• Journal of Microbiology and Biotechnology
• /
• v.7 no.1
• /
• pp.13-20
• /
• 1997

Plant growth-promoting Psudomonas fluorescens GL20 was isolated from a ginseng rhizosphere on chrome azurol Sagar. P. fluorescens GL20 produced a large amount of hydoxamate siderophore in an iron-deficient medium. The siderophore showed significantly high specific activity of 20.2 unit. Using an in vitro antifungal test, P. fluorescens GL20 considerably suppressed growth of phytopathogenic fungus Fusarium solani, inhibiting spore germination and germ tube elongation. In pot trials of kidney beans with P. fluorescens GL20, disease incidence was remarkably reduced up to $68{\%}$ compared with that of F. solani alone, and plant growth was also increased nearly 1.6 fold as compared to that of the untreated control, promoting elongation and development of the roots. These results indicate that the plant growth-promoting activity of P. fluorescens GL20 can play an important role in biological control of soil-borne plant disease in a rhizosphere, enhancing the growth of plants.

• Journal of Plant Biotechnology
• /
• v.43 no.1
• /
• pp.119-124
• /
• 2016

Anthocyanin accumulation and plant growth were examined in petunia (NT and $T_2$ transgenic plants) by determining the effects of different sources of light and varying light/dark cycles. Red light significantly enhanced anthocyanin content of B-peru+mPAP1; however, it had a negative effect on anthocyanin production in RsMYB1 plants. In general, white light was found to be reasonable for anthocyanin accumulation in all plants. In case of light/dark cycles, application of seven days of light:14 days of dark significantly enhanced anthocyanin content. We found that anthocyanin content detected in transgenic plants expressing anthocyanin regulatory transcription factor genes (B-peru+mPAP1 or RsMYB1) was higher than that in NT plants in all treatments. Plant growth was also influenced by the different light sources and dark/light cycles. Taken together, our results suggest that light source and light/dark cycle play an important role in anthocyanin production and plant growth. The choice of the optimal conditions is also important for anthocyanin production and plant growth depending on NT or transgenic plants carrying anthocyanin regulatory transcription factors.

• Journal of Microbiology
• /
• v.43 no.6
• /
• pp.510-515
• /
• 2005

The growth of red pepper plants was enhanced by treatment with the rhizobacterium, Bacillus cereus MJ-1. Red pepper shoots showed a 1.38-fold increase in fresh weight (fw) and roots showed a 1.28-fold fw gain. This plant growth-promoting rhizobacterium (PGPR) has been reported to produce gibberellins (GAs). Other GAs-producing rhizobacteria, Bacillus macroides CJ-29 and Bacillus pumilus CJ-69, also enhanced the fw of the plants. They were less effective than B. cereus MJ-1, though. The endogenous GAs content of pepper shoots inoculated with MJ-1 was also higher than in shoots inoculated with CJ-29 or CJ-69. When inoculated with MJ-1, bacterial colonization rate of the roots was higher than that of roots inoculated with CJ-29 or CJ-69. These results support the idea that the plant growth-promoting effect of the bacteria also positively related with the efficiency of root colonization by the bacteria. In addition, we identified the major endogenous GAs of the red pepper as originating from both the early C-13 hydroxylation and the early non C-13 hydroxylation pathways, with the latter being the predominant pathway of GA biosynthesis in red pepper shoots.

• Journal of Plant Biology
• /
• v.37 no.4
• /
• pp.397-402
• /
• 1994

Possible roles of polyamines in the inhibition of cell elongation in Ranunculus petioles were investigated. Exogenously apoplied polyamines greatly inhibited the auxin-induced petiole growth, while treatment of the tissue with $\alpha$-difluoromethylarginine, the inhibitor of putrescine biosynthesis, further enhanced the growth in the presence of IAA. Inhibitory effect of spermine can also be apparent for fusicoccin-induced elongation, but not for growth induced by a low pH. Spermine also suppressed the ethylene-enhanced growth in the presence of auxin. Using computer-based video digitizer system, the inhibitory effects of spermine on petiole growth were kinetically analyzed. Auxin-induced growth was characterized by an initial and transient growth with a highly elevated rate followed by a steady growth with a slightly reduced rate. Spermine treatment was found to shorten the duration of the initial phase of growth, and to reduce the rates of both the initial and steady growth as well. The latent period for auxin induction was not affected by spermine.

• The Plant Pathology Journal
• /
• v.31 no.3
• /
• pp.310-315
• /
• 2015

Certain bacterial species associate with plant roots in soil. The plant growth-promoting rhizobacteria (PGPR) stimulate plant growth and yield in greenhouse and field. Here, we examined whether application of known bacilli PGPR strains stimulated growth and asexual reproduction in the succulent plant Kalanchoe daigremontiana. Four PGPR strains B. amyloliquefaciens IN937a, B. cereus BS107, B. pumilus INR7, and B. subtilis GB03 were applied to young plantlets by soil-drenching, and plant growth and development was monitored for three months. Aerial growth was significantly stimulated in PGPR-inoculated plants, which was observed as increases in plant height, shoot weight, and stem width. The stimulated growth influenced plant development by increasing the total number of leaves per plant. Treatment with bacilli also increased the total root biomass compared with that of control plants, and led to a 2-fold increase in asexual reproduction and plantlet formation on the leaf. Collectively, our results firstly demonstrate that Bacillus spp. promote vegetative development of K. daigremontiana, and the enhanced growth stimulates asexual reproduction and plantlet formation.

• Korean Journal Plant Pathology
• /
• v.11 no.4
• /
• pp.292-297
• /
• 1995

We developed an in vitro assay method for evaluating plant growth promotion and providing an evidence that the growth promotion is rendered by growth enhancing factors. The amendment of culture filtrates of Trichoderma harzianum T95 and Gliocladium virens G872 and G872B in Murashige and Skoog (MS) agar medium enhanced the cotyledon growth of cucumber in terms of fresh weight and primary leaf area of cucumber cotyledon cuttings, of which the treatment of G. virens G872B was the most effective. The mycelial culture filtrate of G872B was more effective in the growth promotion than its conidial germling filtrate. The addition of 1% sucrose in MS mineral medium with 0.1% culture filtrates of the antagonists (T95 and G872B) was optimum for enhancing the effect of the filtrates on the growth of cotyledon cuttings in vitro. When cucumber seeds treated with G872B, Pseudomonas putida Pf3 or the G872B-Pf3 mixture were planted in a greenhouse, the rate of seed germination, biomass of shoot and root, and yield of cucumber fruits were increased, especially by G872B or the G872B-Pf3 mixture. Correspondingly, cucumber fruit yields in early to middle-cycles of harvest were significantly greater in the plots of G872B than the control and Pf3-treated plots, and the final yield was highest in the plots of the G872B-Pf3 mixture applications.

• Mycobiology
• /
• v.42 no.2
• /
• pp.158-166
• /
• 2014

In this study, bacterial strains were isolated from soils from 30 locations of Samcheok, Gangwon province. Of the isolated strains, seven showed potential plant growth promoting and antagonistic activities. Based on cultural and morphological characterization, and 16S rRNA gene sequencing, these strains were identified as Paenibacillus species. All seven strains produced ammonia, cellulase, hydrocyanic acid, indole-3-acetic acid, protease, phosphatase, and siderophores. They also inhibited the mycelial growth of Fusarium oxysporum f. sp. radicis-lycopersici in vitro. The seven Paenibacillus strains enhanced a range of growth parameters in tomato plants under greenhouse conditions, in comparison with non-inoculated control plants. Notably, treatment of tomato plants with one identified strain, P. polymyxa SC09-21, resulted in 80.0% suppression of fusarium crown and root rot under greenhouse conditions. The plant growth promoting and antifungal activity of P. polymyxa SC09-21 identified in this study highlight its potential suitability as a bioinoculant.

• Journal of Plant Biotechnology
• /
• v.50
• /
• pp.215-224
• /
• 2023

Disinfecting water containing pathogenic microbes is crucial to the food safety of fresh green agricultural products. The UV-activated peracetic acid (UV/PAA) treatment process is an efficient advanced oxidation process (AOP) and a versatile approach to disinfecting waterborne pathogens. However, its effects on plant growth remain largely unknown. This study found that low-dose UV/PAA treatment induced moderate oxidative stress but enhanced the innate immunity of Arabidopsis against Pseudomonas syringae pv. (Pst) DC3000. When applied as water sources, 5- and 10-ppm UV/PAA treatments slightly reduced biomass and root elongation in Arabidopsis seedlings grown under hydroponic conditions. Meanwhile, treatments of the same doses enhanced defense against Pst DC3000 infection in leaves. Accumulation of hydrogen peroxide and callose increased in UV/PAA-treated Arabidopsis samples, and during the post-infection period, UV/PAA-treated seedlings maintained vegetative growth, whereas untreated seedlings showed severe growth retardation. Regarding molecular aspects, priming-related defense marker genes were rapidly and markedly upregulated in UV/PAA-treated Arabidopsis samples. Conclusively, UV/PAA treatment is an efficient AOP for disinfecting water and protecting plants against secondary pathogenic attacks.

• Journal of Environmental Science International
• /
• v.7 no.4
• /
• pp.487-492
• /
• 1998

The experiment was conducted to determine the effects of enhanced UV-B on growth and differential responses among cultivars in soybean. The soybean cultivars subjected to enhanced UV-B irradiation at daily dose of 11.32 kJ $m^{-2}(UV-B_{BE})$ revealed that the growth was significantly depressed. Plant height, leaf number, leaf area and dry weight were inhibited by UV-B irradiation showing differential responses among cultivars used. Danyeubkong seems to be less sensitive to the enhanced W-B irradiation, while Keunolkong more sensitive. Reduction of chlorophyll content was also found significantly greater to Keunolkong. Specific leaf weight an index of leaf thickness, and flavonoid content known as UV-absorbing compounds were significantly Increased in Danyeubkong by UV-B, but those In the other cultivars were not significantly affected. The results indicated that there are cultivar diferences in tile growth and phisiological responses to the enhanced UV-B irradiation and specific leaf weight and UV-absorbing compounds in the leaves were highly related to the sensitivity of soybean by UV-B irradiation.

• KSBB Journal
• /
• v.13 no.5
• /
• pp.530-534
• /
• 1998

The addition of the ceramic powder as state of bare in culture medium has stimulated the growth of Achyranthes japonica in both the disorganized cell and the plantlet. The grwoth rate of Hyoscyamus niger adventitious root and Pylatycodon grandiflorum hairy root was enhanced up to 100 and 250%, respectively, even though Scopolia parviflora hairy root and Hyoscyamus albus adventitious root were not. The ceramic powder has enhanced the growth of H. niger adventitious root even in a test tube immersed into its culture medium to irradiate alone without any direct contact. The ceramic powder seems to have a significant role on both the growth and the physiological action of some plants.