First Report of Rust Caused by Puccinia sasicola on Corylopsis coreana in South Korea.

Korean winter hazel (Corylopsis coreana) is an endemic species of the South Korea (Seo et al. 2016; Kim et al. 2021), which is cultivated as an ornamental plant in this country, but also in China and Japan (Yoon et al. 2016). In July 2022, typical symptoms of a rust disease were observed on C. coreana at Jirisan National Park (35°22'07.7"N 127°34'57.7"E) in Namwon, South Korea. Spermogonia were epiphyllous, densely grouped, pale brown or orange-yellow, round, and 0.23 - 0.38 × 0.19 - 0.41 mm in size. Aecia were hypophyllous, mostly densely grouped, yellow or pale orange, resembling small wart-like galls, and 0.04 - 0.06 × 0.89 - 1.68 mm in size. Aeciospores were hyaline, mostly angularly globose, ellipsoid or oblong-ellipsoid, and 17.8 - 25.2 × 15 - 26.5 µm (average 19.2 × 19.1 µm; n=50) in size. Aeciospore walls were echinulate-verrucose, and 1.1 - 2.2 µm (average 1.7 µm; n=50) in thickness. In December 2022, dark brown telia were observed on the lower surface of Sasa borealis leaves near C. coreana. Telia were mostly scattered but often compacted, brown to dark brown, round, and 1.5 - 1.95 × 1.24 - 1.55 mm in size. Teliospores were either one- or two-celled with a long tapering apex, and light brown to brown in color. One-celled teliospores were globose, and 95.1 - 186.5 × 20.5 - 36.4 µm (average 136.4 × 27.7 µm; n=50) in size. Two-celled teliospores were ellipsoid-cylindrical, and 111.4 - 180.3 × 13.5 - 32.6 µm (average 149 × 21.1 µm; n=50) in size. Side walls of teliospores were golden and 2.2 - 5.5 µm thick (average 3.5 µm; n=50), and pedicels were hyaline, measuring 150 - 300 µm long. Uredinial stage was not observed. Disease symptomology and pathogen morphology were mostly consistent with that of Puccinia sasicola reported in Japan (Hino. 1955). For phylogenetic analysis, genomic DNA was extracted from the aeciospores collected from C. coreana and the teliospores collected from S. borealis. The internal transcribed spacer (ITS) rDNA and the large subunit (LSU) rDNA regions were amplified using ITS5u/ITS4rust (Pfunder and Schürch 2001) and LRust1R/LRust3 (Beenken et al. 2012) primers, respectively. Both sequences were identical for the spores collected from the two different hosts. The sequences were deposited in GenBank (PP171665, PP174211 [ITS], PP171709, PP174356 [LSU]). A GenBank BLAST search revealed 89.53% and 96.78% similarity with Puccinia kusanoi (KX610657) and Puccinia sp. (MT7298241) for ITS and LSU sequences, respectively. In maximum-likelihood phylogenetic analysis of ITS and LSU sequences, the isolates from C. coreana and S. borealis formed a separate clade from other Puccinia species. To test Koch's postulates, leaf disks with telia from S. borealis were directly attached to the adaxial surface of six healthy C. coreana leaves with tape. As controls, healthy S. borealis leaf disks were attached to the adaxial surface of six C. coreana leaves. After four weeks, four inoculated leaves developed small yellow wart-like galls on the abaxial surface, while the control leaves remained symptom-free. The isolates obtained from the inoculated leaves had identical sequences to the original isolate. There are no publicly available sequences for P. sasicola, nor did we find any sequences that match our Puccinia samples. Nevertheless, based on morphological characteristics and life cycle, our isolates closely matched with the previous description of P. sasicola by Hino (1955). To our knowledge, this is the first report of P. sasicola causing leaf rust in C. coreana in South Korea.

How much do field mice prefer dwarf bamboo seeds? Two-choice experiments between seeds of Sasa borealis and several tree species on the forest floor.

Bambusoideae is a taxon of mass-flowering monocarpic perennials with a long life cycle. Forest ecosystems are affected by Bambusoideae seeding and death events in various ways, including an increased abundance of Apodemus spp. The utilization and preference of dwarf bamboo seeds over tree seeds by field mice remain elusive. Therefore, we aimed to determine whether field mice prefer dwarf bamboo to tree seeds. We examined one dwarf bamboo species (Sasa borealis) against four tree species with varying acorn/fruit traits (Castanea crenata, Quercus crispula, Fagus crenata, and Lindera triloba). The seeds were placed in a container in a forest among dead S. borealis culms, with an automatic camera monitoring the setup. The examined seeds were mainly foraged by two field mouse species, Apodemus speciosus and Apodemus argenteus, with preference in the following order: C. crenata, L. triloba, S. borealis, F. crenata, and Q. crispula. Our findings indicated that during S. borealis mast seeding years, predation pressure on F. crenata and Q. crispula seeds could be considerably reduced. This suggests that mast seeding might disrupt the normal pattern of survival, and seed dispersal patterns, potentially altering the forest vegetation composition.

Reproductive characteristics in an understory bamboo and gradual environmental changes after its dieback provide an extended opportunity for overstory tree regeneration in a mixed cool-temperate forest in central Japan.

The reproductive characteristics of understory bamboo and the effects of dieback on overstory tree seedlings through temporal changes in the environment at the forest floor have only been examined in a few bamboo species, due to the unpredictable occurrence of flowering events and long intervals between them but provide valuable information on tree regeneration and succession in a forest with dense dwarf bamboo cover. We investigated environmental conditions and assessed seedlings (< 30-cm tall) of the dwarf bamboo Sasa borealis and overstory tree species at 44-50 measurement points during 2016-2021, which included a S. borealis mass flowering event in 2017. We also conducted seed germination tests to determine germination rates and patterns in S. borealis. Environmental factors affecting seedling recruitment of S. borealis and of overstory trees were analysed using spatiotemporal generalized linear mixed models in the Bayesian framework. We observed gradual temporal changes in the environment, including increasing canopy openness and decreasing maximum height of dead S. borealis culms. The seeds germinated slowly and the emergence of current-year S. borealis seedlings peaked in spring-summer in 2019. The tree seedling density after 2019 increased significantly compared to that before the dieback. The model results suggest that tree seedling establishment was enhanced by increased light availability. Continuous field observation beginning before S. borealis dieback revealed gradually enhanced tree recruitment in response to slow decay of the remaining dead culms and slow recovery of S. borealis. The seedling regeneration pattern of understory bamboo partly contributes to a prolonged opportunity for overstory tree regeneration.

Hot Water Extract of Sasa borealis (Hack.) Makino & Shibata Abate Hydrogen Peroxide-Induced Oxidative Stress and Apoptosis in Kidney Epithelial Cells.

Sasa borealis (Hack.) Makino & Shibata or broad-leaf bamboo is famous for its richness of bioactive natural products and its uses in traditional medicine for its anti-inflammatory, diuretic, and antipyretic properties and preventive effects against hypertension, arteriosclerosis, cardiovascular disease, and cancer. The present study investigated the antioxidant activity of S. borealis hot water extract (SBH) and its effects in ameliorating hydrogen peroxide-induced oxidative stress, using an African green monkey kidney epithelial cell line (Vero). Known polyphenols in SBH were quantified by HPLC analysis. SBH indicated a dose-dependent increase for reducing power, ABTS+ (IC50 = 96.44 ± 0.61 µg/mL) and DPPH (IC50 = 125.78 ± 4.41 µg/mL) radical scavenging activities. SBH markedly reduced intracellular reactive oxygen species (ROS) generation in the Vero cells and increased the protective effects against H2O2-induced oxidative stress by reducing apoptosis. Other than the direct involvement in neutralizing ROS, metabolites in SBH were also found to induce NRF2-mediated production of antioxidant enzymes, HO-1, and NQO1. These findings imply that S. borealis hot water extract can be utilized to create nutraceutical and functional foods that can help to relieve the effects of oxidative stress in both acute and chronic kidney injury.

Streptomyces fuscigenes sp. nov., isolated from bamboo (Sasa borealis) litter.

Three actinomycetes strains, designated JBL-5, JBL-14 and JBL-20T, were isolated from bamboo (Sasa borealis) litter in Damyang, Republic of Korea. Morphological, chemotaxonomic and phylogenetic analyses demonstrated that the three strains belong to the genus Streptomyces. Microscopic observation revealed that the three strains produced Spirales spore chains with smooth surfaces. Phylogenetic analysis based on 16S rRNA gene sequence comparisons revealed that these strains showed the highest sequence similarity to Streptomyces gelaticus NRRL B-2928T (97.8 %), Streptomyces pulveraceus LMG 20322T (97.7 %), Streptomyces intermedius NBRC 13049T (97.7 %), Streptomyces althioticus NRRL B-3981T (97.7 %) and Streptomyces matensis NBRC 12889T (97.7 %). The DNA-DNA hybridization values between strains JBL-5, JBL-14 and JBL-20T were 91.2-92.4 %, and the values between the three strains and their close phylogenetic relatives were also below 70 %. The predominant menaquinones were MK-9 (H4) and MK-9 (H6). The cell wall contained ll-diaminopimelic acid and the whole-cell sugars were arabinose and xylose. The major polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositolmannoside, two unidentified aminolipids, three unidentified aminophospholipids, one unidentified glycolipid and one unidentified lipid. The major cellular fatty acids were iso-C15 : 0, anteiso-C15 : 0, iso-C14 : 0, C18 : 1ω7c and iso-C16 : 0. The DNA G+C contents were 71.8-72.4 mol%. On the basis of phylogenetic analyses and physiological and biochemical characterization, strains JBL-5, JBL-14 and JBL-20T are considered to represent a novel species of the genus Streptomyces, for which the name Streptomyces fuscigenes sp. nov. is proposed. The type strain is JBL-20T (=KACC 18269T=NBRC 110629T).

Anticancer activity of Sasa borealis leaf extract-mediated gold nanoparticles.

Advancements in metal nanoparticle synthesis using plant extracts and their anticancer activity have received significant attention in recent years. The green approach for the synthesis of gold nanoparticles (AuNPs) using leaf extract of Sasa borealis is reported in this study. Synthesis of AuNPs was performed at 50 °C, and nanoparticle formation was observed after 20 min incubation. AuNPs formation was confirmed by the UV-visible spectrum peak at 542 nm. The synthesized AuNPs were oval, spherical with sizes around 10-30 nm observed using the transmission electron microscope. Energy dispersive X-ray analysis was utilized for the detection of elemental compound. The face centered cubic structure was confirmed by X-ray diffraction pattern. The reduction of tetrachloroauric acid into AuNPs by the phytochemical compounds of S. borealis extract was determined by Fourier transform infrared spectroscopy and the presence of biomolecules was studied by GC-MS. The synthesized AuNPs was tested for toxic effect on HEK293 cells and anticancer activity on AGS cells by WST-1® assay. Condensation or fragmentation is a characteristics of apoptosis, which was confirmed by 4,6-diamidino-2-pheynylindole dihydrochoride (DAPI) staining. The S. borealis-mediated AuNPs have good activity as an anticancer agent and it will be beneficial in cancer therapeutics.

Sasa borealis extract exerts an antidiabetic effect via activation of the AMP-activated protein kinase.

Leaf of Sasa borealis, a species of bamboo, has been reported to exhibit anti-hyperglycemic effect. However, its antidiabetic mechanism is not fully understood. In this study, we examined whether an extract of S. borealis activates AMP-activated protein kinase (AMPK) and exerts anti-hyperglycemic effects. Treatment with the S. borealis extract increased insulin signaling and phosphorylation of AMPK and stimulated the expression of its downstream targets, including PPARα, ACO, and CPT-1 in C2C12 cells and PPARα in HepG2 cells. However, inhibition of AMPK activation attenuated insulin signaling and prevented the stimulation of AMPK target genes. The S. borealis extract increased glucose uptake in C2C12 cells and suppressed expression of the gluconeogenic gene, PEPCK in HepG2 cells. The extract significantly reduced blood glucose and triglyceride levels in STZ-induced diabetic mice. The extract enhanced AMPK phosphorylation and increased Glut-4 expression in the skeletal muscle of the mice. These findings demonstrated that the S. borealis extract exerts its anti-hyperglycemic effect through activation of AMPK and enhancement of insulin signaling.

Sasa borealis extract exerts an antidiabetic effect via activation of the AMP-activated protein kinase

Leaf of Sasa borealis, a species of bamboo, has been reported to exhibit anti-hyperglycemic effect. However, its antidiabetic mechanism is not fully understood. In this study, we examined whether an extract of S. borealis activates AMP-activated protein kinase (AMPK) and exerts anti-hyperglycemic effects. Treatment with the S. borealis extract increased insulin signaling and phosphorylation of AMPK and stimulated the expression of its downstream targets, including PPARalpha, ACO, and CPT-1 in C2C12 cells and PPARalpha in HepG2 cells. However, inhibition of AMPK activation attenuated insulin signaling and prevented the stimulation of AMPK target genes. The S. borealis extract increased glucose uptake in C2C12 cells and suppressed expression of the gluconeogenic gene, PEPCK in HepG2 cells. The extract significantly reduced blood glucose and triglyceride levels in STZ-induced diabetic mice. The extract enhanced AMPK phosphorylation and increased Glut-4 expression in the skeletal muscle of the mice. These findings demonstrated that the S. borealis extract exerts its anti-hyperglycemic effect through activation of AMPK and enhancement of insulin signaling.

Sasa borealis leaves extract improves insulin resistance by modulating inflammatory cytokine secretion in high fat diet-induced obese C57/BL6J mice.

Obesity is considered a mild inflammatory state, and the secretion of inflammation-related cytokines rises as adipose tissue expands. Inflammatory cytokines, including tumor necrosis factor-alpha (TNF-alpha), interlukin 6 (IL-6) and monocyte-chemoattractant protein 1 (MCP-1), are modulated by adipose tissue and known to play an important role in insulin resistance which is the common characteristics of obesity related disorders. In this study we analyzed the effects of Sasa borealis leaves extract on inflammatory cytokines and insulin resistance in diet induced obese C57/BL6J mice. The obese state was induced by a high fat diet for 20 weeks and then the mice were divided into two groups; obese control group (OBC, n = 7) and experimental group (OB-SBE, n = 7). The OBC group was fed a high fat diet and the OB-SBE group was fed a high fat diet containing 5% Sasa borealis leaves extract (SBE) for 12 weeks. We also used mice fed a standard diet as a normal control (NC, n = 7). The body weight and adipose tissue weight in the OB group were significantly higher than those in the NC group. The effects of the high fat diet were reduced by SBE treatments, and the body weight and adipose tissue deposition in the OB-SBE group were significantly decreased compared to the OBC group. The OBC group showed higher serum glucose and insulin levels which resulted in a significant increase of incremental area under the curve (IAUC) and HOMA-IR than the NC group. Also, serum leptin, TNF-alpha, and IL-6 levels were significantly higher in the OBC group than in the NC group. In contrast, the OB-SBE group showed a reversal in the metabolic defects, including a decrease in glucose, insulin, IAUC, HOMA-IR, TNF-alpha, IL-6 and leptin levels. These results suggest that BSE can suppress increased weight gain and/or fat deposition induced by a high fat diet and theses effects are accompanied by modulation of the inflammatory cytokines, TNF-alpha and IL-6 secretion resulting in improved insulin resistance.

Effects of Sasa Borealis Leaf Extract on the Glucose Tolerance of Major Foods for Carbohydrate

Sasa borealis leaf has been known to have anti-diabetic properties. In this study, we tried to evaluate the effects of Sasa borealis leaf extract (SBE) on the inhibition of alpha-glucosidase activity and postprandial glycemic response following ingestion of four carbohydrate-rich foods; cooked rice, ramen (instant noodle), noodle, and bread. Fourteen healthy female adults consumed 50 g of glucose (control) or one of the four foods containing 50 g of available carbohydrate with or without 2,000 mg of SBE. The activity of alpha-glucosidase was inhibited dose-dependently by SBE. With SBE, blood glucose concentration at 15 min and the positive area under the curve (AUC) of postprandial glycemic response at 15 min and 30 min after consuming each of the four foods were reduced significantly. As the result, total positive AUC during 120 min was decreased in case of taking cooked rice or bread. Glycemic index and glycemic load of the four foods were declined from 13% to 23% with SBE. The results of this study suggest that SBE may be effective for postprandial glucose control by inhibiting alpha-glucosidase activity.

Sasa borealis leaves extract improves insulin resistance by modulating inflammatory cytokine secretion in high fat diet-induced obese C57/BL6J mice

Obesity is considered a mild inflammatory state, and the secretion of inflammation-related cytokines rises as adipose tissue expands. Inflammatory cytokines, including tumor necrosis factor-alpha (TNF-alpha), interlukin 6 (IL-6) and monocyte-chemoattractant protein 1 (MCP-1), are modulated by adipose tissue and known to play an important role in insulin resistance which is the common characteristics of obesity related disorders. In this study we analyzed the effects of Sasa borealis leaves extract on inflammatory cytokines and insulin resistance in diet induced obese C57/BL6J mice. The obese state was induced by a high fat diet for 20 weeks and then the mice were divided into two groups; obese control group (OBC, n = 7) and experimental group (OB-SBE, n = 7). The OBC group was fed a high fat diet and the OB-SBE group was fed a high fat diet containing 5% Sasa borealis leaves extract (SBE) for 12 weeks. We also used mice fed a standard diet as a normal control (NC, n = 7). The body weight and adipose tissue weight in the OB group were significantly higher than those in the NC group. The effects of the high fat diet were reduced by SBE treatments, and the body weight and adipose tissue deposition in the OB-SBE group were significantly decreased compared to the OBC group. The OBC group showed higher serum glucose and insulin levels which resulted in a significant increase of incremental area under the curve (IAUC) and HOMA-IR than the NC group. Also, serum leptin, TNF-alpha, and IL-6 levels were significantly higher in the OBC group than in the NC group. In contrast, the OB-SBE group showed a reversal in the metabolic defects, including a decrease in glucose, insulin, IAUC, HOMA-IR, TNF-alpha, IL-6 and leptin levels. These results suggest that BSE can suppress increased weight gain and/or fat deposition induced by a high fat diet and theses effects are accompanied by modulation of the inflammatory cytokines, TNF-alpha and IL-6 secretion resulting in improved insulin resistance.

The Effects of the Sasa Borealis Leaves Extract on Plasma Adiponectin, Resistin, C-Reactive Protein and Homocysteine Levels in High Fat Diet-Induced Obese C57/BL6J Mice

As obesity is known to be related to hyperlipidemia, diabetes and coronary heart disease, and other chronic diseases, many researches have focused on functional food materials showing anti-obesity activity. The adipokines secreted by adipose tissue, resistin and adiponectin are known to play an important role in the pathogenesis of chronic diseases directly. C-reactive protein and homocysteine are molecules regulated by adipose tissue indirectly also relate to the chronic diseases. This study was performed to study of the anti-obesity effects of Sasa borealis in diet-induced obese mice (C57/BL6J). The mice were divided into four group: NFD (Normal fat diet), HFD (High fat diet), BSE (High fat diet containing 5% of 70% ethanol extract of Sasa borealis leaves), BLW (High fat diet containing 5% of water extract of Sasa borealis leaves). The experimental diets were fed for 11 weeks. The final body weight of the mice in the groups of BSE and BLW groups were significantly lower than the HFD group. The effects of weight reduction were due to reduced body fat accumulation. The adiponectin levels are significantly decreased in HFD group compared than NFD group and increased taken by Sasa borealis containing diet. The resistin levels are not significantly different between experimental groups. The CRP and homocyteine levels are significantly higher in HFD group than NFD group and significantly decreased by Sasa borealis containing diet, especially BLW group. These results indicate that orally administered Sasa borealis not only has the effect of reducing the body weight and total fat weight, but preferable effect in adiponectin levels and related molecules as CRP and homocysteine. Therefore we expect the Sasa borealis may have an anti-obesity function and anti-metabolic syndrome effect in diet-induced obese mice.