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Related Experiment Video

Updated: Jun 24, 2026

Isolation and Biophysical Study of Fruit Cuticles

Isolation and Biophysical Study of Fruit Cuticles

Published on: March 30, 2012

Endo-beta-mannanase is present in an inactive form in ripening tomato fruits of the cultivar Walter.

M Banik¹, R Bourgault, J D Bewley

¹Department of Botany, University of Guelph, Guelph, Ontario N1G 2W1, Canada.

Journal of Experimental Botany

|February 22, 2001

Summary

This summary is machine-generated.

Tomato cultivar Walter fruits fail to produce active endo-beta-mannanase due to post-transcriptional or post-translational issues, not gene absence or inhibitors. Seeds, however, do produce active enzyme.

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Area of Science:

Plant Biology
Biochemistry
Molecular Biology

Background:

Tomato fruit ripening involves complex enzymatic processes.
Endo-beta-mannanase is crucial for cell wall modification during ripening.
Cultivar differences in enzyme activity can impact fruit development.

Purpose of the Study:

Investigate the cause of inactive endo-beta-mannanase in ripening tomato cv. Walter fruits.
Determine if gene expression, protein presence, or inhibitors are responsible for the lack of activity.
Compare enzyme activity in fruits and seeds of different tomato cultivars.

Main Methods:

Southern blot analysis to detect endo-beta-mannanase genes.
Northern hybridization to assess transcript presence.
Western blot analysis using specific antibodies to detect enzyme protein.
Enzyme activity assays using fruit and seed extracts.

Main Results:

Cultivar Walter possesses endo-beta-mannanase genes and transcripts in ripening fruits.
The enzyme protein is detectable, but inactive, in Walter fruit cell walls.
No inhibitors of endo-beta-mannanase were found in Walter fruit extracts.
Active endo-beta-mannanase is produced in the seeds of Walter and Heinz 1439, especially after germination.

Conclusions:

The inactivity of endo-beta-mannanase in Walter tomato fruits is not due to gene absence, lack of transcripts, or inhibitors.
The issue likely lies in post-transcriptional or post-translational modification of the enzyme.
Seed tissues exhibit active endo-beta-mannanase, suggesting differential regulation between fruit and seed.