Intercellular Air Space
The ubiquity of interconnected air-filed intercellular spaces in thick plant tissues were demonstrated over 90 years ago, wherein such spaces are present in almost every plant tissue – both thick and thin —but received remarkably little attention in research and textbooks. The intercellular air space is vital in the process of photosynthesis and to other roles in the function of the plants. Higher plants have interconnected air spaces due to the fact that they undergo respiration in all massive plant tissue, such as large fruits, and potato tubers, at least during growth and development.
Other Intercellular air space Functions
Aside from its common function, the Intercellular air space serves as pathways for diffusion of carbon dioxide (CO2) for photosynthesis. This space (with adjacent cells) in the leaf also provides refractive index discontinuities that cause the leaf to scatter much of the incoming radiation. Aquatic plants or plant part floats in water because of the air-filed intercellular spaces. Respiration of crop plant roots submerged in flooded soils to a distance of several centimeters from an air source is possible because of diffusion of air in longitudinally interconnected air-filled intercellular spaces.
With the use of a small maize example of roots, the thickness at which a plant tissue needs air spaces to facilitate respiration can be approximately calculated. Due to the fact that the intercellular spaces of small roots are not radially interconnected, it does not function as a major path in the radial movement of oxygen (O2) but when such roots are in aerated soil, they can obtain oxygen through the root tissue’s radial movement.