• Journal of the Korean Institute of Landscape Architecture
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• v.41 no.5
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• pp.1-8
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• 2013

In order to evaluate 2 extensive green roof systems(Sedum Box Roof System and Roof-rainwater Utilization System) for urban greening and select ground-cover plants, which can adapt well to the drought tolerance in an extensive green roof system on 12 species. This study was carried out in order to suggest an experimental base in assessment of the Green Roof-rainwater Utilization System and selecting the drought resistance of plants. Adopting the natural drought method, this paper studies the drought resistance of 12 kinds of ground cover plants. The drought-resistance of ground cover plants subjected to dry processing time were evaluated using relative water content on leaves, relative electric conductivity and chlorophyll content in 12 kinds of plants, and the relation between soil water content under drought stress. Drought resistance of the plants were subject to rooftop drought resistance treatments. The result showed that with the increase of stress time, the relative water content and chlorophyll content on leaves were in a downward trend while the relative electric conductivity was in an upward trend. Among the 12 species of ground cover plants, excluding Pulsatilla koreana, Ainsliaea acerifolia was selected for rooftop plants because they showed resistance to drought strongly and took adaptive ability. These results showed that drought tolerance of plants in Roof-rainwater Utilization System were stronger than the Sedum Box Roof System. Therefore, the Roof-rainwater Utilization System is good for plants. It helps them adapt well to the drought tolerance in rooftops and can be used for urban greening.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.38-38
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• 2017

Water stress obstructs rice growth mainly by oxidative damage in biological cells to cause a reduction of leaf photosynthesis and evapotranspiration processes. In this study, exogenous application of vanillic acid (VA) and p-hydroxybenzoic acid (PHBA) to improve drought tolerance of two Oryza sativa cultivars, Q2 and Q8 was tested. The drought evaluation based on leaf phenotypes to show that both Q2 and Q8 resulted in remarkable water-stress tolerance induced by leaf spraying pretreatment of mixed solution of $50{\mu}M\;VA+50{\mu}M\;PHBA$. The mixtures of $25{\mu}M\;VA+25{\mu}M\;PHBA$ and $50{\mu}M\;VA+50{\mu}M\;PHBA$ treated on Q2 and Q8 in water deficit condition also indicated that total phenols, total flavonoids, and DPPH radical scavenging activity were significantly greater their controls. In general, the accumulation of individual phenolic acids was increased in exogenous phenolic treatments, as compared with controls. Particularly, Q2 obtained a considerable amount of endogenous PHBA after application of $50{\mu}M\;VA$, $25{\mu}M\;VA+25{\mu}M\;PHBA$, and $50{\mu}M\;VA+50{\mu}M\;PHBA$ (0.18 mg/g DW, 0.71 mg/g DW, and 1.41 mg/g DW, respectively); and a negligible content of VA (0.003 mg/g DW) appeared uniquely in the treatment of $50{\mu}M\;VA$. Similarly, Q8 also absorbed a significant quantity of PHBA in $50{\mu}M\;PHBA$, $25{\mu}M\;VA+25{\mu}M\;PHBA$, and $50{\mu}M\;VA+50{\mu}M\;PHBA$ treatments (0.15 mg/g DW, 0.15 mg/g DW, and 0.22 mg/g DW, respectively). In addition, the spraying $50{\mu}M\;PHBA$ and $25{\mu}M\;VA+25{\mu}M\;PHBA$ on Q8 leaves induced similar amount of drought tolerance of Q2 and Q8 were improved, paralleled with the increased amounts of endogenous phenolics revealed that VA and PHBA played an important role to enhance drought tolerance in rice.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.33-33
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• 2017

Water stress obstructs rice growth mainly by oxidative damage in biological cells to cause a reduction of leaf photosynthesis and evapotranspiration processes. In this study, exogenous application of vanillic acid (VA) and p-hydroxybenzoic acid (PHBA) to improve drought tolerance of two Oryza sativa cultivars, Q2 and Q8 was tested. The drought evaluation based on leaf phenotypes to show that both Q2 and Q8 resulted in remarkable water-stress tolerance induced by leaf spraying pretreatment of mixed solution of $50{\mu}M\;VA+50{\mu}M\;PHBA$. The mixtures of $25{\mu}M\;VA+25{\mu}M\;PHBA$ and $50{\mu}M\;VA+50{\mu}M\;PHBA$ treated on Q2 and Q8 in water deficit condition also indicated that total phenols, total flavonoids, and DPPH radical scavenging activity were significantly greater their controls. In general, the accumulation of individual phenolic acids was increased in exogenous phenolic treatments, as compared with controls. Particularly, Q2 obtained a considerable amount of endogenous PHBA after application of $50{\mu}M\;VA$, $25{\mu}M\;VA+25{\mu}M\;PHBA$, and $50{\mu}M\;VA+50{\mu}M\;PHBA$ (0.18 mg/g DW, 0.71 mg/g DW, and 1.41 mg/g DW, respectively); and a negligible content of VA (0.003 mg/g DW) appeared uniquely in the treatment of $50{\mu}M\;VA$. Similarly, Q8 also absorbed a significant quantity of PHBA in $50{\mu}M\;PHBA$, $25{\mu}M\;VA+25{\mu}M\;PHBA$, and $50{\mu}M\;VA+50{\mu}M\;PHBA$ treatments (0.15 mg/g DW, 0.15 mg/g DW, and 0.22 mg/g DW, respectively). In addition, the spraying $50{\mu}M\;PHBA$ and $25{\mu}M\;VA+25{\mu}M\;PHBA$ on Q8 leaves induced similar amount of VA (0.04 mg/g DW). Meanwhile, there were no trace of VA and PHBA found in controls. The levels of drought tolerance of Q2 and Q8 were improved, paralleled with the increased amounts of endogenous phenolics revealed that VA and PHBA played an important role to enhance drought tolerance in rice.

• BMB Reports
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• v.42 no.5
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• pp.271-276
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• 2009

Sweetpotato (Ipomoea batatas (L). Lam.) is relatively tolerant to unfavorable growth conditions such as drought, yet has not been exploited to provide a better understanding of the molecular basis of drought stress tolerance. We obtained 983 high-quality expressed sequence tags of 100 bp or longer (average length of 700 bp) from cDNA libraries of detached white fibrous root tissues by subjecting them to dehydration for 6 h. The 431 cDNAs were each assigned a function by alignment using the BLASTX algorithm. Among them, three genes associated with various abiotic stresses and nine genes not previously associated with drought stress were selected for expression pattern analysis through detailed reverse transcription-polymerase chain reaction. The direct and indirect relationships of the 12 genes with drought tolerance mechanisms were ascertained at different developmental stages and under various stress conditions.

• BMB Reports
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• v.47 no.1
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• pp.27-32
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• 2014

Plant abiotic stress tolerance has been modulated by engineering the trehalose synthesis pathway. However, many stress-tolerant plants that have been genetically engineered for the trehalose synthesis pathway also show abnormal development. The metabolic intermediate trehalose 6-phosphate has the potential to cause aberrations in growth. To avoid growth inhibition by trehalose 6-phosphate, we used a gene that encodes a bifunctional in-frame fusion (BvMTSH) of maltooligosyltrehalose synthase (BvMTS) and maltooligosyltrehalose trehalohydrolase (BvMTH) from the nonpathogenic bacterium Brevibacterium helvolum. BvMTS converts maltooligosaccharides into maltooligosyltrehalose and BvMTH releases trehalose. Transgenic rice plants that over-express BvMTSH under the control of the constitutive rice cytochrome c promoter (101MTSH) or the ABA-inducible Ai promoter (105MTSH) show enhanced drought tolerance without growth inhibition. Moreover, 101MTSH and 105MTSH showed an ABA-hyposensitive phenotype in the roots. Our results suggest that over-expression of BvMTSH enhances drought-stress tolerance without any abnormal growth and showes ABA hyposensitive phenotype in the roots.

• Molecules and Cells
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• v.41 no.11
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• pp.979-992
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• 2018

Potato (Solanum tuberosum L.) is the third most important food crop, and breeding drought-tolerant varieties is vital research goal. However, detailed molecular mechanisms in response to drought stress in potatoes are not well known. In this study, we developed EMS-mutagenized potatoes that showed significant tolerance to drought stress compared to the wild-type (WT) 'Desiree' cultivar. In addition, changes to transcripts as a result of drought stress in WT and drought-tolerant (DR) plants were investigated by de novo assembly using the Illumina platform. One-week-old WT and DR plants were treated with -1.8 Mpa polyethylene glycol-8000, and total RNA was prepared from plants harvested at 0, 6, 12, 24, and 48 h for subsequent RNA sequencing. In total, 61,100 transcripts and 5,118 differentially expressed genes (DEGs) displaying up- or down-regulation were identified in pairwise comparisons of WT and DR plants following drought conditions. Transcriptome profiling showed the number of DEGs with up-regulation and down-regulation at 909, 977, 1181, 1225 and 826 between WT and DR plants at 0, 6, 12, 24, and 48 h, respectively. Results of KEGG enrichment showed that the drought tolerance mechanism of the DR plant can mainly be explained by two aspects, the 'photosynthetic-antenna protein' and 'protein processing of the endoplasmic reticulum'. We also divided eight expression patterns in four pairwise comparisons of DR plants (DR0 vs DR6, DR12, DR24, DR48) under PEG treatment. Our comprehensive transcriptome data will further enhance our understanding of the mechanisms regulating drought tolerance in tetraploid potato cultivars.

• Journal of Microbiology and Biotechnology
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• v.32 no.5
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• pp.582-593
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• 2022

Among abiotic stresses in plants, drought and chilling stresses reduce the supply of moisture to plant tissues, inhibit photosynthesis, and severely reduce plant growth and yield. Thus, the application of water stress-tolerant agents can be a useful strategy to maintain plant growth under abiotic stresses. This study assessed the effect of exogenous bio-based 2,3-butanediol (BDO) application on drought and chilling response in tomato and turfgrass, and expression levels of several plant signaling pathway-related gene transcripts. Bio-based 2,3-BDOs were formulated to levo-2,3-BDO 0.9% soluble concentrate (levo 0.9% SL) and meso-2,3-BDO 9% SL (meso 9% SL). Under drought and chilling stress conditions, the application of levo 0.9% SL in creeping bentgrass and meso 9% SL in tomato plants significantly reduced the deleterious effects of abiotic stresses. Interestingly, pretreatment with levo-2,3-BDO in creeping bentgrass and meso-2,3-BDO in tomato plants enhanced JA and SA signaling pathway-related gene transcript expression levels in different ways. In addition, all tomato plants treated with acibenzolar-S-methyl (as a positive control) withered completely under chilling stress, whereas 2,3-BDO-treated tomato plants exhibited excellent cold tolerance. According to our findings, bio-based 2,3-BDO isomers as sustainable water stress-tolerant agents, levo- and meso-2,3-BDOs, could enhance tolerance to drought and/or chilling stresses in various plants through somewhat different molecular activities without any side effects.

• Journal of The Korean Society of Grassland and Forage Science
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• v.43 no.2
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• pp.67-74
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• 2023

To understand antioxidant enzyme response of two contrasting Arundinella hirta ecotypes to drought stress, drought-tolerant Youngduk and drought-sensitive Jinju-1, were comparatively analyzed changes in the enzymatic activities of peroxidase (POD), ascorbate peroxidase (APX), catalase (CAT), superoxide dismutase (SOD), and glutathione reductase (GR). Two ecotypes, drought-tolerant Youngduk and drought-sensitive Jinju-1 were subjected to drought stress by withholding water for 12 days. ROS accumulation level and electrolytic leakage were significantly increased in both A. hirta ecotypes by drought stress treatment but less in Youngduk than Jinju-1. The RWC significantly decreased in both the drought stress-treated ecotypes as compared to control, but less in Youngduk than Jinju-1. Soluble sugar and protein content were increased more in drought stress-treated Youngduk as compared to Jinju-1. The activities of antioxidant enzymes such as SOD, CAT, POD, APX, and GR increased significantly in both the drought stress-treated ecotypes Youngduk and Jinju-1 as compared to control. The increase in antioxidant enzyme activity level was more prominent in drought stress-treated Youngduk as compared to Jinju-1. Taken together, these results suggest that Youngduk was more tolerant to drought stress than Jinju-1, and seem to indicate that tolerance of A. hirta to drought stress is associated with increased activity of antioxidant enzymes.

• Proceedings of the Korean Society of Grassland Science Conference
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• 2002.09a
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• pp.22.1-22
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• 2002

• Proceedings of the Plant Resources Society of Korea Conference
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• 2022.09a
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• pp.29-29
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• 2022

The fast-changing climatic conditions make plants to be vulnerable to many abiotic stresses. Drought stress is one of the limiting factors that affect pepper production in water deficient regions. It affects plant growth and development by altering physiological, morphological, and metabolic processes. Breeding drought tolerant varieties is one of the mitigation strategies to overcome the ever increasing drought disaster. Hence, screening of new drought tolerant pepper genotypes is essential. The current study was aimed to identify new drought tolerant genotypes among the collection of pepper genetic resources. In total, 70 pepper genotypes were screened for drought tolerance after exposure to drought stress condition. The pepper genotypes were classified as highly tolerant, intermediate, or severely sensitive to drought stress based on the phenotypic analysis. Consequently, 13 genotypes significantly exhibited higher recovery rate after drought stress and were classified as highly tolerant. Comparative analysis of morphological and physiological parameters and expression of drought responsive genes between tolerant and susceptible pepper genotypes will be presented and discussed. The identified tolerant genotypes will be useful resources for breeding drought tolerant pepper cultivars.