• Plant Biotechnology Reports
• /
• 제5권2호
• /
• pp.169-175
• /
• 2011

In this study, the JIP test was exploited to assess drought-tolerance of transgenic rice overexpressing OsNAC10. Two types of promoters, RCc3 (root-specific) and GOS2 (constitutive), were used to drive the transcription factor OsNAC10, a gene involved in diverse functions including stress responses. Three-month-old plants were exposed to drought for 1 week and their fluorescence kinetics was evaluated. Our results showed that drought-treated non-transgenic plants (NT) have higher fluorescence intensity at the J phase (2 ms) compared to transgenic plants, indicating a decline in electron transport beyond the reduced plastoquinone ($Q_A^-$). As manifested by negative L bands, transgenic plants also showed higher energetic connectivity and stability over NT plants under drought conditions. Also, the pool size of the end electron acceptor at the photosystem I was reduced more in NT than in transgenic plants under drought conditions. Furthermore, the transgenic plants had higher $PI_{total}$, a combined parameter that reflects all the driving forces considered in JIP test, than NT plants under drought conditions. In particular, the $PI_{total}$ of the RCc3:OsNAC10 plants was higher than that of NT plants, which was in good agreement with their differences in grain yield. Thus, the JIP test proved to be practical for evaluating drought-tolerance of transgenic plants.

• Molecules and Cells
• /
• 제39권3호
• /
• pp.250-257
• /
• 2016

Abiotic stresses such as drought and low temperature critically restrict plant growth, reproduction, and productivity. Higher plants have developed various defense strategies against these unfavorable conditions. CaPUB1 (Capsicum annuum Putative U-box protein 1) is a hot pepper U-box E3 Ub ligase. Transgenic Arabidopsis plants that constitutively expressed CaPUB1 exhibited drought-sensitive phenotypes, suggesting that it functions as a negative regulator of the drought stress response. In this study, CaPUB1 was over-expressed in rice (Oryza sativa L.), and the phenotypic properties of transgenic rice plants were examined in terms of their drought and cold stress tolerance. Ubi:CaPUB1 T3 transgenic rice plants displayed phenotypes hypersensitive to dehydration, suggesting that its role in the negative regulation of drought stress response is conserved in dicot Arabidopsis and monocot rice plants. In contrast, Ubi:CaPUB1 progeny exhibited phenotypes markedly tolerant to prolonged low temperature ($4^{\circ}C$) treatment, compared to those of wild-type plants, as determined by survival rates, electrolyte leakage, and total chlorophyll content. Cold stress-induced marker genes, including DREB1A, DREB1B, DREB1C, and Cytochrome P450, were more up-regulated by cold treatment in Ubi:CaPUB1 plants than in wild-type plants. These results suggest that CaPUB1 serves as both a negative regulator of the drought stress response and a positive regulator of the cold stress response in transgenic rice plants. This raises the possibility that CaPUB1 participates in the cross-talk between drought and low-temperature signaling pathways.

• Molecules and Cells
• /
• 제21권3호
• /
• pp.389-394
• /
• 2006

Human seven-in-absentia (SIAH)-interacting protein (SIP) is a component of the E3 ligase complex targeting beta-catenin for destruction. Arabidopsis has one SIP protein (AtSIP) with 32% amino acid sequence identity to SIP. To investigate the functions of AtSIP, we isolated an atsip knockout mutant, and generated transgenic plants overexpressing AtSIP. The growth rates and morphologies of the atsip and transgenic plants were indistinguishable from those of wild type. However, atsip plants were more susceptible to Pseudomonas syringae infection, and the transgenic plants overexpressing AtSIP were more resistant. Consistent with this, RNA blot analysis showed that the AtSIP gene is strongly induced by wounding and hydrogen peroxide treatment. In addition, when plants were infected with P. syringae, AtSIP was transiently induced prior to PR-1 induction. These observations show that Arabidopsis AtSIP plays a role in resistance to pathogenic infection.

• Journal of Bio-Environment Control
• /
• 제10권3호
• /
• pp.197-206
• /
• 2001

The depletion of stratospheric ozone is regarded as a major environmental threat to plant growth and ecosystem. The ozone depletion has caused plants to be exposed to an increased penetration of solar ultraviolet-B (UV-B) radiation in the 280-320 nm wavelength range. Enhanced UV-B radiation may have influence on plants biological functions in many aspects including inhibition of photosynthesis, DNA damage, lipid peroxidation, changes in morphology, phenology, and biomass accumulation. To cope with the damage by UV radiation, plants have evolved to have protective mechanisms, such as photorepair, accumulation of UV-absorbing compounds, leaf thickening and activation of antioxidative enzymes. The objective of this review is to address the effects of enhanced UV-B on plant growth, UV-B action mechanisms and protection and protection mechanisms in plants.

• The Plant Pathology Journal
• /
• 제17권2호
• /
• pp.88-93
• /
• 2001

Oxidative stress is one of the major limiting factor in plant productivity. Reactive oxygens species (ROS) generated during metabolic processes damage cellular functions and consequently lead to disease, senescence and cell death. Plants have evolved an efficient defense system by which the ROS is scavenged by antioxidant enzymes such as superoxide dismutase (SOD) and ascorbate peroxidase (APX). Attempts to reduce oxidative damages under the stress conditions have included the manipulation of 갠 scavenging enzymes by gene transfer technology. Increased SOD activities of transgenic plants lead to increased resistance against oxidative stresses derived from methyl viologen (MV), and from photooxidative damage caused by high light and low temperature. Transgenic tobacco plants overexpressing APX showed reduced damage following either MV treatment of photooxidative treatment. Overexpression of glutathion reductase (GR) leads to increase in pool of ascorbate and GSH, known as small antioxidant molecules. These results indicate through overexpression of enzymes involved in ROS-scavenging could maintain or improve the plant productivities under environment stress condition. In this study, the rational approaches to develop stress-tolerant plants by gene manipulation of antioxidant enzymes will be introduced to provide solutions for the global food and environmental problems in the $21^\textrm{st}$ century.

• Korean Journal of Ecology and Environment
• /
• 제53권4호
• /
• pp.436-444
• /
• 2020

Airborne particulate matter (APM) is increasingly recognized that it has adverse impacts on environment and human public health. As plants can have a potential to reduce APM significantly by its deposition on leaves, considerable efforts has been made to use them as a biofilter. However, APM accumulation on plants can induce physiological and morphological alterations in plants. The present review aimed to synthesize the methods and results of the recent relevant research on interactions between plants and APM, especially from an ecological perspective, and briefly took into account the current status in Korea on this actively increasing research area.

• Nuclear Engineering and Technology
• /
• 제54권3호
• /
• pp.909-916
• /
• 2022

To study the developments and variations of unsafe behaviors in nuclear power plants thus reduce the possibility of human-related accidents, this paper, based on the Game Theory, focused on the changes in benefits of the Department of Management, Operational and Emergency in a nuclear power plant, and established the expected revenue functions of these departments. Additionally, the preventive measures of unsafe behaviors in nuclear power plants were also presented in terms of these 3 departments. Results showed that the violations of the Operation Department (OD) and the Emergency Department (ED) were not only relevant with the factors such as their own risks, costs, and the responsibility-sharing due to accidents, but also affected by the safety investments from the Management Department (MD). Furthermore, results also showed that the accident-induced responsibility-sharing of both the OD and the ED would rise, if the MD increased the investments in safety. As a result, the probability of violation behaviors of these 3 departments would be attenuated consciously, which would reduce the unsafe behaviors in the nuclear power plants significantly.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• 제8권5호
• /
• pp.19-27
• /
• 2005

The earth is a huge magnet. All organisms live under the magnetism of earth. The magnetism influences the ions in the cells of organisms and variously functions to lives as well. The medical treatment with magnet has come down from the ancient, it has an effect on the plants' growth. But there are no scientific studies about the influences of magnetism on plant growth. Accordingly, the experiment about the influence of magnetism on several foliage plants was carried out in this study. The promotion of plants' growth led by magnetism will be the method to save the management cost of horticultural market by early shipment. As a results of this experiment, plants treated with magnets showed excellent growth especially in length growth. The experiment results of the respective plants are the following. 1. Rhapis flabelliformis : This have grown so very well in the container lined with magnets as time goes by. Showing the significant(p<0.05) differences, the length growth of Height and Length of leaves was especially distinguished. 2. Howea belmoreana : This has grown well in all containers. Showing the significant(p<0.05) differences, the length growth of Height and Length of leaves was especially distinguished. 3. Chamaedorea seifrizii : There have been the growth differences between Height and Length of leaves as time goes by. The growth of Height and Length of leaves in the container lined with magnets has been excellent. The number of leaves and number of branch generally had no big differences but the growth of Height and Length of leaves was excellent in the magnet container. The method of plant growth promotion with magnet should save the management cost for this reason. Therefore the succeeding studies about the plant growth under the influence of magnet intensity and kind must be performed. The studies with various plants are needed to activate the program for growing plants with magnet.

• Journal of Plant Biotechnology
• /
• 제44권1호
• /
• pp.19-26
• /
• 2017

Rapid progress in epigenetic studies has resulted in genome wide information of genetic functions, other than DNA sequence information. However, insufficient understanding and unclear research direction in epigenetics has failed to attract many researchers. Here, we review the sexual reproduction processes that are particularly related to epigenetics in plants. We aim to elucidate the roles of epigenetic information and molecular mechanisms involved in the complex sexual reproduction process of plants, and examine their biological significance.

• Journal of Plant Biotechnology
• /
• 제4권4호
• /
• pp.135-141
• /
• 2002

Agrobacterium-mediated transformation has been unsuccessful for monocot plants except for a few important crops such as barley, rice, maize and wheat. We discussed here that a successful transformation of monocots demands certain critical conditions. The requirements for an efficient transformation are a selection of target tissues competent for plant regeneration and Agrobacterium-infection, and various factors promoting Agrobacterium-infection. The factors were divided into two to activate Agrobacterium and to increase plant cell's susceptibility against Agrobacterium. Optimization of these factors significantly increased transformation efficiency of zoysia grass and rice plants. A technical improvement in transformation system for monocots will promote improvement of the breed as well as a study of gene functions in monocots.