Endo‐β‐mannanase is present in an inactive form in ripening tomato fruits of the cultivar Walter

Fruits of the tomato cultivar Walter undergo normal development to the red‐ripe stage but, unlike those of the cultivar Trust, they do not produce any active endo‐β‐mannanase. Reasons for this failure to produce the enzyme were sought. The cv. Walter contains genes for endo‐β‐mannanase, as shown by...

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Bibliographic Details
Published inJournal of experimental botany Vol. 52; no. 354; pp. 105 - 111
Main Authors Banik, Mitali, Bourgault, Richard, Bewley, J. Derek
Format Journal Article
LanguageEnglish
Published Oxford Oxford University Press 01.01.2001
OXFORD UNIVERSITY PRESS
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Summary:Fruits of the tomato cultivar Walter undergo normal development to the red‐ripe stage but, unlike those of the cultivar Trust, they do not produce any active endo‐β‐mannanase. Reasons for this failure to produce the enzyme were sought. The cv. Walter contains genes for endo‐β‐mannanase, as shown by Southern blot analysis, and transcripts for the enzyme are present in ripening fruits, as revealed using Northern hybridization. Moreover, the enzyme protein is detectable by Western blots using an endo‐β‐mannanase‐specific antibody from tomato. In addition, the inactive enzyme is localized appropriately in the wall regions of the outer layers of the fruit (skin and outer pericarp). Mixing inactive fruit extracts of cv. Walter, in excess, with extracts from cv. Trust fruits, which contain active enzyme, leads to an increase rather than a reduction in enzyme activity, showing that there are no inhibitors of endo‐β‐mannanase in cv. Walter fruits. Similar results were obtained with fruits of the tomato cv. Heinz 1439. In contrast to the situation in fruits, the seeds of both cvs Walter and Heinz 1439 produce active enzyme, especially following germination.
Bibliography:ark:/67375/HXZ-55S3SD50-N
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local:520105
PII:1460-2431
ObjectType-Article-1
SourceType-Scholarly Journals-1
ObjectType-Feature-2
content type line 23
ISSN:0022-0957
1460-2431
DOI:10.1093/jexbot/52.354.105