• Journal of Microbiology and Biotechnology
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• v.19 no.10
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• pp.1250-1258
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• 2009

Bacillus spp., as a type of plant growth-promoting rhizobacteria (PGPR), were studied with regards promoting plant growth and inducing plant systemic resistance. The results of greenhouse experiments with tobacco plants demonstrated that treatment with the Bacillus spp. significantly enhanced the plant height and fresh weight, while clearly lowering the disease severity rating of the tobacco mosaic virus (TMV) at 28 days post-inoculation (dpi). The TMV accumulation in the young non-inoculated leaves was remarkably lower for all the plants treated with the Bacillus spp. An RT-PCR analysis of the signaling regulatory genes Coil and NPR1, and defense genes PR-1a and PR-1b, in the tobacco treated with the Bacillus spp. revealed an association with enhancing the systemic resistance of tobacco to TMV. A further analysis of two expansin genes that regulate plant cell growth, NtEXP2 and NtEXP6, also verified a concomitant growth promotion in the roots and leaves of the tobacco responding to the Bacillus spp.

• Journal of Biosystems Engineering
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• v.43 no.1
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• pp.30-36
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• 2018

Purpose: The objective of this study is to evaluate the effect of cultivation conditions on the growth and glucosinolate content of Chinese cabbage and kale. Methods: Chinese cabbage and kale were grown in three different cultivation conditions, including a plant factory, greenhouse, and open field. Samples were collected at two harvesting times (10 d and 20 d after transplanting the seedlings). Nine growth parameters (plant height, plant width, number of leaves, petiole diameter, SPAD readout, leaf length, leaf width, stem diameter, and plant weight) were measured immediately after harvesting, and the samples were freeze-dried and stored until the glucosinolate content was analyzed. Mean values of the growth parameters and glucosinolate contents were evaluated using Duncan's multiple range tests. Results: The results indicated that the plant parameters of the Chinese cabbage and kale were greater for plants grown in the plant factory and greenhouse. The plant height, width, and weight showed significant differences in the Duncan's multiple range tests at a 5% level. The plant factory also produced greater contents of most of the glucosinolates. Conclusions: Three different cultivation conditions significantly affected the growth and glucosinolate contents of Chinese cabbage and kale. Further study is necessary to investigate other functional components and different vegetable varieties.

• Journal of Environmental Science International
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• v.15 no.2
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• pp.157-162
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• 2006

This experiment was carried out to investigate the effects of mercury and arsenic on the growth of Arabidopsis thaliana when treated with three different concentrations. When treated with mercury, there was no noticeable difference in the growth of the plant between the group treated with $0.5\;{\mu}g/L$ (the effluent standard established by the Ministry of Environment) and the group treated with the concentration 100 times higher. They both showed almost the same level of growth as that of the normal plant. But the group of the concentration 10 times higher showed significantly $10\%$ more growth compared with the normal plant. When treated with arsenic, the three different groups all showed a little more growth compared with the normal plant. Interestingly, the group of the concentration 10 times higher than the official standard concentration of arsenic $(50\;{\mu}g/L)$ showed the highest level of growth, significantly $20\%$ more than the normal plant. These results show that some amount of mercury and arsenic in the soil do not have much effect on the growth of Arabidopsis thaliana, and that optimum concentrations of mercury and arsenic can even stimulate the growth of the plant.

• Plant Biotechnology Reports
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• v.4 no.3
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• pp.179-183
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• 2010

Ethylene is a key gaseous hormone that controls various physiological processes in plants including growth, senescence, fruit ripening, and responses to abiotic and biotic stresses. In spite of some of these positive effects, the gas usually inhibits plant growth. While chemical fertilizers help plants grow better by providing soil-limited nutrients such as nitrogen and phosphate, overusage often results in growth inhibition by soil contamination and subsequent stress responses in plants. Therefore, controlling ethylene production in plants becomes one of the attractive challenges to increase crop yields. Some soil bacteria among plant growth-promoting rhizobacteria (PGPRs) can stimulate plant growth even under stressful conditions by reducing ethylene levels in plants, hence the term "stress controllers" for these bacteria. Thus, manipulation of relevant genes or gene products might not only help clear polluted soil of contaminants but contribute to elevating the crop productivity. In this article, the beneficial soil bacteria and the mechanisms of reduced ethylene production in plants by stress controllers are discussed.

• Korean Journal of Agricultural Science
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• v.50 no.4
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• pp.759-771
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• 2023

Plant growth-promoting rhizobacteria (PGPR) are naturally occurring bacteria that intensively colonize plant roots and are crucial in promoting the crop growth. These beneficial microorganisms have garnered considerable attention as potential bio-inoculants for sustainable agriculture. PGPR directly interacts with plants by providing essential nutrients through nitrogen fixation and phosphate solubilization and accelerating the accessibility of other trace elements such as Cu, Zn, and Fe. Additionally, they produce plant growth-promoting phytohormones, such as indole acetic acids (IAA), indole butyric acids (IBA), gibberellins, and cytokinins.PGPR interacts with plants indirectly by protecting them from diseases and infections by producing antibiotics, siderophores, hydrogen cyanide, and fungal cell wall-degrading enzymes such as glucanases, chitinases, and proteases. Furthermore, PGPR protects plants against abiotic stresses such as drought and salinity by producing 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase and modulating plant stress markers. Bacteria belonging to genera such as Bacillus, Pseudomonas, Burkholderia, Pantoa, and Enterobacter exhibit multiple plant growth-promoting traits, that can enhance plant growth directly, indirectly, or through synergetic effects. This comprehensive review emphasizes how PGPR influences plant growth promotion and presents promising prospects for its application in sustainable agriculture.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.53-53
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• 2022

Modem agricultural production needs to provide sustainable management practices that are eco-friendly and low cost. Plant extracts are a cost-effective and environmentally friendly alternative to synthetic plant growth regulators. This study was therefore carried out to investigate the effects of various plant extracts produced using different extraction methods on the vegetative growth of rice under laboratory and greenhouse conditions. For this study, seventeen plant extracts were made from plant species such as leaves of M. arvense, C. asiatica, M. oleifera, V. radiata, V. unguiculate, P. guajava, A. vera, and A. tuberosum, aboveground plant parts of C. rotundus, M. sativa, and P. frutescens, roots of R. undulatum, tubers of A. sativum, leaves and stems of G. max (cv. Taegwang) as well as rice straw and hulls (cv. Hopyeong). As a test crop, we applied these extracts to rice plants. For the purpose of making our extracts, some plant materials and species were collected in fields and others were purchased from Chonnam Hanyaknonghyup Cooperation (South Korea). Leaves, roots, and aboveground plant parts of plant species were dried, ground, extracted (water, boiling water and ethanol) and fermented. Rice growth promotion effects were determined using plant extracts at 0, 0.05, 0.1, 0.5, and 1% concentrations under petri dish conditions. Seven selected plant extracts were applied to rice seeds with soil drench application or seedling at 3-4 leaf stages with soil and foliar applications under greenhouse conditions. For comparison with extracts, we used urea at 0.6%. Of the 17 water extracts used in this study, 10 extracts reduced rice growth, but the other 7 extracts (P. guajava, A. vera, A. tuberosum, M. sativa, A. sativum, and G. max) increased growth by 40-60% on compared to the control in Petri dish bioassay. Thus, these 7 extracts were selected for further study. Under greenhouse conditions, rice growth also increased by 20-40% when the same 7 extracts were applied to rice seeds using soil drench application. Furthermore, at the 3-4 leaf stage rice growth also increased 30-80% or 30-60% when the same 7 extracts were applied using soil and foliar applications. Overall, the 7 extracts produced higher rates of growth promotion when soil drench application was used than when foliar application was used. In the case of boiling water and ethanol extracts, rice growth increased only 20% in response to both soil drench and foliar application of the same 7 extracts. Rice growth promotion was greater when extracts were produced using water extraction method than boiling water and ethanol extraction methods. Most notably, the 7 water extracts used in this study produced higher rates of growth promotion than urea at 0.6% which is typically used for crop growth promotion. Overall, the 7 water extracts when applied using soil drenching method can be used as effective growth promotors of rice in organic agriculture.

• Journal of Plant Biology
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• v.19 no.1
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• pp.1-6
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• 1976

This study was carried out to investigate the formation of precipitates between lead ion and the essential anions of plants, the effects of lead concentration on seed germination and plant growth in water and soil culture, and the germinating and growing recovery of inhibited seed germination and plant growth by lead. Four kinds of the seeds (Glycine max M., Triticum vulgare V., Setaria viridis (L) P. De Beauvois, and Digitoria sanguinalis (L) Scopoli var) were germinated and growth in water and soil culture included the different concentrations of lead for five days. The seeds and plants inhibited germination and growth by lead were transferred to lead free Hoagland solution and the growing recovery was observed. The precipitates of lead ion were observed in the solution of both acidity and alkalinity included each anion of $H_2PO_4^-, HPO_4^{2-}, PO_4^{3-}, SO_4^{2-} and MoO_4^{2-}$ in a room temperature, whereas the precipitates between lead ion and other anions were observed largely in the solution of alkalinity, so that it seemed that lead could be remained in the state of non-soluble in plant and soil. The inhibition of germination and growth in the water culture was observed in 100ppm of lead, whereas the inhibition in the case of the soil culture was observed in 10000ppm of lead. The difference of the effected concentration between water and soil culture in germination and the growth was 100 times. When the seed and plant inhibited the growth in 5000ppm or 10000ppm of lead for five days were transferred to lead free Hoagland solution, the recovery of germination and growth was observed in three days. This growing recovery was different according to the kinds of plant and concentrations of lead. It seemed that plant growth could be inhibited by the inhibition of the metabolism concerned with the precipitates between lead iion and other anions.

• Journal of Plant Biology
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• v.8 no.1_2
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• pp.5-10
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• 1965

The effect of radioactive sulfur-35 on the growth and tissue respiration in rye, Secale cereale L., seedlings were studied in this investigation. The growth and respiration rate of the materials treated with the different intensities of radioactivity, represented by the different concentration(${\mu}c$) of radioactive sulfur were shown similar effects in treated groups as those of Gamma-ray or X-ray irradiation on plant materials. However, in the groups of ($0.1{\mu}c$ and ($0.4{\mu}c$ S35-solution, the growth and respiration rate were stimulated somewhat more clearly than in case of control. And the higher concentration groups, $1.6{\mu}c$, $6.4{\mu}c$, and $25.6{\mu}c$ were depressed of the growth and tissue respiration rate. The present data could be explained on the basis that the higher concentration treatments with the radioactive isotope did produce injury to the plant metabolism generally, but the moderate treatment would stimulate to the plant growth and tissue respiration.

• Journal of Environmental Science International
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• v.27 no.10
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• pp.821-829
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• 2018

This study was conducted to examine the influence of Light-Emitting Diode (LED) light quality in urban agricultural plant factories on the growth and development of Seolhyang strawberry daughter plants in order to improve the efficiency of daughter plant growth and urban agriculture. LED light quality by demonstrated that above-ground growth and development were greatest for daughter plant 2. Daughter plant 1 showed the next highest growth and development, followed by daughter plant 3. Among the different qualities of LED light, the stem was thickest and growth rate of leaves was highest for R + B III (LED quality: red 660 nm + blue 450 nm/photosynthetic photon flux density (PPFD): $241-243{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$) and lowest for R (red $660nm/115-117{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$). Plant height, leaf width, petiole length, and the leaf growth rate were highest for W (white fluorescent lamp/$241-243{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$) and lowest for R + B I (red 660nm+blue 450nm/$80-82{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$). For above-ground growth and development, as the plants surpassed the seedling age, mixed light (red + blue), rather than monochromatic light (red or blue), and higher PPFD values tended to increase development. Regarding the quality of the LED light, daughter plant 2 showed the highest chlorophyll content, followed by daughter plant 1, and daughter plant 3 showed the least chlorophyll content. When the wavelength was monochromatic, chlorophyll content increased, compared to that when PPFD values were increased. Mixed light vitality was highest in daughter plant 2, followed by 1, and 3, showed increased photosynthesis when PPFD values were high with mixed light, in contrast to the results observed for chlorophyll content.

• Journal of Plant Biotechnology
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• v.33 no.4
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• pp.257-262
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• 2006

The paper evaluated the behavior of in vitro culture responses from a diverse set of Indica rice (Oryza sativa L.) genotypes. Significant differences were found in embryogenic callus induction frequency, callus growth and plant regeneration frequency when mature embryos of 11 cultivars, breeding lines and land races were compared. Genotype as well as plant growth regulator influenced the plant regeneration frequency. Callus induction frequency was not correlated with callus growth as well as plant regeneration frequency. The regenerated plants could grow to normal, fertile plants after they were successfully established in soil.