A new coelomycetes fungal species, Pestalotiopsis pallidotheae, is described. This endophytic fungus, isolated from a leaf of Japanese andromeda (Pieris japonica), has knob-tipped appendages on the apical and basal cells of the conidia. The conidial morphology is similar to that of Pestalotiopsis theae except that the color of the median cells is paler in P. pallidotheae. Molecular analyses of the ITS1-5.8S rRNA-ITS2 site placed P. pallidotheae in a group different from P. theae.

Pestalopezia brunneopruinosa, the type species of Pestalopezia in Leotiomycetes, produces typical cup-shaped ascomata. Because its asexual morph has conidia comprised of five cells including apical and basal appendages and three pigmented median cells, it was first described as Pestalotia gibbosa, which belongs to Sordariomycetes. This contradiction has not been resolved due to the difficulty in isolating this fungus in culture. In this study, we isolated separate strains from the sexual morph and the asexual morph for molecular analysis. Phylogenetic trees of Sporocadaceae based on internal transcribed spacer, partial β-tubulin, and partial translation elongation factor 1-alpha sequence datasets revealed that both strains fall into the same taxon, in a clade in Pestalotiopsis sensu stricto alongside P. gaultheriae and P. spathulata. We provide the first evidence that fungi producing cup-shaped ascomata in Pestalotiopsis belong to Sordariomycetes, and we have proposed the transfer of Pestalopezia brunneopruinosa to Pestalotiopsis gibbosa.

(1) Background: Silene latifolia is a dioecious plant, whose sex is determined by XY-type sex chromosomes. Microbotryum lychnidis-dioicae is a smut fungus that infects S. latifolia plants and causes masculinization in female flowers, as if Microbotryum were acting as a sex-determining gene. Recent large-scale sequencing efforts have promised to provide candidate genes that are involved in the sex determination machinery in plants. These candidate genes are to be analyzed for functional characterization. A virus vector can be a tool for functional gene analyses; (2) Methods: To develop a viral vector system in S. latifolia plants, we selected Apple latent spherical virus (ALSV) as an appropriate virus vector that has a wide host range; (3) Results: Following the optimization of the ALSV inoculation method, S. latifolia plants were infected with ALSV at high rates in the upper leaves. In situ hybridization analysis revealed that ALSV can migrate into the flower meristems in S. latifolia plants. Successful VIGS (virus-induced gene silencing) in S. latifolia plants was demonstrated with knockdown of the phytoene desaturase gene. Finally, the developed method was applied to floral organ genes to evaluate its usability in flowers; (4) Conclusion: The developed system enables functional gene analyses in S. latifolia plants, which can unveil gene functions and networks of S. latifolia plants, such as the mechanisms of sex determination and fungal-induced masculinization.