First Report of Powdery Mildew Caused by Golovinomyces adenophorae on Adenophora triphylla var. japonica in Korea.

Adenophora triphylla var. japonica (Campanulaceae), known as Japanese lady bell, is native to East Asia. It has been used as a medicinal plant but is widely cultivated in Korea as an indigenous vegetable (Park et al. 2011). In the summer of 2020, about 100 plants in an experimental plot at the National Institute of Forest Science, Seoul, Korea, showed powdery mildew symptoms with a 100% disease incidence. Signs first appeared as white colonies, subsequently expanding over the leaves, stems, and inflorescences. Infected young shoots were elongated and became slender. Chasmothecia were found in late October. Voucher specimens were deposited in the Korea University Herbarium (KUS-F). Conidiophores arising from the lateral part of the hyphae were upright, 100 to 220 × 10 to 12 µm, and produced 2 to 5 immature conidia in chains with sinuate edge lines. Basal parts of foot-cells in conidiophores were curved. Conidia were barrel-shaped to ellipsoid, 26 to 40 × 14 to 20 µm, and produced germ tubes on the perihilar position of the conidia. Chasmothecia with short mycelioid appendages were gregarious, 144 to176 µm in diam., and contained 8 to 22 asci. Asci were clavate-saccate with short stalks, 60 to 82 × 28 to 42 µm, and contained two spores. Ascospores were broadly ellipsoid, cytoplasm-dense without vacuoles, colorless, and 22 to 28 × 12 to 18 µm. The structures and measurements were consistent with those of Golovinomyces adenophorae (R.Y. Zheng & G.Q. Chen) Heluta (Braun & Cook, 2012). To confirm the morphology-based identification, two herbarium specimens (KUS-F29252 and F31898) were sequenced for the internal transcribed spacer (ITS) and large subunit (LSU) regions with PM10/ITS4 and PM3/TW14 primers, respectively (Bradshaw and Tobin, 2020). A Blastn search revealed high similarities in the ITS and LSU sequences, with 99.81% (538/539 bp) and 99.86% (697/698 bp) to G. adenophorae sequences (AB077633 and AB077632), respectively. All resulting sequences were deposited in GenBank under accession numbers OR841069-70 for ITS and OR841071 for LSU. A pathogenicity test was performed through inoculation by gently dusting the conidia from a detached symptomatic leaf onto the leaves of five healthy plants. Five non-inoculated plants served as controls. Following inoculation, plants were covered with plastic film and maintained in a greenhouse (24 to 32°C) until symptoms developed. Powdery mildew colonies developed on the inoculated plants after twelve days, whereas the control plants remained symptomless. The inoculated pathogen was confirmed morphologically and molecularly by the sequence comparison aforementioned, fulfilling Koch's postulates. Based on morphological characteristics and the sequencing data, the powdery mildew was identified as G. adenophorae. The association of G. adenophorae and Adenophora spp. has been known in China, Japan, Kazakhstan, and the Far East of Russia (Farr and Rossman, 2023). This is the first report of powdery mildew caused by G. adenophorae on A. triphylla var. japonica in Korea. Since the commercial cultivation of this plant aims to harvest young shoots as one of the most popular vegetables in Korea, appropriate control measures for the powdery mildew should be considered.

Meibum Expressibility Improvement as a Therapeutic Target of Intense Pulsed Light Treatment in Meibomian Gland Dysfunction and Its Association with Tear Inflammatory Cytokines.

Many recent studies have demonstrated the efficacy of intense pulsed light (IPL) for the treatment of meibomian gland dysfunction (MGD); however, its effective treatment targets have not yet been elucidated. This study aimed to investigate the baseline characteristics associated with an improvement in symptoms after IPL treatment; to examine the course of change in inflammatory tear cytokines, meibomian gland function, and tear stability; and to investigate the correlation between cytokines and ocular surface parameters. Thirty participants underwent three sessions of IPL treatment. During each examination, tear film lipid layer interferometry, meibography, tear meniscus height measurement, tear sampling, and slit-lamp examination were performed, and the Ocular Surface Disease Index (OSDI) questionnaire was administered. Meibum quality, meibum expressibility, lid margin abnormality, tear film break-up time (TBUT), ocular surface staining, and the OSDI significantly improved after treatment. Poor meibum expressibility and short TBUT were associated with greater recovery in the OSDI after IPL. Tear levels of IL-4, IL-6, IL-10, IL-17A, and TNF-α decreased after IPL, and IL-6, and TNF-α were correlated with the improvement in meibum expressibility. Therefore, IPL treatment improved meibomian gland function, stabilized the tear film, and decreased ocular surface inflammation. Patients with obstructive MGD and tear instability were more likely to experience an improvement in ocular discomfort after IPL treatment.

TP53 alteration determines the combinational cytotoxic effect of doxorubicin and an antioxidant NAC.

The anticancer effect of doxorubicin is closely related to the generation of reactive oxygen species. On the contrary, doxorubicin-induced reactive oxygen species induces heart failure, a critical side effect of doxorubicin. Antioxidant supplementation has been proposed to reduce the side effects. However, the use of antioxidants may hamper the anticancer effect of doxorubicin. In this study, doxorubicin-induced reactive oxygen species was shown to differentially affect cancer cells based on their TP53 genetic status; doxorubicin-induced apoptosis was attenuated by an antioxidant, N-acetylcysteine, in TP53 wild cells; however, N-acetylcysteine caused a synergistic increase in the apoptosis rate in TP53-altered cells. N-acetylcysteine prevented phosphorylation of P53 protein that had been induced by doxorubicin. However, N-acetylcysteine increased the cleavage of poly (ADP-ribose) polymerase in the presence of doxorubicin. Synergy score of 26 patient-derived cells were evaluated after the combination treatment of doxorubicin and N-acetylcysteine. The synergy score was significantly higher in TP53-altered group compared with those in TP53 wild group. In conclusion, TP53 genetic alteration is a critical factor that determines the use of antioxidant supplements during doxorubicin treatment.

Multi-locus tree and species tree approaches toward resolving a complex clade of downy mildews (Straminipila, Oomycota), including pathogens of beet and spinach.

Accurate species determination of plant pathogens is a prerequisite for their control and quarantine, and further for assessing their potential threat to crops. The family Peronosporaceae (Straminipila; Oomycota) consists of obligate biotrophic pathogens that cause downy mildew disease on angiosperms, including a large number of cultivated plants. In the largest downy mildew genus Peronospora, a phylogenetically complex clade includes the economically important downy mildew pathogens of spinach and beet, as well as the type species of the genus Peronospora. To resolve this complex clade at the species level and to infer evolutionary relationships among them, we used multi-locus phylogenetic analysis and species tree estimation. Both approaches discriminated all nine currently accepted species and revealed four previously unrecognized lineages, which are specific to a host genus or species. This is in line with a narrow species concept, i.e. that a downy mildew species is associated with only a particular host plant genus or species. Instead of applying the dubious name Peronospora farinosa, which has been proposed for formal rejection, our results provide strong evidence that Peronospora schachtii is an independent species from lineages on Atriplex and apparently occurs exclusively on Beta vulgaris. The members of the clade investigated, the Peronospora rumicis clade, associate with three different host plant families, Amaranthaceae, Caryophyllaceae, and Polygonaceae, suggesting that they may have speciated following at least two recent inter-family host shifts, rather than contemporary cospeciation with the host plants.

Coupling Spore Traps and Quantitative PCR Assays for Detection of the Downy Mildew Pathogens of Spinach (Peronospora effusa) and Beet (P. schachtii).

Downy mildew of spinach (Spinacia oleracea), caused by Peronospora effusa, is a production constraint on production worldwide, including in California, where the majority of U.S. spinach is grown. The aim of this study was to develop a real-time quantitative polymerase chain reaction (qPCR) assay for detection of airborne inoculum of P. effusa in California. Among oomycete ribosomal DNA (rDNA) sequences examined for assay development, the highest nucleotide sequence identity was observed between rDNA sequences of P. effusa and P. schachtii, the cause of downy mildew on sugar beet and Swiss chard in the leaf beet group (Beta vulgaris subsp. vulgaris). Single-nucleotide polymorphisms were detected between P. effusa and P. schachtii in the 18S rDNA regions for design of P. effusa- and P. schachtii-specific TaqMan probes and reverse primers. An allele-specific probe and primer amplification method was applied to determine the frequency of both P. effusa and P. schachtii rDNA target sequences in pooled DNA samples, enabling quantification of rDNA of P. effusa from impaction spore trap samples collected from spinach production fields. The rDNA copy numbers of P. effusa were, on average, ≈3,300-fold higher from trap samples collected near an infected field compared with those levels recorded at a site without a nearby spinach field. In combination with disease-conducive weather forecasting, application of the assays may be helpful to time fungicide applications for disease management.