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Use of plant growth-promoting rhizobacteria to control stress responses of plant roots
Kang, Bin-Goo,Kim, Woo-Taek,Yun, Hye-Sup,Chang, Soo-Chul The Korean Society of Plant Biotechnology 2010 Plant biotechnology reports Vol.4 No.3
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.
스마트온실의 에너지 분석 모델 개발 및 냉방 패키지 성능 분석
구자빈(Goo Ja-Bin),신학종(Shin Hak-jong),곽영훈(Kwak Young-Hoon),허정호(Huh Jung-Ho) 한국태양에너지학회 2021 한국태양에너지학회 논문집 Vol.41 No.6
Through active cooling, smart farms equipped with environmental control systems can overcome the limitations of existing greenhouses that are closed due to heat damage in summer. The control system can extend the crop harvest period by maintaining growth temperature and maintain fixed crop quality throughout the year. Accordingly, there is an increasing need for a cooling performance analysis model for smart farm cooling system applications. Therefore, in this study, a cooling package applicable to greenhouses was proposed, and the energy consumption of the cooling package was analyzed using EnergyPlus. Through consideration and analysis of previous studies, three cooling packages, which included natural ventilation and shading – basic cooling methods – were set up. A greenhouse energy model was developed for a smart farm in Naju. Prior to modeling the cooling packages, the predicted temperature and relative humidity performance of the greenhouse model was verified based on 24-hour measurement data from 9/16 to 9/17 for greenhouses without cooling. The greenhouse model showed performance that satisfied the recommended error value of MBE = -5.8, -6.3% and Cv(RMSE) = 8.7, 8.9% at the dry bulb temperature and relative humidity, respectively. On the basis of the verified model, plant evapotranspiration was simulated using the Stanghellini model, and cooling performance was analyzed using the three cooling package models. Package 1 showed an energy consumption of 20 W/㎡, which is advantageous in terms of energy cost, but cannot maintain an appropriate growth environment. Packages 2 and 3 were found to be disadvantageous in terms of energy cost because of their relatively high energy consumption, but could be advantageous in maintaining growth temperature.
벤로형 온실의 냉방설비 패키지 적용 타당성 분석도구 개발
구자빈(Ja Bin Goo),신학종(Hak Jong Shin),곽영훈(Young Hoon Kwak),허정호(Jung Ho Huh) 대한설비공학회 2021 대한설비공학회 학술발표대회논문집 Vol.2021 No.6
Due to the high temperature and humid summer temperatures in Korea, most of them are closed because they cannot maintain the proper growing environment of cultivated crops. Therefore, the need for cooling systems such as heat pump is increasing along with cooling using facility elements such as shading screens and ventilation windows to suppress high-temperature damage and grow throughout the year. Accordingly, in this work, we aimed to present a tool to form applicable cooling packages to maintain an appropriate growth environment in greenhouses and analyze the feasibility of package application based on energy requirements and cost aspects of cooling packages. In this work, three applicable cooling packages were formed to maintain the proper growth environment of greenhouses, and each package was combined with conditions by scale, region, crop, and covering materials to form a total of 1,296 simulation data. Based on this, we present a feasibility analysis program for package application under each condition by utilizing EXCEL to present the thermal environment, energy requirements and performance results of greenhouses. It is believed to be able to help fundamental energy-efficient greenhouse operations in that it enables a brief primary feasibility analysis for real farmers or non-experts who are difficult to utilize energy simulations.
Hyun Woo Goo,Dong Hun Kim,Seoung Soo Lee,Sung Bin Park,Tae-Hwan Lim 대한영상의학회 2002 Korean Journal of Radiology Vol.3 No.4
Objective: To determine whether the size of a perfusion defect seen at myocardial perfusion MR imaging represents the extent of irreversibly damaged myocardium in acute reperfused myocardial infarction. Materials and Methods: In nine cats, reperfused myocardial infarction was induced by occlusion of the left anterior descending coronary artery for 90 minutes and subsequent reperfusion for 90 minutes. At single-slice myocardial perfusion MR imaging at the midventricular level using a turbo-FLASH sequence, 60 short-axis images were sequentially obtained with every heart beat after bolus injection of gadomer-17. The size of the perfusion defect was measured and compared with both the corresponding unstained area seen at triphenyl tetrazolium chloride (TTC) staining and the hyperenhanced area seen at gadophrin-2-enhanced MR imaging performed in the same cat six hours after myocardial perfusion MR imaging. Results: The sizes of perfusion defects seen at gadomer-17-enhanced perfusion MR imaging, unstained areas at TTC staining, and hyperenhanced areas at gadophrin-2-enhanced MR imaging were 20.4±4.3%, 29.0±9.7%, and 30.7±10.6% of the left ventricular myocardium, respectively. The perfusion defects seen at myocardial perfusion MR imaging were significantly smaller than the unstained areas at TTC staining and hyperenhanced areas at gadophrin-2- enhanced MR imaging (p < .01). The sizes of both the perfusion defect at myocardial perfusion MR imaging and the hyperenhanced area at gadophrin-2-enhanced MR imaging correlated well with the sizes of unstained areas at TTC staining (r = .64, p = .062 and r = .70, p = .035, respectively). Conclusion: In this cat model, the perfusion defect revealed by myocardial perfusion MR imaging underestimated the true size of acute reperfused myocardial infarction. The defect may represent a more severely damaged area of infarction and probably has prognostic significance.