O-Acyl Sugars Protect a Wild Tobacco from Both Native Fungal Pathogens and a Specialist Herbivore. Issue 1 (8th March 2017)

• Record Type: Journal Article
• Authors: Luu, Van Thi; Weinhold, Alexander; Ullah, Chhana; Dressel, Stefanie; Schoettner, Matthias; Gase, Klaus; Gaquerel, Emmanuel; Xu, Shuqing; Baldwin, Ian T.
• Is Part Of: Plant physiology. Volume 174:Issue 1(2017)
• Page Start: 370
• Page End: 386
• Publication Date: 2017-03-08
• Subjects: Plant physiology -- Periodicals; Botany -- Periodicals; Periodicals; Electronic journals; 571.2
• DOI: 10.1104/pp.16.01904
• Languages: English
• ISSNs: 0032-0889

Abstract

Abstract : O-Acyl sugars, trichome-specific metabolites, function as direct defenses against native pathogens and herbivores of a wild tobacco. 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 β-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.