• Journal of Microbiology and Biotechnology
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• 제31권8호
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• pp.1045-1059
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• 2021

Various abiotic stressors like drought, salinity, temperature, and heavy metals are major environmental stresses that affect agricultural productivity and crop yields all over the world. Continuous changes in climatic conditions put selective pressure on the microbial ecosystem to produce exopolysaccharides. Apart from soil aggregation, exopolysaccharide (EPS) production also helps in increasing water permeability, nutrient uptake by roots, soil stability, soil fertility, plant biomass, chlorophyll content, root and shoot length, and surface area of leaves while also helping maintain metabolic and physiological activities during drought stress. EPS-producing microbes can impart salt tolerance to plants by binding to sodium ions in the soil and preventing these ions from reaching the stem, thereby decreasing sodium absorption from the soil and increasing nutrient uptake by the roots. Biofilm formation in high-salinity soils increases cell viability, enhances soil fertility, and promotes plant growth and development. The third environmental stressor is presence of heavy metals in the soil due to improper industrial waste disposal practices that are toxic for plants. EPS production by soil bacteria can result in the biomineralization of metal ions, thereby imparting metal stress tolerance to plants. Finally, high temperatures can also affect agricultural productivity by decreasing plant metabolism, seedling growth, and seed germination. The present review discusses the role of exopolysaccharide-producing plant growth-promoting bacteria in modulating plant growth and development in plants and alleviating extreme abiotic stress condition. The review suggests exploring the potential of EPS-producing bacteria for multiple abiotic stress management strategies.

• Journal of Plant Biotechnology
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• 제31권2호
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• pp.109-113
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• 2004

산화스트레스에 내성을 지닌 형질전환 감자 식물체를 개발하기 위하여 산화스트레스에 의해 발현이 강하게 유도되는 SWPA2 프로모터에 CuZnSOD와 APX 유전자가 엽록체에서 동시에 발현되도록 연결한 형질전환 벡터 (pSSA-K)를 제작한 후 Agrobacterium 매개로 형질전환 하였다. 기관 발생 경로에 의해 kanamycin 저항성 식물체를 재분화 시킨후 Southern 분석으로 외래 유전자가 안정적으로 감자 게놈내로 삽입되었음을 확인하였다. 형질전환 감자 식물체의 잎 조직에 10$\mu$M methyl viologen을 처리하여 산화스트레스 내성 검정을 조사한 결과 형질전환체는 MV에 대해 강한 내성을 지님을 확인하였다. 내성을 보인 개체 중에서 환경스트레스에 대한 내성 조사를 위하여 품종별로 2 개체씩 선발하였다. 선발된 식물체는 건조, 고온 등의 여러 가지 환경스트레스 내성검정에 이용될 것이며 향후 복합재해 내성 감자 품종이 개발될 수 있을 것으로 기대한다.

• Journal of Plant Biotechnology
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• 제37권4호
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• pp.425-441
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• 2010

Forages are the backbone of sustainable agriculture. They includes a wide variety of plant species ranging from grasses, such as tall fescue and bermudagrass, to herbaceous legumes, such as alfalfa and white clover. Abiotic stresses, especially salinity, drought, temperature extremes, high photon irradiance, and levels of inorganic solutes, are the limiting factors in the growth and productivity of major cultivated forage crops. Given the great complexity of forage species and the associated difficulties encountered in traditional breeding methods, the potential from molecular breeding in improving forage crops has been recognized. Plant engineering strategies for abiotic stress tolerance largely rely on the gene expression for enzymes involved in pathways leading to the synthesis of functional and structural metabolites, proteins that confer stress tolerance, or proteins in signaling and regulatory pathways. Genetic engineering allows researchers to control timing, tissue-specificity, and expression level for optimal function of the introduced genes. Thus, the use of either a constitutive or stress-inducible promoter may be useful in certain cases. In this review, we summarize the recent progress made towards the development of transgenic forage plants with improved tolerance to abiotic stresses.

• 식물병연구
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• 제24권3호
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• pp.242-247
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• 2018

Pseudomonas chlororaphis O6 induces systemic tolerance in plants against drought stress. A volatile, 2R, 3R-butanediol, produced by the bacterium causes partial stomatal closure, thus, limiting water loss from the plant. In this study, we report that applications of extracellular polymeric substances (EPS) from P. chlororaphis O6 to epidermal peels of leaves of Arabidopsis thaliana also reduce the size of stomatal openings. Growth of A. thaliana seedlings with applications of the EPS from P. chlororaphis O6 reduced the extent of wilting when water was withheld from the plants. Fluorescence measurements showed photosystem II was protected in the A. thaliana leaves in the water stressed EPS-exposed plants. These findings indicate that P. chlororaphis O6 has redundancy in traits associated with induction of mechanisms to limit water stress in plants.

• Journal of Plant Biotechnology
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• 제42권3호
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• pp.168-179
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• 2015

We previously identified the rice gene, OsSAP, as an encoder of a highly conserved putative senescence-associated protein that was shown to have anti-apoptotic activity. To confirm the role of OsSAP in inducing abiotic stress tolerance in rice, we introduced OsSAP and AtBI-1, a plant homologue of Bax inhibitor-1, under the control of the CaMV 35S promoter into the rice genome through Agrobacterium-mediated transformation. The OsSAP transformants showed a similar chlorophyll index after salinity treatments with AtBI-1. Furthermore, we compared the effects of salinity stress on leaves and roots by examining the hormone levels of abscisic acid (ABA), jasmonic acid (JA), gibberellic acid (GA3), and zeatin in transformants compared to the control. With the exception of phytohormones, stress-induced changes in hormone levels putatively related to stress tolerance have not been investigated previously. Hormonal level analysis confirmed the lower rate of stress in the transformants compared to the control. The levels of ABA and JA in OsSAP and AtBI-1 transformants were similar, where stress rates increased after one week and decreased after a two week period of drought; there was a slightly higher accumulation compared to the control. However, a similar trend was not observed for the level of zeatin, as the decrease in the level of zeatin accumulation differed in both OsSAP and AtBI-1 transformants for all genotypes during the early period of salinity stress. The GA3 level was detected under normal conditions, but not under salinity stress.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2020년도 추계학술대회
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• pp.133-133
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• 2020

• 한국자원식물학회지
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• 제11권1호
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• pp.93-100
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• 1998

This study was to investigate the dry weight, the amount of Na+ and K+ water potential and leaf photosynthesis rate in plants for determining the salt tolerance mechanism in rice cultivars on soil and solution culture with NaCl. The results obtained in this study are summarized as follows ; In general, rice cultivars, cv. Tetep and Jinbu, having high salt tolerance in ID(identified on dry matter production level) showed the higher salt tolerance in RGR (relative growth rate), compared with rice cultivars(cv. Nonglim 41ho, Dunraebyeo and Sobackbyeo) having low salt tolerance. The contents of Na in rice differed depending on culivars and plant parts. Tetep contained 2.9times higher amounts of Na+ than leaf blade and root part. High salt tolerance cultivar Obongbyeo showed a larger decrease in osmotic potential than low salt tolerance cultivar Dunraebyeo suggesting that osmotic adjustment was developed under salt stress conditions in a salt tolerant cultivar . In order to know the IY(identified on grain yeild level using rice cultivars having different salt tolerance the capacity of photosyntheiss was investigated. The capapcity of photosynthesis in cv. Tetep and Obongbyeo having high salt tolerance was much higher that in cv.Dunraebyeo and Nonglim 41 having low salt tolerance.

• Journal of Plant Biotechnology
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• 제42권1호
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• pp.19-24
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• 2015

식물은 여러 환경스트레스에 적응하기 위해 스트레스 내성 유전자의 발현 혹은 proline, trehalose, glycine betaine (GB) 등과 같이 삼투압을 조절하는 compatible solute를 생성하면서 진화해 왔다. GB는 고염, 저온 등 환경스트레스 조건에서 식물의 엽록체에서 축적되는 물질 중 하나이다. 토양 박테리아 Arthrobacter globiformis에서 분리한 choline oxidase (codA) 유전자는 choline을 GB로 전환하는 기능을 한다. 본 연구에서는 산화스트레스 유도성 SWPA2 프로모터의 발현조절 하에 codA 유전자를 엽록체에 과발현시킨 형질전환 고구마 식물체(SC식물체)를 제작하여 다양한 환경스트레스 조건에서의 특성을 분석하였다. SC 식물체는 methyl viologen (MV)에 의한 산화스트레스와 건조 처리 조건에서 내성 증가를 보였다. $5{\mu}M$ MV 처리시 형질전환 식물체는 GB의 함량이 증가하였고 낮은 수준의 이온 전도도를 보였다. 건조 스트레스 조건에서 형질전환 식물체는 codA 유전자의 발현이 증가하였으며, 대조구 보다 높은 상대수분함량을 유지하였다. 따라서 본 연구결과의 SC식물체는 고염, 건조토양 등 조건 불리지역에 재배하면 바이오매스를 증가시킬 수 있을 것으로 예상된다.

• 한국식물생명공학회:학술대회논문집
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• 한국식물생명공학회 2004년도 생명공학 실용화를 위한 비젼
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• pp.25-28
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• 2004

• 한국식물생명공학회:학술대회논문집
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• 한국식물생명공학회 2002년도 추계학술대회
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• pp.49-58
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• 2002

Oxidative stress derived from reactive oxygen species (ROS) is one of the major damaging factors in plants exposed to environmental stress. In order to develop the platform technology to solve the global food and environmental problems in the 21s1 century, we focus on the understanding of the antioxidative mechanism in plant cells, the development of oxidative stress-inducible antioxidant genes, and the development of transgenic plants with enhanced tolerance to stress. In this report, we describe our recent results on industrial transgenic plants by the gene manipulation of antioxidant enzymes. Transgenic tobacco plants expressing both superoxide dismutase (SOD) and ascorbate peroxidase (APX) in chloroplasts were developed and were evaluated their protection effects against stresses, suggesting that simultaneous overexpression of both SOD and APX in chloroplasts has synergistic effects to overcome the oxidative stress under unfavorable environments. Transgenic tobacco plants expressing a human dehydroascorbate reductase gene in chloroplasts were showed the protection against the oxidative stress in plants. Transgenic cucumber plants expressing high level of SOD in fruits were successfully generated to use the functional cosmetic purpose as a plant bioreactor. In addition, we developed a strong oxidative stress-inducible peroxidase promoter, SWPA2 from sweetpotato (Ipomoea batatas). We anticipate that SWPA2 promoter will be biotechnologically useful for the development of transgenic plants with enhanced tolerance to environmental stress and particularly transgenic cell lines engineered to produce key pharmaceutical proteins.