Double Gamers-Can Modified Natural Regulators of Higher Plants Act as Antagonists against Phytopathogens? The Case of Jasmonic Acid Derivatives.

Nicolò Orsoni,Giorgio Spadola,Franco Bisceglie,Francesca Degola,Roberta Ghizzoni,Walter Chitarra,Francesco M Restivo,Caterina Morcia,Luca Nerva,Elżbieta Mielniczuk,Agnieszka Jamiołkowska,Valeria Terzi,Stefano Delbono,Giorgio Pelosi

doi:10.3390/ijms21228681

Abstract

As key players in biotic stress response of plants, jasmonic acid (JA) and its derivatives cover a specific and prominent role in pathogens-mediated signaling and hence are promising candidates for a sustainable management of phytopathogenic fungi. Recently, JA directed antimicrobial effects on plant pathogens has been suggested, supporting the theory of oxylipins as double gamers in plant-pathogen interaction. Based on these premises, six derivatives (dihydrojasmone and cis-jasmone, two thiosemicarbazonic derivatives and their corresponding complexes with copper) have been evaluated against 13 fungal species affecting various economically important herbaceous and woody crops, such as cereals, grapes and horticultural crops: Phaeoacremonium minimum, Neofusicoccum parvum, Phaeomoniella chlamydospora, Fomitiporia mediterranea, Fusarium poae, F. culmorum, F. graminearum, F. oxysporum f. sp. lactucae, F. sporotrichioides, Aspergillus flavus, Rhizoctonia solani, Sclerotinia spp. and Verticillium dahliae. The biological activity of these compounds was assessed in terms of growth inhibition and, for the two mycotoxigenic species A. flavus and F. sporotrichioides, also in terms of toxin containment. As expected, the inhibitory effect of molecules greatly varied amongst both genera and species; cis-jasmone thiosemicarbazone in particular has shown the wider range of effectiveness. However, our results show that thiosemicarbazones derivatives are more effective than the parent ketones in limiting fungal growth and mycotoxins production, supporting possible applications for the control of pathogenic fungi.

Highlights

Synthesized from α-linolenic acid originating from chloroplast membranes, jasmonic acid (JA) is regarded as a key player among the molecules that play a role in plant defense, signaling and development; it is known to be involved, together with other phytohormones, in the host defense response and immune signaling modulation
Thiosemicarbazone metal complexes and those of copper(II) in particular, are known to produce interesting biological effects showing that the coordination compounds own effective properties at lower concentrations with respect to the parent organic molecules and these properties are often related to reactive oxygen species (ROS) production or other pathways involving the metal ion [23]
Relative to the biological activity of compounds on both primary and secondary metabolisms, some interesting differences between the JA-derivatives were found—natural ketones did not show any fungistatic effect on fungal pathogens affecting grapevine and linked to grapevine esca disease, as well as pathogens affecting horticulture crops; a slight inhibitory activity was recorded on cereals contaminating species (Fusarium and Aspergillus spp)

Summary

Introduction

Synthesized from α-linolenic acid originating from chloroplast membranes, jasmonic acid (JA) is regarded as a key player among the molecules that play a role in plant defense, signaling and development; it is known to be involved, together with other phytohormones (e.g., salicylic acid, ethylene, indole-3-acetic acid, abscisic acid, cytokinin and gibberellin), in the host defense response and immune signaling modulation. With the idea of exploiting the potential of JA derivatives to interfere with fungal development and metabolism, a panel of six JA-derived molecules (two ketones of natural origin, di-hydrojasmone and cis-jasmone, their thiosemicarbazonic derivatives and the corresponding copper complexes) was evaluated against 13 fungal species affecting various economically important herbaceous and woody crops such as cereals, grape and horticultural plants. All these fungi cause relevant yield and quality losses and are characterized by different life cycle, pathogenicity behavior, transmission mode and effects on both plants and derived products. Even though different in their life cycle, they share the responsibility for affecting agricultural yield losses, especially in the horticultural crops cultivated in temperate regions [20]

Methods

Results

Discussion

Conclusion