Genetically modified (GM) crops have been developed worldwide through the recombinant DNA technology and commercialized by various agricultural biotechnological companies. Commercialization of GM crops will be required the assessment of risk associated with the release of GM crops. In this study, we carried out to provide the molecular characterization of introduced T-DNA in transgenic rice T4 ~ T6 generation lines harboring a pepper MsrB2 gene under the control of stress inducible Rab21 promoter, as a part of biosafety evaluation for drought-tolerant transgenic rice (CaMsrB2). We identified the structure and sequence of transformation vector of T-DNA and analyzed insertion sites, flanking sequences, and generational stability of inserted T-DNA in transgenic rice lines. The transformation vector was consisted of right border, a drought-tolerant CaMsrB2 gene unit, a selectable marker herbicide resistance unit, and left border in a sequential order. Based on the adaptor-ligation PCR and whole genome sequence database, we confirmed that T-DNA was introduced at the position of 41,737,284 bp of chromosome No. 1. From the generational stability study, T-DNAs were stably inherited through the T4 to T6 generations, and also stable expression of bar gene from T-DNA was confirmed. These results will be filed to biosafety assessment document of CaMsrB2 rice.
Genetically modified (GM) plant claims to be the solution to global poverty, and potentially solving environmental change and food requirement by increased human population. In this study, we were evaluating agronomic characteristics and chemical properties of two GM drought-tolerant rice (CaMsrB2-8 and CaMsrB2-23) compared with donor cultivars (Ilmi). Statistical analysis agronomic characteristics GM and donor rice showed no significant difference between both of them. Yield and appearance of rice grain, GM rice was a similar to the donor rice. Chemical composition analysis showed that GM drought-tolerant rice has no different with donor rice. This result indicated that GM drought tolerant rice has no big significant difference agronomic character and chemical properties; it can be solve food shortages in spite of drought condition.
As the drought is getting worse, Lot of studies related to drought stress in plant have been conducted. Recently whole genome sequencing of Brassica rapa ssp which is important vegetable crop to East Asians has been completed to enable Omic research. It is known that the drought damages occur in the early stage of plant development. Here, we performed shotgun proteomics analysis of B. rapa to observe the morphological characters, monitor the expression patterns of the identified proteins during drought stress, and detect the proteins related to drought stress. The three week old B. rapa grown in density of single plant in a single pot were used. Drought stress were treated as that a single plant in soil was removed from the pot and the plant with soil was exposed to air and light without watering. Leaves were immediately harvested before drought treatment, 24hr after drought treatment, and 48hr after drought treatment. The protein expression patterns were monitored by a quantitative shotgun proteomics analysis. Extracted proteins were separated in 1D-SDS-PAGE then the gel sliced into seven pieces. Chopped gels were ingel-digested. Peptides were assigned to mass spectrometry (Q-Exactive). The ms/ms spectra were analyzed through Proteome Discoverer. By combining all of the identified proteins in the seven sliced gel samples, total B. rapa proteome reference map was completed. Protein expression patterns were investigated by comparing the quantity of protein. With shotgun proteomic approach, we evaluated the changes in the quantity and finally discovered the candidate proteins related with drought stress.
Drought tolerance is the ability of a plant to live, grow, and reproduce properly with limited water supply or under periodic conditions of water deficit. However, the climate changes and worldwide water shortages would result in the loss of applied water to irrigated land, increasing soil water deficit. To control the situation, we have carried out the international joint research project for the aim of developing that drought tolerance common wheat and durum wheat in Korea and Tunisia. Total 79 (41 common wheat, 39 durum wheat) Tunisian lines and 33 Korean wheat cultivars were incorporated in this study. Drought stress was applied for 25 days of stopping irrigation from the 3-leaf stage followed by re-watering for restoration in greenhouse. We selected top 13 (5 Korean line, 8 Tunisian line) tolerant lines and 11 (5 Korean, 6 Tunisian) susceptible lines based on growth parameter analysis. Primers (Operon primers and wheat Dreb1 gene) that have been known to be related drought resistance were applied to explain selected population. The correlation between PCR-based length polymorphism of selected lines and their resistance were evaluated. The obtained primer information will aid selection for drought tolerance durum as well as hexaploid common wheat.
Plant growth under water-deficit conditions adversely affects many key processes. Efforts to understand drought stress-related defense mechanisms have revealed a host of plant genes using molecular approaches in rice. Here, we report the novel finding that OsCTR1 E3 ligase regulates both chloroplast-localized chloroplast protein 12 (OsCP12) and ribosomal protein 1 (OsRP1) in protein levels and subcellular localization. The results of a yeast-two hybrid assay, bimolecular fluorescence complementation assay, ubiquitination assay, subcellular localization, and a protein degradation assay support the hypothesis that OsCTR1 functions in trafficking inhibition and proteolysis of OsCP12 and OsRP1 via the ubiquitin 26S proteasome pathway. Heterogeneous overexpression of OsCTR1 in Arabidopsis showed ABA-hypersensitive phenotype in seed germination, seedling growth, and stomatal closure. The transgenic plants also exhibited improvement of water-deficit tolerance with an accumulation of hydrogen peroxide production. These results demonstrate that the OsCTR1 E3 ligase might positively regulate the cellular functions of OsCP12 and RP1 related to photosynthesis under drought stress conditions in rice.
Low temperature is a major factor restrict to growth and limiting productivity of rice crops. We used a cDNA microarray approach to monitor the expression profile of rice (Oryza sativa) under chilling stress and identified 20 chilling inducible genes in previously study. Ten such genes encoding bHLH, metal transporter and, zinc finger protein with unknown functions showed a significant change in expression under various abiotic stresses. Among them, OsCHI1 (Os07g15460), OsCHI2 (Os02g43660), and OsCHI3 (Os01g61160), were selected for further study. They have structural features such as metal-binding signature sequences in their protein sequences, and OsCHI genes were expressed in root of rice seedling and induced in chilling and salt or drought. Expression of OsCHI1, OsCHI3 and OsCHI2 were targeted to membrane and ER when transiently expressed in tobacco cell, respectively. The Arabidopsis (Arabidopsis thaliana) transgenic plants overexpressing showed increased tolerance to salt and drought stress in the seed germination and root elongation than that of wild type. This comprehensive study provides insight into the biological function of OsCHIs, which may be useful in understanding how rice plants adapt to unfavorable environmental conditions.
This study was conducted to provide basic data for high-throughput screening (HTS) system construction based on phenomics. Rice (Oryza sativa cv. Chucheongbyeo) seedlings in vegetative growth stage were grown in the glass house and treated with 0, 3.75, 7.5, 15, and 30% (w/v) of polyethylene glycol (PEG) to give osmotic stress. Three days after PEG treatment, hyper-spectral reflectance images were obtained and analyzed after removing background image in several steps. The reflectance of rice seedlings treated with 15 and 30% of PEG solutions were significantly different at 680 nm, where differences in the chlorophyll reflectance spectrum and visual symptoms were not observed. These results thus indicate that hyper-spectral reflectance observed at 680 nm can be used to screen drought tolerant rice lines. A HTS system equipped with this hyper-spectral reflectance system may play an important role of future rice breeding program.
Drought and salinity are the major abiotic stresses which are being continued to hamper the ecosystem and agriculture of the affected region. Plant species have adaptations to enhance their ability to tolerate stresses through physiological adjustment. Therefore, substantial amount of research are ongoing to provide insights about those mechanisms which enlighten the stress tolerance in plant. In this study, several rice cultivars were collected from the different parts of the world and ion accumulation experiments were conducted to select the best stress tolerant cultivar in drought and salt stress environment.
For stress treatment, five rice cultivars were subjected to salt (200 mM NaCl) and drought (200 mM Mannitol) for 72h. Later Na+, Ca++, K+ concentrations in shoot and root samples were examined at different time interval. In both drought and salt stress, rice cultivar C201 (collected for uzbekistan) showed the lowest levels of Na+ ion and Na+: K+ ratio compared to other cultivars. It was significant parallel observation with pokkali (known salt tolerant cultivar). In this preliminary study, it was observed the C201 had more stress tolerant in terms of ion accumulation; however detail physiological studies are required to strengthen the idea regarding the best stress tolerant physiotype.
This study was conducted to figure out the differences in physiological responses, e.g. growth, photosynthetic activity and water potential, and photoinhibition tolerance in photosystem between superior and inferior families of Pinus densiflora under drought condition. Superior which is KW85 and inferior which is KW40 families were selected using progeny test results of height growth. In 2007, seeds were collected from seed orchard. In 2008, seedlings were produced and cultivated, and from April 2009 drought treatment was started with shading treatment and plants were harvested in Sept. 2009. There was no significant difference in height growth between families. In case of leaf water potential, KW85 showed higher water potential under drought condition. But there was no significant difference in drought with shading treatment. There was no difference in photosynthetic rate but stomatal conductance and transpiration rate of KW85 showed lower value than KW40. So water use efficiency of KW85 showed higher value in every treatment. Non-photochemical quenching of KW40 showed higher value in drought treatment, but there was no significant difference in control and drought with shading treatment. Xanthophyll cycle pool size of KW85 showed higher value in drought treatment, but in drought with shading treatment KW40 showed higher value. Selected superior family showed higher drought tolerance according to water use efficiency, and it also has effective non-photochemical quenching ability. In contrast inferior family respond more sensitively in photoinhibition under drought condition.
가뭄저항성벼의 복수세대에 대한 후대안정성을 서던 블롯과 PCR로 분석한 결과, 가뭄저항성벼의 CaMsrB2-8 T4 ~ T6 세대에서는 도입된 모든 유전자들이 안정적으로 도입되어 있으며, T-DNA 구성요소 이외의 backbone DNA는 가뭄저항성벼에 삽입되지 않았음을 확인하였다. 목적 유전자인 CaMsrB2와 제초제 저항성 선발 마커인 bar가 가뭄저항성벼의 CaMsrB2-8 T4 ~ T6 세대에서 안정적으로 발현됨을 검증하였다. 제초제 저항성 선발 마커로 도입된 PAT 단백질의 발현 분석 결과에서도 CaMsrB2-8 T4 ~ T6의 3세대에서 생육시기별, 부위별로 안정적으로 발현됨을 입증하였다. 도입유전자의 삽입 위치를 확인한 결과, 가뭄저항성벼 CaMsrB2-8의 도입유전자가 벼 1번 염색체 내에서 intergenic한 상태로 안정적으로 유지되고있음을 확인하였다. 이상의 분석 기법을 통해 복수세대에서 가뭄저항성벼의 도입 유전자들이 안정적으로 유지되고 목적 단백질들이 안정적으로 발현되고 있음을 확인하였다.
Recently, the occurrences of droughts have been increased because of global warming and climate change. Water resources that mostly rely on groundwater are particularly vulnerable to the impact of precipitation variation, one of the major elements of climate change, are very sensitive to changes in the seasonal distribution as well as the average annual change in the viewpoint of agricultural activity. In this study, the status of drought for the present and future on Jeju Island which entirely rely on groundwater using SPI and PDSI were analyzed considering regional distribution of crops in terms of land use and fluctuation of water demand. The results showed that the precipitation distribution in Jeju Island is changed in intensity as well as seasonal variation of extreme events and the amount increase of precipitation during the dry season in the spring and fall indicated that agricultural water demand and supply policies would be considered by regional characteristics, especially the western region with largest market garden crops. Regarding the simulated future drought, the drought would be mitigated in the SPI method because of considering total rainfall only excluding intensity variation, while more intensified in the PDSI because it considers the evapotranspiration as well as rainfall as time passed. Moreover, the drought in the northern and western regions is getting worse than in the southern region so that the establishment of regional customized policies for water supply in Jeju Island is needed.
본 연구에서는 가뭄빈도해석을 위해 이변량 확률분포함수를 적용하였으며, 가뭄 특성(가뭄 지속기간과 심도)의 상호 관계를 고려하여 지역적 가뭄특성을 종합적으로 판단하였다. 또한 단변량 가뭄해석의 한계점을 극복하기 위한 방안으로 이변량 가뭄해석을 수행하였으며, 이를 위해 코플라 함수를 적용하였다. 가뭄 발생의 확률 및 경향성을 종합적으로 나타내어 줄 수 있는 결합 확률밀도함수를 추정한 후, 지점별 가뭄빈도해석 및 과거 최대가뭄사상에 대한 단변량 및 이변량 재현기간을 산정하여 비교·분석하였다. 또한, 우리나라의 과거 최대가뭄사상에 대한 가뭄위험도분석을 위해, 연속되는 50년과 100년 동안 최소 한번 발생하는 확률(과거 최대가뭄사상 크기의 가뭄)을 강우관측지점별로 계산하여 가뭄위험지역을 예상하였다. 그러나 우리나라와 같이 강수자료의 기록연한이 짧은 경우에는 이변량 가뭄빈도해석을 수행하는 데 큰 불확실성을 야기할 가능성이 있다. 그러므로 가뭄해석 결과의 불확실성을 정량화시키기 위한 방안으로 강수모의기법을 활용하였으며, 그 결과 관측된 가뭄사상으로 추정된 이변량 가뭄빈도곡선에 대한 5%, 25%, 50%, 75%, 그리고 95%의 신뢰구간을 제시할 수 있었다. 또한 가뭄 지속기간과 심도의 95% 신뢰수준에 대한 이변량 가뭄재현기간의 경계값(상한값 및 하한값)을 추정하였다. 그 결과 불확실성의 원인은 가뭄빈도해석 시 고려되었던 두 변량에 대한 낮은 상관성으로 인해, 확률적인 방법으로 결합분포모형을 추정하는 데 있어 발생한 불확실성인 것으로 확인되었다.
본 연구의 목적은 기록된 관측가뭄자료를 이용하여 수문기상 기반의 국내 가뭄판단기준을 제시하는데 있다. 과거 1991년에서 2009년까지 기록된 가뭄사례를 수집한 후, 관측기상정보와 LSM(Land Surface Model)으로부터 생산된 수문정보를 이용하여 백분위 해석을 수행하였다. 기간별 가뭄판단기준을 도출하기 위해 객관적 가뭄평가 기법인 ROC(Relative Operating Characteristics) 분석을 이용하였다. 국내 가뭄기준은 대표적으로 강수 및 유출이 지속기간 3개월에 평년대비 35% 이하, 토양수분이 지속기간 2개월의 35% 이하 그리고 증발산량이 지속기간 3개월에 65% 이상으로 나타났다. 가뭄판단기준의 적용성 평가를 위해 SPI(3)와의 ROC 분석을 수행한 결과 SPI(3)에 비해 적용성이 높은 것으로 나타났다. 또한 가뭄판단기준에 대한 지역별 분석을 수행한 결과 공간적으로 가뭄상황을 적절히 반영하는 것을 확인하였다.
가뭄은 불가피성과 반복성을 가진 자연 현상이므로 가뭄 발생 전 사전대비계획과 가뭄발생시 가뭄관리체계 구축을 통해 그 피해를 최소화해야 한다. 본 연구에서는 대상지역의 가뭄심도를 평가하여 가뭄상황에 대처하고자 우리나라에 적합한 가뭄 분류기준을 제시하였다. 관측년수 30년 이상의 강우자료를 확보한 61개 지점에 대해 1973년부터 37년 기간의 월강우량 자료를 사용하였고, 현재 국가에서 사용하고 있는 가뭄상황단계를 그대로 적용하여 가뭄 구간을 총 4등급으로 구분하였다. 기존의 주요 가뭄발생현황을 참고하여 우리나라에 맞는 가뭄심도의 분류기준을 가뭄 발생의 누가확률 98~100%는 예외적인 가뭄, 94-98%는 극심 가뭄, 90~94%는 심한 가뭄, 86~90%는 보통 가뭄으로 구분하였다. 각 지점의 가뭄지수(SPI, PDSI)를 내림차순으로 작성하여 가뭄심도 분류기준에 맞는 가뭄지수의 정량적 값을 산정하였다.
SPI와 PDSI의 가뭄심도 분류 결과와 실제 가뭄을 비교하기 위해 년 단위 비교와 월 단위 비교를 분석한 결과, 년 단위 비교와 SPI의 월 단위 비교는 각 지역의 가뭄지수 평가가 대부분 일치하게 나타났으나 같은 기간의 PDSI의 월 단위 비교는 일치하지 않는 기간도 나타났다. 이는 이들 지수의 상호보완에 대한 추후 연구의 필요성을 보여주는 것으로 판단되었다.
본 연구에서는 copulas 기반의 결합가뭄지수를 적용한 가뭄심도-영향면적-지속기간 곡선을 작성하여 가뭄의 시공간적 거동을 살펴보았다. 우리나라 전국 60개 지점의 기상청 월 강수량 자료로부터 JDI를 산정한 후, 이를 다시 EOF와 Kriging 기법을 이용하여 10 × 10 km의 공간적 해상도를 가진 JDI 값으로 할당하였다. 격자기반의 JDIs를 가뭄의 지속기간별 영향면적별로 분석하고, 우리나라의 가뭄 사상을 표현하기 위하여 JDI-SAD 곡선을 작성하였다. JDI-SAD 곡선을 통하여 과거에 발생한 가뭄 사상을 시공간적으로 특성화할 수 있다. 또한 현재의 가뭄 상황에 대한 정확한 영향평가에 기여할 것으로 기대된다.
본 연구에서는 기상학적 가뭄지수인 SPI(Standardized Precipitation Index)를 이용한 가뭄 빈도해석을 통하여 남한지역에서 발생했던 과거가뭄사상의 시, 공간적 분포 특성을 정량적으로 평가하고자 한다. 가뭄의 심도별, 지역별 발생빈도를 추정하기 위하여 Drought Spell 분석을 실시하였고, 또한 남한지역을 대상으로 심한 가뭄에 대한 가뭄우심지역의 공간적 분포특성을 평가하기 위하여 가뭄의 지속기간별 가뭄빈도해석을 통해 기상관측소별 SDF (severity-duration-frequency) 곡선을 작성하고 이를 이용하여 남한지역을 대상으로 하는 가뭄우심도(Potential Drought Hazard Map)를 작성하였다. 가뭄단계별 과거의 발생빈도를 분석한 결과, 금강, 낙동강, 섬진강 유역에서 심한가뭄과 극한가뭄단계의 발생빈도가 매우 큰 것으로 나타났으며 가뭄빈도해석을 통해 작성된 SDF 곡선에서도 한강유역에 위치한 서울관측소에 비해 금강, 낙동강, 섬진강 유역에 위치한 대전, 대구, 광주 관측소의 재현기간별 가뭄심도가 심하게 나타났다. 가뭄빈도해석을 통해 작성된 가뭄우심도에서는 한강 유역과 낙동강 유역의 상류 지역에 비해 금강, 섬진강, 영산강 유역이 가뭄에 취약했던 지역으로 분석되었으며 가뭄단계별 발생빈도와 유사한 결과를 나타내었다. 계절별 가뭄우심도의 경우 봄철에 가장 자주 가뭄이 발생하였으며 짧은 지속기간의 가뭄이 자주 발생했던 것으로 나타났다.
가뭄은 자연의 무시할 수 없는 재해이며, 비록 가뭄의 정의가 많이 있지만 가뭄은 장기간의 강우의 부족으로부터 기인한다. 기상학적 가뭄심도의 정도를 표현하기 위해 널리 이용되는 표준강수지수(Standardized Precipitation Index, SPI)는 강수 이외의 기온과 관련된 변수를 고려하지 않기 때문에 기후변동으로 인한 강수, 증발산 등의 물수지 변화를 고려할 수 없다는 한계점이 있다. 그러나 최근에 SPI와 유사하지만 기후변동으로 인한 강수 변화뿐만 아니라 기온의 변동성이 미치는 영향을 반영할 수 있는 새로운 개념의 가뭄지수인 표준강수 증발산지수(Standardized Precipitation Evapotranspiration Index, SPEI)가 개발되었다. 본 연구에서는 기상청 산하의 60개 기상관측소의 1973~2011년까지 기상자료를 대상으로 SPEI를 적용하여 남한지역의 가뭄발생의 변화를 평가하였다. 적용 결과, 전국적으로 SPI와 SPEI 모두 봄과 겨울에 가뭄이 심화되고 여름철에는 가뭄이 완화되는 경향을 보였으며, SPEI는 SPI보다 가뭄심도를 크게 나타내었다. 또한, 지속기간 12개월의 SPI와 SPEI는 전반적으로 6년 내외의 저빈도 주기성을 갖는 극심한 가뭄이 반복되고 있음을 보였다.
Tocopherols (α-, β-, γ- and δ-tocopherols) represent a group of lipophilic antioxidants which are synthesized only by photosynthetic organisms. It is widely believed that protection of pigments and proteins of photosynthetic system and polyunsaturated fatty acids from oxidative damage caused by reactive oxygen species (ROS) is the main function of tocopherols. In the present study, NtTC, which encodes a tobacco tocopherol cyclase ortholog, was cloned and characterized. Compared with control plants, NtTC transgenic rice showed higher tolerance to drought stress, and total tocopherol content increased by 52 % in leaf. Additionally, total antioxitant activity of NtTC transgenic lines was increased significantly by 19%. These results demonstrate that over-expressing NtTC could improve the tolerance to abiotic stress in rice, and tocopherols play a crucial role in the protection of oxidative stress.
Environmentally inflicted stress (abiotic stress) such as high drought stress could be limiting the plant productivity. The mechanism of drought stress signaling in plant related with anti-apoptosis has not yet been full described. Understanding drought stress signaling is key to producing drought-tolerant plant. In this study we recently have identified Oryza sativa genes related abiotic stress water deficit. Abiotic stress related genes were screened from Oryza sativa cDNA library and identified gene by yeast functional screening. The yeast expression showed that they east cell grow well on SD-galactose-Leu-Ura-. The screening of over than 7000 clones from Oryza sativa cDNA libraries has been identified. 28 clones that survived following BAX-expression on inducible galactose medium. R12H780 clones confirmed protein prediction like putative senescence-associated-protein. This gene contains an open reading frame (ORF) of 108 amino acids. Transcription of R12H780 was induced in response to drought stresses, RT-PCR analysis showed transcript level in plant strongly detected in earliest time of drought stress treatment. Yeast transformed with R12H780 gene displayed markedly improved tolerance to PEG treatment, and high salinity in comparison to the control yeast (vector only). The results indicate R12H780 expression represents a new type of drought stress related gene with anti-apoptotic in Oryza sativa and endows tolerance to several types abiotic stress.
Transgenic cymbidium plants containing drought and salt stresses tolerance genes were produced by using a highly efficient Agrobacterium-mediated transformation system.
The gene (AtSZF2) is salt and drought stresses tolerant gene and transferred into cymbidium plants. These transgenic cymbidium plants are investigated for gene introduction by PCR and analyzed by salt and drought stresses to check its gene expression. To investigate the gene expression of AtSZF2, leaves of transgenic cymbidium plants were soaked in salt solution (200 mM NaCl). Also, transgenic cymbidium plants were kept under no watering for 6 weeks to check the expression of drought stress tolerance. As a result, wild type plants showed more damage than transgenic plants under salt treatment. Further, transgenic cymbidium plants retained green color and healthy status, while wild type plants showed no tolerance after 6 weeks of no-watering treatment.