Changes in the location of polyphenol oxidase in potato (Solanum tuberosum L.) tuber during cell death in response to impact injury: comparison with wound tissue

• Published in: Planta Vol. 207; no. 3; pp. 449 - 460
• Main Authors: Partington, J.C, Smith, C, Bolwell, G.P
• Format: Journal Article
• Language: English
• Published: Berlin Springer-Verlag 01.01.1999; Springer
• Subjects: apoptosis; biochemistry; Biological and medical sciences; Bruises; catechol oxidase; Catechol Oxidase - analysis; Cell Death; cell membranes; Cell walls; color; Cytoplasm; enzyme activity; Enzymes; Fundamental and applied biological sciences. Psychology; gene expression; Immunohistochemistry; injuries; mechanical damage; Messenger RNA; Oxidases; Physiological diseases. Varia; Phytopathology. Animal pests. Plant and forest protection; Polyphenols; protein synthesis; protein transport; quantitative analysis; Solanum tuberosum; Solanum tuberosum - enzymology; spatial distribution; Starches; Tubers; Discoloration; Enzyme; Immunocytochemistry; Solanum tuberosum; Catechol oxidase; Bruise; Potato; Cell death; Dicotyledones; Angiospermae; Tuber; Spermatophyta; Oxidoreductases; Tuber plant; Solanaceae; Localization
• ISSN: 0032-0935; 1432-2048
• DOI: 10.1007/s004250050504

In order to elucidate the nature of the response of potato to impact injury at the biochemical level, changes in the location of the enzyme responsible for the discoloration, polyphenol oxidase, were determined using immunogold location with an antibody specific for potato tuber polyphenol oxidase. Tissue printing revealed that the enzyme was distributed throughout the tuber. Following impact injury, both tissue printing and quantitative electron microscopy indicated that there was no increase in the level of the enzyme although there was subcellular redistribution of polyphenol oxidase. This redistribution was first apparent at 12 h after impact, as determined by the use of confocal immunolocation, and coincided with loss of membrane integrity. These changes were examined in parallel with a number of stress-related parameters in both impact and wound responses. Wounding was accompanied by active gene expression and protein synthesis, leading to metabolic activity and tissue repair. In contrast, the bruising response was characterised by a limited active response and vital-staining methods indicated that after 16 h the tissue undergoes cell death.