57. 根寄生雑草Striga gesnerioides種子の発芽を誘導するストライゴラクトンの構造要求性(口頭発表,植物化学調節学会第46回大会)

概要

論文の詳細を見る
Strigolactones are highly potent germination stimulants for seeds of the parasitic weeds Striga and Orobanche spp. A synthetic strigolactone GR24 induces germination of seeds of several root parasitic plants including O. minor and S. hermonthica, but not S. gesnerioides. Germination of the latter is only elicited by cowpea root exudates or alectrol, isolated from its root exudates. The recent proposal that the true structure of alectrol is the same as that of orobanchyl acetate, suggests that a modification in the B-ring of the strigolactones is important for germination induction of S. gesnerioides seeds. In the present study, 4-hydroxy-GR24 (HO-GR24) and 4-acetoxy-GR24 (AcO-GR24) were prepared and evaluated for ability to induce germination of parasitic plant seeds. Racemic mixtures of these compounds induced seed germination of S. hermonthica and O. minor. However, S. gesnerioides seeds did not respond to any of the compounds. The seeds responded to the (8bR,2'R)-isomer of HO-GR24. The stereoisomer of GR24 with the same configuration induced negligible germination. Some stereoisomers of GR24 and its analogs acted as effective inhibitor for induction of seed germination by cowpea root exudates. The results suggested that both an oxidized substituent at C-4 and the configuration of the tricyclic lactone and the D ring are essential structural requirements for induction of germination in S. gesnerioides seeds.
2011-10-03