 d after girdling, the IAA content in the recovering bark (RB) increased markedly while that of ABA decreased. The opposite pattern was observed during progressive re-establishment of the tissues. Immuno-localization showed that most of the IAA was located in the RB tissue layers undergoing cell division, dedifferentiation and (re)differentiation, such as xylary rays, immature xylem, phellogen and cambial regions. This study also provides evidence that IAA and ABA are involved in the bark reconstitution.
authors.affiliation: Peking University, College of Life Sciences, Dept of Plant Molecular and Developmental Biology, Beijing 100871, PR China.
authors.forename: Kalima N'Koma
authors.initials: KN
authors.lastname: Mwange
authors.forename: Hong-Wei
authors.initials: HW
authors.lastname: Hou
authors.forename: Ke-Ming
authors.initials: KM
authors.lastname: Cui
mesh_terms: D000040:Abscisic Acid / Q000378:metabolism*; D002454:Cell Differentiation; D031283:Eucommiaceae / Q000166:cytology / Q000502:physiology*; D007210:Indoleacetic Acids / Q000378:metabolism*; D024301:Plant Bark / Q000166:cytology / Q000378:metabolism*
chemical_list: D007210:Indoleacetic Acids; C030737:indoleacetic acid; D000040:Abscisic Acid