Numerous environmental stresses, such as abiotic and biotic stresses, cause significant yield loss in crops and can significantly affect their development. Un the field conditions, crops are exposed to a variety of concurrent stresses. Combined high temperature and linked diseases can cause considerable damage that eventually leads to crop death. Hence, this study was conducted to characterize the genes encoding the nucleotide-binding site (NBS) motif obtained from transcriptome profiles of two cabbage genotypes with contrasting responses to heat stress. We selected 80 up-regulated genes form a total of 264 loci, among which 17 were confirmed to be complete and incomplete members of the TIR-NBS-LRR (TNL) class families, and another identified as a NFYA-HAP2 family member. Expression analysis using qRT-PCR revealed that 8 genes showed significant responses to heat shock treatment and F. oxysporum infection. Additionally, in the commercial B. oleracea cultivars with resistance to F. oxysporum, Bol007132, Bol016084, and Bol030522 genes showed dramatically higher expression levels in the F. oxysporum resistant line than the intermediate and susceptible lines. The results of this study may facilitate the identification and development of molecular markers based on multiple stress resistance genes related to heat and fungal stress under field conditions in B. oleracea.

Among the abiotic stresses, heavy metal (HM) toxicity is thought to be one of the major abiotic stresses leading to hazardous effects in plants. In spite of its potential physiological and economical significance, morphological alterations induced by heavy metals in plants have so far been grossly overlooked. In the present study, the morphological and physiological changes were observed in the leaf of sorghum plants treated with different concentrations (0, 50, 100, and 150 μM) of CdCl2. Results revealed that plants endured reduction in growth and morphological changes amazingly altered by cadmium. The growth of sorghum seedlings treated with 150 μM cadmium was more inhibited than that of sorghum seedlings treated with 100 μM Cd, 50μM and non-treated plants. The morphological characteristics revealed that the cadmium stress inhibited the root and shoot elongation after growing the rise seedling in the presence of cadmium. In the case of ion concentration, the concentrations of Zn2+, Ca2+ were decreased whereas Fe2+ concentration was increased except 100 μM under cadmium stress. In confocal microscopy, results showed that the absorption degree of cadmium was increased by the higher concentration of cadmium. The fluorescence intensity of cadmium was also increased. Thus, it seemed that cadmium has an influence on sorghum in the case of early stages of sorghum. This study reported the effects of heavy metal, cadmium on the growth and physiological characteristics of sorghum seedlings, hoping to provide references on the mechanism of heavy metal damaging plants, and phyto-remediation for heavy metal polluted soil.

We investigated whether sound could alter gene expression in plants. Using a sound-treated subtractive library, a set of sound-responsive genes in plants was demonstrated through mRNA expression analyses. Of them, the rbcS and ald genes, which are light responsive, up-regulated their expression with sound treatment in both light and in dark conditions. This suggested that sound could be used as a gene regulator instead of light. When we analyzed ald gene expression using various single wavelengths, a significant increase in mRNA levels was found at 125 or 250 Hz but decreased at 50 Hz, indicating that the gene responded to sound in a wavelength-specific manner. To determine whether the ald promoter respond to sound, we generated transgenic rice plants harboring the chimeric gene consisting of a 1,506-bp promoter fragment of the ald gene fused to Escherichia coli GUS reporter gene. Analyses of mRNA expressison level of three independent transgenic lines sound-treated with 50 or 250 Hz for 4 h showed that the Gus gene expression in all three transgenic lines was up regulated by 250 Hz, but down regulated by 50 Hz. These results correlated with sound responsive mRNA expression pattern observed for the ald gene in rice plants, indicating that the 1,506-bp ald promoter confers sound-responsiveness on a reporter gene in transgenic rice plants. We also investigated whether sound waves could improve salt tolerance in rice seedling. The rice seedlings were sound treated with 800 Hz for 1hr, and then treated with 0, 75, 150, and 225mM NaCl for 3 days to observe changes in physiological and morphological aspects. Sound treatment seedlings resulted in enhanced salt stress tolerance, mainly demonstrated by the sound treated seedlings exhibiting of increased root relative water contents (RWC), root length and weight, photochemical efficiency (ratio of variable to maximum fluorescence, Fv/Fm), and germination rate under salt stress condition. This demonstrates that a specific sound wave might be used, not only to alter gene expression in plant, but also to improve salt stress tolerance.

To determine the expression levels of genes related to the salt stress response in rice, gene expression profiles were investigated through microarray analysis using the rice mutant line Till-II-877. There were no significant changes in physiological response under salt stress of the mutant increased less than that in the WT. The intensity of gene expression was analyzed and compared between the wild type and mutant lines using a microarray. Among the most significantly affected pathways, α-linolenic acid metabolism and linoleic acid metabolism (in lipid metabolism), fructose and mannose metabolism and glycolysis-gluconeogenesis (in carbohydrate metabolism), cysteine and methionine metabolism (in amino acid metabolism), and carbon fixation (in the energy metabolism of photosynthetic organisms) showed changes in gene expression levels under salt stress. These results further our understanding of the effects of salt stress in rice and may aid in the development of salt-tolerant rice cultivars.

This study was conducted to investigate plant body temperature response of soybean (Glycine max) to saline stress. Two-weeks-old seedlings of soybean in V1 growth stage were treated with 0, 10, 20, 40, 80 and 160 mM of NaCl for salt stress. Thermal images acquired using Flir T-420 (US) were obtained at 4 days after treatment. Soybean leaf temperature increased with increasing NaCl concentration, resulting in significant positive correlation between soybean leaf temperature and stress intensity (P < 0.01). Leaf temperature of soybean was significantly different at 160 mM of NaCl, where no visual symptom was observed. Therefore, soybean leaf temperature can be used for evaluating the response of soybean to salt stress as a non-destructive and phenomic parameter. Non-destructive diagnosis of soybean leaf temperature may be a key parameter in a high throughput screening (HTS) system in breeding program for salt stress tolerance soybean cultivars.

The response of the freshwater microalga Chlorella vulgaris to mercuric ion (Hg2+) stress was examined using chlorophyll a fluorescence image analysis and O-J-I-P analysis as a way to monitor the toxic effects of mercury on water ecosystems. The levels of photosynthetic pigments, such as chlorophyll a and b and carotenoids, decreased with increasing Hg2+ concentration. The maximum photochemical efficiency of photosystem Ⅱ(Fv/Fm) changed remarkably with increasing Hg2+ concentration and treatment time. In particular, above 200 μM Hg2+, considerable mercury toxicity was seen within 2 h. The chlorophyll a fluorescence transient O-J-I-P was also remarkably affected by Hg2+; the fluorescence emission decreased considerably in steps J, I, and P with an increase in Hg2+ concentration when treated for 4 h. Subsequently, the JIP-test parameters (Fm, Fv/Fo, RC/CS, TRo/CS, ETo/CS, ΦPO, ΨO and ΦEO) decreased with increasing Hg2+ concentration, while N, Sm, ABS/RC, DIo/RC and DIo/CS increased. Therefore, a useful biomarker for investigating mercury stress in water ecosystems, and the parameters Fm, ΦPO, ΨO, and RC/CS can be used to monitor the environmental stress in water ecosystems quantitatively.

Physiological responses to salinity stress were evaluated in six rice genotypes differing in their tolerance to salinity at the seedling stage. Susceptible genotypes ('Dongjingbyeo', 'Hwayeongbyeo', and 'IR29') showed salt injury symptoms (mean 8.8) and higher visual score under salt stress than that of tolerant ones ('Pokkali', 'IR74009', and 'IR73571'). As salinity affects growth and physiological parameters, the six genotypes thus showed significant reduction because of salt stress. Tolerant Japonica/Indica bred lines ('IR74009', 'IR73571') showed lower reduction, 33.9%, 34.5%, and 50%, respectively, in plant seedling height, dry shoot weight and dry root weight than those of the susceptible Japonica varieties ('Dongjingbyeo', 'Hwayeongbyeo'), and the highest reduction under salt stress was observed in dry root weight, followed by dry shoot weight and seedling height, respectively. Shoot Na+ concentration of IR74099 and IR73571 was lower than that of the susceptible varieties, 'Dongjinbyeo' and 'Hwayeongbyeo'. There were no significant differences among genotypes in root Na+ concentration. Shoot K+ concentration showed a reverse tendency compared to shoot Na+ concentration. IR74009 and IR73571 had considerably lower ratio compared to 'Dongjinbyeo' and 'Hwayeongbyeo' in Na+/K+ ratio of their shoot and was not different the tolerant check, 'Pokkali'.

Low temperature stress is one of the major negative factors affecting vegetative and reproductive growth of rice. To better understand responses of rice plants to low temperature we analyzed transcriptome expression patterns in glumous flower of cold-tolerant japonica rice variety, Stejaree45, and cold-susceptible variety, HR19621-AC6 at booting stage under cold water irrigation. A total of 2,411 probes were differentially expressed by low temperature in glumous flowers of the two varieties. Some important genes involved in hormone biosynthesis showed variety-specific regulation. Expression of GA20ox3 and GA2ox, among the genes involved in GA biosynthesis, was regulated differentially in the two varieties. Among the genes involved in IAA biosynthesis, YUCCA1 and TAA1:1 showed variety-specific regulation. Among the genes involved in cytokinin biosynthsis and signaling, expression of LOG, HK1 and HK3 was significantly down-regulated only in the cold-susceptible variety. Among the genes involved in ABA biosynthesis, NSY and AAO3 were down-regulated only in the cold-tolerant variety. In general, genes involved in GA, IAA and cytokinin biosynthesis responded to cold temperature in such a way that capacity of those bioactive hormones is maintained at relatively higher levels under cold temperature in the cold-tolerant variety, which can help minimize cold stress imposed to developing reproductive organs in the cold-tolerant variety.

Over the past few decades Miscanthus has been studied as a potential bioenergy crop in Europe but not much been studied in Korea although Korea has many native Miscanthus species and genetic resources. Because of their features, such as low demands of fertilizers and other agrochemicals, high water use efficiency and high productivity, Miscanthus can be cultivated in marginal lands. However, it is not known how Miscanthus can survive in saline soil and what extent Miscanthus can tolerate salt stress, one of main abiotic stresses in reclaimed lands or dry climates. Therefore, this study was conducted to investigate physiological response of Miscanthus species to salt stress and thus to establish a salt stress threshold. Miscanthus sinensis and M. sacchariflorus showed similar responses to salt stress. Chlorophyll contents, photosynthesis and plant growth were all significantly affected by salt stress. Both species were completely killed at > 100 mM NaCl. The GR50 values estimated by non-linear regression analysis with the logistic model were 116.2 mM and 63.1 mM for M. sinensis and M. sacchariflorus, respectively. These GR50 values can be used as their thresholds of salt stress. Further studies will be conducted to screen salt-tolerant Miscanthus genotypes.

Global warming means not only increase in average air temperature but also increase in frequency of extreme weathers such as extremely high temperature over 45oC. Crops are generally sensitive to high temperature during their reproductive growth stage. This experiment was thus conducted to investgate physiological responses of rice (Oryza sativa cv. Chucheong) and soybean (Glycine max cv. Sinpaldal) to high temperature (HT) stress at their reproductive stage. Rice and soybean were exposed to different degrees of high temperature stress by keeping them in a growth cabinet deisnged to maintain air temperature up to 45oC for at least 5 hours in a day for different durations, 0, 1, 2, 3, and 4 days. HT stress treatment delayed heading and flowering of rice and increased the sterility of its' main panicle with increasing duration of HT treatment; 19.7 43.4, 68.1, 81.5 and 91.1% at 0, 1, 2, 3 and 4 days HT treatment, respectively. Increasing sterility due to HT treatment thus resulted in significant rice yield loss; 5.07 4.27, 4.32, 4.51 and 3.62 g/plant at 0, 1, 2, 3 and 4 days of HT treatment, respectively. Soybean was also significantly affected by HT stress in its pod formation and sterility, particularly along the vertical stem. Increasing pod sterility with increasing HT treatemnt thus resulted in significant soybean yield loss.

애기장대의 AtSIZ3(At1g08910) 유전자에 T-DNA를 삽입한 세 종류의 변이형에 저온(4℃), 고온(37℃) 및 건조스트레스를 처리하여 유묘의 생장반응과 유전자 발현을 조사하였다. 저온과 고온처리에 의해서는 야생형과 변이형간에 유묘생장에 유의한 차이를 보이지 않았다. 야생형과 변이형 식물체에 10일간의 건조스트레스를 처리하면 야생형은 재 관수에 의해 모든 식물체가 재생하였으나 변이형은 모두 고사하였고, 10일간의 건조처리로 변이형은 야생형에 비해 유묘생장이 평균 62.9%가 억제되는 것으로 나타났다. 야생형에서 AtSIZ3 유전자는 4℃의 저온처리에서 무처리를 보다 20%정도 발현이 감소하는 반면, 37℃ 고온처리에서는 3.7배, 건조처리에서는 4.5배가 증가하였다. 이 결과로 보아 AtSIZ3 유전자는 식물의 건조내성과 밀접한 연관이 있을 것으로 판단된다.

본 연구의 목적은 장기간 저항운동 강도별 스트레스를 지칭하는 호르몬의 분비 차이를 제시하는 것이며, 타 연구 논의의 차별화로 배제된 심리적 관련 변인을 기술하였다. 연구대상은 C 대학교 남자대학생 17명으로 최대하 및 최대운동 강도별로 각각 6주간의 저항운동 실시 후 네 시점별 성장호르몬과 테스토스테론 및 코르티솔의 차이 결과, 남성호르몬을 제외한 성장 및 코르티솔 변화는 안정시에 비해 운동직후 유의하게 증가하였으며, 6주 전후 변화는 코르티솔만이 네 시점별 유의한 증가가 있었다. 분비 차이의 의미로, 성장호르몬 증가는 운동 강도별 모두 유의하게 증가하였으며, 남성호르몬은 유의한 변화가 없었으며, 최대강도 운동의 경우 코르티솔은 6주 후 평소 안정 시에도 증가되어 있었다. 장기간 운동처치의 생리적인 결과 해석에 심리적 변화를 고려하여야 하며 부정적인 스트레스로 변환되지 않도록 심리적인 여러 변인 연구가 병행되어야 하겠다.

Gene-expression analysis is increasingly important in biological research, with real-time reverse PCR (RTPCR) becoming the method of choice for high-throughput and accurate expression profiling of selected genes. However, this technique requires important preliminary work for standardizing and optimizing the many parameters involved in the analysis. Plant stress studies are more and more based on gene expression. The analysis of gene expression requires sensitive and reproducible measurements for specific mRNA sequence. Several genes are regulated in response to abitoic stresses, such as salinity, and their gene products function in stress response and tolerance. The design of the primers and TaqMan probes for real-time PCR assays were carried out using the Primer ExpressTM software 3.0. The PCR efficiency was estimated through the linear regression of the dilution curve. To understand the expression pattern of various genes under salt stressed condition, we have developed a unique public resource of 9 stress-related genes in poplar. In this study, real-time RT-PCR was used to quantify the transcript level of 10 genes (9 stress-related genes and 1 house keeping gene) that could play a role in adaptation of Populus davidiana. Real-time RT-PCR analyses exhibited different expression ratios of related genes. The data obtained showed that determination of mRNA levels could constitute a new approach to study the stress response of P. davidiana after adaptation during growth in salinity condition.