Comprehensive Genome Analysis on the Novel Species Sphingomonas panacis DCY99(T) Reveals Insights into Iron Tolerance of Ginseng

Plant growth-promoting rhizobacteria play vital roles not only in plant growth, but also in reducing biotic/abiotic stress. Sphingomonas panacis DCY99(T) is isolated from soil and root of Panax ginseng with rusty root disease, characterized by raised reddish-brown root and this is seriously affects ginseng cultivation. To investigate the relationship between 159 sequenced Sphingomonas strains, pan-genome analysis was carried out, which suggested genomic diversity of the Sphingomonas genus. Comparative analysis of S. panacis DCY99(T) with Sphingomonas sp. LK11 revealed plant growth-promoting potential of S. panacis DCY99(T) through indole acetic acid production, phosphate solubilizing, and antifungal abilities. Detailed genomic analysis has shown that S. panacis DCY99(T) contain various heavy metals resistance genes in its genome and the plasmid. Functional analysis with Sphingomonas paucimobilis EPA505 predicted that S. panacis DCY99(T) possess genes for degradation of polyaromatic hydrocarbon and phenolic compounds in rusty-ginseng root. Interestingly, when primed ginseng with S. panacis DCY99(T) during high concentration of iron exposure, iron stress of ginseng was suppressed. In order to detect S. panacis DCY99(T) in soil, biomarker was designed using spt gene. This study brings new insights into the role of S. panacis DCY99(T) as a microbial inoculant to protect ginseng plants against rusty root disease

A Growth-Promoting Bacteria, Paenibacillus yonginensis DCY84T Enhanced Salt Stress Tolerance by Activating Defense-Related Systems in Panax ginseng

Panax ginseng (C.A. Mayer) is a well-known medicinal plant used in traditional medicine in Korea that experiences serious salinity stress related to weather changes or incorrect fertilizer application. In ginseng, the use of Paenibacillus yonginensis DCY84T to improve salt stress tolerance has not been thoroughly explored. Therefore, we studied the role of P. yonginensis DCY84T under short-term and long-term salinity stress conditions in a controlled environment. In vitro testing of DCY84T revealed high indole acetic acid (IAA) production, siderophore formation, phosphate solubilization and anti-bacterial activity. We determined that 10-min dip in 1010 CFU/ml DCY84T was sufficient to protect ginseng against short-term salinity stress (osmotic stress) upon exposure to 300mM NaCl treatment by enhancing nutrient availability, synthesizing hydrolyzing enzymes and inducing osmolyte production. Upon exposure to salinity stress (oxidative and ionic stress), strain DCY84T-primed ginseng seedlings were protected by the induction of defense-related systems such as ion transport, ROS scavenging enzymes, proline content, total sugars, and ABA biosynthetic genes, as well as genes involved in root hair formation. Additionally, ginseng primed with DCY84T and exposed to 300mM NaCl showed the same metabolite profile as control ginseng plants, suggesting that DCY84T effectively reduced salt stress. These results indicated that DCY84T can be widely used as a microbial inoculant to protect ginseng plants against salinity stress conditions

Aluminium resistant, plant growth promoting bacteria induce overexpression of Aluminium stress related genes in Arabidopsis thaliana and increase the ginseng tolerance against Aluminium stress

anax ginseng is an important cash crop in the Asian countries due to its pharmaceutical effects, however the plant is exposed to various abiotic stresses, lead to reduction of its quality. One of them is the Aluminum (Al) accumulation. Plant growth promoting bacteria which able to tolerate heavy metals has been considered as a new trend for supporting the growth of many crops in heavy metal occupied areas. In this study, twelve bacteria strains were isolated from rhizosphere of diseased Korean ginseng roots located in Gochang province, Republic of Korea and tested for their ability to grow in Al-embedded broth media. Out of them, four strains (Pseudomonas simiae N3, Pseudomonas fragi N8, Chryseobacterium polytrichastri N10, and Burkholderia ginsengiterrae N11-2) were able to grow. The strains could also show other plant growth promoting activities e.g. auxins and siderophores production and phosphate solubilization. P. simiae N3, C. polytrichastri N10, and B. ginsengiterrae N11-2 strains were able to support the growth of Arabidopsis thaliana stressed by Al while P. fragi N8 could not. Plants inoculated with P. simiae N3, C. polytrichastri N10, and B. ginsengiterrae N11-2 showed higher expression level of Al-stress related genes, AtAIP, AtALS3 and AtALMT1, compared to non-bacterized plants. Expression profiles of the genes reveal the induction of external mechanism of Al resistance by P. simiae N3 and B. ginsengiterrae N11-2 and internal mechanism by C. polytrichastri N10. Korean ginseng seedlings treated with these strains showed higher biomass, particularly the foliar part, higher chlorophyll content than non-bacterized Al-stressed seedlings. According to the present results, these strains can be used in the future for the cultivation of ginseng in Al-persisted locations

Photoluminescent And Self-Assembled Hyaluronic Acid-Zinc Oxide-Ginsenoside Rh2 Nanoparticles And Their Potential Caspase-9 Apoptotic Mechanism Towards Cancer Cell Lines

Background: Zinc oxide nanoparticles (ZnO NPs) are used in modern cancer therapy based on their specific target, efficacy, low toxicity and biocompatibility. The photocatalytic performance of Zinc oxide (ZnO) nanocomposites with hyaluronic acid (HA) was used to study anticancer properties against various human cancer cell lines. Methods: Zinc oxide (ZnO) nanocomposites functionalized by hyaluronic acid (HA) were prepared by a co-precipitation method (HA-ZnONcs). The submicron-flower-shaped nanocomposites were further functionalized with ginsenoside Rh2 by a cleavable ester bond via carbodiimide chemistry to form Rh2HAZnO. The physicochemical behaviors of the synthesized ZnO nanocomposites were characterized by various analytical and spectroscopic techniques. We carried out 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide (MTT) assay to evaluate the toxicity of Rh2HAZnO in various human cancer cells (A549, MCF-7, and HT29). Furthermore, to confirm the apoptotic effects of Rh2HAZnO and to determine the role of the Caspase-9/p38 MAPK pathways by various molecular techniques such as RT-PCR and Western blotting. Furthermore, Rh2HAZnO induced morphological changes of these cell lines, mainly intracellular reactive oxygen species (ROS) were observed by ROS staining and nucleus by Hoechst staining. Results: We confirmed that Rh2HAZnO exhibits the anti-cancer effects on A549 lung cancer, HT29 colon cancer, and MCF7 breast cancer cells. Moreover, intracellular reactive oxygen species (ROS) were observed in three cancer cell lines. Rh2HAZnO induced apoptotic process through p53-mediated pathway by upregulating p53 and BAX and downregulating BCL2. Specifically, Rh2HAZnO induced activation of cleaved PARP (Asp214) in A549 lung cancer cells and upregulated Caspase-9/phosphorylation of p38 MAPK in other cell lines (HT29 and MCF-7). Furthermore, Rh2HAZnO induced morphological changes in the nucleus of these cell lines. Conclusion: These results suggest that the potential anticancer activity of novel Rh2HAZnO nanoparticles might be linked to induction of apoptosis through the generation of ROS by activation of the Caspase-9/p38 MAPK pathway

Humibacter ginsengiterrae sp. nov., and Humibacter ginsengisoli sp. nov., isolated from soil of a ginseng field

Two novel Gram-staining-positive bacteria, designated DCY60T and DCY90T, were isolated from soil of a ginseng field in the Republic of Korea. 16S rRNA gene sequence comparisons showed the two novel strains were closely related to members of the genus Humibacter with greatest similarity to Humibacter antri KCTC 33009T (98.8 and 98.4 % for DCY60T and DCY90T, respectively). The predominant menaquinones present were MK-11 and MK-12. The major fatty acids were anteiso-C17 : 0 and summed feature 8 containing C18 : 1ω7c and/or C18 : 1ω6c. The DNA G+C contents of strains DCY60T and DCY90T were 62.8 and 66.8 mol%, respectively. The peptidoglycan of both strains contained the amino acids ornithine, 2,4-diaminobutyric acid, alanine, glutamic acid and glycine. The cell-wall sugars of strain DCY60T comprised glucose, galactose, rhamnose and xylose, while strain DCY90T contained glucose, galactose, rhamnose and ribose. The major polar lipids of both strains were phosphatidylglycerol, an unidentified glycolipid, and an unknown phospholipid. On the basis of the phenotypic analysis strains DCY60T and DCY90T represent novel species of the genus Humibacter, for which names Humibacter ginsengiterrae sp. nov. (type strain DCY60T = KCTC 33520T = JCM 30079T) and Humibacter ginsengisoli sp. nov. (type strain DCY90T = KCTC 33521T = JCM 30080T) are proposed

Burkholderia ginsengiterrae sp. nov. and Burkholderia panaciterrae sp. nov., antagonistic bacteria against root rot pathogen Cylindrocarpon destructans, isolated from ginseng soil

Strain DCY85T and DCY85-1T, isolated from rhizosphere of ginseng, were rod-shaped, Gram-reaction-negative, strictly aerobic, catalase positive and oxidase negative. 16S rRNA gene sequence analysis revealed that strain DCY85T as well as DCY85-1T belonged to the genus Burkholderia and were closely related to Burkholderia fungorum KACC 12023T (98.1 and 98.0 % similarity, respectively). The major polar lipids of strain DCY85T and DCY85-1T were phosphatidylethanolamine, one unidentified aminolipid and two unidentified phospholipids. The major fatty acids of both strains are C16:0, C18:1ω7c and summed feature 3 (C16:1ω6c and/or C16:1ω7c). The predominant isoprenoid quinone of each strain DCY85T and DCY85-1T was ubiquinone (Q-8) and the G+C content of their genomic DNA was 66.0 and 59.4 mol%, respectively, which fulfill the characteristic range of the genus Burkholderia. The polyamine content of both DCY85T and DCY85-1T was putrescine. Although both DCY85T and DCY85-1T have highly similar 16S rRNA and identical RecA and gyrB sequences, they show differences in phenotypic and chemotaxonomic characteristics. DNA–DNA hybridization results proved the consideration of both strains as two different species. Based on the results from our polyphasic characterization, strain DCY85T and DCY85-1T are considered novel Burkholderia species for which the name Burkholderia ginsengiterrae sp. nov and Burkholderiapanaciterrae sp. nov are, respectively, proposed. An emended description of those strains is also proposed. DCY85T and DCY85-1T showed antagonistic activity against the common root rot pathogen of ginseng, Cylindrocarpon destructans. The proposed type strains are DCY85T (KCTC 42054T = JCM 19888T) and DCY85-1T (KCTC 42055T = JCM 19889T)

A Growth-Promoting Bacteria, Paenibacillus yonginensis DCY84T Enhanced Salt Stress Tolerance by Activating Defense-Related Systems in Panax ginseng

Panax ginseng (C.A. Mayer) is a well-known medicinal plant used in traditional medicine in Korea that experiences serious salinity stress related to weather changes or incorrect fertilizer application. In ginseng, the use of Paenibacillus yonginensis DCY84T to improve salt stress tolerance has not been thoroughly explored. Therefore, we studied the role of P. yonginensis DCY84T under short-term and long-term salinity stress conditions in a controlled environment. In vitro testing of DCY84T revealed high indole acetic acid (IAA) production, siderophore formation, phosphate solubilization and anti-bacterial activity. We determined that 10-min dip in 1010 CFU/ml DCY84T was sufficient to protect ginseng against short-term salinity stress (osmotic stress) upon exposure to 300 mM NaCl treatment by enhancing nutrient availability, synthesizing hydrolyzing enzymes and inducing osmolyte production. Upon exposure to salinity stress (oxidative and ionic stress), strain DCY84T-primed ginseng seedlings were protected by the induction of defense-related systems such as ion transport, ROS scavenging enzymes, proline content, total sugars, and ABA biosynthetic genes, as well as genes involved in root hair formation. Additionally, ginseng primed with DCY84T and exposed to 300 mM NaCl showed the same metabolite profile as control ginseng plants, suggesting that DCY84T effectively reduced salt stress. These results indicated that DCY84T can be widely used as a microbial inoculant to protect ginseng plants against salinity stress conditions

Biosynthesis of Anisotropic Silver Nanoparticles by Bhargavaea indica

The strain Bhargavaea indica DC1 isolated from four-year-old P. ginseng rhizospheric soil was used to perform rapid and extracellular biosynthesis of anisotropic silver nanoparticles. The ultraviolet-visible (UV-vis) spectra of the reaction mixture containing silver nanoparticles showed a peak at 460 nm, corresponding to the surface plasmon absorbance of silver nanoparticles. Field-emission transmission electron microscopy (FE-TEM) structural characterization revealed the nanobar, pentagon, spherical, icosahedron, hexagonal, truncated triangle, and triangular nanoparticles, with the size range from 30 to 100 nm. The energy-dispersive X-ray (EDX) analysis and elemental mapping results also confirmed that the silver was the predominant component of isolated nanoparticles. The X-ray diffraction (XRD) results correspond to the purity of silver nanoparticles and dynamic light scattering (DLS) result indicated that the average diameter of particles was 111.6 nm. In addition, enhancement in antimicrobial activity of commercial antibiotics was observed against various pathogenic microorganisms such as Vibrio parahaemolyticus, Salmonella enterica, Staphylococcus aureus, Bacillus anthracis, Bacillus cereus, Escherichia coli, and Candida albicans

A Large Bandgap Shift in InGaAs(P)/InP Multi-Quantum Well Structure Obtained by Impurity-Free Vacancy Diffusion Using SiO2 Capping and its Application to Photodetectors

In this paper, we have investigated the bandgap tuning in the InGaAs (P)/ InP multiquantum well (MQW) structure obtained by impurity-free vacancy diffusion (IFVD) using low temperature photoluminescence (PL). The MQW intermixing was performed in a rapid thermal annealer (RTA) using the dielectric capping materials, Si02 and SiNX. The Si02 capping was successfully used with InGaAs cap layer to cause a large bandgap tuning effect in the InGaAs/InP MQW material. The blue shift of bandgap energy after RTA treatment was as much as 185 and 230 meV at 750 t and 850 t, respectively, with its value controllable using annealing time and temperature. Samples with Si02-InP or SiN-InGaAs cap layer combinations, on the other hand, did not show any significant energy shifts. The absorption spectra taken from the same samples confimed the energy shifts obtained using PL. The process developed can be readily applied to fabrication of photodetectors that are sensitive to wavelength and/or polarization.This work was fmancially supported in part by OERC(Opto-Electronic Research Center) through the grant # 97K3-0809- 02-06-1 and by the SPRC (Semiconductor Physics Research Center) of Korea. The authors thank U. H. Lee and Prof. D. Lee of Chung Nam National Univ. for their help with the absorption measurement