Strawberry fatty acyl glycosides enhance disease protection, have antibiotic activity and stimulate plant growth

Carlos Grellet Bournonville,Björn Welin,Alicia Mamaní De Marchese,María Fernanda Trejo,Atilio Pedro Castagnaro,María Paula Filippone,Pía De Los Ángeles Di Peto,Alicia Susana Couto,Juan Carlos Díaz Ricci

doi:10.1038/s41598-020-65125-7

Abstract

An increasing interest in the development of products of natural origin for crop disease and pest control has emerged in the last decade. Here we introduce a new family of strawberry acyl glycosides (SAGs) formed by a trisaccharide (GalNAc-GalNAc-Glc) and a monounsaturated fatty acid of 6 to 12 carbon atoms linked to the glucose unit. Application of SAGs to Arabidopsis thaliana (hereafter Arabidopsis) plants triggered a transient oxidative burst, callose deposition and defense gene expression, accompanied by increased protection against two phytopathogens, Pseudomonas viridiflava and Botrytis cinerea. SAGs-induced disease protection was also demonstrated in soybean infected with the causal agent of target spot, Corynespora cassiicola. SAGs were shown to exhibit important antimicrobial activity against a wide-range of bacterial and fungal phytopathogens, most probably through membrane destabilization, and the potential use of SAGs as a biofungicide for postharvest disease protection was demonstrated on lemon fruits infected with Penicillium digitatum. Plant growth promotion by application of SAGs was shown by augmented primary root elongation, secondary roots development and increased siliques formation in Arabidopsis, whereas a significant increment in number of seed pods was demonstrated in soybean. Stimulation of radicle development and the induction of an auxin-responsive reporter system (DR5::GUS) in transgenic Arabidopsis plants, suggested that SAGs-stimulated growth at least partly acts through the auxin response pathway. These results indicate that strawberry fatty acid glycosides are promising candidates for the development of environmental-friendly products for disease management in soybean and lemon.

Highlights

An increasing interest in the development of products of natural origin for crop disease and pest control has emerged in the last decade
We present a group of strawberry trisaccharide fatty acid esters, not previously described, which activate innate plant pathogen defense reactions, stimulate plant growth and exhibit important antimicrobial activity
Aqueous extracts from strawberry leaves were fractionated by normal phase (Fig. 1A) and anionic exchange phase chromatography (Fig. 1B) and selected fractions were tested for protective effect against a pathogenic strain of Pseudomonas viridiflava on Arabidopsis plants (Fig. 1C)

Summary

Introduction

An increasing interest in the development of products of natural origin for crop disease and pest control has emerged in the last decade. Stimulation of radicle development and the induction of an auxin-responsive reporter system (DR5::GUS) in transgenic Arabidopsis plants, suggested that SAGs-stimulated growth at least partly acts through the auxin response pathway These results indicate that strawberry fatty acid glycosides are promising candidates for the development of environmental-friendly products for disease management in soybean and lemon. Biocontrollers or biopesticides have been developed for pest and disease control in many crops[8,9] All these products of biological origin are more readily degradable and less persistent than chemical fertilizers and pesticides, which make them amenable as replacement for traditional agrochemicals in a sustainable crop production system. Industrial interest in fatty acyl glycosides of natural origin (biosurfactants) has recently increased due to their low toxicity, high biodegradability, foaming capacity, high selectivity and specificity at extreme temperatures, pH and salinity

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Conclusion