METABOLISM OF JASMONATES IN PLANTS

(-) – Jasmonic acid (JA) and its stereoisomer (+)-7-iso-JA are the major representatives of a new group of native plant growth regulators (jasmonates) widespread in plants and possessing hormone-like properties.
Further members of the group are cucurbic acid (CA) and a number of structurally related cyclopentanoidal acids as well as amino acid and glucosyl conjugates, metabolically formed.

Biotransformation of /2-¹⁴C/labelled JA and dihydro-JA in barley shoots gave the same pattern of metabolities which were isolated, purified and structurally elucidated by physical methods (GC-MS, NMR, ORD). A primary step, hy6droxylation, yielded the 11-OH and 12-OH derivatives of JA. Reduction of the C-6 keto group resulted in CA- related compounds, both with hydroxylated and non-hydroxylated side-chain.
Following O-glucosylation gave their 0(6)-, 0(11)- and 0)12)- glucosides, respectively.
Another major route of JA metabolism is conjugation with certain amino acids, in case of barley seedlings val and ile.
In tomato and potato cell suspensions JA is rapidly metabolized too.
Besides metabolites known from barley shoots, the JA--D-gentiobiosyl and JA-D-glucopyranosyl esters were identified as the major metabolites for the first time.

The physiological role of different metabolities is under investigation and will be discussed.

VII International Symposium on Plant Growth Regulators in Fruit Production

G. Sembdner, C. Bruckner, A. Kehlen, H.D. Knofel, R. Kramell, A. Meyer, O. Miersch

https://doi.org/10.17660/ActaHortic.1993.329.43