Studies on chilling injury in plant cells I. Ultrastructural changes associated with chilling injury in callus tissues of <italic>Cornus stolonifera</italic><xref ref-type="fn" rid="fn1"><sup>1</sup></xref><xref ref-type="fn" rid="fn2"><sup>2</sup></xref>

Abstract

This study was designed to elucidate the primary ultrastructural changes associated with chilling injury of cultured cells of Cornus stolonifera (TK-1). The cultured cells suffered serious injury after exposure to 0°C for longer than 24 hr, while no injury was observed with less than 12 hr of treatment. Early ultrastructural responses to chilling treatment were detected in proplastids and the rough endoplasmic reticulum within 12 hr of treatment. A remarkable ultrastructural change in the tonoplast, i.e., invagination, infolding and partial disruption, became apparent in the 24-hr stage of chilling treatment. No visible change, however, was observed in mitochondria, nuclei and plasma membranes within 24 hr. Upon exposure to 0°C for 48 hr, an abrupt degradation proceeded in the cytoplasm. The sequential ultrastructural changes observed in cell organdies, especially proplastids, rough endoplasmic reticulum and the tonoplast, were closely related to the degradation of the cells caused by chilling treatment.