Involvement of Ethylene in Responses of Etiolated Bean Hypocotyl Hook to Coumarin 1
AUTOR(ES)
Morgan, Page W.
RESUMO
Coumarin, at concentrations between 1.0 and 0.1 mm, inhibited red light-induced opening of the etiolated bean hypocotyl hook. In addition, anthocyanin synthesis and geotropic bending were inhibited. Coumarin stimulated ethylene synthesis, and ethylene was shown to mediate the inhibitory actions of coumarin. This conclusion was supported by: (a) the parallel concentration dependence and time sequence of hook closing and ethylene synthesis, (b) the restriction of the bulk of coumarin-induced ethylene production to the curved portion of the hook where opening is expressed, (c) the ability of both coumarin and ethylene to reclose partially opened hooks, and (d) the ability of exogenous ethylene, in the amounts produced by coumarintreated hooks, to duplicate the inhibitory effects of coumarin. There was an increasing stimulation of growth of the straight portion of the hypocotyl hook section as coumarin concentrations were increased from 0.1 to 1.0 mm. This action of coumarin was not duplicated by ethylene and occurred regardless of the presence or absence of added ethylene. The results of this study suggest that many actions of coumarin in growth systems are mediated by ethylene produced in response to the coumarin.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=396458Documentos Relacionados
- Effect of the Hypocotyl Hook on Greening in Etiolated Cucumber Cotyledons 1
- Response of the Hypocotyl Hook of Bean Seedlings to Radiant Energy and Other Factors123
- Relation of Glycosidases to Bean Hypocotyl Growth 1
- The Arabidopsis eer1 Mutant Has Enhanced Ethylene Responses in the Hypocotyl and Stem1
- Concentration Dependencies of Some Effects of Ethylene on Etiolated Pea, Peanut, Bean, and Cotton Seedlings 1