O-Acyl Sugars Protect a Wild Tobacco from Both Native Fungal Pathogens and a Specialist Herbivore.
Plant Physiol
; 174(1): 370-386, 2017 May.
Article
en En
| MEDLINE
| ID: mdl-28275149
ABSTRACT
O-Acyl sugars (O-AS) are abundant trichome-specific metabolites that function as indirect defenses against herbivores of the wild tobacco Nicotiana attenuata; whether they also function as generalized direct defenses against herbivores and pathogens remains unknown. We characterized natural variation in O-AS among 26 accessions and examined their influence on two native fungal pathogens, Fusarium brachygibbosum U4 and Alternaria sp. U10, and the specialist herbivore Manduca sexta At least 15 different O-AS structures belonging to three classes were found in N. attenuata leaves. A 3-fold quantitative variation in total leaf O-AS was found among the natural accessions. Experiments with natural accessions and crosses between high- and low-O-AS accessions revealed that total O-AS levels were associated with resistance against herbivores and pathogens. Removing O-AS from the leaf surface increased M. sexta growth rate and plant fungal susceptibility. O-AS supplementation in artificial diets and germination medium reduced M. sexta growth and fungal spore germination, respectively. Finally, silencing the expression of a putative branched-chain α-ketoacid dehydrogenase E1 ß-subunit-encoding gene (NaBCKDE1B) in the trichomes reduced total leaf O-AS by 20% to 30% and increased susceptibility to Fusarium pathogens. We conclude that O-AS function as direct defenses to protect plants from attack by both native pathogenic fungi and a specialist herbivore and infer that their diversification is likely shaped by the functional interactions among these biotic stresses.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Nicotiana
/
Hojas de la Planta
/
Azúcares
/
Resistencia a la Enfermedad
Límite:
Animals
Idioma:
En
Revista:
Plant Physiol
Año:
2017
Tipo del documento:
Article
País de afiliación:
Alemania