Data/hora: 08/06/2024 02:16:58

Biblioteca(s): 	Embrapa Pantanal.	
Data corrente: 	23/05/1996	
Data da última atualização: 	23/05/1996	
Autoria: 	CARPENTER, J. R.; MITCHELL, C. A.	
Título: 	Flood-induced shift of electron flow between cyanide-sensitive and alternative respiratory pathways in roots of tolerant and intolerant tree species.	
Ano de publicação: 	1980	
Fonte/Imprenta: 	Journal of the American Society of Horticultural Science, v.105, n.5, p.688-690, 1980.	
Idioma: 	Inglês	
Conteúdo: 	Effects of cyanide (as KCN) and/or salicylhidroxamic acid (SHAM) on respiratory rates (Qo2) of excised tree roots were evaluated before and after flooding intact plants. CN, an inhibitor of cytochrome oxidase stimulated Qo2 in flood-intolerant sugar maple (Acer sac- charum Marsh.) and Japanese yew (Taxus cuspidata Sieb and Zucc.), but not in flood-to- lerant red maple (Acer rubrum L.) and inhibited Qo2 in very flood-tolerant baldeypress (Ta- xodium distichum (L.) Rich). Eight days of flooding eliminated CN- stimulation of Qo2 in su- gar maple SHAM an inhibitor of the alternative oxidase, had little on Qo2 of any species when used alone, but greatly inhibited Qo2 of all species when combined with KCN, indi- cating the presence of substantial amounts of bolth respiratory pathways in flood-tolerant and intolerant species, as well as the ability of electrons to flow from one pathway to ano- ther when one is blocked by a specific inhibitor. Flooding reduced root respiration capaci- ty in all species, affecting intolerant species the most and tolerant the least. The excepti- on was Qo2 of dormant Taxus roots, which was not inhibited by flooding. CN-sensitive Qo2 was lost from roots of intolerant species in particular, and to alesser extent from more tolerant species. A limiting level of O2 (0.5%) suppressed SHAM-sensitive Qo2 more than CN-sensitive Qo2, indicating a greater affinity for O2 by the CN-sensitive pathway. The evidence is consistent with a model for relative flood tolerance based upon differential da- mage to the aerobic respiratory mechanism.	
Palavras-Chave: 	Cyanide; Plant; SHAM.	
Thesagro: 	Cianeto; Oxigênio; Planta.	
Thesaurus Nal: 	Acer saccharum; oxygen; Taxodium distichum; Taxus cuspidata.	
Categoria do assunto: 	--	
Registro original: 	Embrapa Pantanal (CPAP)	
Exemplares: 	CPAP - (31988-1) - ADC - SP - -- - SP2464 -  - 2464 - DIS