• Horticultural Science & Technology
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• v.33 no.4
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• pp.575-584
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• 2015

Drought stress is a crucial environmental factor determining crop survival and productivity. The goal of this study was to clearly identify a new drought stress-tolerance gene in Brassica rapa. From KBGP-24K microarray data with the B. rapa ssp. pekinensis inbred line 'Chiifu' under drought stress treatment, a gene which was named BrDSR (B. rapa Drought Stress Resistance) was chosen among 738 drought-responsive unigenes. BrDSR function has yet to be determined, but its expression was induced over 6-fold by drought. To characterize BrDSR, the gene was isolated from B. rapa inbred line 'CT001' and found to contain a 438-bp open reading frame encoding a 145 amino acid protein. The full-length cDNA of BrDSR was used to construct an over-expression vector, 'pSL100'. Tobacco transformation was then conducted to analyze whether the BrDSR gene can increase drought tolerance in plants. The BrDSR expression level in T1 transgenic tobacco plants selected via PCR and DNA blot analyses was up to 2.6-fold higher than non-transgenic tobacco. Analysis of phenotype clearly showed that BrDSR-expressing tobacco plants exhibited more tolerance than wild type under 10 d drought stress. Taking all of these findings together, we expect that BrDSR functions effectively in plant growth and survival of drought stress conditions.

• Ecology and Resilient Infrastructure
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• v.10 no.3
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• pp.64-72
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• 2023

Biopolymer is a versatile material used in food processing, medicine, construction, and soil reinforcement. 𝛽-glucan is one of the biopolymers that improves the soil water content and ion adsorption in a drought or toxic metal contaminated land for plant survival. We analyzed drought stress damage reduction in sweet potatoes (Ipomoea batatas L. cv. Sodammi) by measuring the growth and major protein expression and activity under 𝛽-glucan soil amendment. The result showed that sweet potato leaf length and width were not affected by drought stress for 14 days, but sweet potatoes grown in 𝛽-glucan-amended soil showed an effect in preventing wilting caused by drought in phenotypic changes. Under drought stress, sweet potato leaves did not show any changes in electrolyte leakage, but the relative water content was higher in sweet potatoes grown in 𝛽-glucan-amended soil than in normal soil. 𝛽-glucan soil amendment increased the expression of plasma membrane (PM) H⁺-ATPase, but it decreased the aquaporin PIP2 (plasma membrane intrinsic protein 2) in sweet potatoes under drought stress. Moreover, water maintenance affected the PM H⁺-ATPase activity, which contributed to tolerance under drought stress. These results indicate that 𝛽-glucan soil amendment improves the soil water content during drought and affects the water supply in sweet potatoes. Consequently, 𝛽-glucan is a potential material for maintaining soil water contents, and analysis of the major PM proteins is one of the indicators for evaluating the biopolymer effect on plant survival under drought stress.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.62 no.3
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• pp.241-248
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• 2017

Yield of potato is largely influenced by drought stress. This study was conducted in Gangneung and Cheongju during the spring cropping of potato. Potatoes in the Gangneung area were affected by drought but there was no damage due to drought in Cheongju. During the early-growth stage, the contents of inorganic components like available phosphate and growth characteristics of the potato leaf in Cheongju were significantly higher than those in Gangneung but there was no difference after the flowering stage. It was considered that the potato plants cultivated in Cheongju could vigorously grow than that of Gangneung under drought stress. In addition, the content of calcium (Ca), which is a secondary messenger related to aging, was found to be higher in potato plants grown in Cheongju than in Gangneung and accumulated more quickly in potato plants of Cheongju. Because magnesium (Mg) was also found to be higher in potato plants from Gangneung by a wide margin, this phenomenon was thought be related with drought stress. The amounts of all inorganic components absorbed from soil were higher in Cheongju than in Gangneung, showing a relatively higher plant biomass in Cheongju. Correlations of development indexes related to leaf showed less or no relation in Gangneung. According to yield characteristics of the harvest stage, although yield was greatly reduced under drought stress condition, the rate of commercial yield was not significantly affected under the drought stress condition. Consequently, it was considered that these responses to drought stress could be utilized to stabilize potato production under the stressful conditions associated with abnormal climate.

• Proceedings of the Korea Water Resources Association Conference
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• 2019.05a
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• pp.397-397
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• 2019

With the consequences of climate change becoming more evident, research on climate-associated risks has become a basis for climate adaptation and mitigation. Amongst the different sectors and natural resources considered in assessing such risks, drought is one impact to our environment that experiences stress from climate change but is often overlooked and has the potential to bring severe consequences when drought occurs. For example, when temperatures are higher, water demand increases and water supply decreases; when precipitation patterns fluctuate immensely, floods and droughts occur more frequently at greater magnitudes, putting stress on ecosystems. Hence, it is important for us to evaluate drought risk to observe how different climate change and socioeconomic scenarios can affect this vital life resource. In this study, we review the context of drought risk on the basis of climate change impacts and socioeconomic indicators. As underlined in the IPCC AR5 report, the risks are identified by understanding the vulnerability, exposure, and hazards of drought. This study analyzed drought risk on a global scale with different RCP scenarios projected until the year 2099 with a focus on the variables population, precipitation, water resources, and temperature.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.64 no.4
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• pp.432-440
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• 2019

Global climate change exerts adverse effects on maize production. Among abiotic stresses, drought stress during the tasseling stage (VT) can increase anthesis-silking intervals (ASI) and decrease yield. We performed an evaluation of ASI and yield using a drought-sensitive line (Ki3) and a drought-tolerant line (Ki11) to analyze the correlation with ASI and yield. Moreover, the de novo data of Ki11 were analyzed to find putative novel transcripts related todrought stress in tropical maize. A total of 182 transcripts, with a log2 ratio >1.5, were found by comparing drought conditions to a control. The top 40 transcripts of high expression levels in the de novo analysis were selected and analyzed with PCR. Of the 40 transcripts, six novel transcripts were detected by quantitative real-time PCR (qRT-PCR) using seedling and VT stage samples. Five transcripts (transcripts_1, 12, 34, 35, and 40) were up-regulated in the Ki11 shoot at seedling stage, and transcripts_1, 12, and 40 were up-regulated at the re-watering stage after 12 h of drought stress. The transcripts_32 and 34 were up-regulated at the VT stage. Hence, transcript_34 possibly plays a significant role in drought tolerance during the seedling and VT stages. The transcript_32 was identified as chloramphenicol acetyltransferase (CAT) by Pfam domain analysis. The function of the other transcripts remained unknown. Further characterization of these novel transcripts in genetic regulation will be of great value for the improvement of maize production.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.153-153
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• 2017

Potato (Solanum tubersosum L.) is susceptible to various environmental stresses such as frost, high temperature, and drought. Enhancement of potato drought tolerance can reduce yield loss under drought that has negative effect on potato tuber growth. Genetic engineering can be utilized to achieve this goal, but such approaches using endogenous potato genes have rarely been applied. Since unpredictable global weather changes cause more severe and frequent water limiting conditions, improvement of potato drought tolerance can minimize such adverse effects under drought and can impact on sustainable potato production. Genetic engineering can be utilized to improve potato drought tolerance, but such approaches using endogenous potato genes have rarely been applied. We were obtained AtbZIP28 gene transgenic potato plants. It is identified transcript levels at various stress conditions, polyethylene glycol (PEG), NaCl, abscisic ${\underline{acid}}$ (ABA). Also, For identification to regulate ER stress response genes in AtbZIP28 gene transgenic potato plant, we screened seven potato genes from RNA-seq analysis under TM treatment. Five and two genes were up- and down-regulated by TM, respectively. Their expression patterns were re-examined at stress agents known to elicit TM, DTT, DMSO and salt stress.

• Horticultural Science & Technology
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• v.31 no.6
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• pp.677-686
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• 2013

Edible canna is a productive starch source in some tropical and semitropical regions. In these regions, water deficit stress is one of factors that limit the crop yield. In the present study, we investigated seven physiological indexes and photosynthetic responses of three edible canna (Canna edulis Ker.) cultivars ('PLRF', 'Xingyu-1', and 'Xingyu-2') under 35 days drought stress. Our results indicated that drought treatment caused visible wilting symptoms in all cultivars, especially in 'Xingyu-1'. Coupled with the increase of wilting symptoms, relative water content (RWC) and chlorophyll content decreased progressively, malondialdehyde (MDA) content gradually increased, and key antioxidant enzymes such as superoxide dismutase (SOD), peroxidase (POD), catalase (CAT) activities increased first and then decreased in all three cultivars. The effect of water stress was more pronounced in 'Xingyu-1' than in 'PLRF' and 'Xingyu-2', and in lower leaves than in upper leaves. In addition, 35 days drought stress also significantly reduced the photosynthetic capacity. Consistent with antioxidant parameters, photosynthetic changes of 'Xingyu-2' were less than those of the other cultivars under water deficit stress. Drought stress caused a significant increase of water use efficiency (WUE) in 'Xingyu-2', but little in 'PLRF', and obvious decrease in 'Xingyu-1'. These results indicated that 'Xingyu-2' was more tolerant to drought stress than 'PLRF' and 'Xingyu-1' by maintaining lower lipid peroxidation and higher antioxidant enzyme activities.

• Korean Journal of Soil Science and Fertilizer
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• v.48 no.3
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• pp.213-217
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• 2015

Soil moisture shortage can reduce yield of waxy corn because maize is one of the sensitive crops to the drought stress. Farmers cannot irrigate due to limited water resource and irrigating facilities although applying water is the most effective practice to solve the drought problem. The study was conducted to investigate the pre-treatment effect of salicylic acid on reducing drought damage of waxy corn (Zea mays L.). Salicylic acid at concentration of 0.2 mM was applied at seven-leaf stage or ten-leaf stage three times. Drought stress was imposed by withholding irrigation from 11 days before anthesis to 10 days after anthesis. Application of salicylic acid significantly increased ear length by 11.0~12.3% and yield by 8.8~11.3% compared with non-treated control, indicating that the drought injuries of waxy corn can be alleviated through pre-treatment of salicylic acid at the vegetative stage.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.181-181
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• 2017

Global warming and climate change have been one of the most important problems last 2 decades. Global warming is known to cause abnormal climate and influence ecology, food production and human health. According to climate change model global warming is causing expansion of drought and increase of evaporation. Therefore, securing water in agriculture has been an important issue for crop cultivation. As potato is susceptible to drought, water shortage generally results in decrease of yield and decrease of biomass. In this research, we investigated characteristics of inorganic nutrient absorption and growth of plants grown under drought condition. Plants were sampled in sites of Cheong-ju and Gangneung, where the severity of drought stress were different. During the growth period in Gangneung, total rainfall in 2016 decreased by 50% compared with those in last 5 years average. Especially, there was almost no rain in tuber enlargement period (from mid-May to mid-June). On the other hand, the total rainfall in of Cheong-ju was is similar to those in last 5 years average. Inorganic components including K, Ca and Mg and plant growth factors such as plant length, stem length, leaf area index and plant biomass were investigated. Tuber yields in both areas were investigated at harvest. Growth period of plants was is longer in Cheong-ju than that in Gangneung. Contents of all inorganic components were higher in plants grown in Cheong-ju than in Gangneung. The results were attributed to higher production of plant biomass in Cheong-ju. Considering the results, severe drought stress conditions in Gangneung accelerated plant aging and resulted in low plant growth. Although total yield was greatly reduced under drought stress the rate of commercial yield was is not significantly different with non-drought conditions.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.4
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• pp.310-317
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• 2006

This study was conducted to investigate the influence of drought stress during the pod developing and seed filling stage on source-sink relationships of soybean (Glycine max). Drought treatments were imposed by withholding water at the full-pod stage, 19 days after flowering, and then limited watering was relieved at 15 days after the initiation of drought treatment. Soybean seed yield was reduced by 39% mainly due to decreased pod number under drought stress, but the 100-seed weight was relatively less reduced. In spite of the 15-day drought during the full-pod stage, soybean produced good seeds showing similar l00-seed weight, protein, starch and soluble sugar content to those from the well-watered. Although drought during the full-pod stage caused source limitations; i.e. accelerated leaf senescence and reduced leaf soluble sugars, it did not cause limitations of other source characteristics such as SGR and leaf starch level. This is because the reduction in size of sinks, such as pod and seed abortions compensated for source limitations, resulting in balanced source-sink as expressed by LAR and the ratio of leaf area to seed dry weight. Drought stress during the pod developing and seed filling stage did not disrupt the source-sink balance