Cell wall differentiation and stages involved with intercellular gas space opening

Area of Science:

• Plant Biology
• Cell Biology
• Plant Anatomy

Background:

• Intercellular gas systems are crucial for plant aeration and gas exchange.
• Previous research suggested the pectic middle lamella's direct role in initiating these systems.

Purpose of the Study:

• To investigate the ultrastructural and cytochemical mechanisms of intercellular gas system development in plants.
• To clarify the role of cell wall components in the formation of intercellular spaces.

Main Methods:

• Ultrastructural cytochemistry was employed to study Pisum sativum root and Phaseolus aureus hypocotyl.
• Techniques included incubation with EDTA, DMSO, pectinases, cellulases, PATAg staining, and ultracryotomy.

Main Results:

• Intercellular gas system development involves sequential cell wall reconstruction, initiated by a distinct 'splitting layer'.
• The splitting layer is insoluble in common wall-degrading agents and lacks polysaccharide reactivity.
• This layer exhibits beta-glycerophosphatase activity and splits like a 'zip fastener', forming intercellular spaces with a non-glucidic coat.

Conclusions:

• The pectic middle lamella is not directly involved in initiating the aerating system.
• Specialized cell wall substructures, particularly the splitting layer, are key to intercellular space formation.
• This process ensures cell wall polysaccharides remain covered during air space development.