A comprehensive review on Moringa oleifera nanoparticles: importance of polyphenols in nanoparticle synthesis, nanoparticle efficacy and their applications.

Moringa oleifera is one of the popular functional foods that has been tremendously exploited for synthesis of a vast majority of metal nanoparticles (NPs). The diverse secondary metabolites present in this plant turn it into a green tool for synthesis of different NPs with various biological activities. In this review, we discussed different types of NPs including silver, gold, titanium oxide, iron oxide, and zinc oxide NPs produced from the extract of different parts of M. oleifera. Different parts of M. oleifera take a role as the reducing, stabilizing, capping agent, and depending on the source of extract, the color of solution changes within NP synthesis. We highlighted the role of polyphenols in the synthesis of NPs among major constituents of M. oleifera extract. The different synthesis methods that could lead to the formation of various sizes and shapes of NPs and play crucial role in biomedical application were critically discussed. We further debated the mechanism of interaction of NPs with various sizes and shapes with the cells, and further their clearance from the body. The application of NPs made from M. oleifera extract as anticancer, antimicrobial, wound healing, and water treatment agent were also discussed. Small NPs show better antimicrobial activity, while they can be easily cleared from the body through the kidney. In contrast, large NPs are taken by the mono nuclear phagocyte system (MPS) cells. In case of shape, the NPs with spherical shape penetrate into the bacteria, and show stronger antibacterial activity compared to the NPs with other shapes. Finally, this review aims to correlate the key characteristics of NPs made from M. oleifera extract, such as size and shape, to their interactions with the cells for designing and engineering them for bio-applications and especially for therapeutic purposes.

The state of plant-based food development and its prospects in the Indonesia market.

Innovations in food biotechnology reflect the increasing demand for healthy food and the change in conventional dietary patterns to plant-based diets, encouraging the development of functional products and opening new perspectives for industry interests. In addition, the development of vegetable-based products is supported by several studies that state that plant-based diets help reduce the risk of diseases, reduce stress, and even help maintain healthy body weight, making this diet a promising development for the future. The industry mainly uses fermentation techniques to obtain plant-based foodstuffs. However, fermentation is just one method that can develop probiotic products. Other methods include high moisture extrusion cooking and applying shear cells, for instance, for developing vegetable meats. This article summarizes trends and shifts in eating preferences, the response of the respective industry, and the future potential of plant-based products.

Chitosan, chitosan nanoparticles and modified chitosan biomaterials, a potential tool to combat salinity stress in plants.

Chitosan being non-toxic, biocompatible, and biodegradable gained considerable interest among agriculturists. Our research review discusses about the role of Cs, chitosan nanoparticles (CsNPs), and modified chitosan biomaterials (CsBMs) under salt stress to improve growth parameters such as plant height, weight, stem width, fruit yield, pigments such as chlorophyll a, b, total chlorophyll, and carotenoid contents, as well as antioxidant and non-antioxidative enzymes. Upon Cs treatment and salt stress, total aminoacids (TAA), glutamic acids, and gamma-aminobutyric acid (GABA) were increased. Furthermore, Cs activated SOS1 pathway and increased various gene transcripts involved in sodium compartmentalization, proton motive force, energy production, and phenol metabolism. On the other hand, CsNPs and modified CsBMs treated plants under salinity stress increased indole terpene alkaloid metabolism, defense related genes, decreased ROS production by enhancing JA signaling, increased essential oil, anthocyanins, membrane stability, alkaloids, and diterpene glycosides. This is the first review that specifically brings insights about the physiological and biochemical parameters of the plants by comparing Cs/CsNPs/modified CsBMs treatment options under salt stress and encourages the use of CsNPs and modified CsBMs compared to Cs for better plant function under salinity stress.

Comparative study of polyphenolic compound extraction from empty palm fruit bunches and sugarcane pulp.

Polyphenolic compounds have many benefits, one of which being their efficacy as antioxidants. They can be extracted from various parts of plants and from agricultural waste. In this research, sugarcane pulp, and empty palm fruit bunches from the palm oil production were investigated as potential raw materials. This study aims to determine solvents and easy-to-perform extraction methods that show the highest effectivity in regards to total phenolic and flavonoid yield and the correlated antioxidant activity. Extraction methods comprised maceration, Soxhlet extraction, and ultrasound assisted extraction (UAE); solvents that were investigated included water, 70% methanol and 70% ethanol. The antioxidant activity was measured by the DPPH (diphenyl-2-picrylhydrazyl) method and FRAP (Ferric Reduction Ability of Plasma) method. Based on the amount of polyphenol compounds as well as the antioxidant activity, the experiments showed that Soxhlet extraction with 70% methanol as solvent worked best for palm bunch waste and sugar cane pulp, resulted in about two times higher values for total phenolic content, flavonoid content and FRAP antioxidant activity as well as extract mass (yield) compared to the results from other extraction methods or solvents used in this experiment. The antioxidant activity of the extracts as measured by DPPH method seemed also to be promising, although the trend among solvent and extraction method was rather inconclusive.

Overexpression of the PanaxginsengCYP703 Alters Cutin Composition of Reproductive Tissues in Arabidopsis.

Cytochrome P450 (CYP) catalyzes a wide variety of monooxygenation reactions in plant primary and secondary metabolisms. Land plants contain CYP703, belonging to the CYP71 clan, which catalyzes the biochemical pathway of fatty acid hydroxylation, especially in male reproductive tissues. Korean/Asian ginseng (Panax ginseng Meyer) has been regarded as one of important medicinal plant for a long time, however the molecular mechanism is less known on its development. In this study, we identified and characterized a CYP703A gene in P. ginseng (PgCYP703A4), regarding reproductive development. PgCYP703A4 shared a high-sequence identity (81-83%) with predicted amino acid as CYP703 in Dancus carota, Pistacia vera, and Camellia sinensis as well as 76% of amino acid sequence identity with reported CYP703 in Arabidopsis thaliana and 75% with Oryza sativa. Amino acid alignment and phylogenetic comparison of P. ginseng with higher plants and known A. thaliana members clearly distinguish the CYP703 members, each containing the AATDTS oxygen binding motif and PERH as a clade signature. The expression of PgCYP704B1 was only detected in P. ginseng flower buds, particularly in meiotic cells and the tapetum layer of developing anther, indicating the conserved role on male reproduction with At- and Os- CYP703. To acquire the clue of function, we transformed the PgCYP703A4 in A. thaliana. Independent overexpressing lines (PgCYP703A4ox) increased silique size and seed number, and altered the contents of fatty acids composition of cutin monomer in the siliques. Our results indicate that PgCYP703A4 is involved in fatty acid hydroxylation which affects cutin production and fruit size.

Overexpression of a novel cytochrome P450 monooxygenase gene, CYP704B1, from Panax ginseng increase biomass of reproductive tissues in transgenic Arabidopsis.

Cytochrome P450 monooxygenase 704B (CYP704B), a member of the CYP86 clan, was found to be needed in Arabidopsis and rice to biosynthesize precursors of sporopollenin through oxidizing fatty acids. In the present study, we cloned and characterized a CYP704B gene in Panax ginseng, named PgCYP704B1. It shared high sequence identity (98-99%) with CYP704 of Arabidopsis, Theobroma cacao, and Morus notabilis. The phylogenetic comparison of ginseng and higher plants between the members of CYP86 clan revealed that ginseng CYP704 was categorized as a group of CYP704B with dicot plants. The expression of PgCYP704B1 is low in the stem, leaf, and fruit, and high in flower buds, particularly detected in the young gametic cell and tapetum layer of the developing anther. Arabidopsis plants overexpressing PgCYP704B1 improved plant biomass such as plant height, siliques and seed number and size. A cytological observation by transverse and longitudinal semi-thin sections of the siliques cuticles revealed that the cell length increased. Furthermore a chemical analysis showed that PgCYP704B1ox lines increased their cutin monomers contents in the siliques. Our results suggest that PgCYP704B1 has a conserved role during male reproduction for fatty acid biosynthesis and its overexpression increases cutin monomers in siliques that eventually could be used for seed production.

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.

Metabolic dynamics and physiological adaptation of Panax ginseng during development.

KEY MESSAGE: The dynamics of metabolites from leaves to roots of Panax ginseng during development has revealed the tissue-specific and year-specific metabolic networks. Being an essential Oriental medicinal plant, ginseng (Panax ginseng Meyer) is a slow-growing perennial herb-accumulating pharmaceutically active metabolites such as ginsenosides in roots during growth. However, little is known about how ginseng plants survive in the harsh environments such as winter cold and summer heat for a longer period and accumulates those active metabolites as the plant grows. To understand the metabolic kinetics in both source and sink organs such as leaves and roots of ginseng plant, respectively, and to assess the changes in ginsenosides biosynthesis during ginseng growth, we investigated the metabolic profiles from leaves and roots of 1-, 4-, and 6-year-old field-grown ginseng plants. Using an integrated non-targeted metabolomic approach, we identified in total 348 primary and secondary metabolites, which provided us for the first time a global metabolomic assessment of ginseng during growth, and morphogenesis. Strikingly, the osmoprotectants and oxidized chemicals were highly accumulated in 4- and 6-year-old ginseng leaves suggested that ginseng develop a wide range of metabolic strategies to adapt unfavorable conditions as they mature. In 6-year-old plants, ginsenosides were decreased in leaves but increased in roots up to 1.2- to sixfold, supporting the view that there is a long-distance transport of ginsenosides from leaves to roots as ginseng plants mature. Our findings provide insights into the metabolic kinetics during the development of ginseng plant and this could complement the pharmacological importance of ginseng and its compounds according to their age.

Complete genome sequence of Paenibacillus yonginensis DCY84T, a novel plant Symbiont that promotes growth via induced systemic resistance.

This article reports the full genome sequence of Paenibacillus yonginensis DCY84T (KCTC33428, JCM19885), which is a Gram-positive rod-shaped bacterium isolated from humus soil of Yongin Forest in Gyeonggi Province, South Korea. The genome sequence of strain DCY84T provides greater understanding of the Paenibacillus species for practical use. This bacterium displays plant growth promotion via induced systemic resistance of abiotic stresses.

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

Panax 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.

Cytological analysis of ginseng carpel development.

Panax ginseng Meyer, commonly known as ginseng, is considered one of the most important herbs with pharmaceutical values due to the presence of ginsenosides and is cultivated for its highly valued root for medicinal purposes. Recently, it has been recognized that ginseng fruit contains high contents of triterpene such as ginsenoside Re as pharmaceutical compounds. However, it is unclear how carpel, the female reproductive tissue of flowers, is formed during the three-year-old growth before fruit is formed in ginseng plants. Here, we report P. ginseng carpel development at the cytological level, starting from the initial stage of ovule development to seed development. The carpel of P. ginseng is composed of two free stigmas, two free styles, and one epigynous bilocular ovary containing one ovule in each locule. Based on our cytological study, we propose that the female reproductive development in P. ginseng can be classified into seven stages: early phase of ovule development, megasporogenesis, megagametogenesis, pre-fertilization, fertilization, post-fertilization, and seed development. We also describe the correlation of the female and male gametophyte development and compare morphological differences in carpel development between ginseng and other higher plants. One unique feature for ginseng seed development is that it takes 40 days for the embryo to develop to the early torpedo stage and that the embryo is small relative to the seed size, which could be a feature of taxonomic importance. This study will provide an integral tool for the study of the reproductive development and breeding of P. ginseng.

Overexpression of Panax ginseng sesquiterpene synthase gene confers tolerance against Pseudomonas syringae pv. tomato in Arabidopsis thaliana.

Sesquiterpenes are an abundant group belonging to the terpenoid family, with a C15 structure comprise of three isoprene units. Many sesquiterpenes are volatile compounds and it act as chemical messenger in plant signalling, particularly in the defense mechanism against biotic and abiotic stresses. Panax ginseng Meyer is important medicinal herbs with various reported pharmacological efficacies in which its triterpenoid saponins, called ginsenosides, were mostly studied. However, there have been few studies on volatile sesquiterpenes compounds regulation on P. ginseng. As slow-growing perennial plant, P. ginseng received many kind of stresses during its cultivation. The pathogen attack is one of the most devastated perturbation for ginseng yield. Thus, we aimed to analyze P. ginseng STS gene (PgSTS) expressions in ginseng organs as well as mono-, sesquiterpenes contents from ginseng seedlings treated with elicitors. qRT-PCR and GC-MS analysis showed that two elicitors- salicylic acid (SA) and methyl jasmonate (MeJA) triggered PgSTS expression at different time points and significantly induced mono-, sesquiterpene yield. Overexpression of PgSTS in Arabidopsis also induced high terpene content and conferred tolerance against Pseudomonas syringae pv. tomato infection. These results suggested that PgSTS transcripts are involved in terpenoid biosynthesis in response to environmental stress mediated by MeJA and SA elicitors; thus, generate tolerance against pathogen attack.

PgLOX6 encoding a lipoxygenase contributes to jasmonic acid biosynthesis and ginsenoside production in Panax ginseng.

Ginsenosides, the valuable pharmaceutical compounds in Panax ginseng, are triterpene saponins that occur mainly in ginseng plants. It was shown that in vitro treatment with the phytohormone jasmonic acid (JA) is able to increase ginsenoside production in ginseng plants. To understand the molecular link between JA biosynthesis and ginsenoside biosynthesis, we identified a JA biosynthetic 13-lipoxygenase gene (PgLOX6) in P. ginseng that promotes ginsenoside production. The expression of PgLOX6 was high in vascular bundles, which corresponds with expression of ginsenoside biosynthetic genes. Consistent with the role of PgLOX6 in synthesizing JA and promoting ginsenoside synthesis, transgenic plants overexpressing PgLOX6 in Arabidopsis had increased amounts of JA and methyl jasmonate (MJ), increased expression of triterpene biosynthetic genes such as squalene synthase (AtSS1) and squalene epoxidase (AtSE1), and increased squalene content. Moreover, transgenic ginseng roots overexpressing PgLOX6 had around 1.4-fold increased ginsenoside content and upregulation of ginsenoside biosynthesis-related genes including PgSS1, PgSE1, and dammarenediol synthase (PgDDS), which is similar to that of treatment with MJ. However, MJ treatment of transgenic ginseng significantly enhanced JA and MJ, associated with a 2.8-fold increase of ginsenoside content compared with the non-treated, non-transgenic control plant, which was 1.4 times higher than the MJ treatment effect on non-transgenic plants. These results demonstrate that PgLOX6 is responsible for the biosynthesis of JA and promotion of the production of triterpenoid saponin through up-regulating the expression of ginsenoside biosynthetic genes. This work provides insight into the role of JA in biosynthesizing secondary metabolites and provides a molecular tool for increasing ginsenoside production.

Cytological characterization of anther development in Panax ginseng Meyer.

Ginseng (Panax ginseng), a valued medicinal herb, is a slow-growing plant that flowers after 3 years of growth with the formation of a solitary terminal umbel inflorescence. However, little is known about cytological events during ginseng reproduction, such as the development of the male organ, the stamen. To better understand the mechanism controlling ginseng male reproductive development, here, we investigated the inflorescence and flower structure of ginseng. Moreover, we performed cytological analysis of anther morphogenesis and showed the common and specialized cytological events including the formation of four concentric cell layers surrounding male reproductive cells followed by subsequent cell differentiation and degeneration of tapetal cells, as well as the formation of mature pollen grains via meiosis and mitosis during ginseng anther development. Particularly, our transverse section and microscopic observations showed that the ginseng tapetal layer exhibits obvious nonsynchronous cell division evidenced by the observation of one or two tapetal layers frequently observed in one anther lobe, suggesting the unique control of cell division. To facilitate the future study on ginseng male reproduction, we grouped the anther development into 10 developmental stages according to the characterized cytological events.

Sphingomonas panaciterrae sp. nov., a plant growth-promoting bacterium isolated from soil of a ginseng field.

Strain DCY91(T), a Gram-stain-negative, rod-shaped, aerobic, non-motile bacterium, was isolated from soil of ginseng field in Gyeonggi province, South Korea. Strain DCY91(T) shared the highest 16S rRNA gene sequence similarity with Sphingomonas mucosissima DSM 17494(T) (98.55%), Sphingomonas dokdonensis KACC 17420(T) (98.11%) and Sphingomonas xinjiangensis DSM 26736(T) (96.68%). The strain DCY91(T) was found to able to grow best in trypticase soy agar at 28 °C, at pH 7 and at 0.5 % NaCl. Ubiquinone 10 was identified as the isoprenoid quinone. The major polar lipids were identified as sphingoglycolipid, diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol and phosphatidylcholine. The major fatty acids of strain DCY91(T) were identified as unsaturated C18:1 ω7c and saturated C16:0. The major polyamine content was sym-homospermidine. The DNA G + C content was determined to be 65.8 mol% (HPLC). After 6 days of incubation, strain DCY91(T) produced 9.64 ± 1.73 and 33.73 ± 4.66 µg/ml indole-3-acetic acid, using media without L-tryptophan and supplemented with L-tryptophan, respectively. Strain DCY91(T) was also weakly solubilized phosphate and produced siderophores. On the basis of the phenotypic characteristics, genotypic analysis and chemotaxonomic characteristics, strain DCY91(T) is considered to represent a novel species of the genus Sphingomonas, for which the name Sphingomonas panaciterrae sp. nov. is proposed. The type strain is DCY91(T) (=KCTC 42346(T) =JCM 30807(T)).

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.

Cupriavidus yeoncheonense sp. nov., isolated from soil of ginseng.

A novel bacterial strain, DCY86(T) (=KCTC 42053(T) = JCM 19890(T)) was isolated from soil of a ginseng field in Yeoncheon province (38°04'00″N 126°57'00″E), Republic of Korea using a serial dilution method. Strain DCY86(T) was observed to be Gram-stain negative, strictly aerobic, to grow optimally at 25-30 °C, at pH 7-7.5 and on tryptic soya agar medium. The cells were found to be sensitive to ceftazidine and tetracycline. Based on 16S rRNA gene sequence comparisons, strain DCY86(T) was found to be most closely related to Cupriavidus basilensis LMG 18990(T) (98.48 %), Cupriavidus numazensis LMG 26411(T) (98.34 %), Cupriavidus pinatabonesis KCTC 22125(T) (98.34 %) and Cupriavidus laharis KCTC 22126(T) (98.00 %). The G+C content was determined to be 64.23 mol %. The only isoprenoid quinone detected in strain DCY86(T) was ubiquinone Q-8. The major polar lipids were identified as diphosphatidylglycerol, phosphtidylethanolamine, phosphatidylglycerol, unidentified aminophosphoglycolipids and unidentified phospholipids. The major fatty acids were identified as C16:0 summed feature 3 (C16:1 ω7c/ω6c and/or iso-C15 : 0 2-OH) and summed feature 8 (C18:1 ω7c and/or C18:1 ω6c). These data support the affiliation of strain DCY86(T) to the genus Cupriavidus. Strain DCY86(T) was also found to be able to solubilize phosphate and produce siderophores. The results of physiological and biochemical tests enabled strain DCY86(T) to be differentiated genotypically and phenotypically from the recognized species of the genus Cupriaividus. Therefore, the novel isolate can be considered to represent a novel species, for which the name Cupriavidus yeoncheonense sp. nov. is proposed here. The type strain is DCY86(T) (=KCTC 42053(T) = JCM 19890(T)).

Paenibacillus yonginensis DCY84(T) induces changes in Arabidopsis thaliana gene expression against aluminum, drought, and salt stress.

Current agricultural production methods, for example the improper use of chemical fertilizers and pesticides, create many health and environmental problems. Use of plant growth-promoting bacteria (PGPB) for agricultural benefits is increasing worldwide and also appears to be a trend for the future. There is possibility to develop microbial inoculants for use in agricultural biotechnology, based on these beneficial plant-microbe interactions. For this study, ten bacterial strains were isolated from Yongin forest soil for which in vitro plant-growth promoting trait screenings, such as indole acetic acid (IAA) production, a phosphate solubilization test, and a siderophore production test were used to select two PGPB candidates. Arabidopsis thaliana plants were inoculated with Paenibacillus yonginensis DCY84(T) and Micrococcus yunnanensis PGPB7. Salt stress, drought stress and heavy metal (aluminum) stress challenges indicated that P. yonginensis DCY84(T)-inoculated plants were more resistant than control plants. AtRSA1, AtVQ9 and AtWRKY8 were used as the salinity responsive genes. The AtERD15, AtRAB18, and AtLT178 were selected to check A. thaliana responses to drought stress. Aluminum stress response was checked using AtAIP, AtALS3 and AtALMT1. The qRT-PCR results indicated that P. yonginensis DCY84(T) can promote plant tolerance against salt, drought, and aluminum stress. P. yonginensis DCY84(T) also showed positive results during in vitro compatibility testing and virulence assay against X. oryzae pv. oryzae Philippine race 6 (PXO99). Better germination rates and growth parameters were also recorded for the P. yonginensis DCY84(T) Chuchung cultivar rice seed which was grown on coastal soil collected from Suncheon. Based on these results, P. yonginensis DCY84(T) can be used as a promising PGPB isolate for crop improvement.

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

Strain DCY85(T) and DCY85-1(T), 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 DCY85(T) as well as DCY85-1(T) belonged to the genus Burkholderia and were closely related to Burkholderia fungorum KACC 12023(T) (98.1 and 98.0 % similarity, respectively). The major polar lipids of strain DCY85(T) and DCY85-1(T) were phosphatidylethanolamine, one unidentified aminolipid and two unidentified phospholipids. The major fatty acids of both strains are C16:0, C18:1 ω7c and summed feature 3 (C16:1 ω6c and/or C16:1 ω7c). The predominant isoprenoid quinone of each strain DCY85(T) and DCY85-1(T) 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 DCY85(T) and DCY85-1(T) was putrescine. Although both DCY85(T) and DCY85-1(T) 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 DCY85(T) and DCY85-1(T) are considered novel Burkholderia species for which the name Burkholderia ginsengiterrae sp. nov and Burkholderia panaciterrae sp. nov are, respectively, proposed. An emended description of those strains is also proposed. DCY85(T) and DCY85-1(T) showed antagonistic activity against the common root rot pathogen of ginseng, Cylindrocarpon destructans. The proposed type strains are DCY85(T) (KCTC 42054(T) = JCM 19888(T)) and DCY85-1(T) (KCTC 42055(T) = JCM 19889(T)).