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SUMMARY: The grapevine industry is of high economic importance in several countries worldwide. Its growing market demand led to an acceleration of the entire production processes, implying increasing use of water resources at the expense of environmental water balance and the hydrological cycle. Furthermore, in recent decades climate change and the consequent expansion of drought have further compromised water availability, making current agricultural systems even more fragile from ecological and economical perspectives. Consequently, farmers' income and welfare are increasingly unpredictable and unstable. Therefore, it is urgent to improve the resilience of vineyards, and of agro‐ecosystems in general, by developing sustainable and environmentally friendly farming practices by more rational biological and natural resources use. The PRIMA project PROSIT addresses these challenges by characterizing and harnessing grapevine‐associated microbiota to propose innovative and sustainable agronomic practices. PROSIT aims to determine the efficacy of natural microbiomes transferred from grapevines adapted to arid climate to commonly cultivated grapevine cultivars. In doing so it will test those natural microbiome effects on drought tolerance. This multidisciplinary project will utilize in vitro culture techniques, bioimaging, microbiological tests, metabolomics, metabarcoding and epigenetic analyses. These will be combined to shed light on molecular mechanisms triggered in plants by microbial associations upon water stress. To this end it is hoped that the project will serve as a blueprint not only for studies uncovering the microbiome role in drought stress in a wide range of species, but also for analyzing its effect on a wide range of stresses commonly encountered in modern agricultural systems. Significance Statement: This Perspective Review manuscript focuses on innovative and sustainable solutions to drought stress in viticulture, representing the core research of the "Plant Microbiome in Sustainable Viticulture (PROSIT)" project funded by the PRIMA Foundation with the support of the Horizon 2020 Program. [ABSTRACT FROM AUTHOR]

Fungi of genera Phlyctema and Neofabraea are the causal agents of bull's eye rot, a major postharvest disease of pome fruits. To investigate their morphological and genetic diversity, isolates obtained in Italy and Chile from decayed fruit and rainwater between 2014 and 2019 were grown on two agar media, inoculated onto four fruit cultivars and compared using four marker genes. Consistent intra‐ and interspecies phenotypic differences were recorded among isolates identified as P. vagabunda (two main morphotypes, PvM‐I and PvM‐II, were distinguished) and N. kienholzii. In particular, the Chilean isolates belonging to PvM‐I showed low sporulation in vitro, while isolates belonging to PvM‐II showed the most abundant sporulation and also formed conidiomata deep within fruit tissue. Host cultivar influenced the disease incidence in unwounded, inoculated fruit. Cripps Pink and Golden Delicious apples favoured the formation of P. vagabunda conidiomata and macroconidia, while Granny Smith apples and/or Kaiser pears restricted sporulation of some isolates of PvM‐I. Mycelial cords of P. vagabunda and N. kienholzii were consistently recorded in inoculated fruit, suggesting their possible involvement as a source of inoculum. Propagules of P. vagabunda were present in rainwater collected from apple plants from September to October in Italy. According to sequence analysis of ITS, EF‐1α, TUB2 and ACT1 regions of the fungi, 12 distinct sequence types were identified, three of which were characteristic of isolates from the Southern Hemisphere. The condensed maximum‐likelihood phylogenetic tree separated the 50 P. vagabunda isolates into six phylogroups, suggesting a correlation with their geographical distribution. [ABSTRACT FROM AUTHOR]

Wine yeasts can be natural hosts for dsRNA, ssRNA viruses and retrotransposon elements. In this study, high-throughput RNA sequencing combined with bioinformatic analyses unveiled the virome associated to 16 Saccharomyces cerevisiae and 8 non-Saccharomyces strains of oenological interest. Results showed the presence of six viruses and two satellite dsRNAs from four different families, two of which—Partitiviridae and Mitoviridae—were not reported before in yeasts, as well as two ORFan contigs of viral origin. According to phylogenetic analysis, four new putative mycoviruses distributed in Totivirus, Cryspovirus, and Mitovirus genera were identified. The majority of commercial S. cerevisiae strains were confirmed to be the host for helper L-A type totiviruses and satellite M dsRNAs associated with the killer phenotype, both in single and mixed infections with L-BC totiviruses, and two viral sequences belonging to a new cryspovirus putative species discovered here for the first time. Moreover, single infection by a narnavirus 20S-related sequence was also found in one S. cerevisiae strain. Considering the non-Saccharomyces yeasts, Starmerella bacillaris hosted four RNAs of viral origin—two clustering in Totivirus and Mitovirus genera, and two ORFans with putative satellite behavior. This study confirmed the infection of wine yeasts by viruses associated with useful technological characteristics and demonstrated the presence of complex mixed infections with unpredictable biological effects. [ABSTRACT FROM AUTHOR]