Cellular, physiological, and molecular aspects of recovery and induction mechanisms in the wound response of Solanum tuberosum tuber tissue.

摘要

Potato tuber slices served as a model system for the study of wound-induced differentiation. Carbon dioxide (10% in air) was investigated as a primary factor in maintaining wounded tissue in an undifferentiated, proliferative state, as compared with the determinate formation of would periderm in slices aged in air. In this context mRNA population of tubers and slices was examined, with particular emphasis on the effect of carbon dioxide on specific wound-related and periderm-related changes.; The source and composition of mRNA used for polysome assembly following wounding was studied. Stored mRNA in tubers was found to serve as a template for polysome assembly in vivo for at least six hours following wounding. New species of mRNA were synthesized thereafter.; The effect of CO{dollar}sb2{dollar} on the mRNA population of slices aged for 6 h or longer was studied by in vitro translation and Northern blot analysis of extracted mRNA. Carbon dioxide was found to affect periderm-related mRNA induction, but not induction of other wound-related mRNAs. Whereas carbon dioxide suppresses the induction of mRNA encoding anionic isoperoxidase (an enzyme mediating suberin synthesis during periderm formation) in slices of newly formed tubers, but not in slices of long dormant tubers, it failed to modulate non-periderm related genes; carbon dioxide failed to inhibit induction of mRNA encoding WUN-1 and WUN-2 (two wound-induced genes), and carbon dioxide failed to stem the disappearance of mRNA encoding patatin (a tuber-specific storage protein with acyl-hydrolase activity).