Current Issue 2021. Vol.40, Iss.1

Orginal Articles

• Identification of G Protein Coupled Receptors Expressed in Fat Body of Plutella Xylostella in Different Temperature Conditions

  Kwang Ho Kim, Dae-Weon Lee / Korean Journal of Environmental Agriculture / 2021 / v.40, no.1, 1-12

  https://doi.org/10.5338/KJEA.2021.40.1.1

  Abstract Full-Text PDF

  Abstract

  

  BACKGROUND:

  G protein-coupled receptors (GPCRs) are widely distributed in various organisms. Insect GPCRs shown as in vertebrate GPCRs are membrane receptors that coordinate or involve in various physiological processes such as learning/memory, development, locomotion, circadian rhythm, reproduction, etc. This study aimed to identify GPCRs expressed in fat body and compare the expression pattern of GPCRs in different temperature conditions.

  METHODS AND RESULTS:

  To identify GPCRs genes and compare their expression in different temperature conditions, total RNAs of fat body in Plutella xylostella larva were extracted and the transcriptomes have been analyzed via next generation sequencing method. From the fat body transcriptomes, genes that belong to GPCR Family A, B, and F were identified such as opsin, gonadotropinreleasing hormone receptor, neuropeptide F (NPF) receptor, muthuselah (Mth), diuretic hormone receptor, frizzled, etc. Under low temperature, expressions of GPCRs such as C-C chemokine receptor (CCR), opsin, prolactin-releasing peptide receptor, substance K receptor, Mth-like receptor, diuretic hormone receptor, frizzled and stan were higher than those at 25℃. They are involved in immunity, feeding, movement, odorant recognition, diuresis, and development. In contrast to the control (25℃), at high temperature GPCRs including CCR, gonadotropin-releasing hormone receptor, moody, NPF receptor, neuropeptide B1 receptor, frizzled and stan revealed higher expression whose biological functions are related to immunity, blood-brain barrier formation, feeding, learning, and reproduction.

  CONCLUSION:

  Transcriptome of fat body can provide understanding the pools of GPCRs. Identifications of fat body GPCRs may contribute to develop new targets for the control of insect pests.

• Photodegradation of Mixtures of Tetracycline, Sulfathiazole, and Triton X-100 in Water

  Seong Ho Yun, Sungjong Lee, Eun Hea Jho, Joon-Kwan Moon / Korean Journal of Environmental Agriculture / 2021 / v.40, no.1, 13-19

  https://doi.org/10.5338/KJEA.2021.40.1.2

  Abstract Full-Text PDF

  Abstract

  

  BACKGROUND:

  Chemicals such as antibiotics and surfactants can enter agricultural environment and they can be degraded by natural processes such as photolysis. These chemicals exist in mixtures in the environment, but studies on degradation of the mixtures are limited. This study compares the photodegradation of Triton X-100 (TX) and antibiotics [tetracycline (TC) and sulfathiazole (STH)] when they are in a single solution or in mixtures.

  METHODS AND RESULTS:

  TC, STH, and TX solutions were exposed to UV-A for the photodegradation tests for 14 days. The residual TC, STH, and TX concentrations were analyzed by using HPLC. The TC degradation was similar regardless of the presence of TX, while the TX degradation was lower in the presence of TC. The STH degradation was similar regardless of the presence of TX, while the TX degradation was greater in the presence of STH. However, the STH degradation was slower in the TC-STH-TX mixture than in the STH-TX mixture. Also, the TX degradation was negligible in the TC-STH-TX mixture. The results show that the photodegradation of TC, STH, and TX can be different in mixtures. This can be attributed to the different emission and absorption wavelengths of each compound and interaction between these compounds and photoproducts.

  CONCLUSION:

  Overall, this study emphasizes that photodegradation of single chemicals and chemical mixtures can be different, and more studies on single compounds as well as mixtures are required to understand the fate of chemicals in the environment in order to manage them properly.

• Antibacterial Activity of Streptomyces sp. J46 against Bacterial Shot Hole Disease Pathogen Xanthomonas arboricola pv. pruni

  Jeong Eun Lee, Da Jung Lim, In Seon Kim / Korean Journal of Environmental Agriculture / 2021 / v.40, no.1, 20-32

  https://doi.org/10.5338/KJEA.2021.40.1.3

  Abstract Full-Text PDF

  Abstract

  

  BACKGROUND:

  Bacterial shot hole of stone fruits is a seriuos plant disease caused by Xanthomonas arboricola pv. pruni (Xap). Techniques to control the disease are required. In this study, microorganisms with antibacterial activity were isolated to develop as a microbial agent against the bacterial shot hole.

  METHODS AND RESULTS:

  An isolate with the strongest activity among the isolates was identified as Streptomyces avidinii based on 16S rRNA gene sequence analysis and designated Streptomyces sp. J46. J46 showed suppression of bacterial leaf spot with a control value of 90% at 10 times-diluted cell free supernatant. To investigate antibacterial metabolites produced by J46, the supernatant of J46 was extracted with organic solvents, and the extracts were subjected to chromatography works. Antibacterial metabolites were not extractable with organic solvents. Both reverse and normal phase techniques were not successful because the metabolites were extremely water soluble. The antibacterial metabolites were not volatiles but protein compounds based on hydrolysis enzyme treatment.

  CONCLUSION:

  Our study suggests that Streptomyces sp. J46 may be a potential as an microbial agent against bacterial shot hole. Further study to identify the metabolites is required in more detail.

• Effects of Phosphogypsum Application on Field Soil Properties and Yield and Quality of Garlic (Allium sativum L.)

  Young-Nam Kim, Ju Young Cho, Young-Eun Yoon, Hyoen Ji Choe, Mi Sun Cheong, Mina Lee, Kwon-Rae Kim, Yong Bok Lee / Korean Journal of Environmental Agriculture / 2021 / v.40, no.1, 33-39

  https://doi.org/10.5338/KJEA.2021.40.1.4

  Abstract Full-Text PDF

  Abstract

  

  BACKGROUND:

  Globally, large amounts of phosphogypsum (PG), which is a by-product of the phosphate fertilizer production, is deposited in open areas. As PG contains calcium, phosphate, and sulphate, it can be used as a soil amendment in farmlands. This study was conducted to investigate the effects of PG application on properties of field soil and yield and quality of garlic (Allium sativum L.), and to seek appropriate level of PG application into the field.

  METHODS AND RESULTS:

  This experiment was conducted by applying PG at four different levels that were adjusted based on 65% calcium base saturation in the field soil: 0% (control), 50% (PG50, 100 kg/10a), 100% (PG100, 200 kg/10a), and 150% (PG150, 300 kg/10a). Following cultivation, soil electrical conductivity (EC), organic matter, available P and exchangeable Ca increased, whilst soil pH decreased. With increase in PG application level, soil EC and exchangeable Ca increased. PG application increased concentrations of water soluble Ca and SO4 across the soil profile, especially in PG150. The highest yield of garlic was found in PG100 treatment. The plant’s uptake for N, P, Ca, and S increased by PG applications, but that for K decreased. Moreover, concentrations of S-related amino acids such as cysteine and methionine in garlic increased by PG applications. The increased content of nutrients and amino acids with PG supply might improve yield, quality, and favor of the crop.

  CONCLUSION:

  Overall, PG application at 200 kg/10a into a field had the best effect on improving soil fertility as well as yield and quality of garlic. Further studies are required to maximize efficiencies of PG supply in soil management and production of various crops.

• Characteristics and Mechanisms of Phosphate Sorption by Calcined Oyster Shell

  Jong-Hwan Park, Jae-Young Heo, Su-Lim Lee, Jae-Hoon Lee, Se-Wook Hwang, Hyeon-Ji Cho, in-Hyeuk Kwon, Young-Ho Chang, Dong-Cheol Seo / Korean Journal of Environmental Agriculture / 2021 / v.40, no.1, 40-48

  https://doi.org/10.5338/KJEA.2021.40.1.5

  Abstract Full-Text PDF

  Abstract

  

  BACKGROUND:

  Although the calcined oyster shell can be used as a calcium-rich adsorbent for phosphate removal, information about it is limited. The purpose of this study was to evaluate the phosphate adsorption characteristics and its mechanism using calcined oyster shells.

  METHODS AND RESULTS:

  In this study, calcined oyster shell (C-OS600) was prepared by calcining oyster shells (P-OS) at 600℃ for 20 min. Phosphate adsorption by C-OS600 was performed under various environmental conditions. Phosphate adsorption by C-OS600 occurred rapidly at the beginning of the reaction, and the time to reach equilibrium was less than 1 h. The optimal isotherm and kinetic models for predicting the adsorption of phosphate by C-OS600 were the Langmuir isotherm and pseudo-second order kinetic model, respectively, and the maximum adsorption capacity derived from the Langmuir isotherm was 68.0 mg/g. The adsorption properties of phosphate by C-OS600 were dominantly influenced by the initial pH and C-OS600 dose. In addition, SEM-EDS and FTIR analysis clearly showed a difference in C-OS600 before and after phosphate adsorption, which proved that phosphate was adsorbed on the surface of C-OS600.

  CONCLUSION:

  Overall, the calcined oyster shell can be considered as an useful and effective adsorbent to treat wastewater containing phosphate.

• Assessment of Rhizosphere Microbial Community Structure in Tomato Plants after Inoculation of Bacillus Species for Inducing Tolerance to Salinity

  Sung-Je Yoo, Shin Ae Lee, Hang-Yeon Weon, Jaekyeong Song, Mee Kyung Sang / Korean Journal of Environmental Agriculture / 2021 / v.40, no.1, 49-59

  https://doi.org/10.5338/KJEA.2021.40.1.6

  Abstract Full-Text PDF

  Abstract

  

  BACKGROUND:

  Soil salinity causes reduction of crop productivity. Rhizosphere microbes have metabolic capabilities and ability to adaptation of plants to biotic and abiotic stresses. Plant growth-promoting bacteria (PGPB) could play a role as elicitors for inducing tolerance to stresses in plants by affecting resident microorganism in soil. This study was conducted to demonstrate the effect of selected strains on rhizosphere microbial community under salinity stress.

  METHODS AND RESULTS:

  The experiments were conducted in tomato plants in pots containing field soil. Bacterial suspension was inoculated into three-week-old tomato plants, one week after inoculation, and -1,000 kPa-balanced salinity stress was imposed. The physiological and biochemical attributes of plant under salt stress were monitored by evaluating pigment, malondialdehyde (MDA), proline, soil pH, electrical conductivity (EC) and ion concentrations. To demonstrate the effect of selected Bacillus strains on rhizosphere microbial community, soil microbial diversity and abundance were evaluated with Illumina MiSeq sequencing, and primer sets of 341F/805R and ITS3/ITS4 were used for bacterial and fungal communities, respectively. As a result, when the bacterial strains were inoculated and then salinity stress was imposed, the inoculation decreases the stress susceptibility including reduction in lipid peroxidation, enhanced pigmentation and proline accumulation which subsequently resulted in better plant growth. However, bacterial inoculations did not affect diversity (observed OTUs, ACE, Chao1 and Shannon) and structure (principle coordinate analysis) of microbial communities under salinity stress. Furthermore, relative abundance in microbial communities had no significant difference between bacterial treated- and untreated-soils under salinity stress.

  CONCLUSION:

  Inoculation of Bacillus strains could affect plant responses and soil pH of tomato plants under salinity stress, whereas microbial diversity and abundance had no significant difference by the bacterial treatments. These findings demonstrated that Bacillus strains could alleviate plant’s salinity damages by regulating pigments, proline, and MDA contents without significant changes of microbial community in tomato plants, and can be used as effective biostimulators against salinity stress for sustainable agriculture.

• Transition Characteristics and Risk Assessment of Heavy Metal(loid)s in Barley (Hordeum vulgare L.) Grown at the Major Producing Districts in Korea

  Da-Young Kim†, Won-Il Kim†, Ji-Hyock Yoo, Oh-Kyung Kwon, Il Kyu Cho / Korean Journal of Environmental Agriculture / 2021 / v.40, no.1, 60-66

  https://doi.org/10.5338/KJEA.2021.40.1.7

  Abstract Full-Text PDF

  Abstract

  

  BACKGROUND:

  The concern over heavy metal(loid)s in arable land and agricultural products increases for public health in recent years. This study aims to identify transition characteristics of heavy metal(loid)s and to assess dietary risk in barley grown at the major producing districts in Korea.

  METHODS AND RESULTS:

  The soil and barley samples were collected from 38 locations around the major producing districts at Jeollabuk-do in Korea for the propose of examining the concentrations of heavy metal(loid)s. The 34 barley samples were separately purchased on the market for the same survey. The average concentration and range of arsenic (As), cadmium (Cd) and lead (Pb) in barley grown at the major producing districts in Korea were 0.037 (0.016-0.094), 0.028 (0.004-0.083) and 0.137 (0.107-0.212) mg kg^-1, respectively. Currently, the maximum allowable level for barley Pb is set at 0.2 mg kg^-1 in Korea, and the monitoring results suggested that some samples exceeded the maximum allowable level and required appropriate farming management. Bio-concentration factor values by heavy metal(loid)s in barley were high at Cd, copper (Cu) and zinc (Zn), similar to other crops, while As and Pb were low, indicating low transferability.

  CONCLUSION:

  Human exposure to As, Cd and Pb through dietary intake of barley might not cause adverse health effects due to relatively low concentrations, although the Pb in some barley was detected higher than the maximum allowable level. Further study on uptake and accumulation mechanism of Pb by barley might be required to assess the human health risk associated with soil contamination.

• Reduction of Dissolved Fe(III) by As(V)-tolerant Bacteria Isolated from Rhizosphere Soil

  Anamika Khanal, Yoonjin Song, Ahyeon Cho, Ji-Hoon Lee / Korean Journal of Environmental Agriculture / 2021 / v.40, no.1, 67-72

  https://doi.org/10.5338/KJEA.2021.40.1.8

  Abstract Full-Text PDF

  Abstract

  

  BACKGROUND:

  Biological iron redox transformation alters iron minerals, which may act as effective adsorbents for arsenate [As(V)] in the environments. In the viewpoint of alleviating arsenate, microbial Fe(III) reduction was sought under high concentration of As(V). In this study, Fe(III)-reducing bacteria were isolated from the wild plant rhizosphere soils collected at abandoned mine areas, which showed tolerance to high concentration of As(V), in pursuit of potential agents for As(V) bioremediation.

  METHODS AND RESULTS:

  Bacterial isolation was performed by a series of enrichment, transfer, and dilutions. Among the isolated strains, two strains (JSAR-1 and JSAR-3) with abilities of tolerance to 10 mM As(V) and Fe(III) reduction were selected. Phylogenetic analysis using 16S rRNA genesequences indicated the closest members of Pseudomonas stutzeri DSM 5190 and Paenibacillus selenii W126, respectively for JSAR-1 and JSAR-3. Ferric and ferrous iron concentrations were measured by ferrozine assay, and arsenic concentration was analyzed by ICP-AES, suggesting inability of As(V) reduction whereas ability of

  CONCLUSION:

  Fe(III)-reducing bacteria isolated from the enrichments with arsenate and ferric iron were found to be resistant to a high concentration of As(III) at 10 mM. We suppose that those kinds of microorganisms may suggest good application potentials for As(V) bioremediation, since the bacteria can transform Fe while surviving under Ascontaminated environments. The isolated Fe(III)-reducing bacterial strains could contribute to transformations of iron minerals which may act as effective adsorbents for arsenate, and therefore contribute to As(V) immobilization