Data/hora: 30/05/2024 16:53:34

Biblioteca(s): | Embrapa Mandioca e Fruticultura.
Data corrente: | 08/04/1996
Data da última atualização: | 08/04/1996
Autoria: | LAZAN, H.; MOHD.; SELAMAT, K.; ALI, Z. M.
Afiliação: | Department of Biochemistry, facult of Life Sciences, University Kebangsaan Malaysia.
Título: | B-Galactosidase, polygalacturonase and pectinesterase in differential softening and cell wall modification during papaya fruit ripening.
Ano de publicação: | 1995
Fonte/Imprenta: | Physiologia Plantarum, 95, 106-112, 1995.
Idioma: | Inglês
Conteúdo: | Papaya (Carica papaya L. cv. Eksotika) fruit softens differentially in relation to position of the tissue. The inner mesocarp tissue is softer, and its firmness decreases more rapidly during ripening than that outher mesocarp tissue. As the fruit ripens, pectin solubility and depolymerisation increase. Hemicellulose, too, appears to be depotin lymerised but, unlike pectins, this apparent degradation of hemicellulose is associated with an increase rather than a decrease in its level. Pectin and hemicellulose depolymerisation began in the inner mesocarp tissue at about the same time  as B-galactosidase (EC 3.2.1.23) activitystarted to increase and tissue firmness began to decrease more rapidly. In contrast, pectin solubilisation in both outer and inner mesocarptissues occured steadily throughout ripening  at a comparable rate and paralleled closely tho increase of polygalacturonase (PG; EC 3.2.1.67) and pectinesterase (EC 3.1.1.11). In general, irrespective of enzyme distribution, tissue softening during repening was more closely related to changes in B-galactosidase activity than to PG or pectinesteraseactivity. Papaya, B-galactosidase appears to be an important wall degrading enzyme and may contribute significantly to differential softening, perhaps by complementing the action of polygalacturonase. Polygalacturonase activity increased with increasing depth of the mesocarp tissue. as did softening of the fruit.
Palavras-Chave: | B-galatosidase; Cell wall; Differential softening; Fruit repening; Papaya; Pectin; Pectinestrease.
Thesagro: | Bioquímica; Carica Papaya; Enzima; Mamão; Maturação.
Thesaurus Nal: | hemicellulose; polygalacturonase.
Categoria do assunto: | --
Registro original: | Embrapa Mandioca e Fruticultura (CNPMF)
Exemplares: | CNPMF - (3657-1) - ADC - AP - -- - 581.105 -  - 581.105 - DIS