Double-Stranded RNAs (dsRNAs) as a Sustainable Tool against Gray Mold (Botrytis cinerea) in Grapevine: Effectiveness of Different Application Methods in an Open-Air Environment.

Luca Nerva,Marco Sandrini,Walter Chitarra,Giorgio Gambino

doi:10.3390/biom10020200

Abstract

Grapevine is one of the most important and globally widespread fruit species, with a high impact on the economy of many countries but with an intense environmental effect. Therefore, new environmentally friendly defense strategies against fungal pathogens are needed for more sustainable agriculture. A novel emerging approach is spray-induced gene silencing (SIGS), which concerns the exogenous application of double-stranded RNA (dsRNA) inducing enhanced plant resistance against fungal pathogens. Here, we tested the ability of SIGS to prevent and counteract infection of Botrytis cinerea, one of the most economically impacting pathogens of grapevine. In particular, we tested three independent approaches for dsRNA delivery into plants: (i) high pressure spraying of leaves; (ii) petiole adsorption of dsRNAs; (iii) postharvest spraying of bunches. We demonstrated that independently from the method of application, SIGS can reduce virulence of the fungus. Moreover, we also observed three different levels of efficacy depending on the method of application. Thus, the present data provide crucial information on the possibility to exploit SIGS as an alternative sustainable and ecofriendly strategy for grapevine pre- and postharvest protection.

Highlights

The global population is exponentially growing and, together with the ongoing climate changing scenario, is threatening food security [1]
A novel emerging approach is spray-induced gene silencing (SIGS), which concerns the exogenous application of double-stranded RNA inducing enhanced plant resistance against fungal pathogens
We tested three independent approaches for double-stranded RNA (dsRNA) delivery into plants: (i) high pressure spraying of leaves; (ii) petiole adsorption of dsRNAs; (iii) postharvest spraying of bunches

Summary

Introduction

The global population is exponentially growing and, together with the ongoing climate changing scenario, is threatening food security [1]. By means of sRNAs sequencing, transgenic expression of fungal sRNAs, and pathogenicity tests, the authors demonstrated that B. cinerea produces several specific sRNA molecules able to shut down key genes of the plant immune system. This result was confirmed by further experiments in which transgenic plants with impaired RNAi machinery displayed lower susceptibility, as well as mutant fungal strains for two proteins involved in sRNAs processing displaying lower virulence [17]. We report the possibility to control pre- and postharvest gray mold infections by using SIGS, an environmental friendly and sustainable alternative to fungicides

Plant Material

Findings

RNA Extraction and Northern Blot Analysis