STRUCTURE-ACTIVITY-RELATIONSHIPS OF JASMONATES IN THE INDUCTION OF EXPRESSION OF 2 PROTEINASE-INHIBITOR GENES OF POTATO

Expression of genes coding for wound-inducible cathepsin D inhibitor ( CDI) and proteinase inhibitor II (PI-II) of potato were induced in lea ves upon treatment with methyl jasmonate (MJA) with similar time and c oncentration dependences. The response of CDI and PI-II genes to vario us compounds structurally related to MJA were also similar to each oth er. For the induction of expression of these proteinase inhibitor gene s, an acetyl side chain, whether or not it is methylated, at the C-1 p osition, an n-pentenyl side chain at the C-2 position, and a keto grou p at the C-3 position of the cyclopentane ring of JA were all importan t for its activity. These structural requirements of MJA-related compo unds for the induction of proteinase inhibitor genes seemed to be diff erent from those for the induction of potato tuber formation, the prom otion of leaf senescence, and the inhibition of seedling growth.