INVESTIGATION OF THE MECHANICS OF SINGLE TOMATO FRUIT CELLS

Abstract

ABSTRACT The mechanical behavior of single tomato fruit cells has been characterized using high strain‐rate microcompression testing. Single cells isolated by gentle washing from inner pericarp tissue were compressed to a wide range of deformations at a speed of 1500 µ m/s, and then released. The cells were larger than any tested previously by microcompression, and had very low initial turgor. Force‐deformation data were modeled to find cell wall material properties, assuming water loss during compression could be neglected because of fast compression. Repeat compression‐release experiments were conducted to discover when cell deformation was no longer recoverable upon release. Cells from three commercially grown tomatoes were elastic to deformations of just over 11%. The elastic moduli of the cell walls were found by modeling to be 30 to 80 MPa, significantly lower than suspension‐cultured cell walls. The cell walls yielded at about 2% wall strain. High‐speed compression testing is a powerful tool for studying low turgor cells, such as those found during ripening.