Intercellular deformation in compressed organs.
Calbo, A. G.; Nery, A. A.; Paula Herrmann, P. S. de;
Annals of Botany Year: 1995 Vol: 76 Issue: 4 Pages: 365-370 Ref: 25 ref.
1995
บทคัดย่อ
Compression can occur during plant development and in postharvest procedures. Using a pressure chamber, compression was applied to carrots (cv. Brasilia, stored for 1 month at 0 deg C), potatoes (cv. Achat, stored at 10 deg for 2 months), mature-green and red tomatoes (cv. Santa Cruz) and sweet potatoes (cv. Coquinho), covered with a plastic sealant. Intercellular deformations, evaluated from the internal atmosphere removal rate, were observed in carrots, potatoes and sweet potatoes. The maximum internal gas volume removed in these kinetic assays was close to the intercellular air volume (Vg) measured by the pycnometric method. Presumably a compression larger than the average organ turgor was required to remove all Vg, and above this point the cells should become completely flattened against each other. The intercellular deformation caused by a compressing load, observed by constant pressure volumetry, induced a reduction in the endogenous O2 concentration at the stressed area, according to pola
rographic measurements. Cellular deformations and eventual Vg flooding caused by water movement from the symplasm to the apoplasm of externally compressed organs were distinct from the usual pressure chamber assays, where all cells are exposed to homogeneous gas pressurization without the development of forces to cause large cellular deformation and intercellular flooding. These gas transport restrictions were suggested as potential causes for postharvest deterioration in fragile commodities subjected to compression.