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Differences of gene expression between salinity-stressed and control rice ( Oryza sativa L. ssp. indica) cultivar "Zhaiyeqing 8" were compared using differential display PCR (DD-PCR) technique. Sequence analysis of one salt-inducible cDNA clone revealed that this clone represented a new member of rice translation elongation factor lA (eEF1A) gene family and was tentatively named REF1A. Northern blot hybridization using REF1A fragment as a probe was performed to investigate the expression of rice translation elongation factor lA gene in response to various environmental factors. It was observed that expression of the eEF1A gene in rice shoots was dramatically induced by salinity stress or exogenous application of abscisic acid (ABA). The induction of this gene by ABA stress occurred more quickly than that by salinity stress. In addition, expression of rice translation elongation factor lA gene was also induced by drought (15% PEG6000), cold (4 ℃ ) or heat-shock (37 ℃ ) stresses. The results suggested that the induction of translation elongation factor lA gene expression by environmental stresses might reflect the general adaptive response of rice plants to the adverse circumstances.  相似文献   

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Rice (Oryza sativa L.) seedlings were germinated under waterin darkness for 5 or 6 days (submerged seedlings) and then inair for 1 day. Control seedlings were germinated in air, indarkness, for 5 or 6 days (aerobic seedlings). Changes in levelsof antioxidants and in the extent of oxidative damage afterexposure of submerged seedlings to air were studied. -Tocopherol,which inhibits lipid peroxidation, was present in submergedseedlings at about 3 times the level found in aerobically growncontrols, and higher levels than in controls were maintainedfor 24 h after transfer of the seedlings to air. Products oflipid peroxidation were present at a one-third of the levelsfound in aerobic controls, and their levels increased aftertransfer to air. However, these levels remained lower than thosein aerobic controls even after 24 h of contact with air. Carotenoids,which are considered to protect chlorophyllous compounds againstphotooxidation, were not found in submerged seedlings, but theirlevels increased after exposure of the seedlings to air. Lightat an intensity that did not cause photooxidative damage tochlorophyllous compounds in aerobic controls induced photobleachingof these compounds in submerged seedlings during the early stagesof adaptation to air. However, the extent of photobleachingdiminished as adaptation to air proceeded, and photobleachingwas no longer detected after 24 h of adaptation to air. Thus,the system for protection of cellular membranes from lipid peroxidationin the post-hypoxic phase appeared already to exist in submergedseedlings. However, the system for protection of pigments fromphotobleaching was poorly developed in submerged seedlings andwas fully active only after 24 h of adaptation to air. 1Present address: Department of Biology, Faculty of Science,Shizuoka University Shizuoka, 422 Japan 2Present address: Research Institute for Bioresources, OkayamaUniversity, Kurashiki, 710 Japan  相似文献   

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Low temperature can greatly restrict the growth and development of rice. The rice seedlings show growth retardation, lamina wrap, and part of blade even died under the condition of low temperature. In order to get more information about cold stress responses in rice, two dimensional electrophoresis and bioinformatics analysis of mass spectrometry were used to preliminary survey the cold tolerance of cold sensitive line 9311 and cold resistance variety Fujisaka 5 under cold stress. Two dimensional electrophoresis maps of 9311 and Fujisaka 5 were established under cold treatment. With analysis of bioinformation, the proteins were found involve in many aspects of rice development. The largest category of proteins is functioning on metabolism. By comparing the proteins from the two varieties, it can be found that most proteins from 9311 were down-regulated and were up-regulated in Fujisaka 5. The results showed that the membrane composition and structure were damaged, metabolism changed dramatically and rice defense system was activated under the cold stimulation. Fifty-nine proteins related to the resistance of cold stress were identified in our study, and we have investigated and classified all of their biological functions. The importance of our study are providing some conduct for the research of rice resistant to cold stress, supporting auxiliary technique for rice varieties and widening the search field of cold tolerance in plants.  相似文献   

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水稻幼苗在外源·OH和1O2氧化胁迫下,体内脯氨酸明显积累,而和H2O2处理对稻苗体内脯氨酸含量无影响。强光亦能诱导稻苗体内脯氨酸积累。脯氨酸预处理则显著抑制·OH、1O2及强光所诱导的稻苗膜脂过氧化作用。在活性氧的产生/检测系统中,脯氨酸对·OH和1O2所引发反应有明显的竞争效应,但对和H2O2的作用没有形响。这些都表明,氧化胁迫下稻苗体内积累的脯氨酸具有抗氧化作用;脯氨酸对活性氧的清除有一定的专一性,即只对·OH和1O2有明显的清除活性。  相似文献   

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本研究通过农杆菌介导的转化技术,将水稻尿苷二磷酸葡萄糖焦磷酸化酶基因(OsUgp2)与大肠杆菌海藻糖-6-磷酸合成酶/海藻糖-6-磷酸合成酶磷脂酶融合基因(otsAB)共表达载体转化水稻愈伤组织,对获得的转基因植株分别进行干旱和寒冷处理,试图明确OsUgp2和otsAB共表达是否可以进一步提高转基因水稻植株的抗胁迫能力.表型观察结果显示OsUgp2和otsAB共表达植株(ABU)经干旱和寒冷处理后恢复生长的能力,较otsAB和OsUgp2分别过量表达的转化植株(AB和U)均有所提高.定量PCR检测结果显示:经干旱处理后,转化植株ABU中otsAB和OsUgp2的表达量较未处理植株分别提高1.92倍和1.67倍,与转化植株AB和U中otsAB和OsUgp2表达的增加量相近;而寒冷处理后,转化植株ABU中otsAB和Os-Ugp2的表达量分别增加2.68倍和2.04倍,明显高于转化植株AB和U中otsAB和OsUgp2表达的增加量.液相色谱检测结果显示:OsUgp2和otsAB共表达和单表达均可以提高转化植株中海藻糖的生物合成量,且共转化植株ABU中海藻糖的含量在干旱和寒冷处理前后均是最高的.干旱和寒冷处理后,共转化植株ABU中蔗糖含量的增加也较明显.本研究结果表明OsUgp2和otsAB共表达可以增加转基因水稻植株中海藻糖和蔗糖分子的含量,同时转基因水稻植株的抗旱和耐冷胁迫的能力也得到了一定提高.  相似文献   

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Although many chemotherapeutic strategies against cancer have been developed, pancreatic cancer is one of the most aggressive and intractable types of malignancies. Therefore, new strategies and anti-cancer agents are necessary to treat this disease. Metformin is a widely used drug for type-2 diabetes, and is also known as a promising candidate anti-cancer agent from recent studies in vitro and in vivo. However, the mechanisms of metformin’s anti-cancer effects have not been elucidated. We demonstrated that metformin suppressed the expression of miR-221, one of the most well-known oncogenic microRNAs, in human pancreatic cancer PANC-1 cells. Moreover, we showed that the down-regulation of miR-221 by metformin caused G1-phase arrest via the up-regulation of p27, one of the direct targets of miR-221. Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is also a promising agent for cancer treatment. While recent studies showed that treatment with only TRAIL was not effective against pancreatic cancer cells, the present data showed that metformin sensitized p53-mutated pancreatic cancer cells to TRAIL. Metformin induced the expressions of death receptor 5 (DR5), a receptor for TRAIL, and Bim with a pro-apoptotic function in the downstream of TRAIL-DR5 pathway. We suggest that the up-regulation of these proteins may contribute to sensitization of TRAIL-induced apoptosis. The combination therapy of metformin and TRAIL could therefore be effective in the treatment of pancreatic cancer.  相似文献   

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高效准确鉴定苗期耐寒性是水稻(Oryza sativa)耐寒研究的前提。基于流动水浴温度均一这一特性, 建立了一种恒温水浴鉴定水稻幼苗耐寒性方法。该方法中环境温度设定为20°C, 水浴温度设定为4°C。根据对2个水稻亚种不同材料的处理结果, 总结出几种常见品种的低温处理时间与存活率参考值, 并对操作过程中的一些注意事项进行了说明。  相似文献   

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高效准确鉴定苗期耐寒性是水稻(Oryza sativa)耐寒研究的前提。基于流动水浴温度均一这一特性, 建立了一种恒温水浴鉴定水稻幼苗耐寒性方法。该方法中环境温度设定为20°C, 水浴温度设定为4°C。根据对2个水稻亚种不同材料的处理结果, 总结出几种常见品种的低温处理时间与存活率参考值, 并对操作过程中的一些注意事项进行了说明。  相似文献   

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分析了水稻幼苗低温胁迫前后膜脂和膜脂脂肪酸含量变化。结果表明,经胆固醇处理的幼苗叶和根细胞膜脂中LPC、PS和PG含量比对照下降少,PA含量增加也较少。胆固醇处理的幼苗叶和根棕榈酸(16:0)增加量和亚麻酸(18:3)与IUFA减少量均明显比对照少。试验结果证明,水稻幼苗叶片和根系的抗冷力与PA含量和脂肪酸不饱和程度变化有密切关系。外源胆固醇处理水稻幼苗能阻止低温对膜脂的破坏作用,提高幼苗抗低温胁迫能力。  相似文献   

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When rice seedlings grown for 10 and 20 days were subjected to in vitro drought stress of −0.5 and −2.0 MPa for 24 h, an increase in the concentration of superoxide anion (O2.−), increased level of lipid peroxidation and a decrease in the concentration of total soluble protein and thiols was observed in stressed seedlings compared to controls. The concentration of H2O2 as well as ascorbic acid declined with imposition of drought stress, however glutathione (GSH) concentration declined only under severe drought stress. The activities of total superoxide dismutases (SODs) as well as ascorbate peroxidase (APX) showed consistent increases with increasing levels of drought stress, however catalase activity declined. Mild drought stressed plants had higher guaiacol peroxidase (GPX) and chloroplastic ascorbate peroxidase (c-APX) activity than control grown plants but the activity declined at the higher level of drought stress. The activities of enzymes involved in regeneration of ascorbate i.e. monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR) and glutathione reductase (GR) were higher in drought stressed plants compared to controls. Results suggest that drought stress induces oxidative stress in rice plants and that besides SOD, the enzymes of ascorbate-glutathione cycle, which have not been studied in detail earlier under stressful conditions, appear to function as important component of antioxidative defense system under drought stress.  相似文献   

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低温胁迫下氯丙嗪和氯化镧对水稻幼苗脯氨酸积累的影响   总被引:9,自引:0,他引:9  
低温胁迫下水稻幼苗质膜透性增大、相对含水量(RWC)下降、丙二醛(MDA)含量增加,同时脯氨酸(Pro)积累。以氯丙嗪(CPZ)和氯化镧(LaCl3)对水稻幼苗预处理以阻碍Ca2+·CaM(钙调素)信使传导后,加剧了低温胁迫下水稻幼苗质膜透性的增加、RWC的下降、MDA含量的增加和Pro的积累,说明水稻幼苗受伤害程度将加重。  相似文献   

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The purpose of this study was to investigate the renal and hepatic oxidative damage and toxicity caused by dietary high vanadium in broilers. A total of 420 one-day-old avian broilers were divided into six groups and fed on a corn–soybean basal diet as control diet (vanadium 0.073 mg/kg), and five high vanadium diets (vanadium 5 mg/kg, high vanadium group I; 15 mg/kg, high vanadium group II; 30 mg/kg, high vanadium group III; 45 mg/kg, high vanadium group IV; and 60 mg/kg, high vanadium group V) throughout the experimental period of 42 days. The results showed that the renal and hepatic superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities, ability to inhibit hydroxy radical, and malondialdehyde (MDA), glutathione, and vanadium contents were not significantly changed in high vanadium group I and II when compared with those of the control groups. However, the SOD and GSH-Px activities, ability to inhibit hydroxy radical, and GSH content were significantly decreased, and the MDA and vanadium contents were markedly increased in high vanadium groups III, IV, and V. At the same time, the lesions were also observed in the kidney and liver of high vanadium groups III, IV, and V. The renal tubular epithelial cells showed granular degeneration and vacuolar degeneration, and hepatocytes showed granular degeneration, vacuolar degeneration, and fatty degeneration. It was concluded that dietary vanadium in the range of 30–60 mg/kg could cause oxidative damage and vanadium accumulation, which induced renal and hepatic toxicity and lesions. The renal and hepatic function was finally impaired in boilers.  相似文献   

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Liangyoupeijiu is a super high-yield hybrid rice. Despite its advantages with respect to yield and grain quality, it is sensitive to cold, which keeps it from being widely cultivated. We subjected Liangyoupeijiu seedlings to 4 ℃ cold treatment, then extracted the leaf proteins. After 2-D gel electrophoresis separation and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry analysis, a series of differentially displayed proteins were identified. Some metabolism-associated proteins were found among the downregulated proteins, such as carbamoyl phosphate synthetase, transketolase 1, dihydrolipoamide dehydrogenase and glyceraldehyde 3-phosphate dehydrogenase. The upregulated proteins included both stress-resistance proteins such as nucleoside diphosphate kinase I and proteins that are negative for rice growth, such as FtsH-like protein, plastid fusion and/or translocation factor (Pftf) and actin. Our results indicate that cold may inhibit Liangyoupeijiu growth through decreasing metabolic activity and damaging cell structure.  相似文献   

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