• 한국작물학회지
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• 제47권2호
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• pp.95-101
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• 2002

To investigate the changes in the composition and pool size of nitrogen metabolites under drought stress, white clover (Trifolium repens L.) were exposed to -0.04MPa (well-watered, control) or to -0.12MPa (drought-stressed) of soil water potential during 28 days. Dry weight of leaves in drought-stressed plants was remarkably decreased by 45% and 74% within 14 days and 28 days, respectively, compared with control. For nitrate concentration after 28 days of treatment, a significant difference (1.6 times higher in drought-stressed plants) was observed only in stolon. NH$_3$-NH$_4$$^{+}$ concentration in all three organs of drought-stressed plants linearly increased to more than 1.6 times higher level at 28 day when compared to the initial level (day 0), while the increasing rate in control was much less than that of drought-stressed plants. Proline concentrations in drought-stressed plants remarkably increased and reached to 7, 13 and 17 times higher level at 28 day compared to control. Protein concentration in leaves of drought-stressed plants tended to decrease, while it slightly increased during the first 14 days and reached a plateau afterward in control. There was not significant difference in the proteins concentration of stolon and roots throughout experimental period. On SDS-PAGE analysis, two major proteins specifically induced by drought stress (16-kD and 18-kD) were detected in stolon.n.

• 한국환경농학회지
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• 제29권2호
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• pp.159-164
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• 2010

Imidacloprid is a systemic insecticide which has been used widely in various crops to control insects. In the present study, we demonstrated that pre-treatment of imidacloprid significantly induced tolerance to drought in plant. Relative water content, chlorophyll levels, and recovery rate upon rehydration after drought stress in tobacco plants pre-treated with imidacloprid were higher levels than the control plants. Induced drought tolerance by imidacloprid treatments in red pepper was also demonstrated by measurement of recovery rate and fresh weight upon drought stress. Taken together, our results suggest that imidacloprid, in addition to exerting direct insecticidal activity, may also protect plants by induced tolerance to drought in plant.

• BMB Reports
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• 제46권1호
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• pp.31-36
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• 2013

Heat shock proteins play an important role in plant stress tolerance and are mainly regulated by heat shock transcription factors (Hsfs). In this study, we generated transgenic rice over-expressing OsHsfA7 and carried out morphological observation and stress tolerance assays. Transgenic plants exhibited less, shorter lateral roots and root hair. Under salt treatment, over-expressing OsHsfA7 rice showed alleviative appearance of damage symptoms and higher survival rate, leaf electrical conductivity and malondialdehyde content of transgenic plants were lower than those of wild type plants. Meanwhile, transgenic rice seedlings restored normal growth but wild type plants could not be rescued after drought and re-watering treatment. These findings indicate that over-expression of OsHsfA7 gene can increase tolerance to salt and drought stresses in rice seedlings.

• 자원환경지질
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• 제54권6호
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• pp.649-657
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• 2021

This paper aims to study the impact of natural disasters on per capita income in Vietnam both the short and long-term, specifically impact loss of income caused by the extreme drought 2013 for agriculture, forestry and fishery in Phu Yen Province, Central Vietnam. The study valued economic damage by applying the synthetic control method (SCM), which is a statistical method to evaluate the effect of an intervention (e.g. natural disasters) in different case studies. It estimates what would have happened to the treatment group if it had not received the treatment by constructing a weighted combination of control units (e.g. control provinces). The results showed that the 2013 drought caused a decrease in income per capita, mainly in the agriculture, forestry, and fishery sector in Phu Yen. The reduced income was estimated to be VND 160,000 (1 USD = 23,500 VND (2021)) for one person per month, accounting for 11% of total income per capita and continued to affect the income 6 years later. Therefore, authorities need to invest in preventive solutions such as early and accurate warnings to help people to be more proactive in disaster prevention.

• 한국작물학회지
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• 제64권4호
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• pp.344-352
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• 2019

본 연구는 최근 세계적인 기후변화로 인해 기상이변이 생기면서 우리나라의 경우 2012년 이후로 꾸준히 이앙기인 5~6월에 비가 거의 오지 않고 평년보다 온도가 상승하는 봄 가뭄 현상이 나타나고 있다. 유묘기 한발에 의한 피해양상과 그로 인한 수량감소와 미질특성 변화를 구명하고자 2017년부터 2018년까지 2년간 수행한 주요 결과를 요약하면 다음과 같다. 1. 한발처리시기에 따른 벼의 초기 생육특성을 확인한 결과 초장의 경우 모든 시험구가 무처리구에 비해 감소하였고 경수의 경우 이앙 후 3일, 10일 경부터 한발처리한 시험구에서 30%가량 감소하였다. 이앙 후 20일 경부터 한발 처리한 시험구에서는 감소율이 3.7%로 20일 이후에 한발피해 시 경수 감소는 적은 것으로 사료된다. 2. 한발처리시기에 따른 벼 후기 생육과 수량구성요소 조사 결과 이앙 후 3일 경부터 한발처리한 시험구에서 피해가 가장 컸고 수수의 경우 이앙 후 3일부터 한발처리한 시험구에서 약 30% 감소피해를 입은 반면 이앙 후 20일부터 한발처리 한 경우 뿌리활착 이후에 한발피해를 받아 수수에는 영향을 크게 받지는 않았으나 등숙비율이 감소하였다. 수당립수는 무처리에 비해 모두 감소하였고 천립중은 무처리구에 비해 초기 한발피해가 크지 않았다. 3. 품종별 한발처리시기에 따른 생육 및 수량구성요소를 분석해본 결과 조생종인 해담쌀이 초기 한발피해에 따른 수량감소가 30%로 가장 크게 나타났으며 이는 조생종이 중만생종에 비해 기본영양생장기가 짧아 초기 피해를 출수 전에 회복하지 못하여 유효분얼수 등 수량구성요소 전반에 걸쳐 피해를 입기 때문인 것으로 사료된다. 4. 쌀의 경점도를 분석한 결과 무처리구와 이앙 후 20일 경에 한발피해 받은 시험구는 초기에 한발피해를 받은 시험구에 비해 경도와 단백질 함량이 낮고 강하점도는 높으며 치반점도는 낮아지는 등 밥맛이 양호한 특성을 나타내었다. 그러므로 한발피해를 초기에 받으면 미질에도 영향을 주는 것으로 사료된다.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2018년도 추계학술대회
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• pp.179-179
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• 2018

Potato (Solanum tubersosum L.) is susceptible to various environmental stresses such as salt, high temperature, and drought. Especially, potato tuber growth is greatly affected by drought that causes not only yield reduction but also loss of tuber quality. 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, (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.

• 한국작물학회지
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• 제51권4호
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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

• 한국환경농학회지
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• 제40권4호
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• pp.290-294
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• 2021

BACKGROUND: Barley sprouts contain a large number of secondary metabolites such as polyphenols, saponarin, and policosanols. The synthesis of such secondary metabolites occurs as a defense mechanism against external environmental stresses. In particular, it has been widely known that drought stress (DS) increases the content of flavonoids in plants. The objective of this study was to investigate the effects of drought stress treatment on the saponarin content in barley sprouts during the growing period. METHODS AND RESULTS: In this study, changes in saponarin content with different DS exposure periods and times were evaluated under the hydroponic system. For establishing different DS treatment periods, water supply was stopped for 1, 2, and 3 days, once leaf length was at 10 cm. To control different DS treatment times, water supply was stopped for 2 days, once leaf lengths were 5, 10, and 15 cm. As a result, the water potential of barley sprouts decreased from -0.8 MPa (before DS treatment) to -1.2, -2.4, and -3.2 MPa (after DS treatment), and reversely recovered to -0.8 MPa after re-irrigation. When 10 cm leaves were subjected to DS for 1 and 2 days, the saponarin content increased by 12 and 10%, respectively, while it increased by 19% when DS was applied to the 5 cm leaves. CONCLUSION(S): The results of this study suggest that drought stress at the early stage of growth (5 cm) is most helpful to increase the saponarin content of barley sprouts.

• Journal of Plant Biotechnology
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• 제38권3호
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• pp.203-208
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• 2011

We transferred Dhn5 (dehydrin5) gene from barley to poplar to determine the effect of its expression on the transgenic poplars. The results from northern blot analysis showed that the expression level of gene varied among the transgenic lines. During their culture on tissue culture media, the transgenic poplars formed vigorous growing callus in the presence of 5% PEG. When the transgenic poplars were growing in pots and witheld watering, they stayed much healthier than nontransgenic poplars. The transgenic poplars showed higher rates of photosynthetic rates, stomatal conductance and evaporation rates under the drought stress, although there was no significant difference in soil water content within the treatments. The relative electrical conductivity of the transgenic poplars after 20% PEG treatment was lower than that of nontransgenic poplars. The results provide evidence that the expression of hvDhn5 gene conferred drought tolerance in the transgenic poplars.

• 한국약용작물학회지
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• 제17권5호
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• pp.328-334
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• 2009

Experimental purpose was to evaluate growth characteristic and abscisic acid (ABA) responses against salt/drought stresses. In the shoot biomass, creeping thyme was tolerated in mild NaCl stress, ranging 0 to 100 mM, while it was severely reduced in higher salinity. Under constant drought stress, the shoot biomass of creeping thyme showed a worse value compared to that of 100 mM NaCl treatment. Chlorophyll degradation was more severe in immature leaf than mature leaf under salt and drought stresses. In salt stress, immature leaf produced much amounts of ABA compared to mature leaf and also immature leaf showed faster increase of ABA than that of mature leaf. In drought stress, immature leaf responded to stress within 24 hours by the increase of ABA, while mature leaf responded to at 72 hours. Our results recommended that the optimal salinity level of creeping thyme was 50~100 mM NaCl.