• 한국작물학회지
• /
• 제44권2호
• /
• pp.129-133
• /
• 1999

Excessive soil water at vegetative growth stages during the rainy season induces yield losses in soybeans. Our objectives were to obtain basic information about the cultivar differences and to understand the stress-tolerance process for due to excessive soil water. Previous experiments revealed soybean genotypic differences in tolerance to excessive soil water. A field experiment was conducted at the Research Farm of Korea University near Seoul on 21 May 1998. Soybean[Glycine max (L.) Merrill] cultivars, 'Hannamkong' (sensitive) and 'Taekwan-gkong'(tolerant) were planted in vinyl-lined plots(1.2 x 4.2 x 0.3 m deep) and control plots. Drip irrigation began at VI growth stage to submerge the soil surface. Three weeks of excessive soil water treatment reduced all growth parameters measured to soybean plants. Excessive soil water stress resulted in decreases of N, P, K, Ca, Mg and Cu, and increases of Fe and Mn contents in soybean leaves. The stress index of tolerant cultivars under excessive soil water showed no large difference in soybean growth characteristics measured at three growth stages. However, K, Ca, Mg, Fe and Mn contents in soybean leaves appeared to differ between sensitive and tolerant cultivars. From the above results, stress and tolerance indices are proposed for a method to test cultivar differences in plant responses within a species under adverse growth environments.

• Journal of Microbiology and Biotechnology
• /
• 제23권2호
• /
• pp.149-155
• /
• 2013

Heterologous expression of a putative $K^+/H^+$ antiporter of Streptomyces coelicolor A3(2) (designated as sha4) in E. coli and Streptomyces hygroscopicus JCM4427 showed enhanced tolerance to $K^+$ stress, acidic-pH shock, and/or geldanamycin production under $K^+$ stress. In a series of $K^+$ extrusion experiments with sha4-carrying E. coli deficient in the $K^+/H^+$ antiporter, a restoration of impaired $K^+$ extrusion activity was observed. Based on this, it was concluded that sha4 was a true $K^+/H^+$ antiporter. In different sets of experiments, the sha4-carrying E. coli showed significantly improved tolerances to $K^+$ stresses and acidic-pH shock, whereas sha4-carrying S. hygroscopicus showed an improvement in $K^+$ stress tolerance only. The sha4-carrying S. hygroscopicus showed much higher geldanamycin productivity than the control under $K^+$ stress condition. In another set of experiments with a production medium, the secretion of geldanamycin was also significantly enhanced by the expression of sha4.

• 약학회지
• /
• 제29권4호
• /
• pp.188-192
• /
• 1985

김등은 한국산 인삼의 부탄올분획이 마우스의 모르핀 내성 및 의존성 형성을 억제하였고 rat의 모르핀에 의한 내성 형성 및 dopamine 수용체 초과민성 형성을 억제한다고 보고 하엿다. 저자들은 Takagi가 보고한 인삼의 중추신경계를 억제시키는 protopanaxadiol (PD) 분획과 중추신경계를 흥분시키는 protopanaxatriol (PT) 분획을 사용하여 모르핀의 내성형성에 미치는 활성 분획을 추적할 목적으로 진통작용에 대한 내성 형성 억제 체온 상승 또는 강하 억제작용 체중감소 억제작용 등을 실험하였다.

• 한국환경과학회지
• /
• 제19권5호
• /
• pp.585-590
• /
• 2010

This study attempted to facilitate various groundcover plants, related to phytoremediation material, and advance shade plants with a heavy metal tolerance to contaminated soil in an urban shade space. Saxifraga stolonifera, which has commonly been used a landscape shade plants, was evaluated to determine its heavy metal tolerance to different concentrations(Control, $100mg{\cdot}kg^{-1}$, $250mg{\cdot}kg^{-1}$ and $500mg{\cdot}kg^{-1}$ treatment) of Cd, Pb and Zn in soil. The growth of Saxifraga stolonifera showed no significant tendency after the initial transplantation, but showed distinct changes with the respective treatment heavy metal types and concentrations over time. Especially, severe chlorosis, with more yellowish green leaves, was observed, with inhibition at Cd concentrations greater than $100mg{\cdot}kg^{-1}$. Conversely, no external symptoms or growth retardation were observed with Pb and Zn concentrations less than $500mg{\cdot}kg^{-1}$. Therefore, Saxifraga stolonifera can be applied as a long term phytoremediation species in soil contaminated with low concentrations of heavy metal in urban shade spaces.

• 한국정밀공학회지
• /
• 제11권2호
• /
• pp.50-64
• /
• 1994

Cutter deflections in the ball-end milling process is one of the main causes of the machining errors on a free-form surface. In order to avoid machining errors in this process, a methodology avoiding these machining errors on the free-form surfaces has been developed. In this method, feedrates in the finish cuts are adjusted for the prevention of machining errors. A model for the prediction of machining errors on the free-form surface is analytically derived as a function of feed and normal vector at the surface of contact point by the cutter. This model is applied to the dertermination of the adjusted feedrates which satisfy the machining tolerance of the surface. In the finish cuts of a simple curved surface, the suggested model is examined by the measurements of the generated machining error on this surface. And also, this surface is machined with the adjusted feedrates for the given machining tolerance. The measured machining errors on this surface are compared with the given tolerance. In this comparisons, it is shown that the predicted errors are fairly good agreement with the test results.

• Journal of Plant Biotechnology
• /
• 제44권3호
• /
• pp.287-295
• /
• 2017

Water temperature is one of the major factors that impacts the growth and life cycle of Pyropia tenera, one of the most valuable and cultivated marine red algae belonging to Bangiales (Rhodophytes). We analyzed transcriptome from gametophyte of P. tenera under normal and high temperature conditions, and identified four small heat shock proteins (sHSPs). They have no significant amino acid sequence homology with known proteins in public databases except PhsHSP22 from Pyropia haitanensis. PtsHSP19.3 gene responded to high temperature but slightly or not to desiccation, freezing or high salt condition. When the PtsHSP19.3 gene was overexpressed in Chlamydomonas reinhardtii, transformed Chlamydomonas lines revealed much higher growth rate than that of control cells under heat stress condition. Transformed cells also grew well in those of the control cell onto the medium containing high salt or $H_2O_2$. When the PtsHSP19.3 was fused to GFP and introduced into tobacco protoplast, fluorescence was detected at several spots. Results indicate that PtsHSP19.3 may form super-molecular assembles and be involved in tolerance to heat stress.

• Molecules and Cells
• /
• 제39권6호
• /
• pp.447-459
• /
• 2016

Many studies have been conducted to understand plant stress responses to salinity because irrigation-dependent salt accumulation compromises crop productivity and also to understand the mechanism through which some plants thrive under saline conditions. As mechanistic understanding has increased during the last decades, discovery-oriented approaches have begun to identify genetic determinants of salt tolerance. In addition to osmolytes, osmoprotectants, radical detoxification, ion transport systems, and changes in hormone levels and hormone-guided communications, the Salt Overly Sensitive (SOS) pathway has emerged to be a major defense mechanism. However, the mechanism by which the components of the SOS pathway are integrated to ultimately orchestrate plant-wide tolerance to salinity stress remains unclear. A higher-level control mechanism has recently emerged as a result of recognizing the involvement of GIGANTEA (GI), a protein involved in maintaining the plant circadian clock and control switch in flowering. The loss of GI function confers high tolerance to salt stress via its interaction with the components of the SOS pathway. The mechanism underlying this observation indicates the association between GI and the SOS pathway and thus, given the key influence of the circadian clock and the pathway on photoperiodic flowering, the association between GI and SOS can regulate growth and stress tolerance. In this review, we will analyze the components of the SOS pathways, with emphasis on the integration of components recognized as hallmarks of a halophytic lifestyle.

• Plant Breeding and Biotechnology
• /
• 제1권1호
• /
• pp.1-8
• /
• 2013

Low-temperature stress is an important factor controlling the growth and development of rice (Oryza sativa L.) in temperate region. In this study, a molecular linkage map consisting of 136 SSR markers was employed to identify QTL associated with cold tolerance at the seedling stage. 80 recombinant inbred lines (RILs) from an intersubspecific cross between Milyang23 (O. sativa ssp. Indica) and Hapcheonaengmi3, a japonica weedy rice and the parents were evaluated for leaf discoloration and SAPD value of seedlings. Rice plants were grown for 15 days in the low-temperature condition (13/20℃ day/night) and the control condition (25/20℃ day/night) in the growth chamber. The degree of leaf discoloration showed a highly significant correlation with the SPAD value in the low-temperature plot (r = -0.708, P < 0.0001). A total of four QTLs for SPAD were identified and the phenotypic variance explained by each QTL ranged from 5.4 to 16.0%. Two QTLs detected in the control condition were located on chromosomes 2 and 5, respectively. Two QTL on chromosomes 1 and 4 were detected at the low-temperature condition and Hapcheonaengmi3 alleles increased the SPAD values at these loci. Substitution mapping was conducted to delimit the position of qSPA-4 using introgression lines derived from the same cross. Results indicated that qSPA-4 was located in a 810-Kb region flanked by RM16333 and RM16368. The results indicated that Hapcheonaengmi3 contains QTL alleles that are likely to improve cold tolerance of Indica rice.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
• /
• pp.327-327
• /
• 2000

Derivation of a slab dimension from the desired tolerance degrades the product quality, resulting in significant yield loss by trimming. This necessitates the dimensional control system to be operated in tighter dimensional accuracy. This paper presents an integral approach to a dimensional control system design taking into account the interaction between the edging process and the gap rolling process. To investigate the effects of each process controller, a simple PID controller is adopted as a preliminary study. The control performance is analyzed in detail in terms of the system response accuracy for various operating conditions.

• Journal of Information Technology Applications and Management
• /
• 제23권1호
• /
• pp.25-32
• /
• 2016

Using a sample of employees in various hospitality organizations, we proposed that individual disposition such as tolerance for ambiguity, positve affectivity, internal locus of control, and self-efficacy, will influence hospitality employees' resitance to change. The results supported hypotheses. Ultimately, we hope the results of this study provide propoer guidelines with hospitality managers and employees to decrease thiere resistance to change such as new IS implementation and thus increase their willingness to adopt in implementing new IS.