Grapevines (Vitis vinifera) are colonized by ubiquitous microorganisms known as endophytes, which may have advantageous or neutral effects without causing disease symptoms. Certain endophytes are uncultivable, so culture-independent approaches such as next generation sequencing (NGS) can help for a better understanding of their ecology and distribution. To date, there are no studies which directly link NGS results with taxa derived from a culturing approach, integrating morphological and multi-gene phylogenetic analysis of endophytes. In this study, a culture-dependent and high-resolution culture-independent approach (next generation sequencing) were used to identify endophytes in grapevine stems. In the culture-dependent approach, a total of 94 isolates were recovered from 84 of 144 healthy grapevine stem fragments (colonization rate = 58.3%). The study is unique as we used subsets of combined multi-gene regions to identify the endophytes to species level. Based on each multi-gene phylogenetic analysis, 28 species belong to 19 genera (Acremonium, Alternaria, Arthrinium, Ascorhizoctonia, Aspergillus, Aureobasidium, Bipolaris, Botryosphaeria, Botrytis, Chaetomium, Cladosporium, Curvularia, Hypoxylon, Lasiodiplodia, Mycosphaerella, Nigrospora, Penicillium, Phoma, Scopulariopsis) were identified. A higher number of culturable fungi were obtained from 13 year-old vines, followed by eight and three year-old vines. In the culture-independent approach, a fungal richness of 59 operational taxonomic units (OTU) was detected, being highest in 13 year-old grapevines, followed by eight and three years. Even though the cultivation approach detected lower fungal richness, the results related to stem are consistent for fungal community composition and richness. Comparison of the fungal taxa identified by the two approaches resulted in an overlap of 53% of the fungal genera. Due to interspecific variability of the sequences from NGS, in many cases the OTUs (even with the highly abundant ones) were only assignable to order, family or genus level. Incorporating multi-gene phylogenies we successfully identified many of the NGS derived OTUs with poor taxonomic information in reference databases to the genus or species levels. Hence, this study signifies the importance of applying both culture-dependent and culture-independent approaches to study the fungal endophytic community composition in Vitis vinifera. This principle could also be applied to other host species and ecosystem level studies.

Botryosphaeriaceae are an important fungal family that cause woody plant diseases worldwide. Recent studies have established a correlation between environmental factors and disease expression; however, less is known about factors that trigger these diseases. The current study reports on the 43.3 Mb de novo genome of Lasiodiplodia theobromae and five other genomes of Botryosphaeriaceae pathogens. Botryosphaeriaceous genomes showed an expansion of gene families associated with cell wall degradation, nutrient uptake, secondary metabolism and membrane transport, which contribute to adaptations for wood degradation. Transcriptome analysis revealed that genes involved in carbohydrate catabolism, pectin, starch and sucrose metabolism, and pentose and glucuronate interconversion pathways were induced during infection. Furthermore, genes in carbohydrate-binding modules, lysine motif domain and the glycosyl hydrolase gene families were induced by high temperature. Among these genes, overexpression of two selected putative lignocellulase genes led to increased virulence in the transformants. These results demonstrate the importance of high temperatures in opportunistic infections. This study also presents a set of Botryosphaeriaceae-specific effectors responsible for the identification of virulence-related pathogen-associated molecular patterns and demonstrates their active participation in suppressing hypersensitive responses. Together, these findings significantly expand our understanding of the determinants of pathogenicity or virulence in Botryosphaeriaceae and provide new insights for developing management strategies against them.

Grapevine anthracnose is an important disease, responsible for mild to severe yield losses in grape production, and is also an important post harvest disease. The disease was studied in vineyards in six provinces in China, with 34 isolates obtained from diseased grapes. Multi-gene (ACT, ITS, GAPDH, TUB2 and CHS) analysis coupled with morphology showed that Colletotrichum aenigma, C. hebeiense sp. nov. and C. viniferum were associated with grapevine anthracnose in China. Colletotrichum aenigma is reported for the first time as associated with grapevine anthracnose. Colletotrichum hebeiense is a new species introduced here. Pathogenicity testing showed that all species can infect grapes, causing anthracnose however, virulence of species and isolates showed great variation. Phylogenetic analysis showed that C. viniferum is a cryptic species and its taxonomy needs to be resolved in the future.