Botrytis bunch rot caused by Botrytis cinerea is one of the most economically significant post-harvest diseases of grapes. In the present study, we showed that the bacterial strain Bvel1 is phylogenetically affiliated to Bacillus velezensis species. The strain Bvel1 and its secreted metabolites exerted an antifungal activity, under in vitro conditions, against B. cinerea. UHPLC–HRMS chemical analysis revealed that iturin A2, surfactin-C13 and -C15, oxydifficidin, bacillibactin, L-dihydroanticapsin, and azelaic acid were among the metabolites secreted by Bvel1. Treatment of wounded grape berries with Bacillus sp. Bvel1 cell culture was effective for controlling grey mold ingress and expansion in vivo. The effectiveness of this biological control agent was a function of the cell culture concentration of the antagonist applied, while preventive treatment proved to be more effective compared to curative. The strain Bvel1 exhibited an adequate colonization efficiency in wounded grapes. The whole-genome phylogeny, combined with ANI and dDDH analyses, provided compelling evidence that the strain Bvel1 should be taxonomically classified as Bacillus velezensis. Genome mining approaches showed that the strain Bvel1 harbors 13 antimicrobial biosynthetic gene clusters, including iturin A, fengycin, surfactin, bacilysin, difficidin, bacillaene, and bacillibactin. The results provide new insights into the understanding of the endophytic Bacillus velezensis Bvel1 biocontrol mechanism against post-harvest fungal pathogens, including bunch rot disease in grape berries.

Powdery mildew disease, caused by the obligate biotrophic fungal pathogen Podosphaera xanthii, is the most reported and destructive disease on cultivated Cucurbita species all over the world. Recently, the appearance of highly aggressive P. xanthii isolates has led to powdery mildew outbreaks even in resistant crops, making disease management a very difficult task. To challenge this, breeders rely on genetic characteristics for powdery mildew control. Analysis of commercially available intermediate resistant courgette (Cucurbita. pepo L. var. cylindrica) varieties using cytological, molecular and biochemical approaches showed that the plants were under a primed state and induced systemic acquired resistance (SAR) responses, exhibiting enhanced callose production, upregulation of salicylic acid (SA) defense signalling pathway genes and accumulation of SA and defense metabolites. Additionally, the intermediate resistant varieties showed an altered epigenetic landscape in histone marks that affect transcriptional activation. We demonstrated that courgette plants had enriched H3K4me3 marks on SALICYLIC ACID-BINDING PROTEIN 2 and YODA genes of the Pm-0 interval introgression, a genomic region that confers resistant to Cucurbits against P. xanthii. The open chromatin of SALICYLIC ACID-BINDING PROTEIN 2 and YODA genes was consistent with genes’ differential expression, induced SA pathway, altered stomata characteristics and activated SAR responses. These findings demonstrate that the altered epigenetic landscape of the intermediate resistant varieties modulates the activation of SALICYLIC ACID-BINDING PROTEIN 2 and YODA genes leading to induced gene transcription that primes courgette plants.

Children acquire quite late scalar implicatures associated with quantification and have the tendency to interpret existential quantifiers as universals (e.g., Smith, 1980; Noveck, 2001; Papafragou and Musolino, 2003). Free choice Items (FCIS) are also associated with scalar implicatures depending on whether they are full set or subset FCIs (e.g., Vlachou 2012, 2020). This paper presents experimental results showing that 9-, 10- and 11-year-old children and adults perform better on full set than on subset FCIs. It is argued that adults perform better than children in sentences with subset FCIs as the “not-all” pragmatic inference is acquired late. Difficulties in sentences with subset FCIs in adults are due to absence of domain alternatives.

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