Utilize este identificador para referenciar este registo: http://hdl.handle.net/10400.14/2842
Título: Polygalacturonase-mediated dissolution and depolymerization of pectins in solutions mimicking the pH and mineral composition of tomato fruit apoplast
Autor: Almeida, Domingos P. F.
Huber, Donald J.
Palavras-chave: Calcium
Cell wall
Lycopersicon esculentum
Pectinmethylesterase
Polyuronides
Polygalacturonase
Data: 2007
Editora: Elsevier
Citação: "Plant science". ISSN 0168-9452. 172: 6 (2007) 1087-1094
Resumo: The effects of polygalacturonase (PG) on pectin dissolution and depolymerization were examined in cell walls from mature-green tomato fruit incubated in a conventional (C) buffer (30 mMsodium acetate, 150 mMNaCl, pH 4.5) and in buffers mimicking the apoplastic solution of maturegreen (MG) and ripe fruit (R). Pectin dissolution from cell walls was much higher in C-buffer than in MG- or R-buffers. Buffered phenol inactivated cell walls incubated in C-buffer released 4.9 mg mg 1 pectin, which increased to 86.4 mg mg 1 when PG was added. In the R-buffer, PG increased the pectin dissolution from inactive cell walls from 0.5 to 18.3 mg mg 1. However, when the assay was conducted in buffer mimicking maturegreen fruits, added PG did not increase pectin dissolution. The release of uronic acids from active cell walls in C-buffer and R-buffer was consistently lower than that from inactive walls due to the activity of pectinmethylesterase. Gel filtration profiles of CDTA-soluble pectins extracted from cell walls previously incubated in C-buffer or R-buffer with PG reveal that the enzyme is capable of hydrolyzing insoluble, ionically bound, pectins. These data support the idea that pH and mineral composition of the fruit apoplast provide a means for biochemical regulation of cell wall metabolism.
URI: http://hdl.handle.net/10400.14/2842
Versão do Editor: http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TBH-4NBBYKR-1&_user=10&_coverDate=06%2F30%2F2007&_rdoc=1&_fmt=high&_orig=search&_origin=search&_sort=d&_docanchor=&view=c&_searchStrId=1493817930&_rerunOrigin=google&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=a8e321dca46300fb4482fb4bc08bb3ac&searchtype=a
Aparece nas colecções:ESB - Artigos em revistas internacionais com Arbitragem / Papers in international journals with Peer-review

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