Water Permeability during Tomato Fruit Development in Normal and rin Nonripening Mutant

Area of Science:

• Plant Physiology
• Molecular Biology
• Biochemistry

Background:

• Fruit ripening is a complex developmental process involving biochemical and physical changes.
• Membrane permeability is hypothesized to play a role in fruit ripening, potentially facilitating nutrient and metabolite transport.

Purpose of the Study:

• To investigate the relationship between membrane permeability and fruit ripening in tomatoes.
• To compare membrane permeability changes during development in a normal ripening tomato strain and a nonripening mutant.

Main Methods:

• Measured membrane permeability using the [(3)H]water efflux rate from tomato pericarp disks.
• Compared two isogenic tomato (Lycopersicon esculentum Mill) strains: Rutgers (normal) and rin (nonripening mutant).
• Assessed permeability at different stages of fruit development.

Main Results:

• A significant increase in membrane permeability was observed in Rutgers tomato tissue after ripening had commenced, indicated by ethylene and CO(2) evolution and lycopene synthesis.
• The nonripening rin mutant exhibited no increase in tissue permeability throughout its development.
• These findings indicate that increased membrane permeability is not the initial event in tomato fruit ripening.

Conclusions:

• The study does not support the hypothesis that increased membrane permeability is the primary trigger for fruit ripening.
• The nonripening rin mutant's failure to exhibit normal permeability increases highlights the role of permeability changes in the ripening process, albeit not as an initiating factor.