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

• KOREAN JOURNAL OF CROP SCIENCE
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• v.50 no.5
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• pp.325-331
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• 2005

Seedlings of two rice genotyopes, cvs. Ilpumbyeo and Gancheokbyeo, were exposed to 0, 50 and 100 mM NaCl in nutrient solution for nine days. Plants were collected at the interval of 3 days and organic and inorganic solutes in leaves and roots and antioxidative enzyme activity in leaves were determined. Under salinity, the accumulation of soluble sugars occurred considerably in the older leaves of stressed seedlings compared to younger leaves and roots. The endogenous Na+ contents markedly increased at higher NaCl concentration in leaves and roots of seedlings, though it was higher accumulated in roots. Salinity resulted in an excessive proline accumulation in the stressed plants. A more pronounced increase was observed in Gancheokbyeo leaves. SOD activity in Impumbyeo cannot found any remarkable change, whereas, in Gancheokbyeo, its activity was rapidly decreased. CAT and POD activities increased with an increase in NaCl concentration in both genotypes. In sum­mary, the high capacity of rice seedlings to overcome an unfavorable growth condition such salt stress appears to be related to an adequate partition of organic solutes between shoots and roots and to changes in absorption, transport and re-translocation of salts.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.69 no.1
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• pp.1-14
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• 2024

High soil salinity is the most severe threat to global rice production as it causes a significant decline in rice yield. Here, we investigated the effects of various plant extracts on rice plant stress associated with high salinity. Additionally, we examined various physiological and biochemical parameters such as growth, photosynthetic activity, chlorophyll content, and lipid peroxidation - in rice plants after treatment with selected plant extracts under salt stress conditions. Of the 11 extracts tested, four - soybean leaf, soybean stem, moringa (Moringa oleifera), and Undaria pinnatifida extracts - were found to effectively reduce salt stress. A reduction of only 3-23% in shoot fresh weight was observed in rice plants under salt stress that were treated with these extracts, compared to the 43% reduction observed in plants that were exposed to stress but not given plant extract treatments (control plants). The effectiveness varied with the concentration of the plant extracts. Water content was higher in rice plants treated with the extracts than in the control plants after 6 d of salt stress, but not after 4 d of salt stress. Although photosynthetic efficiency (Fv/Fm), electron transport rate (ETR), and the content of pigments (chlorophyll and carotenoid) varied based on the types and levels of stress and the extracts that the rice plants were treated with, generally, photosynthetic efficiency and pigment content were higher in the treated rice compared to control plants. Reactive oxygen species (ROS), such as superoxide radicals, hydrogen peroxide (H₂O₂), and malondialdehyde (MDA), increased as the duration of stress increased. ROS and MDA levels were lower in the treated rice than in the control plants. Proline and soluble sugar accumulation also increased with the duration of the stress period. However, proline and soluble sugar accumulation were lower in the treated rice than in the control plants. Generally, the values of all the parameters investigated in this study were similar, regardless of the plant extract used to treat the rice plants. Thus, the extracts found to be effective can be used to alleviate the adverse effects of stress on rice crops associated with high-salinity soils.

• Journal of Applied Biological Chemistry
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• v.56 no.2
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• pp.109-112
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• 2013

Azole fungicides are one of the most wide-spread antifungal compounds in agriculture and pharmaceutical applications. Their major mode of action is the inhibition of ergosterol biosynthesis, giving depletion of ergosterol, precursors and abnormal steroids. However, metabolic consequences of such inhibition, other than steroidal metabolitesare not well established. Comprehensive metabolic profiles of Saccharomyces cerevisiae has been presented in this study. Wild type yeast was treated either with glucose as control or azole fungicide (ketoconazole). Both polar metabolites and lipids were analyzed with gas chromatography-mass spectrometry. Approximately over 180 metabolites were characterized, among which 18 of them were accumulated or depleted by fungicide treatment. Steroid profile gives the most prominent differences, including the accumulation of lanosterol and the depletion of zymosterol and ergosterol. However, the polar metabolite profile was also highly different in pesticide treatment. The concentration of proline and its precursors, glutamate and ornithine were markedly reduced by ketoconazole. Lysine and glycine level was also decreased while the concentrations of serine and homoserine were increased. The overall metabolic profile indicates that azole fungicide treatment induces the depletion of many polar metabolites, which are important in stress response.

• Analytical Science and Technology
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• v.12 no.5
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• pp.441-446
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• 1999

The changes of amino acids in the cotyledons of spring - and winter radishes were analysed during the abscisic acid (ABA). ABA plus cycloheximide (CH) and ABA plus polyamine (PA) treatment. The total contents of amino acids were increased in spring radishes, and decreased in winter radishes by ABA. The contents of hydrophilic amino acids, proline, glycine, serine and cysteine in spring radishes (expecially proline), and of cysteine, leucine and phenylalanine in winter radishes (expecially cysteine and leucine)were increased, CH treatment resulted in the accumulation of amino acids by the inhibition of new synthesized protein, which synthesized against ABA induced dehydration both of radishes. On the contrary, the contents of amino acids were decreased in spring radishes, and increased in winter radishes during PA treatment. These results indicated that the accumulated hydrophilic amino acids and new synthesized proteins induced the adaptation of dehydration against stress and the role of ABA in accelerating of stress adaptation was mediated by polyamines.

• Horticultural Science & Technology
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• v.33 no.5
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• pp.625-632
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• 2015

Drought is a severe abiotic stress that affects global crop production. A drought model was created for 'Toyonoka' Fragaria ${\times}$ ananassa, and the effects of drought stress on contents of proline, sugars, and antioxidant enzyme activities were investigated. Strawberry transplants with identical growth were chosen for the experiments and the randomized design included four replications (10 plants per block). The experimental sets differed in the moisture level of the culture medium relative to the range of moisture content as follows: control, 70-85%; mild drought stress, 50-60%; moderate drought stress, 40-50%; and severe drought stress, 30-40%. Drought stress was imposed by limiting irrigation. Plants were sampled and physiological parameters w ere measured on 0, 2, 4, 6, 8, and 10 days after the commencement of droughts tress. The water potential of strawberry leaves decreased in the plants under mild, moderate, and severe stress during the course of the water stress treatment and exhibited a significant difference from the control. Strawberry leaves subjected to drought stress had higher accumulation of proline, sugars, and malondialdehyde, and higher activities of superoxide dismutase, peroxidase, and catalase than leaves of control plants. Malondialdehyde levels increased in parallel with the severity and duration of drought stress. By contrast, antioxidant enzyme activity displayed dynamic responses to drought stress, first increasing and subsequently decreasing as the severity and duration of drought stress increased. These results suggest that strawberry plants respond to drought stress by altering the activities of antioxidant enzymes and the levels of osmotically active metabolites. These biochemical response changes may confer adaptation to drought stress and improve the capacity of plants to withstand water-deficit conditions.

• Journal of Ecology and Environment
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• v.47 no.4
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• pp.241-249
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• 2023

Background: This study analyzed the drought responses of five forest tree species grown in Korean peninsula, Korean fir Abies koreana (Ak), eastern white pine Pinus strobus (Ps), keyaki Zelkova serrata (Zs), tulip tree Liriodendron tulipifera (Lt), and Japanese elm Ulmus japonica (Uj). Physiological (chlorophyll, root collar diameter [RCD]) and biochemical responses (non-structural carbohydrates, proline, lipid peroxidase and abscisic acid [ABA]) of the plants grown under mild (MD) and severe drought (SD) were compared. Results: In this study, three soil moisture regimes: control (100% precipitation), MD (60% reduction in precipitation) and SD (20% reduction in precipitation) were applied. Soil moisture content showed high water content in control site compared to MD and SD. A decline in RCD was found for Korean fir, keyaki, and tulip plants, with eastern white pine and Japanese elm showing no significant decline to the prolonged drought exposure (both MD and SD). Total chlorophyll showed a significant decline in Korean fir and tulip, with the sugar levels indicating a significant increase in Korean fir and keyaki species under SD compared to control plants. Non-significant decline in sugar level was noted for eastern white pine and Japanese elm. High accumulation of ABA, malondealdehyde and proline was noted in Korean fir, tulip, and keyaki under SD compared to control. Signs of tree mortality was only observed in Korean fir under MD (38%) and SD (43%). Conclusions: The observed findings indicate the drought responses of five tree species. The majority of the morpho-physiological (especially mortality) and biochemical variables assessed in our study indicate superior long-term drought resistance of Ps and Uj compared to the highly sensitive Ak, and moderately sensitive Lt and Zs. The results provided will help species selection for afforestation programs and establishment of sustainable forests, especially of drought-tolerant species, under increased frequency and intensity of spring and summer droughts.

• Journal of Plant Biotechnology
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• v.42 no.2
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• pp.129-134
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• 2015

In order to compare salt tolerance among potato cultivars (Solanum tuberosum L.), in vitro plants of each cultivar were cultured on the Murashige and Skoog's medium containing different levels of NaCl (0, 75, 150, and 225 mM). The suitable level of NaCl for a comparison of the shoot and root growth between potato cultivars was 75mM. Shoot length and weight were better in 'Dejima', 'Superior', 'Jayoung', and 'Haryeong' than in other cultivars such as 'Goun' and 'Atlantic'. Normal root growth was observed in 'Seohong', 'Superior', and 'Haryeong', while 'Goun', 'Atlantic', 'Dejima', 'Jowon', and 'Chuback' showed no root. Proline contents in all the cultivars increased as affected by NaCl levels, then the increase amount was fewer in the cultivars showed a better growth in both shoot and root than in others showed a poor growth. As a result of this study, 'Superior' and 'Haryeong' were determined as salt tolerant cultivars and therefore using these cultivars it would be possible to potato production at salt arable land such as reclaimed tidal.

• Proceedings of the Korean Society of Crop Science Conference
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• 2023.04a
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• pp.156-156
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• 2023

Salinity is a major abiotic stress that limits rice productivity in many regions of the world. In order to develop salt stress tolerant rice plants, genetic engineering is a promising approach. We characterized the molecular function of rice C3H2C3 as a really interesting new gene (RING). Oryza sativa RING finger protein H2-3 (OsRFPH2-3) was highly expressed in 100 mM NaCl. To identify the localization of OsRFPH2-3, we fused vectors that include C-terminal GFP protein (35S;;OsRFPH2-3-GFP). OsRFPH2-3 was expressed in the nucleus in rice protoplasts. An in vitro ubiquitin assay demonstrated that OsRFPH2-3 possessed E3-ubiquitin ligase activity. However, the mutated OsRFPH2-3 were not possessed any E3-ubiquitin ligase activity. Under salinity conditions, OsRFPH2-3-overexpressing plants exhibited higher chlorophyll, proline, SOD, POD, CAT, and soluble sugar contents and lower H₂O₂ accumulation than wild-type plants, supporting transgenic plants with enhanced salinity tolerance phenotypes. OsRFPH2-3-overexpressing plants exhibited low Na+ accumulation and Na+/K+ ratios in their roots. Theses results suggest that overexpression of OsRFPH2-3 can make plant insensitivity about salinity conditions.

• Horticultural Science & Technology
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• v.34 no.6
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• pp.818-829
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• 2016

This study evaluated the responses of 18 potato cultivars to three levels of salinity stress (electrical conductivity, EC: 1.0, 4.0, and $8.0dS{\cdot}m^{-1}$). Stem, leaf, root, chlorophyll, tuber yield, and proline content were investigated and statistically analyzed using analysis of variance (ANOVA) and correlations. Stem number and stem diameter were not affected by salinity, but stem length and aerial weight showed highly significant responses to salinity. Aerial weight decreased with increasing salinity levels in most cultivars, while it increased in some the cultivars 'Daejima', 'Goun', 'Haryeong', and 'LT-8'. Leaf number, leaf area index, and leaf weight were most significantly affected by salinity and the cultivar ${\times}$ salinity interaction. Root length, root weight, total chlorophyll and chlorophyll a were affected by salinity, but not by the cultivar ${\times}$ salinity interaction. The opposite trend was shown in chlorophyll b. Although there was great variability among cultivars, tuber yield decreased in all cultivars, and was most significantly influenced by salinity and the cultivar ${\times}$ salinity interaction. 'Superior', 'Kroda', 'Romana', and 'Duback' gave better tuber yields under salinity at EC 4.0 and $8.0dS{\cdot}m^{-1}$ than the cultivars with better aerial weights. Proline content was increased by salinity in all cultivars, and was more remarkable in the cultivars with better aerial weights than in cultivars such as 'Superior' and 'Kroda' with better tuber yields. Leaf number, leaf area index, leaf weight, and root length parameters were considered to be useful criteria in the evaluation of salt tolerance because of their high positive correlation with tuber yield; however, given its negative correlation with tuber yield under high salinity, proline content was not. Salinity tolerances varied greatly among potato cultivars. The low correlation between growth and yields of aerial parts under high salinity suggests that, in commercial agriculture, it might be more practical to compare relative yields to controls. Additionally, 'Superior', 'Kroda', 'Romana', and 'Duback' might be very useful cultivars to use in breeding programs to develop salinity-tolerant potatoes, as well as for sustainable potato production in saline areas.