Fungi are the primary infectious agents in plants causing significant economic losses in agroindustry. Traditionally, these pathogens have been treated with different synthetic fungicides such as hydroxianilides, anilinopyrimidines, and azoles, to name a few. However, the indiscriminate use of these chemicals has increased fungi resistance in plants. Natural products have been researched as a control, and an alternative to these synthetic fungicides since they are not harmful to health and contribute to the environment caring. This review describes plants extracts, essential oils, and active compounds or secondary metabolites as antifungal agents both, in vitro and in vivo. Active compounds have been recently described as the best candidates for the control of phytopathogenic fungi. When metabolized by plants, these compounds concentrations rely on the environmental conditions and pathogens incidence. However, one issue regarding the direct application of these preformed compounds in plants touch upon their low persistence in the environment, and their even lower bioavailability than synthetic fungicides. Hence the challenge is to develop useful formulations based on natural products to increase the compounds solubility facilitating thus their application in the field while maintaining their properties.

Botrytis cinerea is a worldwide spread fungus that causes the grey mold disease, which is considered the most important factor in postharvest losses in fresh fruit crops. Consequently, the control of gray mold is a matter of current and relevant interest for agricultural industries. In this work, a series of phenylpropanoids derived from eugenol were synthesized and characterized. Their effects on the mycelial growth of a virulent and multi-resistant isolate of B. cinerea (PN2) have been evaluated and IC50 values for the most active compounds range between 31–95 ppm. The antifungal activity exhibited by these compounds is strongly related to their chemical structure, i.e., increasing activity has been obtained by isomerization of the double bond or introduction of a nitro group on the aromatic ring. Based on the relationship between the fungicide activities and chemical structure, a mechanism of action is proposed. Finally, the activity of these compounds is higher than that reported for the commercial fungicide BC-1000 that is currently employed to combat this disease. Thus, our results suggest that these compounds are potential candidates to be used in the design of new and effective control with inspired natural compounds of this pathogen.

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Botrytis cinerea attacks a broad range of host causing significant economic losses in the worldwide fruit export industry. Hitherto, many studies have focused on the penetration mechanisms used by this phytopathogen, but little is known about the early stages of infection, especially those such as adhesion and germination. The aim of this work was to evaluate the effect of cuticular waxes compounds from table grapes on growth, germination and gene expression of B. cinerea. To accomplish this, growth was analyzed using as substrate n-alkanes extracted from waxes of fresh fruit (table grapes, blueberries and apricots). Subsequently, the main compounds of table grape waxes, oleanolic acid (OA) and n-fatty alcohols, were mixed to generate a matrix on which conidia of B. cinerea were added to assess their effect on germination and expression of bctub, bchtr and bchex genes. B. cinerea B05.10, isolated from grapes, increased its growth on a matrix composed by table grapes n-alkanes in comparison to a matrix made with n-alkanes from apricot or blueberries. Moreover, at 2.5 h, B05.10 germination increased 17 and 33 % in presence of n-alkanes from table grape, in comparison to conditions without alkanes or with blueberries alkanes, respectively. Finally, expression of bchtr and bchex showed a significant increase during the first hour after contact with n-fatty alcohols and OA. In conclusion, B. cinerea displays selectivity towards certain compounds found in host waxes, mainly n-fatty alcohols, which could be a good candidate to control this phytopathogen in early stages of infection.