Structure-Activity Relationships of Jasmonates in the Induction of Expression of Two Proteinase Inhibitor Genes of Potato

Abstract

Expression of genes coding for wound-inducible cathepsin D inhibitor (CDI) and proteinase inhibitor II (PI-II) of potato were induced in leaves upon treatment with methyl jasmonate (MJA) with similar time and concentration dependences. The response of CDI and PI-II genes to various compounds structurally related to MJA were also similar to each other. For the induction of expression of these proteinase inhibitor genes, an acetyl side chain, whether or not it is methylated, at the C-1 position, an n-pentenyl side chain at the C-2 position, and a keto group at the C-3 position of the cyclopentane ring of JA were all important for its activity. These structural requirements of MJA-related compounds for the induction of proteinase inhibitor genes seemed to be ditferent from those for the induction of potato tuber formation, the promotion of leaf senescence, and the inhibition of seedling growth.