Rapid molecular assay for the evaluation of clove essential oil antifungal activity against wheat common bunt

Maria Teresa Valente; Laura Orzali; Giuliano Manetti; Francesco Magnanimi; Antonio Matere; Valentino Bergamaschi; Alessandro Grottoli; Sara Bechini; Luca Riccioni; Maria Aragona

doi:10.3389/fpls.2023.1130793

Rapid molecular assay for the evaluation of clove essential oil antifungal activity against wheat common bunt

Front Plant Sci. 2023 Jun 5:14:1130793. doi: 10.3389/fpls.2023.1130793. eCollection 2023.

Authors

Affiliations

¹ Council for Agricultural Research and Economics (CREA), Research Centre for Plant Protection and Certification (CREA-DC), Rome, Italy.
² Department of Environmental Biology, Sapienza University of Rome, Rome, Italy.
³ Department of Biology and Biotechnology "Charles Darwin", Sapienza University of Rome, Rome, Italy.

Abstract

Common bunt of durum wheat (DW), Triticum turgidum L. ssp. durum (Desf.) Husn., is caused by the two closely related fungal species belonging to Tilletia genus (Tilletiales, Exobasidiomycetes, Ustilaginomycotina): Tilletia laevis Kühn (syn. T. foetida (Wallr.) Liro.) and T. caries (DC) Tul. (syn. T. tritici (Bjerk.) G. Winter). This is one of the most devastating diseases in wheat growing areas worldwide, causing considerable yield loss and reduction of wheat grains and flour quality. For these reasons, a fast, specific, sensitive, and cost-effective method for an early diagnosis of common bunt in wheat seedlings is urgent. Several molecular and serological methods were developed for diagnosis of common bunt in wheat seedlings but at late phenological stages (inflorescence) or based on conventional PCR amplification, with low sensitivity. In this study, a TaqMan Real Time PCR-based assay was developed for rapid diagnosis and quantification of T. laevis in young wheat seedlings, before tillering stage. This method, along with phenotypic analysis, was used to study conditions favoring pathogen infection and to evaluate the effectiveness of clove oil-based seed dressing in controlling the disease. The overall results showed that: i) the Real Time PCR assay was able to quantify T. laevis in young wheat seedlings after seed dressing by clove oil in different formulations, greatly reducing times of analysis. It showed high sensitivity, detecting up to 10 fg of pathogen DNA, specificity and robustness, allowing to directly analyze crude plant extracts and representing a useful tool to speed up the tests of genetic breeding for disease resistance; ii) temperature was a critical point for disease development when using wheat seeds contaminated by T. laevis spores; iii) at least one of the clove oil-based formulations tested was able to efficiently control wheat common bunt, suggesting that clove oil dressing could represent a promising tool for managing the disease, especially in sustainable farming.

Keywords: Tilletia laevis; Triticum durum; clove oil; real time PCR; seed borne disease; seed dressing; wheat common bunt.

Grants and funding

This work was supported by the project “Riduzione input di origine extra-aziendale per la Difesa delle coltivazioni BIOlogiche mediante approccio agroecologico (DIBIO)”, funded by Ministry of Agriculture, and carried out within the “EUPHRESCO Basic substances as an environmentally friendly alternative to synthetic pesticides for plant protection (BasicS)” project (Objective 2020-C-353).