Data/hora: 25/06/2024 18:09:19

Biblioteca(s): | Embrapa Meio-Norte.
Data corrente: | 17/04/1997
Data da última atualização: | 17/04/1997
Autoria: | ROY-MACAULEY, H.; ZUILY-FODIL, Y.; KIDRIC, M.; PHAM THI, A.; SILVA, J. V. da.
Título: | Effect of drought stress on proteolytic activities in Phaseolus and Vigna leaves from sensitive and resistant plants.
Ano de publicação: | 1992
Fonte/Imprenta: | Physiologia Plantarum, v. 85, n. 1, p. 90-96, 1992.
Idioma: | Inglês
Conteúdo: | Although much information is available concerning the effect of senescence on cell proteolytic activities, few reports are devoted to the impact of drought stress. Our aim was to study the influence of water deficit on the cell proteolytic potential, and to determine whether or not it could be used as a physiological parameter for screening varieties for tolerance to drought. We have used Phaseolus and Vigna species differing in their sensitivity to water deficit: V. unguiculata L. Walp. cv. EPACE (resistant), V. unguiculata L. Walp. cv IT83D (moderately sensitive) and P. vulgaris L. cv. Carioquinha (sensitive). The plants were subjected to controlled water conditions. Proteolytic activities were assayed using azocasein in the case of leaf extracts and [14C]- methylated casein in the case of cell compartments: soluble fraction, membrane fraction and isolated, purified chloroplasts. The results indicate that the leaf extracts contained 3 groups of proteinases with optimum pH at 4.5, 5-6 and 8.5 for the Vigna cultivars and 5.0, 6.5 and 9.0 for the Phaseolus cultivar. The sensitive P. vulgaris Carioquinha showed higher caseinolytic activities than the other two cultivars in response to water deficit. As regards cell fractions, proteolytic activities were determined for pH values of 4.5, 6.0 and 9.0. In soluble fractions of stressed plants, proteolytic activities increased at all the pH values tested; this clearly correlated with the drought sensitivity level of the plants, especially at pH 4.5.
Palavras-Chave: | Caupi; Estresse hidrico.
Thesagro: | Feijão; Phaseolus Vulgaris; Vigna Unguiculata.
Categoria do assunto: | --
Registro original: | Embrapa Meio-Norte (CPAMN)
Exemplares: | CPAMN - (5096-1) - ADC - SP - -- - 10686 -  - S 10686 - DIS