• 한국생물공학회:학술대회논문집
• /
• 2001.11a
• /
• pp.189-192
• /
• 2001

We have investigated the effects of abiotic and biotic stresses on leaf senescence using transgenic tobacco plants, in which cellular contents of polyamines were increased by introducing the genes of polyamine and ethylene biosynthesis in sense or antisense orientation. These transgenic plants showed accumulations of polyamines at higher levels than were found in wild-type. Stress-induced senescence was attenuated in transgenic plants cpmpared with wild-type plants, in terms of total chlorphyll loss and phenotypic changes after oxidative stress of hydrogen peroxide($H_2O_2$), high salinity, acid stress (pH3.0), ABA and fungal pathogen(phytophothora parasitica pv.Nicotianae). Transcripts for antioxidant enzyme, glutathionine-S-transferase and catalase, were also more abundant in transgenic plants than wild-type plants. These result suggested that higher expression of those genes caused a broad-spectrum resistance to abiotic stress/biotic stress. These phenomena indicate that polyamines may play an important role in contributing to the antioxidant defense function in plants. Our findings suggest that facilitate the improvement of stress tolerance of crop plants.

• The Plant Pathology Journal
• /
• v.28 no.1
• /
• pp.107-113
• /
• 2012

Trichomes are specialized epidermal structure having the functions of physical and chemical block against biotic and abiotic stresses. Several studies on $Capsicum$ species revealed that virus and herbivore resistance is associated with trichome-formation. However, there is no research on the structural characterization of trichomes developed on the epidermis of $Capsicum$ spp. Thus, this study attempts to charaterize the trichome morphologies in 5 species of $Capsicum$ using a Field Emission Scanning Electron Microscopy (FESEM). Six main trichome types were identified by their morphology under FESEM. Both glandular and non-glandular types of trichomes were developed on the epidermal tissues of $Capsicum$ spp. The glandular trichome were further classified into type I, IV and VII according to their base, stalk length, and stalk. Non-glandular trichomes were also classified into type II, III, and V based on stalk cell number and norphology. Almost all the species in $C.$ $chinense$ and $C.$ $pubescens$ had glandular trichomes. To our knowledge, this is the first study on classification of trichomes in the genus $Capsicum$ and, our results could provide basic informations for understanding the structure and function of trichomes on the epidermal differentiation and association with biotic stress tolerance.

• Proceedings of the Korean Society of Plant Biotechnology Conference
• /
• 2005.11a
• /
• pp.228-228
• /
• 2005

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2021.10a
• /
• pp.227-227
• /
• 2021

• The Plant Pathology Journal
• /
• v.26 no.2
• /
• pp.110-114
• /
• 2010

WRKY transcription factors are known to be involved in many different biological processes including plant response to biotic stress, abiotic stress, and plant development. WRKY proteins are extensively studied in Arabidopsis. Recently, reports on WRKY proteins are rapidly increasing in the other plant species, especially in rice. Therefore, this review will discuss the function of rice WRKY proteins reported so far.

• Animal Bioscience
• /
• v.35 no.9
• /
• pp.1434-1443
• /
• 2022

Objective: This study was designed to investigate the hypothesis that dietary quercetin (QUE) and coated sodium butyrate (SB) supplementation alleviate oxidative stress in the small intestine of diquat (DIQ)-challenged pullets. Methods: A total of 200 13-week-old pullets were divided into four groups: the control group (CON), the DIQ group, the QUE group, and the coated SB group, and injected intraperitoneally with either saline (CON) or diquat (DIQ, QUE, and SB) to induce oxidative stress on day 0. Results: On the first day, the malondialdehyde and superoxide dismutase (SOD) concentrations in the SB group were significantly different from those in the DIQ and QUE groups (p<0.05), and dietary supplementation with SB increased serum glutathione peroxidase (GSH-PX) levels compared with the DIQ group (p<0.05). Quercetin and SB increased the levels of CLAUDIN-1 and zonula occludens-1 (ZO-1) in the jejunum. On the tenth day of treatment, QUE attenuated the decrease in GSH-PX levels compared to those of the CON group (p<0.05), while SB increased SOD, GSH-PX, and total antioxidant capacity levels compared to those of the DIQ group. Nuclear factor erythroid 2-related factor 2 (NRF2) and heme oxygenase-1 (HO-1) mRNA levels in the QUE and SB groups increased (p<0.05) and CLAUDIN-1 mRNA levels in the QUE and SB groups were upregulated compared to those in the DIQ group ileum tissue. Conclusion: Supplementation of QUE and SB demonstrated the ability to relieve oxidative stress in pullets post DIQ-injection with a time-dependent manner and QUE and SB may be potential antioxidant additives for relieving oxidative stress and protecting the intestinal barrier of pullets.

• Proceedings of the Korean Society of Plant Pathology Conference
• /
• 2003.10a
• /
• pp.77.2-78
• /
• 2003

An EREBP/AP2-type transcription factor (CaPFl) was isolated by DDRT-PCR following inoculation of soybean pustule pathogen Xanthomonas axonopodis pv. glycines Bra which induces HR on pepper leaves. Genomic Southern blot analysis revealed that the CaPFl gene is present as a single copy within the hot pepper genome. The deduced amino acid sequence of CaPFl has two potential nuclear localization signals, a possible acidic activation domain, and an EREBP/AP2 motif that could bind to a conserved cis- element present in promoter region of many stress-induced genes. The mRNA level of CaPFl was induced by both biotic and abiotic stresses. We observed higher-level transcripts in resistance-induced pepper tissues than diseased tissues. Expression of CaPFl is also induced upon various abiotic stresses including ethephon, MeJA, cold stress, drought stress and salt stress treatments. To study the role of CPFI in plant, transgenic Arabidopsis and tobacco plants which express higher level of pepper CaPFl were generated. Global gene expression analysis of transgenic Arabidopsis by cDNA microarray indicated that expression of CaPFl in transgenic plants affect the expression of quite a few GCC box and DRE/CRT box-containing genes. Furthermore, the transgenic Arabidopsis and tobacco plant, expressing CaPFl showed tolerance against freezing temperature and enhanced resistance to Pseudomonas syrnigae pv. tabaci. Taken together, these results indicated that CaPFl is a novel EREBP/AP2 transcription factor in hot pepper plant and it may has a significant role(s) in regulation of biotic and abiotic stresses in plant.

• Proceedings of the Plant Resources Society of Korea Conference
• /
• 2011.10a
• /
• pp.14-14
• /
• 2011

Polyamines (putrescine, spermidine and spermine) play pivotal roles in plant defense to different abiotic and biotic stresses. In order to understand the function of ginseng spermidine synthase gene, a key gene involved in biosynthesis of polyamines, transgenic plant was generated in Arabidopsis. The transgenic plants exhibited high levels of polyamines compared to the untransformed control plants. We investigated the tolerance capacity of transgenic plants to abiotic stresses such as salinity and copper stress. In addition, transgenic plants also showed increased resistance against one of the important fungal pathogens of ginseng, the wilt causing Fusarium oxysporum and one of important bacteria, bacterial blight causing Pseudomonas syringae. However, an activity of the polyamine catabolic enzyme, diamine oxidase (DAO) was increased significantly in F. oxysporum and P. syringae infected transgenic plant. Polyamine catabolic enzymes which may trigger the hypersensitive response (HR) by producing hydrogen peroxide ($H_2O_2$) seem act as an inducer of PR proteins, peroxidase and phenyl ammonium lyase activity. The transgenic plants also contained higher antioxidant enzyme activities, less MDA and $H_2O_2$ under salt and copper stress than the wild type, implying it suffered from less injury. These results strongly suggest an important role of spermidine as a signaling regulator in stress signaling pathways, leading to build-up of stress tolerance mechanisms.

• Korean Journal of Medicinal Crop Science
• /
• v.12 no.5
• /
• pp.360-365
• /
• 2004

Rehmannia glutinosa shows a high level of resistance to the non-selective herbicide paraquat. To characterize the antioxidant enzyme system of R. glutinosa, we comparatively examined the responses of antioxidant enzymes to UV, wounding and a general elicitor yeast extract in R. glutinosa and soybean. The levels of enzyme activities of the two plant species were drastically different between those per fresh weight (general activity) and per protein (specific activity) bases. The general activities of superoxide dismutase (SOD), peroxidase (POX), catalase (CAT), and glutathione reductase (GR) were lower, but that of ascorbate peroxidase (APX) was higher in R. glutinosa than in soybean. The specific activities of the enzymes, however, were about two- to seven-fold higher in R. glutinosa than in soybean, except that of CAT, which was about 12-fold higher in soybean. The general and specific enzyme activities of R. glutinosa relative to those of soybean showed a consistent increase in responses to the stresses only in SOD. The specific activities of SOD and APX were higher in R. glutinosa in all stress treatments. The results might suggest a relatively higher contribution of SOD and APX to the stress tolerance.

• Journal of Plant Biotechnology
• /
• v.4 no.2
• /
• pp.53-58
• /
• 2002

Adverse environmental conditions such as drought, high salt and cold/freezing are major factors that reduces crop productivity worldwide. According to a survey, 50-80% of the maximum potential yield is lost by these "environmental or abiotic stresses", which is approximately ten times higher than the loss by biotic stresses. Thus, improving stress-tolerance of crop plants is an important way to improve agricultural productivity, In order to develop such stress-tolerant crop plants, we set out to identify key stress signaling components that can be used to develop commercially viable crop varieties with enhanced stress tolerance. Our primary focus so far has been on the identification of transcription factors that regulate stress responsive gene expression, especially those involved in ABA-mediated stress response. Be sessile, plants have the unique capability to adapt themselves to the abiotic stresses. This adaptive capability is largely dependent on the plant hormone abscisic acid (ABA), whose level increases under various stress conditions, triggering adaptive response. Central to the response is ABA-regulated gene expression, which ultimately leads to physiological changes at the whole plant level. Thus, once identified, it would be possible to enhance stress tolerance of crop plants by manipulating the expression of the factors that mediate ABA-dependent stress response. Here, we present our work on the isolation and functional characterization of the transcription factors.n factors.