6. ジベレリン生合成中間体ent-カウレンの気相への放出

概要

論文の詳細を見る
ent-Kaurene is a tetracyclic hydrocarbon precursor for gibberellins (GAs) in plants and fungi. To address whether fungal GA biosynthesis enzymes function in plants, we generated transgenic Arabidopsis plants overexpressing ent-kaurene synthase (GfCPS/KS) from a GA-producing fungus Gibberella fujikuroi. GfCPS/KS catalyzes a two-step reaction corresponding to ent-copalyl diphosphate synthase (CPS) and ent-kaurene synthase (KS) activities in plants. When GfCPS/KS was overexpressed and targeted to plastids, a range of GA-deficient phenotypes of the ga1-3 and ga2-1 mutants (defective in CPS and KS, respectively) were restored to wild-type. Unexpectedly, the transgenic lines overproducing GfCPS/KS emitted the GA precursor ent-kaurene into the headspace besides its accumulation in the plant body. When co-cultivated with the ent-kaurene overproducers in a closed environment, the airborne ent-kaurene was able to fully complement the dwarf phenotype of ga1-3 and ga2-1 mutants, but not that of the ga3-1 mutant (defective in ent-kaurene oxidase). These results suggest that ent-kaurene might be efficiently metabolized into bioactive GAs in Arabidopsis when supplied as a volatile. Consistent with the results of co-cultivation experiments, we identified ent-kaurene from the headspace of GfCPS/KS overexpression lines by GC-MS analysis using solid-phase micro-extraction and ODS trapping methods. We also provide evidence that ent-kaurene is released in the headspace of wild-type japanese cedar "Sugi" (Cryptomeria japonica), japanese cypress "Hinoki" (Chamaecyparis obtusa) and Stevia (Stevia rebaudiana) plants, suggesting the occurrence of this hydrocarbon GA precursor as a volatile in nature.
植物化学調節学会の論文
2004-10-13

6. ジベレリン生合成中間体ent-カウレンの気相への放出

スポンサーリンク

概要

著者

関連論文

スポンサーリンク