动脉平滑肌细胞sis／PDGF—B链的表达和调控

介绍平滑肌细胞ｓｉｓ／ＰＤＧＦ－Ｂ链表达和调控的进展。ｃ－ｓｉｓ原癌基因是ＰＤＧＦ－Ｂ的同源基因,将外源的ＰＤＧＦ基因导入哺乳类细胞是研究ＰＤＧＦ功能和调控的重要手段。内皮素ＩＬ、ＴＮＦ、血管紧张素Ⅱ和蛋白激酶Ｃ可调节ｓｉｓ基因的表达。ｓｕｒａｍｉｎ和新霉素的人工合成为拮抗ＰＤＧＦ效应提供广阔的前景。ｃ－ｓｉｓ可通过激活ｃ－ｍｙｃ,ｃ－ｆｏｓ等原癌基因而促进细胞增殖。     

吗啡耐受增加福尔马林致痛大鼠脊髓Fos和NADPH-d阳性神经元的表达

运用Ｆｏｓ免疫组织化学、ＮＡＤＰＨ－ｄ组织化学及Ｆｏｓ／ＮＡＤＰＨ－ｄ双标技术,研究了吗啡耐受对福尔马林致痛大鼠脊髓Ｆｏｓ、ＮＡＤＰＨ－ｄ阳性及Ｆｏｓ／ＮＡＤＰＨ－ｄ双标神经元表达的影响。结果观察到：在非吗啡耐受大鼠,福尔马林诱发的Ｆｏｓ－ｌｉｋｅ ｉｍｍｕｎｏｒｅａｃｔｉｖｉｔｙ（Ｆｏｓ－ＬＩ）主要分布在同侧脊髓背角浅层和颈部,急性静注吗啡可减少Ｆｏｓ－ＬＩ表达;长时间应用吗啡导致福尔马林诱发的     

动脉平滑肌细胞sis／PDGF－B链的表达和调控

介绍平滑肌细胞ｓｉｓ／ＰＤＧＦ－Ｂ链表达和调控的进展。ｃ－ｓｉｓ原癌基因是ＰＤＧＦ－Ｂ的同源基因,将外源的ＰＤＧＦ基因导入哺乳类细胞是研究ＰＤＧＦ功能和调控的重要手段。内皮素、ＩＬ、ＴＮＦ、血管紧张素Ⅱ和蛋白激酶Ｃ可调节ｓｉｓ基因的表达。ｓｕｒａｍｉｎ和新霉素（ｎｅｏｍｙｃｉｎ）的人工合成为拮抗ＰＤＧＦ效应提供广阔的前景。ｃ－ｓｉｓ可通过激活ｃ－ｍｙｃ、ｃ－ｆｏｓ等原癌基因而促进细胞增殖。     

里骆林区常绿阔叶林和人工杉木林气候水文效应

里骆林区常绿阔叶林和人工杉木林气候水文效应黄承标,文受春（广西农学院林学分院南宁５３０００１）（广西龙胜县林业局５４１７００）ＣｌｉｍａｔｉｃａｎｄＨｙｄｒｏｌｏｇｉｃａｌＥｆｆｅｃｔｓｏｆＥｖｅｒｇｒｅｅｎＢｒｏａｄ－ｌｅａｖｅｄａｎｄＡｒｔｉｆｉｃｉａｌＣｈｉｎｅｓｅＦｉｒＦｏｒｅｓｔｓｉｎＬｉｌｕｏＦｏｒｅｓｔｅｄＲｅｇｉｏｎ￥ＨｕａｎｇＣｈｅｎｇｂｉａｏ（ＦｏｒｅｓｔｒｙＣｏｌｌｅｇｅ,ＣｕａｎｇｘｉＡｇｒｉｃｕｌｔｕｒａｌＵｎｉｖｅｒｓｉｔｙ,Ｎａｎｎｉｎｇ５３０００１）,ＷｅｎＳｈｏｕｃｈｕｎ（ＦｏｒｅｓｔｒｙＢｕｒｅａｕ,ＬｏｎｇｓｈｅｎｇＣｏｕｎｔｙ,Ｇｕａｎｇｘｉ５４１７００）;ＣｈｉｎｅｓｅＪｏｕｒｎａｌｏｆＥｃｏｌ－ｏｇｙ,１９９３,１２（３）：１－７．Ｓｉｔｅｉｎｖｅｓｔｉｇａｔｉｏｎｓａｎｄｒｅｓｅａｒｃｈｅｓｉｎ１９８０－１９９０ｓｈｏｗｔｈａｔｅｖｅｒｇｒｅｅｎｂｒｏａｄ－ｌｅａｖｅｄａｎｄａｒｔｉｆｉｃｉａｌＣｈｉｎｅｓｅｆｉｒｆＯｒｅｓｔｓｉｎＬｉｌｕｏｆｏｒｅｓｔｅｄｒｅｇｉｏｎｃａｎｒｅｄｕｃｅｔｈｅｖａｒｉａｔｉｏｎｒａｎｇｅｏｆａｔｍｏｓｐｈｅｒｉｃａｎｄｓｏｉｌｔ     

ras和c-erbB癌基因在特发性肺间质纤维化中的表达

采用原位分子杂交技术和免疫组织化学方法,对８例临床与肺组织学确诊的特发性肺间质纤维化（ＩＰＦ）病人的肺活检组织及７例正常肺组织进行了ｒａｓ和ｃ－ｅｒｂＢ癌基因及其产物的检测。结果：ｒａｓ癌基因产物Ｐ２１在６／８例ＩＰＦ肺组织中呈阳性反应;５／８例ＩＰＦ肺组织ｃ－ｅｒｂＢ－２显免疫阳性反应,而在７例正常肺组织Ｐ２１及ｃ－ｅｒｂＢ－２均无明显表达,原位杂交结果显示ＩＰＦ肺组织没有明显ｒａｓ和ｃ－ｅｒｂＢ癌基因的ＤＮＡ扩增提示ＩＰＦ的病变过程与ｒａｓ和ｃ－ｅｒｂＢ癌蛋白表达增强有关     

河西走廊农户生态系统农田能流和物流数量特征的研究

河西走廊农户生态系统农田能流和物流数量特征的研究李发弟（甘肃农业大学畜牧系,兰州７３００７０）ＱｕａｎｔｉｎｔｉｖｅＣｈａｒａｃｔｅｒｉｓｔｉｃｓｏｆＥｎｅｒｇｙＦｌｏｗａｎｄＮｕｔｒｉｅｎｔＣｙｃｌｉｎｇｏｆＦａｒｍｌａｎｄｉｎａＦａｒｍＥｃｏｓｙｓｔｅｍｉｎＨｅｘｉＣｏｒｒｉｄｏｒ￥ＬｉＦａｄｉ（ＤｅｐａｒｔｍｅｎｔｏｆＡｎｉｍａｌＨｕｓｂａｎｄｒｙ,ＧａｎｓｕＡｇｒｉｃｕｌｔｕｒａｌＵｎｉｔｖｅｒｓｉｔｙ）．ＣｈｉｎｅｓｅＪｏｕｒ－ｎａｌｏｆＥｃｏｌｏｇｙ,１９９３,１２（６）：３７－４０．Ｑｕａｎｔｉｔａｔｉｖｅｃｈａｒａｃｔｅｒｉｓｔｉｃｓｏｆｅｎｅｒｇｙｆｌｏｗａｎｄｎｕｔｒｉｅｎｔｃｙｃｌｉｎｇｏｆｆａｒｍｌａｎｄｓｕｂｓｙｓｔｅｍｉｎａｆａｒｍｅｃｏｓｙｓ－ｔｅｍｉｎＨｅｘｉＣｏｒｒｉｄｏｒｗｅｒｅｓｔｕｄｉｅｄ．Ｔｈｅｒｅｓｕｌｔｓｓｈｏｗｅｄｔｈａｔｔｈｅｄｅｆｌｒｅｅｏｆｏｐｅｎｉｎｇ,ｉｎｐｕｔａｎｄｏｕｔｐｕｔｗｅｒｅｈｉｇｈ,ｔｈｅｒａｔｉｏｏｆｏｕｔｐｕｔｔｏｉｎｐｕｔｏｆｓｕｂｓｉｄｙｅｎｅｒｇｙ,ｎｉｔｒｏｇｅｎａｎｄｐｈｏｓｐｈｏｒｕｓｏｆｔｈｅｆａｒｍｌａｎｄｓｕｂｓｙ     

碱性成纤维细胞生长因子对大鼠肾小球系膜细胞原癌基因c-fos和c-myc表达的影响

在建立大鼠肾小球系膜细胞（ＭＣ）体外培养方法的基础上,通过３Ｈ－ＴｄＲ参入实验,ＲＮＡ印迹分析和斑点杂交观察ｂＦＧＦ对ＭＣＤＮＡ合成及原癌基因ｃ－ｆｏｓ和ｃ－ｍｙｃ表达的影响．结果表明,ｂＦＧＦ作用于ＭＣ１８ｈ,ＭＣ的３Ｈ－ＴｄＲ参入率明显增加（Ｐ＜０．０５）,２４ｈ达到高峰（Ｐ＜０．０１）;ｂＦＧＦ显著诱导原癌基因ｃ－ｆｏｓ和ｃ－ｍｙｃ表达,其表达活性分别于３０ｍｉｎ和１ｈ达到高峰．提示ｂＦＧＦ是ＭＣ的强效丝裂原,其对ＭＣＤＮＡ合成的促进作用与诱导原癌基因ｃ－ｆｏｓ和ｃ－ｍｙｃ表达有关．     

光／暗对玉米叶片果糖—6—磷酸激酶—2和果糖—2,6—二磷酸酯酶活…

比较了照光和黑暗条件下玉米叶片果糖－６－磷酶激酶－２和果糖－２,６－二磷酸酯酶的活力变化。当玉米植株从暗中转入光下后,其叶片ＰＦＫ－２的活力随光照时间的延长而逐渐降低,而ＦＢＰａｓｅ－２活力变化不明显;从光下转入暗后叶片ＰＦＫ－２活力明显上升,ＦＢＰａｓｅ－２活力仍无明显变化;其ＰＦＫ－２／ＦＢＰａｓｅ－２比值在光处理时下降,暗处理时上升。同时叶片中果糖－２,６－二磷酸的含量与ＰＦＫ－２／ＦＢＰａ     

癫痫模型大鼠海马原癌基因c-fos mRNA和蛋白质表达时程的研究

为了探讨癫痫发病机理与原癌基因的关系,将马桑内酯注入侧脑室,于大鼠癫痫发作后不同时间点取材海马,用Ｎｏｒｔｈｅｒｎ印迹杂交和Ｗｅｓｔｅｒｎ印迹分析技术对海马ｃ－ｆｏｓｍＲＮＡ和Ｆｏｓ蛋白表达的动力学进行了定量研究,激光扫描仪定量分析表明：（１）ｃ－ｆｏｓｍＲＮＡ在０．５ｈ表达最高,依次渐减,至４ｈ几无表达;（２）Ｆｏｓ蛋白在１ｈ开始表达,２ｈ最多,以后渐少。以上结果表明：ｃ－ｆｏｓｍＲＮＡ和Ｆｏｓ蛋白的表达随癫痫的发生发展出现规律性变化,ｃ－ｆｏｓｍＲＮＡ是快速,一过性表达,Ｆｏｓ蛋白的表达滞后且延长。提示：ｃ－ｆｏｓ在癫痫发病的基因机制中发挥作用,本文对此进行了讨论。本实验为深入研究癫痫发病的分子机制奠定了基础。     

CCK－8和NDAP对大鼠脑和脊髓组织c－fos表达的影响

为探讨八肽胆囊收缩素（ＣＣｋ－８）和阿片肽相互作用的分子机理,利用抗体免疫沉淀技术研究了ＣＣＫ－８与ＮＤＡＰ（ｋ阿片受体激动剂）对大鼠脑（去皮层和小脑）和脊髓背柱组织Ｆｏｓ蛋白的影响。结果表明,０．１μｍｏｌ／ＬＣＣＫ－８可显著刺激脑和脊髓组织中Ｆｏｓ蛋白增加（分别是对照组的３．８倍和３．６倍）。相同浓度的ＮＤＡＰ对Ｆｏｓ蛋白的生成亦有一定的诱导作用,分别是对照组的２．７倍和２．６倍。ＣＣＫ－８和ＮＤＡＰ共同处理组织,Ｆｏｓ蛋白生成水平相似（脑）或高于（脊髓）ＣＣＫ~－８单独诱导的水平。结果表明,ＣＣＫ－８和ＮＤＡＰ均可直接诱导大鼠脑和脊髓组织ｃ－ｆｏｓ的表达,它们对ｃ－ｆｏｓ表达的相互作用在脑和脊髓中呈现不同的模式。     

Towards a physical description of habitat: quantifying environmental adversity (abiotic stress) in temperate forest and woodland ecosystems

1. Our aim was to develop a quantitative proxy for environmental adversity (abiotic stress) in temperate Eucalyptus and Nothofagus forest and woodland ecosystems.
2. Samples and measurements were collected at 42 sites across a rainfall gradient in southern Australia, an elevation gradient in south-eastern Australia, and a longitudinal transect (temperature gradient) in Patagonia, Argentina.
3. We compared the ability of (a) abiotic variables (14 soil and 21 climatic variables) and (b) the stable carbon isotope (δ¹³C) values of soil organic matter (SOM), to predict variation in leaf area index (LAI; a forest productivity variable).
4. The δ¹³C of SOM (soil aggregates) explained more variation (57%) in LAI than multivariate statistical models that integrated information on many abiotic variables. W* (a climatic water balance model) was also a powerful predictor variable, explaining 37% of the variability in LAI.
5 Synthesis . The stable carbon isotopic signature of soil aggregates is a powerful explanatory variable that may help us to quantify environmental adversity (abiotic stress) in temperate forest and woodland ecosystems.     

外生菌根对植物非生物胁迫的缓解作用及作用机理研究进展

外生菌根在林木共生系统中占据重要的地位,具有提高宿主植物抗逆性的作用.在菌根学领域中,外生菌根与非生物胁迫互作的研究要远少于其他类型的菌根,尤其是缺乏综合、全面的总结性评述.文中总结了近5年来的相关研究,阐述了非生物胁迫(干旱、寒冷、高温、盐碱、重金属和有毒物质)下菌根共生体与植物抗逆性的关系,其他因子与外生菌根协同提...     

Eco-physiological and Biochemical Responses of Rapeseed (Brassica napus L.) to Abiotic Stresses: Consequences and Mitigation Strategies

Rapeseed yield parameters have been altered due to the increased exposure to abiotic stresses. The changing climatic conditions have reduced biomass production and seed yield, which ultimately affect the success of rapeseed crops. The severity and ability of abiotic stresses to act in tandem are a growing concern for agriculture producers across the globe. Rapeseed is one of the most vital cultivars in the world, serving as a major player in edible oil production. Abiotic stress conditions impose various effects on plant metabolism associated with growth stages, soil water storage capacity and plant physiological aspects. Modern agriculture aims to increased plant productivity to ensure global food security for the future. This can be achieved using quality seed, appropriate agricultural practices, measuring pest reduction techniques and understanding crop production challenges. Important tools, including conventional breeding and biotechnological approaches, can be employed to develop abiotic stress tolerance rapeseed. This review highlights the physiological and biochemical responses of rapeseed to abiotic stresses. The review also addresses conventional and modern stress mitigation strategies for the development of climate-smart rapeseed.

     

Friends or Foes? Interplay of facilitation and competition depends on the interaction between abiotic stress and ontogenetic stage

The importance of ontogeny and the degree of abiotic stress in determining the interplay between facilitation and competition is well known. However, their joint effect on the outcome of plant interactions remains poorly understood, especially when a continuous gradient of abiotic stress is considered. Our objective was to evaluate the frequency of association of individuals of Clusia criuva with typical coastal dune species across a gradient of water stress and how this association affects the growth of juveniles and sub-adults. The study was performed in a coastal dune region in South Brazil, where the sandy soil promotes severe water stress. One-year growth of 293 individuals and their distance to the closest humid slacks were measured. This distance is a good surrogate for water stress, since slacks represent proximity to groundwater. The proportion of associated individuals increased with abiotic stress in both ontogenetic stages, but was always greater for juveniles. This suggests that association is progressively more important to guarantee survival as abiotic stress increases. Nonetheless, the benefit of neighbors to growth decreased with abiotic stress, and associated plants grew less than isolated ones in harsher environments. This was mainly true for juveniles, since the height growth of sub-adults was not affected by association or abiotic stress. In our study, facilitation became more intense with environmental severity, increasing survival, although competition also became more influent, reducing growth particularly for younger plants. This demonstrates that ontogenetic stage and abiotic stress must be considered simultaneously in order to better understand interactions among plants.     

Do interactions between plant and soil biota change with elevation? A study on Fagus sylvatica

Theoretical models predict weakening of negative biotic interactions and strengthening of positive interactions with increasing abiotic stress. However, most empirical tests have been restricted to plant-plant interactions. No empirical study has examined theoretical predictions of interactions between plants and below-ground micro-organisms, although soil biota strongly regulates plant community composition and dynamics. We examined variability in soil biota effects on tree regeneration across an abiotic gradient. Our candidate tree species was European beech (Fagus sylvatica L.), whose regeneration is extremely responsive to soil biota activity. In a greenhouse experiment, we measured tree survival in sterilized and non-sterilized soils collected across an elevation gradient in the French Alps. Negative effects of soil biota on tree survival decreased with elevation, similar to shifts observed in plant-plant interactions. Hence, soil biota effects must be included in theoretical models of plant biotic interactions to accurately represent and predict the effects of abiotic gradient on plant communities.     

On the relationship between abiotic stress and co-occurrence patterns: an assessment at the community level using soil lichen communities and multiple stress gradients

The stress‐gradient hypothesis (SGH) predicts a shift from predominant competition to facilitation as abiotic stress increases. Most empirical tests of the SGH have evaluated the interactions between a single or a few pairs of species, have not considered the effects of multiple stress factors, and have not explored these interactions at nested spatial scales. We sampled 63 0.25‐m² plots, each subdivided into 100 5×5 cm and 25 10×10 cm sampling squares, in a semi‐arid Mediterranean environment to evaluate how co‐occurrence patterns among biological soil crusts (BSC)‐forming lichens changed along natural stress gradients driven by water and nutrient (N, P, K) availability. According to the SGH, we tested the hypothesis that the fine‐scale spatial arrangement of BSC‐forming lichens should shift from prevailing interspecific segregation to aggregation as abiotic stress increases. Co‐occurrence patterns ranged from significant species segregation to aggregation at the two spatial scales studied. When using the 5×5 cm grid, more plots showed significant species segregation than aggregation. At this sampling scale, co‐occurrence increased as water and nutrient availability decreased and increased, respectively. Small increases in soil pH promoted species co‐occurrence. Interspecific segregation was promoted as the cover of highly competitive species, such as Diploschistes diacapsis, increased. No significant relationships between co‐occurrence and the surrogates of abiotic stress were observed when data was arranged in a 10×10 cm grid. Our co‐occurrence analyses partially supported predictions from the SGH, albeit the results obtained were dependent on the type of abiotic stress and the spatial scale considered. They show the difficulties of predicting how co‐occurrence patterns change along complex stress gradients, and highlight the need of incorporating the effects of abiotic stress promoted by different resources, such as water and nutrients, into the conceptual framework of the SGH.     

Abiotic stress and induced DNA hypomethylation cause interphase chromatin structural changes in rice rDNA loci

Global climate change, i.e. higher and more variable temperatures, and a gain in soil salinity are increasing plant stress with direct consequences on crop yield and quality levels. Rice productivity is strongly affected by abiotic stress conditions. The regulation of chromatin structure in response to environmental stress is poorly understood. We investigated the interphase chromatin organization from rice plants in non-stress versus stress conditions. We have used a cytogenetic approach, based on fluorescence in situ hybridization (FISH) with 45S, 5S rDNA and centromeric probes on rice tissue sections. The abiotic stress conditions included cold, heat and mild salinity and were applied during seed germination. In contrast to cold, saline and heat stresses caused extensive decondensation of 45S rDNA chromatin and also an increase in the distance between the 2 homologous 5S rDNA loci. 5-Azacytidine (5-AC), a DNA hypomethylating drug, greatly increased 45S rDNA chromatin decondensation and interestingly was able to induce polarization of centromeres in rice interphase nuclei. The abiotic stresses tested did not perturb the spatial position of centromeres, typically with circular arrangement around the nucleolus. The results suggest a role for chromatin plasticity in a world of climate changes.     

Effects of Abiotic and Biotic Stresses on the Internalization and Dissemination of Human Norovirus Surrogates in Growing Romaine Lettuce

Human norovirus (NoV) is the major causative agent of fresh-produce-related outbreaks of gastroenteritis; however, the ecology and persistence of human NoV in produce systems are poorly understood. In this study, the effects of abiotic and biotic stresses on the internalization and dissemination of two human NoV surrogates (murine norovirus 1 [MNV-1] and Tulane virus [TV]) in romaine lettuce were determined. To induce abiotic stress, romaine lettuce was grown under drought and flood conditions that mimic extreme weather events, followed by inoculation of soil with MNV-1 or TV. Independently, lettuce plants were infected with lettuce mosaic virus (LMV) to induce biotic stress, followed by inoculation with TV. Plants were grown for 14 days, and viral titers in harvested tissues were determined by plaque assays. It was found that drought stress significantly decreased the rates of both MNV-1 and TV internalization and dissemination. In contrast, neither flood stress nor biotic stress significantly impacted viral internalization or dissemination. Additionally, the rates of TV internalization and dissemination in soil-grown lettuce were significantly higher than those for MNV-1. Collectively, these results demonstrated that (i) human NoV surrogates can be internalized via roots and disseminated to shoots and leaves of romaine lettuce grown in soil, (ii) abiotic stress (drought) but not biotic stress (LMV infection) affects the rates of viral internalization and dissemination, and (iii) the type of virus affects the efficiency of internalization and dissemination. This study also highlights the need to develop effective measures to eliminate internalized viruses in fresh produce.     

Cortex proliferation in the root is a protective mechanism against abiotic stress

Although as an organ the root plays a pivotal role in nutrient and water uptake as well anchorage, individual cell types function distinctly. Cortex is regarded as the least differentiated cell type in the root, but little is known about its role in plant growth and physiology. In recent studies, we found that cortex proliferation can be induced by oxidative stress. Since all types of abiotic stress lead to oxidative stress, this finding suggests a role for cortex in coping with abiotic stress. This hypothesis was tested in this study using the spy mutant, which has an extra layer of cortex in the root. Interestingly, the spy mutant was shown to be hypersensitive to salt and oxidizing reagent applied to the leaves, but it was as tolerant as the wild type to these compounds in the soil. This result lends support to the notion that cortex has a protective role against abiotic stress arising from the soil.