Molecules | |
Xylosylated Detoxification of the Rice Flavonoid Phytoalexin Sakuranetin by the Rice Sheath Blight Fungus Rhizoctonia solani | |
Hiroaki Toshima1  Shun Katsumata1  Morifumi Hasegawa1  | |
[1] College of Agriculture, Ibaraki University, 3-21-1 Chuo, Ami, Ibaraki 300-0393, Japan; | |
关键词: phytoalexin; flavonoid; rice; Rhizoctonia solani; xylosylation; | |
DOI : 10.3390/molecules23020276 | |
来源: DOAJ |
【 摘 要 】
Sakuranetin (1) is a rice flavanone-type phytoalexin. We have already reported that the metabolites from the detoxification of 1 by Pyricularia oryzae are naringenin (2) and sternbin. In this study, we investigated whether the rice sheath blight fungus Rhizoctonia solani, another major rice pathogen, can detoxify 1. The extract of R. solani suspension culture containing 1 was analyzed by LC-MS to identify the metabolites of 1. Three putative metabolites of 1 were detected in the extract from the R. solani suspension culture 12 h after the addition of 1, and they were identified as 2, sakuranetin-4′-O-β-d-xylopyranoside (3), and naringenin-7-O-β-d-xylopyranoside (4) by NMR, LC-MS/MS, and GC-MS analyses. The accumulation of 2, 3, and 4 reached their maximum levels 9–12 h after the addition of 1, whereas the content of 1 decreased to almost zero within 9 h. The antifungal activities of 3 and 4 against R. solani were negligible, and 2 showed weaker antifungal activity than 1. We concluded that 2, 3, and 4 are metabolites from the detoxification of 1 by R. solani. Xylosylation is a rare and efficient detoxification method for phytoalexins.
【 授权许可】
Unknown