• Korean Journal of Medicinal Crop Science
• /
• v.6 no.1
• /
• pp.11-15
• /
• 1998

This experiment was conducted to investigate the soil temperature. the characteristics of seedling growth and drought resistance of Job's tears under different seeding depth. The changes of soil temperature were similar to the patterns of atmosphere temperature. and the minimum and maximum temperature of the day were at 08: 00 and 16: 00 hours, respectively, and this was 1 hour late compared to the atmospheric temperature. In mean temperature under different soil depth, 3cm and 4cm soil depth were the same as $27.3^{\circ}C$ which was higher than that at 1cm and 2cm soil depth. Percentage of emergence was 81.2% at 4cm soil depth in Yulmoo 1 ho and 88.0% at 3cm soil depth in Yunchon 9 ho, respectively. Days to emergence after seeding was shortest at 1cm seeding depth as about 9 days and was 2 to 3 days later at other soil depth of 2, 3, 4cm compared to 1cm soil depth plot. Plant height and dry matter weight was highest at 3cm soil depth in Yulmoo 1 ho and at 4cm soil depth in Yunchon 9 ho. In the drought conditions, percent of survived plant was highest at 4cm soil depth plot of both varieties as 51.3% and 60.0%, respectively. In the drought conditions, soil depth was positively correlated with % of emergence, days to emergence after seeding, plant height, and dry matter weight per plant.

• Journal of Plant Biotechnology
• /
• v.44 no.3
• /
• pp.220-228
• /
• 2017

Many crops including cereals, tuber crops, feeds, and turf grasses are often damaged by various environmental stresses such as drought, salt, cold, and high temperature, causing the reduction of their productivity. Plants are sessile and cannot escape from environmental stresses. Thus, plants evolve in the direction of overcoming the environmental stresses. Some plant genes such as ARF, ABI3, NAC, HSF, and WRKY are known to respond to environmental stresses as they transcriptionally regulate the stress response pathways. For example, the OsWRKY76 gene contributes to the enhanced resistance to low temperatures and pathogenic infections. The AtWRKY28 also plays a role in environmental stresses. Zoysiagrass (Zoysia japonica Steud.) is popularly grown for gardens and golf courses. However, the function of the WRKY gene, another environmental stress-related gene, is not known in zoysiagrass. In this study, the ZjWRKY3 and ZjWRKY7 genes with one shared WRKY domain have been isolated in zoysiagrass. The expression of these genes increased in response to low temperature, drought, and salt stresses. Furthermore, the infection of the brown patch-causing Rhozoctonia solani induced the expression of ZjWRKY3 and ZjWRKY7. The corresponding proteins bind to the W-box of the Zjchi promoter, possibly regulating their transcriptions. The researchers suggest that the ZjWRKY3 and ZjWRKY7 genes transcriptionally regulate abiotic and biotic stress related downstream genes.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.28 no.4
• /
• pp.451-457
• /
• 1983

This study was conducted to estimate the effect of the drought on the changes of chlorophyll, protein and proline content of upper three leaves, and the grain yield components of barley plant (CV. baegdong) subjected to water stress at four stages: late vegetative, boot, anthesis early grain filling. 1. In comparison with leaf posititions in water stress, the first leaf below flag leaf maintained the highest relative turgidity, chlorophyll and protein content and showed the least proline accumulation. And, in terms of growth stages in water stress, chlorophyll was shown to be highest at anthesis stage, protein being highest at boot stage and proline being least at boot stage. 2. In boot stages, culm and spike length, and Number of grains per spike were remarkably decreased. And the weight of 1000 grains was at least level in the early grain filling stage, and also the grain size was comparatively decreased at boot and two following stages. 3. The protein content of grain by water stress, apart from early grain filling stage, was not significantly affected by water stress at different growth stages. 4. The rate of sterility was particularly increased at boot and anthesis stages. 5. It was eventually concluded that the boot stage among four growth stages, and the flag leaf in 3 leaf positions were mostly damaged by water stress at reproductive growth stage.

• Journal of Life Science
• /
• v.27 no.2
• /
• pp.194-201
• /
• 2017

Rapeseed (Brassica napus L.) is an oil crop classified as Brassicaceae, and it is widely grown worldwide. To develop a drought-resistant rapeseed, the ${\beta}$-glucosidase 1 (AtBG1) gene was introduced into rapeseed because drought- and salt-resistance phenotypes were observed when the AtBG1 gene was overexpressed in arabidopsis. Newly developed genetically modified crop must be proved to be safe. Safety assessments are based on the historical usage and scientific reports of a crop. In this study, we examined the potential acute oral toxicity of AtBG1 protein expressed in genetically modified (GM) rapeseed and calculated the minimum lethal dose at 6 weeks in both male and female ICR mice. AtBG1 protein was fed at a dose of 2,000 mg/kg body weight in five male and five female mice according to the marginal capacity concentration of OECD, 2,000 mg/15 ml/kg. Mortalities, clinical findings, and body weight changes were monitored for 14 days after dosing, and postmortem necropsy was performed on day 14. This study showed that no deaths occurred in the test group, and AtBG1 protein did not result in variations in common symptoms, body weight, and postmortem findings between the two groups. This showed that the minimum lethal dose of AtBG1 protein expressed in transgenic rapeseed exceed 2,000 mg/kg body weight in both sexes.

• Research in Plant Disease
• /
• v.24 no.3
• /
• pp.221-232
• /
• 2018

Rhizobacteria play important roles in plant growth and health enhancement and render them resistant to not only biotic stresses but also abiotic stresses, such as low/high temperature, drought, and salinity. This study aimed to select plant growth promoting rhizobacteria (PGPR) with the capability to mitigate biotic and abiotic stress effects on tomato plants. We isolated a novel PGPR strain, Variovorax sp. PMC12 from tomato rhizosphere. An in vitro assay indicated that strain PMC12 produced ammonia, indole-3-acetic acid (IAA), siderophore, and 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase, which are well-known traits of PGPR. The aboveground fresh weight was significantly higher in tomato plants treated with strain PMC12 than in non-treated tomato plants under various abiotic stress conditions including salinity, low temperature, and drought. Furthermore, strain PMC12 also enhanced the resistance to bacterial wilt disease caused by Ralstonia solanacearum. Taken together, these results indicated that strain PMC12 is a promising biocontrol agent and a biostimulant to reduce the susceptibility of plants to both abiotic and biotic stresses.

• Research in Plant Disease
• /
• v.29 no.2
• /
• pp.188-192
• /
• 2023

Abiotic and biotic stresses have been a serious threat to crop growth and productivity in the agricultural system. In this study, four strains (HS1, H30-3, KJ40, and BC42), which have biological activities related to disease suppression or alleviation of salinity and drought stresses, were tested for broad-spectrum biocontrol activity against anthracnose caused by Colletotrichum orbiculare, a bacterial fruit blotch caused by Acidovorax citrulli, and Fusarium wilt caused by Fusarium oxysporum in cucumber plants. As a result of test, when the four strains were drenched into the soil, anthracnose in cucumber leaves significantly decrease; strain KJ40 suppressed disease incidence by A. citrulli; strain BC42 significantly reduced bacterial fruit blotch and Fusarium wilt compared to control. Therefore, strain KJ40 could be a biocontrol candidate for controlling anthracnose through induced systemic resistance and the disease caused by A. citrulli as well as alleviating drought stress; strain BC42 has broad-spectrum biocontrol activity against anthracnose, Fusarium wilt, and bacterial fruit blotch.

• Journal of Plant Biotechnology
• /
• v.37 no.3
• /
• pp.305-312
• /
• 2010

During a last decade, the introduced traits in commercialized GM crops have been diversified from a simple trait such as herbicide resistance gene or insectresistance gene which are related to the crop production into more complicated traits such as modification of fatty acid or essential amino acid composition, modified coloring pattern of flower. In addition, it was investigated that several other GM crops bearing more refined traits expected to lead next generation are also awaiting for risk assessment (RA) or under field test for the preparation of RA in the near future. These GM crops include abiotic stress resistance including drought or cold, increased biomass, production of bioethanol or diesel, production of pharmaceuticals or functional materials for industrial. In particular, in 2008 and 2009, it was reported that the highest number of GM crops for molecular farming are under developed in laboratory or green house level in all the world. Likewise, in Korea, 171 events from 49 plant species are under developed to introduce several important traits. At present, about 10 events are under field test to select elite lines for RA application. For the first time, herbicide resistance turfgrass developed by Korean research team has been submitted for RA and currently under requested for additional data. Moreover, GM rice resistant to leaf roll (folder) disease is expected as a next event to be submitted for RA application.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.41 no.2
• /
• pp.77-83
• /
• 2021

Rye (Secale cereal L.) is the most tolerant to abiotic stress including low temperature, drought, and unfavorable soil conditions among the winter cereals. Rye is the rapid growth of early spring results from increasing areas for the use of the forage and green manure in the middle part of Korea. "Jungmo2509", a rye cultivar was developed by the National Institute of Crop Science (NICS), RDA in 2014. It was developed from a cross between "Olhomil", a self-compatible cultivar, and "Synthetic II", a self-incompatible line. "Jungmo2509" is an erect plant type and of a middle size, with a green leaf color, a yellowish-white colored culm, and a yellowish brown-colored, small-size grain. The heading date of "Jungmo2509" was April 23, which was 5 days later than that of "Gogu", respectively. But "Jungmo2509" showed greater resistance to lodging compared to that of the check cultivar, with similar to winter hardiness, wet injury, and disease resistance. "Jungmo2509" was a higher to than "Gogu" in terms of protein content (9.4% and 8.0%, respectively), total digestible nutrients (TDN) (55.7% and 55%, respectively). The seed productivity of "Jungmo2509" was approximately 2.08 ton 10a-1, which was 11% lower than that of the check. Almost all rye cultivars are out-crossing due to genes controlling incompatibility, but "Jungmo2509" is higher seed fertility (56%) than that of Gogu (0%). it has self-compatible genes. "Jungmo2509" is erect in plant type and resistance for lodging. Therefore, "Jungmo2509" can produce uniform seeds for processed grains of human consumption and utilize them as parents for breeding the rye hybrids with high forage yields.

• Journal of Plant Biology
• /
• v.13 no.4
• /
• pp.23-31
• /
• 1970

The rice variety, Kwanok, was reared in the water and land beds and transplanted to the reclaimed soil area, having an average salt concentration of 0.39%. Two levels of the moderate and late season cultures with 4 treatments were used. The K and Si contents of the stem part of land bed seedlings were somewhat smaller, but total carbohydrate remarkably larger, the C/N ratio was accordingly greater than water bed seedlings. The rooting ability of land bed seedlings was vigorous markedly in culture solutions, to which added various concentrations of NaCl, The rooting ability of each seedling water not much declined in theculturing solution of up to 9.4mmhos/cm, (0.6%) of salt concentration, but it was drastically declined in the salt concentration over that. It seemed that the critical salt concentration for the rooting rice plant. The land bed seedlings in each salty condition markedly decreased compared with the water bed seeldings in transpiration rate and it showed a stronger drought resistance and contained a large amount of chlorophyll at transplanting stage, and also showed higher stability of chlorophyll at rooting stage in the salt treatment. The number of panicles, panicle weight, number of grains per panicle and ratio of matured grains of the rice plant grown by the land bed seedlings were much greater and 1,000 grain weight was less than from water bed seedlings. The cultural practices with the land bed seedlings increased the rough rice yields by 15% and 11%, respectively, compared with the yields of the moderate and late season cultures by water bed seedlings.

• Journal of the Korea Concrete Institute
• /
• v.28 no.5
• /
• pp.601-609
• /
• 2016

Recently, extreme climate change has been occurring globally not only in the simple form of temperature increases but also in a wide range of extreme climatic events, such as abnormal drought conditions and frequent typhoons. In addition, climate change is delaying the construction period of concrete structures, increasing related economic losses. Forcing construction projects for completion without considering climate change is leading to concrete quality deterioration, poor quality constructions, and consequent casualties and property damage. Therefore, to address these problems and provide a countermeasure to climate change, the present study selected wind speed, and sunlight exposure time as the most important curing conditions among the climate factors affecting concrete structures and examined their effects on the curing and durability of concrete structures. In addition, for the analysis of the experimental results, this study proposed a process of performance based evaluation (PBE) of concrete strength and durability using a method of Satisfaction Curve (SC) generation.