• The Plant Pathology Journal
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• v.34 no.3
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• pp.218-235
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• 2018

Plant growth promoting rhizobacteria and endophytic bacteria were isolated from different varieties of turmeric (Curcuma longa L.) from South India. Totally 50 strains representing, 30 PGPR and 20 endophytic bacteria were identified based on biochemical assays and 16S rDNA sequence analysis. The isolates were screened for antagonistic activity against Pythium aphanidermatum (Edson) Fitzp., and Rhizoctonia solani Kuhn., causing rhizome rot and leaf blight diseases in turmeric, by dual culture and liquid culture assays. Results revealed that only five isolates of PGPR and four endophytic bacteria showed more than 70% suppression of test pathogens in both assays. The SEM studies of interaction zone showed significant ultrastructural changes of the hyphae like shriveling, breakage and desication of the pathogens by PGPR B. cereus (RBacDOB-S24) and endophyte P. aeruginosa (BacDOB-E19). Selected isolates showed multiple Plant growth promoting traits. The rhizome bacterization followed by soil application of B. cereus (RBacDOB-S24) showed lowest Percent Disease Incidence (PDI) of rhizome rot and leaf blight, 16.4% and 15.5% respectively. Similarly, P. aeruginosa (BacDOB-E19) recorded PDI of rhizome rot (17.5%) and leaf blight (17.7%). The treatment of these promising isolates exhibited significant increase in plant height and fresh rhizome yield/plant in comparison with untreated control under greenhouse condition. Thereby, these isolates can be exploited as a potential biocontrol agent for suppressing rhizome rot and leaf blight diseases in turmeric.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 1997.06a
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• pp.47-55
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• 1997

Plant growth promoting fungi(PGPF) obtained from zoysiagrass rhizosphere offer dual advantages - induse systemic disease resistance response in cucumber to C. orbiculare infection and cause enhancement of plant growth and increase yield. PGPF protected plants either by colonizing roots or by their metabolites. PGPF offer an advantage by protecting plants for more than 9 weeks and 6 week in the greenhouse and field. PGPF-induced plants limited pathogen spore germination and decreased the number of infection hyphae on the leaf, and increased lignification at places of attempted pathogen infection, thus reducing the pathogen spread. PGPF elicited increased activities of chitinascs, glucanases, peroxidase, polyphenol oxidase, and phenylalanine ammonia lyase to C. orbiculare infection in cucumber plants. The role of PGPF in elevating cucumber defense response to pathogen infection suggests potential application of PGPF as biological control agents.

• The Plant Pathology Journal
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• v.37 no.2
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• pp.173-181
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• 2021

The genus Streptomyces demonstrates enormous promise in promoting plant growth and protecting plants against various pathogens. Single and consortium treatments of two selected Streptomyces strains (Streptomyces shenzhenensis TKSC3 and Streptomyces sp. SS8) were evaluated for their growth-promoting potential on rice, and biocontrol efficiency through induced systemic resistance (ISR) mediation against Xanthomonas oryzae pv. oryzicola (Xoc), the causal agent of rice bacterial leaf streak (BLS) disease. Seed bacterization by Streptomyces strains improved seed germination and vigor, relative to the untreated seed. Under greenhouse conditions, seed bacterization with consortium treatment TKSC3 + SS8 increased seed germination, root length, and dry weight by 20%, 23%, and 33%, respectively. Single and consortium Streptomyces treatments also successfully suppressed Xoc infection. The result was consistent with defense-related enzyme quantification wherein single and consortium Streptomyces treatments increased peroxidase (POX), polyphenol oxidase, phenylalanine ammonia-lyase, and β,1-3 glucanase (GLU) accumulation compared to untreated plant. Within all Streptomyces treatments, consortium treatment TKSC3 + SS8 showed the highest disease suppression efficiency (81.02%) and the lowest area under the disease progress curve value (95.79), making it the best to control BLS disease. Consortium treatment TKSC3 + SS8 induced the highest POX and GLU enzyme activities at 114.32 µmol/min/mg protein and 260.32 abs/min/mg protein, respectively, with both enzymes responsible for plant cell wall reinforcement and resistant interaction. Our results revealed that in addition to promoting plant growth, these Streptomyces strains also mediated ISR in rice plants, thereby, ensuring protection from BLS disease.

• KSBB Journal
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• v.30 no.3
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• pp.97-102
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• 2015

This study aimed to evaluate the potential plantgrowth promoting effects of potassium polyacrylate, a superabsorbent polymer, and Bacillus sp. SH1RP8, a family of plant-growth-promoting bacteria. Potassium polyacrylate was selected as the polymer for use due to its high molecular weight and its ability to retain and continuously supply moisture. Plant-growth-promoting rhizobacteria (PGPR) were isolated from the soil and applied to plants growing in dry environments, such as saline conditions. The moisture absorption and retention abilities of potassium polyacrylate were evaluated at a high temperature ($50^{\circ}C$) and in a dry condition, during which time the polymer showed a water retention potential of 19606.07% after 29 days. To overcome the reaming problem in the soil environment, natural polymers (such as cellulose) were mixed with the potassium acrylate. The shoot growths of Peucedanum japonicum Thunb and Arundo donax were significantly enhanced when treated with the mixture of the isolated rhizosphere bacterium SH1RP8 and potassium polyacrylate (63.5 and 124.3%, respectively).

• The Plant Pathology Journal
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• v.27 no.2
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• pp.164-169
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• 2011

Previous studies have addressed the management of phyllosphere pathogens by leaf and root-associated microbes. The present study evaluated the effect of the foliar application of three strains of Bacillus spp. on plant growth and fruit quality. The application of a bacilli spore preparation significantly improved leaf growth parameters such as leaf thickness and photosynthesis capacity, indicating that bacilli treatment directly promoted leaf growth. In addition, foliar treatment resulted in an improvement in the key indicators of fruit quality including water, glucose, and sucrose contents. The present results suggest that foliar spraying of beneficial bacilli is a potential treatment of wide application for the improvement of apple quality. Foliar application of bacilli preparation as effective plant growth-promoting rhizobacteria broadens the spectrum of their availability for orchard application.

• Journal of Microbiology and Biotechnology
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• v.12 no.2
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• pp.327-330
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• 2002

A plant growth-promoting substance, FM001, was isolated from the culture broth of Acremonium strictum MJN1. The purification steps included solvent extraction, adsorption chromatography using Diaion HP20, TLC on silica, and HLPC using a C-18 column. The purified FM001 enhanced rice seedling growth by $11.1\%\;and\;34.0\%$ of the dried weight of the shoots and roots, and also radish growth by $26.5\%\;and\;23.7\%$ of the top length and dried weight. FM001 also significantly promoted the growth of red pepper by increasing $32.7\%$ of fruit weight and $11.3\%$ as regards the height. FM001 consisted of C, H, O, N, and S, and its molecular weight was determined to be 537.78 Da. The structure of FM001 resembled brassinosteriods, and it would appear to have great potential as an effective bio-fertilizer.

• Research in Plant Disease
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• v.12 no.1
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• pp.46-50
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• 2006

The microorganisms with the antifungal activity against Phytophthora capsici and Colletotrichum acutatum and the plant growth-promoting activity were screened from a forest and natural fields of Gajang-Dong, Sangju-city. One of the isolates, Streptomyces griseofuscus 200401, was selected as a good plant growth-promoting strain in this study. In greenhouse test, the number of leaf, fresh weight, and dry weight of pepper plants, that were grown with treatment of culture suspension or powder containing S. griseofuscus 200401, were higher than those without the bacterial cells. Cultivation of S. griseofuscus 200401 strain for 7 days in a nutrient rich medium produced ammonium chloride up to 0.13 ${\mu}g/ml$ in the culture solution of S. griseofuscus. Treatment of the selected strain significantly reduced the severity of the late blight of pepper plants to show the equivalent disease control activity to chemical fungicide. This study suggests that S. griseofuscus 200401 strain could be a potential biological agent with the biocontrol activity and the plant growth-promoting activity.

• Journal of Microbiology and Biotechnology
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• v.20 no.12
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• pp.1724-1734
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• 2010

A phosphate-solubilizing bacterial strain isolated from Hippophae rhamnoides rhizosphere was identified as Rahnella sp. based on its phenotypic features and 16S rRNA gene sequence. The bacterial strain showed the growth characteristics of a cold-adapted psychrotroph, with the multiple plant growth-promoting traits of inorganic and organic phosphate solubilization, 1-aminocyclopropane-1-carboxylate-deaminase activity, ammonia generation, and siderophore production. The strain also produced indole-3-acetic acid, indole-3-acetaldehyde, indole-3-acetamide, indole-3-acetonitrile, indole-3-lactic acid, and indole-3-pyruvic acid in tryptophan-supplemented nutrient broth. Gluconic, citric and isocitric acids were the major organic acids detected during tricalcium phosphate solubilization. A rifampicin-resistant mutant of the strain exhibited high rhizosphere competence without disturbance to the resident microbial populations in pea rhizosphere. Seed bacterization with a charcoal-based inoculum significantly increased growth in barley, chickpea, pea, and maize under the controlled environment. Microplot testing of the inoculum at two different locations in pea also showed significant increase in growth and yield. The attributes of cold-tolerance, high rhizosphere competence, and broad-spectrum plant growth-promoting activity exhibited the potential of Rahnella sp. BIHB 783 for increasing agriculture productivity.

• Journal of Microbiology and Biotechnology
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• v.12 no.2
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• pp.249-257
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• 2002

Pseudomonas fluorescens GL20 is a plant growth-promoting rhizobacterium that produces a large amount of hydroxamate siderophore under iron-limited conditions. The strain GL20 considerably inhibited the spore germination and hyphal growth of a plant pathogenic fungus, Fusarium solani, when iron was limited, significantly suppressed the root-rot disease on beans caused by F. solani, and enhanced the plant growth. The mechanism for the beneficial effect of strain GL20 on the disease suppression was due to the siderophore production, evidenced by mutant strains derived from the strain. Analysis of the outer membrane protein profile revealed that the growth of strain GL20 induced the synthesis of specific iron-regulated outer membrane proteins with molecular masses of 85- and 90 kDa as the high-affinity receptors for the ferric siderophore. In addition, a cross-feeding assay revealed the presence of multiple inducible receptors for heterologous siderophores in the strain. In order to induce increased efficacy and potential in biological control of plant disease, a siderophore-overproducing mutant, GL20-S207, was prepared by NTG mutagenesis. The mutant GL20-S207 produced nearly 2.3 times more siderophore than the parent strain. In pot trials of beans with F. solani, the mutant increased plant growth up to 1.5 times compared with that of the parent strain. These results suggest that the plant growth-promoting P. fluorescens GL20 and the genetically bred P. fluorescens GL20-S207 can play an important role in the biological control of soil-borne plant diseases in the rhizosphere.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.15 no.2
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• pp.53-79
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• 2002

To screen the effective materials for hair loss treatment, several natural extracts were tested using in vivo and in vitro test models. Firstly, all test materials were applicated onto the back skin of C57BL／6 mouse and then hair growth promoting effect was measured using hair growth index. As a result, Prunus mume, black bean, Brassica campestris subsp. black sesame and Rubi Fructus showed potent hair growth promoting effect, ranking as 1.5-2.0 of hair growth index. However, there were no plant extracts, which have remarkable potential of growth promotion of human hair dermal papilla cells cultured in vitro. In the experiments of 5${\alpha}$-reductase type Ⅱ inhibition assay, Prunus mume, Eriobotryae Folium showed effective potential to inhibit the activity of 5${\alpha}$-reductase type Ⅱ. To investigate the possible involvement of the effect of several plant extracts on the gene expression of growth factors in human hair dermal papilla cells, RT - PCR analyses were performed. However, there were no plant extracts, which have profound effect on the gene expression of several growth factors such as IGF-I, KGF, HGF and VEGF in the dermal papilla cells. Another tests for inhibition of microbial such as P. acne were also carried out to find whether these plant extracts have anti -microbial activities. Rubi Fructus showed anti -microbial effects on Propionibacterium acnes, which is believed as a pathogen of acne. Together, these results showed several plant extracts can be used for hair growth promotion.