新疆沙冬青叶片氨基酸和蛋白质的测试与分离以及抗冻蛋白的鉴定结果分析

提取并纯化了新疆沙冬青(Ammopiptanthus nanus)叶片总蛋白,得到了适合新疆沙冬青叶片总蛋白提取的最佳缓冲体系;用DEAE52-C分离了各蛋白质组分,并用SDS-PAG测定了纯度和分子量(14~90 kD之间);氨基酸组成分析显示了新疆沙冬青属内种遗传的一致性。对抗冻活性分析讨论证实了与蒙古沙冬青同属的新疆沙冬青中也含有抗冻蛋白(AFPs)。     

施钾对强筋小麦生理特性及产量的效应

以强筋面包小麦临优145为试验材料,于大田生产条件下研究了施用钾肥对强筋小麦叶片光合、膜脂氧化及产量特性的影响.结果显示,适量施钾能显著降低开花14d以后旗叶中超氧阴离子的产生强度和MDA含量,并显著提高旗叶的叶绿素含量、光合速率和籽粒灌浆速率,显著增加千粒重;在施钾(K2O)37.5~150.0kg/hm2范围内,随施钾量增加,各处理产量呈先上升后下降趋势且均比对照极显著增产14.5%~30.7%,各处理间产量差异显著,以施钾(K2O)112.5kg/hm2时籽粒产量最高.结果表明,中产条件下施用钾肥可显著提高强筋小麦籽粒产量,且以施钾(K2O)103.0~112.5kg/hm2为宜.     

Endophytic fungi from <Emphasis Type="Italic">Nerium oleander</Emphasis> L (Apocynaceae): main constituents and antioxidant activity

Diverse endophytic fungi exist within plant aerial tissues, with a global estimate of up to a million undescribed species. These endophytes constitute a rich bio-resource for exploration to discover new natural products. Here we investigate fungal endophytes associated with a medicinal plant, Nerium oleander L. (Apocynaceae). A total of 42 endophytic fungal strains were isolated from the host plant. Total antioxidant capacity, xanthine oxidase inhibitory activity, antimicrobial activity, and total phenolic content (TPC) were evaluated for 16 representative fungal cultures grown in improved Czapek’s broth and for the host plant. The total antioxidant capacities and phenolic contents of the fungal cultures ranged from 9.59 to 150.79 μmol trolox/100 mL culture, and from 0.52 to 13.95 mg gallic acid/100 mL culture, respectively. The fungal culture of an endophytic strain Chaetomium sp. showed the strongest antioxidant capacity, contained the highest level of phenolics, and to some extent inhibited xanthine oxidase activity with an IC₅₀ value of 109.8 μg/mL. A significant positive correlation was found between antioxidant capacity and TPC in the tested samples. Most of the endophytic fungal cultures tested have a wide range of antimicrobial activities, which were not very strong, but much better than those of the host plant. The major bioactive constituents of the fungal cultures were investigated using LC-ESI-MS and GC-MS, and preliminary identification detected phenolics (e.g. phenolic acids and their derivatives, flavonoids) and volatile and aliphatic compounds. This study shows that the endophytic fungi isolated from N. oleander can be a potential antioxidant resource.     

The phylogeny of the social Anelosimus spiders (Araneae: Theridiidae) inferred from six molecular loci and morphology

We use fragments of three nuclear genes (Histone 3, 18SrDNA, and 28SrDNA) and three mitochondrial genes (16SrDNA, ND1, and COI) totalling approximately 4.5kb, in addition to morphological data, to estimate the phylogenetic relationships among Anelosimus spiders, well known for their sociality. The analysis includes 67 individuals representing 23 of the 53 currently recognized Anelosimus species and all species groups previously recognized by morphological evidence. We analyse the data using Bayesian, maximum likelihood, and parsimony methods, considering the genes individually as well as combined (mitochondrial, nuclear, and both combined) in addition to a 'total evidence' analysis including morphology. Most of the data partitions are congruent in agreeing on several fundamental aspects of the phylogeny, and the combined molecular data yield a tree broadly similar to an existing morphological hypothesis. We argue that such congruence among data partitions is an important indicator of support that may go undetected by standard robustness estimators. Our results strongly support Anelosimus monophyly, and the monophyly of the recently revised American 'eximius lineage', although slightly altered by excluding A. pacificus. There was consistent support for the scattering of American Anelosimus species in three clades suggesting intercontinental dispersal. Several recently described species are reconstructed as monophyletic, supporting taxonomic decisions based on morphology and behaviour in this taxonomically difficult group. Corroborating previous results from morphology, the molecular data suggest that social species are scattered across the genus and thus that sociality has evolved multiple times, a significant finding for exploring the causes and consequences of social evolution in this group of organisms.     

Multiple Site Directed Mutagenesis Strategy Based on Total RNA and RT-PCR Method

Site-directed PCR-based mutagenesis methods are widely used to generate mutations. All published methods work on DNA clones carrying the target sequence. However, DNA clones are not always available. We have previously published a RT-PCR-based site-directed mutagenesis method starting from total RNA to overcome this problem. In this article, we report an improvement of our previous method to facilitate introduction of multiple mutations into a target sequence. We demonstrate the efficacy and feasibility of this strategy by mutation of the human β-actin gene. BamHI restriction endonuclease cleavage sites were generated within the gene to assist screening. Using three mutagenic primers in a single RT-PCR reaction, seven different clones were produced carrying three single and four multiple mutations. An investigation of the effect of the cycle number and elongation time of the PCR reactions revealed that both have an influence on the ratio of clones carrying single and multiple mutations. An optimized protocol was established for efficient multiple site-directed mutagenesis.     

Association of total tooth loss with smoking, drinking alcohol and nutrition in elderly Japanese: analysis of national database

Objective: Various factors may be associated with edentulism in elderly people. Association of total tooth loss with smoking, alcohol intake and nutrition in non‐institutionalised elderly Japanese was assessed utilising national database. Materials and methods: Records of independent surveys, the Survey of Dental Diseases (SDD) and the National Nutrition Survey (NNS) in 1999 were electronically linked using the household identification number. Results: Among the records of 6903 subjects in the SDD and 12 763 subjects in the NNS, 6805 records were successfully linked. Overall, prevalence of total tooth loss in adults was very similar in males and females at approximately 7.0%, and the smoking rate was 47.6% and 9.9% respectively. Total tooth loss was a rare phenomenon (<2%) in age groups of <60 years. According to the multiple logistic regression analysis involving 2200 subjects aged 60 years or older, significant variables were age, current smokers and vitamin C intake in males, and age and current smokers in females. The variable for current drinkers was significant in females but the odds ratio was <1.0. No significant relationship was detected with respect to former smokers and drinkers, body mass index, vitamin E intake and blood glucose level. Conclusions: Current smoking was associated with total tooth loss, although smoking rate was low in females. Gender difference in the association was suggestive with respect to drinking alcohol and vitamin C intake.     

A dynamic mass balance model for phosphorus fluxes and concentrations in coastal areas

This paper presents a general, process-based mass balance model (CoastMab) for total phosphorus (TP) in defined coastal areas (at the ecosystem scale). The model is based on ordinary differential equations and calculates inflow, outflow and internal fluxes on a monthly basis. It consists of four compartments: surface water, deep water, erosion/transportation areas for fine sediments and accumulation areas for fine sediments. The separation between surface water and deep water is not done based on water temperature, but on sedimentological criteria instead (from the theoretical wave base). There are algorithms for all major internal TP fluxes (sedimentation, resuspension, diffusion, mixing and burial). Validations were performed using data from 21 different Baltic coastal areas. The results show that the model predicts monthly TP in water and chlorophyll a very well (generally within the uncertainty bands of the empirical data). The model has also been put through sensitivity tests, which show that the most important factor regulating the predictions of the model is generally the TP concentration in the sea beyond the coast. The model is simple to apply, since all driving variables may be accessed from maps or monitoring programs. The driving variables include coastal area, section area (between the defined coastal area and the adjacent sea), mean and maximum depths, latitude (used to predict water temperatures, stratification and mixing), salinity and TP concentration in the sea. Many of the model structures are general and could be used for areas other than those included in this study, e.g., for open coasts, estuaries or tidal coasts, as well as for other substances than phosphorus.     

模拟降雨变化对古尔班通古特沙漠土壤养分及酶活性的影响

土壤酶参与土壤系统的养分循环过程,是联系植物和土壤养分的关键纽带。土壤酶活性对降水格局变化响应敏感,这种响应对于缺水且养分贫瘠的荒漠生态系统显得尤为重要。然而,早春积雪完全融化后首次降雨时间及降雨量如何影响土壤养分及土壤酶活性还鲜见相关报道。以新疆古尔班通古特沙漠为研究区,在早春积雪完全融化后,设置3个首次降雨时间(积雪完全融化后第10天、20天和30天)和3个降雨梯度(5 mm、10 mm和15 mm),于植物生长旺季采集土壤样品,研究土壤养分含量和土壤酶活性的响应特征。结果表明：积雪完全融化后不同首次降雨时间下5mm降雨处理以及积雪完全融化后第30天下各降雨量处理对土壤养分和酶活性影响不显著。积雪完全融化后第10天,随降雨量增加,土壤全碳呈显著先下降后增加趋势,全钾呈显著增加趋势,而土壤微生物量碳呈显著降低趋势;积雪完全融化后第20天,随降雨量增加,速效氮、土壤蔗糖酶活性、土壤微生物量碳氮呈先下降后增加趋势,土壤全碳和多酚氧化酶活性显著下降,土壤全钾和碱性磷酸酶活性显著增加。模拟10 mm降雨,随首次降雨时间推迟,土壤全氮、速效氮、速效磷、土壤蔗糖酶活性和土壤微生物量碳呈增加趋势;...