Low oxygen environment effect on the tomato cell wall composition during the fruit ripening process

Area of Science:

• Plant Physiology
• Fruit Ripening Biology
• Cell Wall Biochemistry

Background:

• Oxygen concentration critically impacts fruit shelf life and quality.
• Understanding cell wall responses to low oxygen is crucial for fruit storage.
• Tomato (Solanum lycopersicum) ripening is sensitive to oxygen levels.

Purpose of the Study:

• Identify cell wall components affected by low oxygen in tomatoes.
• Determine the impact of anoxic (0% O2) and hypoxic (5% O2) conditions on fruit ripening.
• Analyze changes in specific cell wall polysaccharides and proteins.

Main Methods:

• Comparative analysis of tomato fruits at different ripening stages.
• Storage under anoxic (0% O2) and hypoxic (5% O2) conditions.
• Microscopic immunolabelling, enzymatic activity assays, and molecular profiling of cell wall components.

Main Results:

• Low oxygen stress significantly altered cell wall composition, including protein content and polysaccharide distribution.
• Observed changes included callose deposition and altered enzyme activities (e.g., β-1,3-glucanase, GPX).
• Anoxic conditions accelerated ripening changes, while hypoxic conditions slowed them, with effects more pronounced in red ripe than breaker stage tomatoes.

Conclusions:

• Hypoxic and anoxic conditions induce molecular changes in tomato cell walls.
• These alterations represent regulatory and protective mechanisms modulating ripening.
• Cell wall composition is a key factor in tomato's response to altered oxygen levels during storage.