First Report of Leaf Spot Caused by Septoria erigerontis on Conyza sumatrensis in Korea.

Conyza sumatrensis (Retz.) E. Walker (syn. Erigeron sumatrensis) or commonly known as fleabane, is an annual herbaceous plant native to South America. It/span>was accidentally introduced to Korea in the 1930s and became invasive in natural and managed ecosystems of the country (Kim et al. 2008). Leaf spots on this plant were first observed in March 2013 in Jeju (33°29'45"N; 126°26'26"E), and then in February 2017 in Seoguipo (33°14'30"N; 126°32'58"E), Korea. The severity of the disease was estimated to be greater than 50%. Initial symptoms were small, distinct, reddish-brown, then turned into brown spots with dark purplish-brown margins. Conidiomata were pycnidial, epigenous, occasionally hypogenous, scattered, dark brown to rusty brown, globose, embedded in host tissue or partly erumpent, 70 to 165 µm in diameter, with ostioles measuring 10 to 26 µm in diameter. Conidia were straight to flexuous, 24 to 65 × 1.5 to 2.0 µm, hyaline, and 1 to 5 septate. Morphological circumscriptions were consistent with Septoria erigerontis Peck (Verkley et al. 2013). To obtain a monoconidial isolate, conidia were collected from lesions, placed in an Eppendorf tube containing sterile water and streaked onto the surface of 2% water agar (WA) plates supplemented with 100 mg/L of streptomycin sulfate, and after five days transferred onto potato dextrose agar (PDA). The two-week-old colonies incubated at 25°C on PDA had a slightly ruffled, but mostly colorless margin; colonies were 5 to 7 mm in diameter, slightly elevated in the center, surface black, covered with a diffuse to a dense mat of grey aerial mycelium. Voucher specimens were housed in the Korea University Herbarium (KUS-F27274 and F29725), and two cultures were deposited in the Korea Agricultural Culture Collection (Accession Nos: KACC47219 and KACC48297). Nucleotide sequences of the internal transcribed spacer (ITS), translation elongation factor 1-α (EF), actin (ACT), 28S rDNA (LSU), and RNA polymerase II second largest subunit (RPB2) genes obtained from KACC47219 were determined (Verkley et al. 2013) and deposited in GenBank (Accession Nos: OM909018, OM908934, OM974318, OM974319, OM974320). Results of BLASTn search for ITS and LSU were 99-100% identical with reference sequences of Septoria erigerontis (MH865036, MH876473), S. lactucae (MK617321), and S. phlogis (MH876550) in GenBank. Whereas it showed 97% similarity for ACT, 93-94% for EF and RPB2 genes with sequences of S. erigerontis (JQ325031, KF253363, KF252411). Pathogenicity was tested by spraying 20 leaves of four-month-old three potted plants with a conidial suspension (1×104 propagules/mL) harvested from a four-week-old culture (span style="font-family:'Times New Roman'">KACC47219). Ten leaves were used as controls. The plants were placed in a dew chamber at 26°C for 24 h, then moved to a greenhouse. Inoculated leaves developed typical symptoms after seven days, whilst no symptoms were observed on control ones. S. erigerontis was re-isolated from symptomatic lesion and its identity was confirmed by microscopic studies, fulfilling Koch's postulates. Although S. erigerontis has been recorded to be associated with leaf spots of Erigeron spp. and Conyza spp. (Farr and Rossman 2022), there is no previous record of this fungus on C. sumatrensis. To our knowledge, this is the first report of leaf spot caused by S. erigerontis on C. sumatrensis worldwide as well as in Korea. We presume that this fungus may have potential as a biocontrol agent on fleabanes, particularly glyphosate-resistant Conyza species (Sansom et al. 2013). References: Farr, D. F., and Rossman, A. Y. Fungal Databases, Syst. Mycol. Microbiol. Lab., Online publication. ARS, USDA. Accessed 6 February 2022. Kim, C. S., et al. 2008. Korean J. Weed Sci. 28:42. Sansom, M., et al. 2013. Plant Protect. Sci. 49:44. Verkley, G. J. M., et al. 2013. Stud. Mycol. 75:213.

Hazardous effects of eight years of application of four organic waste materials on earthworm numbers and biomass in field lysimeters.

The hazardous effects on the earthworm numbers and biomass of eight consecutive yearly applications of three levels (12.5, 25, and 50 tons of dry matter/ha/y) of four different organic sludges (municipal sewage, industrial sewage, alcohol fermentation processing, and leather processing) to earthworm-free soils were examined using field lysimeters. Results were compared with those of pig manure compost (PMC)-treated soil. Of five species (Amynthas agrestis, A. sangyeoli, A. hupeiensis, Drawida koreana, and D. japonica) from 390 adult specimens collected 4 and 8 years after treatment, the number of species appeared to be lower in sludge-treated soils than in PMC-treated soils. Earthworm populations and biomass were correlated negatively with the pollution index [∑(heavy-metal concentration in soil/tolerable level)/number of heavy metal] 4 and 8 years after treatment. These results suggest that the long-term application of these sludges, particularly from industrial sewage and leather processing, might affect adversely the establishment of Megascolecid and Moniligastrid earthworms in field conditions.

Preparation of sustained release microparticles with improved initial release property.

The objective of this study was to investigate the potential of various formulation strategies to achieve sustained release of the peptide, from injectable poly(D,L-lactide-co-glycolide) (PLGA) and d-alpha-tocopheryl polyethylene glycol 1000 succinate (TPGS) microparticles. The microparticles were prepared by a solvent evaporation method. Peptide loaded PLGA microparticles exhibited a pronounced initial burst release (22.3% in 1 day) and lag phase in phosphate buffer of pH 7.0. In contrast, blending of 5.0% TPGS (8.6% release in 1 day) or 10.0% TPGS (5.5% release in 1 day) in PLGA microparticles reduced initial burst release and the lag-phase time. Incorporation of TPGS in PLGA microparticles further increased drug release, attributable to improved drug encapsulation, increased particle size, and exempt of pores. PLGA+ 10.0% TPGS composite microparticles exhibited the most desirable drug release among all the formulations tested, and demonstrated triphasic release after minimal initial burst.

Contact and fumigant toxicity of oriental medicinal plant extracts against Dermanyssus gallinae (Acari: Dermanyssidae).

The acaricidal activity of methanolic extracts from 40 oriental medicinal plant species and a steam distillate of Cinnamomum camphora towards poultry house-collected adult Dermanyssus gallinae De Geer was examined using direct contact and vapour phase toxicity bioassays. Results were compared with those of 15 acaricides currently used. In filter paper contact toxicity bioassays using adult D. gallinae, C. camphora steam distillate (0.0051 mgcm(-2)) was the most toxic material, followed by extracts from Asarum sieboldii var. seoulens whole plant, Eugenia caryophyllata flower bud and Mentha arvensis var. piperascens whole plant (0.0063-0.0072 mgcm(-2)), based upon 24h LD(50) values. The acaricidal activity of these four plant preparations was almost comparable to that of profenofos (LD(50), 0.003 mgcm(-2)) but less effective than dichlorvos (LD(50), 0.0004 mgcm(-2)). The toxicity of Illicium verum fruit and Lysimachia davurica leaf extracts (0.09 mgcm(-2)) was almost comparable to that of benfuracarb, prothiofos, propoxur and fenthion (0.053-0.070mgcm(-2)). In vapour phase toxicity tests, these plant preparations were more effective in closed containers than in open ones, indicating that the mode of delivery of these plant extracts was largely a result of action in the vapour phase. Plants described herein merit further study as potential D. gallinae control agents.

Effects and possible mechanisms of action of acacetin on the behavior and eye morphology of Drosophila models of Alzheimer's disease.

The human ß-amyloid (Aß) cleaving enzyme (BACE-1) is a target for Alzheimer's disease (AD) treatments. This study was conducted to determine if acacetin extracted from the whole Agastache rugosa plant had anti-BACE-1 and behavioral activities in Drosophila melanogaster AD models and to determine acacetin's mechanism of action. Acacetin (100, 300, and 500 µM) rescued amyloid precursor protein (APP)/BACE1-expressing flies and kept them from developing both eye morphology (dark deposits, ommatidial collapse and fusion, and the absence of ommatidial bristles) and behavioral (motor abnormalities) defects. The reverse transcription polymerase chain reaction analysis revealed that acacetin reduced both the human APP and BACE-1 mRNA levels in the transgenic flies, suggesting that it plays an important role in the transcriptional regulation of human BACE-1 and APP. Western blot analysis revealed that acacetin reduced Aß production by interfering with BACE-1 activity and APP synthesis, resulting in a decrease in the levels of the APP carboxy-terminal fragments and the APP intracellular domain. Therefore, the protective effect of acacetin on Aß production is mediated by transcriptional regulation of BACE-1 and APP, resulting in decreased APP protein expression and BACE-1 activity. Acacetin also inhibited APP synthesis, resulting in a decrease in the number of amyloid plaques.

Fumigant toxicity of cassia and cinnamon oils and cinnamaldehyde and structurally related compounds to Dermanyssus gallinae (Acari: Dermanyssidae).

The toxicity of two cassia oils, four cinnamon oils and (E)-cinnamaldehyde and (E)-cinnamic acid and 34 structurally related compounds to adult Dermanyssus gallinae (De Geer) collected from a poultry house was examined using a vapour-phase mortality bioassay. Results were compared with those of dichlorvos, a conventional acaricide. The cassia and cinnamon oils (cinnamon technical, cinnamon #500, cassia especial, cassia true, cinnamon bark and cinnamon green leaf) exhibited good fumigant toxicity (LD(50), 11.79-26.40 µg cm(-3)). α-Methyl-(E)-cinnamaldehyde (LD(50), 0.45 µg cm(-3)) and (E)-cinnamaldehyde (0.54 µg cm(-3)) were the most toxic compounds and the toxicity of these compounds was comparable to that of dichlorvos (0.30 µg cm(-3)). Potent fumigant toxicity was also observed in allyl cinnamate, ethyl-α-cyanocinnamate, (E)-2-methoxylcinnamic acid and (Z)-2-methoxylcinnamic acid (LD(50), 0.81-0.92 µg cm(-3)). Structure-activity relationships indicate that structural characteristics, such as types of functional groups and carbon skeleton rather than vapour pressure parameter, appear to play a role in determining toxicity. The essential oils and compounds described merit further study as potential acaricides for the control of D. gallinae populations as fumigants with contact action due to global efforts to reduce the level of highly toxic synthetic acaricides in the agricultural environment.

Evidence for heme oxygenase-1 association with caveolin-1 and -2 in mouse mesangial cells.

The interaction of heme oxygenase-1 (HO-1) and caveolin in the cultured mouse mesangial cells (MMC) was investigated. In normal MMCs, high levels of caveolin-2 and low level of caveolin-1 at mRNA and protein level were observed without any detectable expression of caveolin-3. Upon treating the MMCs either with cadmium (Cd) or spermine NONOate (SPER/NO), expression of HO-1 mRNA and protein was increased. Caveolae rich membranous fractions from the MMCs treated with Cd or SPER/NO contained both HO-1 and caveolin-1 or caveolin-2. The experiments of immuno-precipitation showed complex formation between the HO-1 and caveolin-1 or caveolin-2 in the Cd treated MMCs. Confocal microscopic results also support co-localization of HO-1 and caveolin-1 or caveolin-2 at the plasma membrane. Co-localization of caveolins with HO-1 in caveolae suggested that caveolin could also play an important role in regulating the function of HO-1.

Hox genes from the earthworm Perionyx excavatus.

The Hox genes of the oligochaete, Perionyx excavatus, were surveyed using PCR and phylogenetic analysis. We were able to identify 11 different Hox gene fragments. Comparative and phylogenetic analyses revealed that this oligochaete would have at least five Hox genes of the anterior group, including three copies of labial-type, five of the central group and one of the posterior group. This is the first report regarding sequence information and phylogenetic analysis of Hox genes in the earthworm.