Elucidation of the biosynthetic pathway of cis-jasmone in Lasiodiplodia theobromae

In plants, cis -jasmone (CJ) is synthesized from α-linolenic acid (LA) via two biosynthetic pathways using jasmonic acid (JA) and iso -12-oxo-phytodienoic acid ( iso -OPDA) as key intermediates. However, there have been no reports documenting CJ production by microorganisms. In the present study, the production of fungal-derived CJ by Lasiodiplodia theobromae was observed for the first time, although this production was not observed for Botrytis cinerea , Verticillium longisporum , Fusarium oxysporum , Gibberella fujikuroi , and Cochliobolus heterostrophus . To investigate the biosynthetic pathway of CJ in L . theobromae , administration experiments using [18,18,18- 2 H 3 , 17,17- 2 H 2 ]LA (LA-d5), [18,18,18- 2 H 3 , 17,17- 2 H 2 ]12-oxo-phytodienoic acid ( cis -OPDA-d5), [5′,5′,5′- 2 H 3 , 4′,4′- 2 H 2 , 3′- 2 H 1 ]OPC 8:0 (OPC8-d6), [5′,5′,5′- 2 H 3 , 4′,4′- 2 H 2 , 3′- 2 H 1 ]OPC 6:0 (OPC6-d6), [5′,5′,5′- 2 H 3 , 4′,4′- 2 H 2 , 3′- 2 H 1 ]OPC 4:0 (OPC4-d6), and [11,11- 2 H 2 , 10,10- 2 H 2 , 8,8- 2 H 2 , 2,2- 2 H 2 ]methyl iso -12-oxo-phytodienoate ( iso -MeOPDA-d8) were carried out, revealing that the fungus produced CJ through a single biosynthetic pathway via iso -OPDA. Interestingly, it was suggested that the previously predicted decarboxylation step of 3,7-didehydroJA to afford CJ might not be involved in CJ biosynthesis in L . theobromae .