Browsing by Author "Feygenberg, Oleg"

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    Assembly and dynamics of the apple carposphere microbiome during fruit development and storage
    Zhimo, V. Yeka; Kumar, Ajay; Biasi, Antonio; Abdelfattah, Ahmed; Sharma, Vijay Kumar; Salim, Shoshana; Feygenberg, Oleg; Bartuv, Rotem; Freilich, Shiri; Whitehead, Susan R.; Wisniewski, Michael; Droby, Samir (Frontiers, 2022-08-09)
    Microbial communities associated with fruit can contribute to quality and pathogen resistance, but little is known about their assembly and dynamics during fruit development and storage. Three apple cultivars growing under the same environmental conditions were utilized to examine the apple carposphere microbiome composition and structure at different developmental stages and storage. There was a significant effect (Adonis, p <= 0.001) of fruit genotype and its developmental stages and storage times on the fruit surface microbial assemblage and a strong temporal microbial community succession was detected (Mantel test: R <= 0.5, p = 0.001) in both bacterial and fungal communities. A set of 15 bacterial and 35 fungal core successional taxa and members exhibiting differential abundances at different fruit stages were identified. For the first time, we show the existence of underlying universal dynamics in the assembly of fruit-associated microbiomes. We also provide evidence of strong microbial cross-domain associations and uncover potential microbe-microbe correlations in the apple carposphere. Together our findings shed light on how the fruit carposphere assemble and change over time, and provide new insights into fruit microbial ecology.
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    Changes in the Fungal Community Assembly of Apple Fruit Following Postharvest Application of the Yeast Biocontrol Agent Metschnikowia fructicola
    Biasi, Antonio; Zhimo, V. Yeka; Kumar, Ajay; Abdelfattah, Ahmed; Salim, Shoshana; Feygenberg, Oleg; Wisniewski, Michael; Droby, Samir (MDPI, 2021-10-04)
    Recently, increasing focus has been placed on exploring fruit microbiomes and their association with their hosts. Investigation of the fruit surface microbiome of apple has revealed variations in the composition and structure depending on management practices, phenological stages, and spatial distribution on the fruit itself. However, the fate of the fruit surface microbiome assembly and dynamics in apple following interventions such as the application of biocontrol agents remains unknown. The objective of the study was to explore the effect of a postharvest application of a yeast biocontrol agent, Metschnikowia fructicola, on the composition of the epiphytic fungal microbiota on apples during cold storage. Our results demonstrated that the applied biocontrol agent, M. fructicola, persisted in high abundance (>28% relative abundance) on the fruit surface throughout the storage period. The biocontrol application significantly decreased the richness and caused a significant shift in the overall composition and structure of the fungal microbiome relative to untreated or water-treated controls. The yeast application reduced the abundance of several apple fungal pathogens, namely, Alternaria, Aspergillus, Comoclatris, Stemphylium, Nigrospora, Penicillium, and Podosphaera, throughout the cold storage period.
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    Global analysis of the apple fruit microbiome: are all apples the same?
    Abdelfattah, Ahmed; Freilich, Shiri; Bartuv, Rotem; Zhimo, V. Yeka; Kumar, Ajay; Biasi, Antonio; Salim, Shoshana; Feygenberg, Oleg; Burchard, Erik; Dardick, Christopher; Liu, Jia; Khan, Awais; Ellouze, Walid; Ali, Shawkat; Spadaro, Davide; Torres, Rosario; Teixido, Neus; Ozkaya, Okan; Buehlmann, Andreas; Vero, Silvana; Mondino, Pedro; Berg, Gabriele; Wisniewski, Michael; Droby, Samir (2021-03-18)
    We present the first worldwide study on the apple (Malus x domestica) fruit microbiome that examines questions regarding the composition and the assembly of microbial communities on and in apple fruit. Results revealed that the composition and structure of the fungal and bacterial communities associated with apple fruit vary and are highly dependent on geographical location. The study also confirmed that the spatial variation in the fungal and bacterial composition of different fruit tissues exists at a global level. Fungal diversity varied significantly in fruit harvested in different geographical locations and suggests a potential link between location and the type and rate of postharvest diseases that develop in each country. The global core microbiome of apple fruit was represented by several beneficial microbial taxa and accounted for a large fraction of the fruit microbial community. The study provides foundational information about the apple fruit microbiome that can be utilized for the development of novel approaches for the management of fruit quality and safety, as well as for reducing losses due to the establishment and proliferation of postharvest pathogens. It also lays the groundwork for studying the complex microbial interactions that occur on apple fruit surfaces.
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    Identification and Functional Analysis of NLP-Encoding Genes from the Postharvest Pathogen Penicillium expansum
    Levin, Elena; Raphael, Ginat; Ma, Jing; Ballester, Ana-Rosa; Feygenberg, Oleg; Norelli, John; Aly, Radi; Gonzalez-Candelas, Luis; Wisniewski, Michael; Droby, Samir (MDPI, 2019-06-15)
    Penicillium expansum is a major postharvest pathogen that infects different fruits, mainly through injuries inflicted during harvest or subsequent handling after harvest. Several effectors were suggested to mediate pathogenicity of P. expansum in fruit tissue. Among these effectors Nep1-like proteins (NLPs), produced by various microorganisms with different lifestyles, are known for their ability to induce necrosis in dicot plants and were shown to be involved in virulence of several plant-related pathogens. This study was aimed at the identification and functional characterization of two NLP genes found in the genome of P. expansum. The genes were designated Penlp1 and Penlp2 and were found to code type1 and type3 NLP respectively. Necrosis-inducing activity of the two proteins was demonstrated by transient expression in Nicotiana benthamiana leaves. While Penlp1 expression was induced during apple infection and in liquid culture, the highest level of Penlp2 expression was found in ungerminated spores. Deletion of Penlp1, but not Penlp2, resulted in reduced virulence on apples manifested by reduced rate of lesion development (disease severity).