Data/hora: 06/06/2024 02:28:50

Biblioteca(s): | Embrapa Mandioca e Fruticultura.
Data corrente: | 24/03/1993
Data da última atualização: | 24/03/1993
Autoria: | HUBER, D. J.; O'DONOHHUE, E. M.
Afiliação: | Horticultural Sciences Department, University of Florida, Gainesville, Florida 23611-0690.
Título: | Polyuronides in Avocado (Persea americana) and tomato (Lycropersicon esculentum) fruits exhibit markedly different patternos of molecular weight downshifts during ripening
Título original: | Polyuronides in Avocado (Persea americana) and tomato (Lycopersicon esculentum)fruits exhibit markedly different patterns of molecular weight during ripening
Ano de publicação: | 1993
Fonte/Imprenta: | Plant Physiology, v.102, n.2, p.473, 1993
ISSN: | 0032-0889
Idioma: | Inglês
Conteúdo: | Avocado (Persea americana) fruit experience a rapid and extensive loss of fimness during ripening. In this study, we examined whether the chelator solubility and molecular weight of avocado polyuronides paralleled the accumulation of polygalacturonase (PG) activity and loss in fruit firmnes. Polyuronides were derived from ethanolice precipitates of avocado mesocarp prepared using a procedure to rapidly inactivat endogenos enzymes. During ripenin, chelator (cyclohexane-trans-1,2-diamine tetraacetic acid [CDTA])-soluble polyuronides increased from approximately 30 to 40 ug of galacturonic acid equivalents (mg alcohol-insoluble solides)-1in preripe fruit to 150 to 170 ug mg-1in postclimacteric fruit. In preripe fruit, chelator-extractable polyuronides were of high molecular weight and were partially excluded from sepharose CL2B-300 gel filtration media. Avocado polyuronides exhibited marked downshifts in molecular weight during ripening. At the Postclimacteric stage, nearly all chelator- extractable polyuronides,which constituted from 75 to 90% of total cell wall uronic acid  content, eluted near the total volume of the filtration media. Rechromatography of low molecular weight polyuronides on Bio-Gel P-4 disclosed that olingomeric uronic acids are produced in vivo during avocado ripening.
Palavras-Chave: | enzimas; Fitoquimica.
Thesagro: | Solubilidade.
Categoria do assunto: | --
Registro original: | Embrapa Mandioca e Fruticultura (CNPMF)
Exemplares: | CNPMF - (2170-1) - ADC - AP - -- - 581.105 -  - 581.105 - DIS