Natural variation of diterpenoid phytoalexins in cultivated and wild rice species.
Phytochemistry
; 180: 112518, 2020 Dec.
Article
en En
| MEDLINE
| ID: mdl-32950772
ABSTRACT
Rice (Oryza sativa) leaves accumulate phytoalexins in response to pathogen attack. The major phytoalexins in rice are diterpenoids such as momilactones, phytocassanes, and oryzalexins. We analyzed the abundance of momilactones A and B and phytocassanes A and D in UV-light-irradiated leaves of cultivars from the World Rice Core Collection (WRC). Both types of phytoalexins were detected in most cultivars; however, their accumulated amounts varied greatly from cultivar to cultivar. The amounts of momilactones A and B tended to be higher in japonica cultivars than those in indica cultivars. However, the accumulated amounts of phytocassanes were not related to differences in subspecies. In addition, variation in phytoalexin content was observed for seven wild rice species. During the analysis of momilactone A in cultivars from the WRC, two unknown compounds were detected in'Jaguary' and 'Basilanon'. We isolated these compounds from UV-light-irradiated leaves and determined their structures. The compound isolated from 'Jaguary' was an isomer of momilactone A that had an abietane skeleton, while that from 'Basilanon' was di-dehydrogenated phytocassane A; these compounds were denoted as oryzalactone and phytocassane G. Oryzalactone accumulated in only three cultivars, whereas phytocassane G accumulated in almost all of the cultivars from the WRC. These findings indicate the existence of large natural variation in the phytoalexin composition in rice.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Oryza
/
Sesquiterpenos
Idioma:
En
Revista:
Phytochemistry
Año:
2020
Tipo del documento:
Article
País de afiliación:
Japón