新生代全球变化与中国古植物区系的演变

新生代是地质历史最年轻的一个时代 ,当时全球板块运动和岩浆活动强烈而频繁 ,中生代开始的大陆漂移活动继续进行 ,并于早第三纪末开始喜马拉雅运动 ,古地中海逐渐封闭 ,经过一系列的板块碰撞和洋底扩张 ,晚第三纪时地壳构造的基本轮廓和古地理面貌逐渐接近现代。受地壳运动的控制 ,全球新生代气候波动明显 ,早第三纪总体比较温暖 ,晚第三纪气候发生明显分异 ,气温显著下降 ,第三纪末期开始有冰川活动 ,一直持续到更新世末期 ,期间发生多次冰期和间冰期 ,全新世气候逐渐转暖。受上述全球变化的影响 ,我国新生代植物区系纵向演变和横向分异明显 ,早第三纪植物区系主要是纬向分带 ,从古新世到渐新世 ,我国植物区系主要分为北方区和南方区 ;晚第三纪初 ,由于喜马拉雅运动使青藏高原及东部的横断山脉地区持续抬升 ,逐渐形成独立的高原植物区。总体来说 ,晚第三纪植物区系和植被类型逐渐接近现代。第四纪由于青藏高原继续强烈抬升 ,激发了东亚季风 ,使我国的植物区系经向分带更加明显 ,植物区系和植被类型与现代已基本一致 ,到了全新世晚期 ,植物区系的演变除了受全球变化的影响外 ,人类活动的作用也越来越明显     

Combining functional weed ecology and crop stable isotope ratios to identify cultivation intensity: a comparison of cereal production regimes in Haute Provence,France and Asturias,Spain

This investigation combines two independent methods of identifying crop growing conditions and husbandry practices—functional weed ecology and crop stable carbon and nitrogen isotope analysis—in order to assess their potential for inferring the intensity of past cereal production systems using archaeobotanical assemblages. Present-day organic cereal farming in Haute Provence, France features crop varieties adapted to low-nutrient soils managed through crop rotation, with little to no manuring. Weed quadrat survey of 60 crop field transects in this region revealed that floristic variation primarily reflects geographical differences. Functional ecological weed data clearly distinguish the Provence fields from those surveyed in a previous study of intensively managed spelt wheat in Asturias, north-western Spain: as expected, weed ecological data reflect higher soil fertility and disturbance in Asturias. Similarly, crop stable nitrogen isotope values distinguish between intensive manuring in Asturias and long-term cultivation with minimal manuring in Haute Provence. The new model of cereal cultivation intensity based on weed ecology and crop isotope values in Haute Provence and Asturias was tested through application to two other present-day regimes, successfully identifying a high-intensity regime in the Sighisoara region, Romania, and low-intensity production in Kastamonu, Turkey. Application of this new model to Neolithic archaeobotanical assemblages in central Europe suggests that early farming tended to be intensive, and likely incorporated manuring, but also exhibited considerable variation, providing a finer grained understanding of cultivation intensity than previously available.     

Comparative physiological and proteomic analysis of cultivated and wild safflower response to drought stress and re-watering

Drought is one of the major environmental stress that adversely affect the growth and development of oil seed plant, safflower. There is a limited knowledge on proteomic responses to support physiological, biochemical changes in how safflowers can regulate growth and metabolism under drought conditions and followed by re-watering. The changes in morphological, physiological, biochemical and proteomics of safflower genotypes (Carthamus tinctorius L.; Remzibey-05 and Linas, tolerant and sensitive cultivars, respectively, and C. oxyacantha M. Bieb., wild type) after exposure to drought and followed by re-watering have been examined. Drought negatively affected the shoot weight, water content, chlorophyll fluorescence, and biochemical parameters, including photosynthetic pigment, proline, MDA, and H₂O₂ contents and antioxidant enzyme activities in all genotypes, while the re-watering period allowed Remzibey-05 to recover, and it even provided the wild type completely recovered (approximately 100%). A total of 72 protein spots were observed as differently accumulated under treatments. The identified proteins were mainly involved in photosynthesis and carbohydrate, protein, defense, and energy metabolisms. Protein accumulation related to these metabolisms in Remzibey-05 were decreased under drought, while increased following re-watering. However, sensitive cultivar, Linas, could not exhibit an effective performance under drought and recovery when compared with other safflower genotypes. Supplementary InformationThe online version contains supplementary material available at (10.1007/s12298-021-00934-2).     

Effects of exotic and translocated fish species in the inland waters of Turkey

Throughout the world a number of problems have arisen following the introduction of new fish species; impacts of introductions are not limited to biological and ecological effects but may also have socioeconomic implications. Exotic and translocated fish species have become established in various parts of the inland waters of Turkey since the 1950s. The present paper reviewed ecological and economical effects of introduced freshwater fish of Turkey.     

N-butanoyl-l-homoserine lactone (BHL) deficient Pseudomonas aeruginosa isolates from an intensive care unit

Acylated homoserine lactones (AHLs) are self-generated diffusible signal molecules that mediate population density dependent gene expression (quorum sensing) in a variety of Gram-negative bacteria, and several virulence genes of human pathogens are known to be controlled by AHLs. In this study, strains of Pseudomonas aeruginosa, Acinetobacter baumannii, Escherichia coli and Klebsiella pneumoniae, isolated from intensive care patients, were screened for AHL production by using AHL responsive indicator strains of Chromobacterium violaceum CV026 and Agrobacterium tumefaciens NT1. Positive reactions were recorded for all 50 isolates of P. aeruginosa and 10 isolates of Acinetobacter baumannii with Agrobacterium tumefaciens NT1. Surprisingly, most P. aeruginosa isolates gave negative results with C. violaceum CV026 in contrast to previous reports. This suggests that the new isolates of P. aeruginosa either failed to make short chain AHLs or the level of the signal molecule is very low.     

细菌分裂蛋白及FtsZ抑制剂的研究进展

近年来,由于抗生素的滥用,耐药性细菌广泛出现,对人体健康的威胁日益严峻.随着临床用药的选择不断减少,迫切需要开发新的抗菌药物,特别是新作用机制的抗菌分子来对抗出现的耐药菌.细胞分裂温度敏感.突变体Z (filamenting temperature-setnsitive mutant Z,FtsZ)作为细菌分裂的必需蛋白质,是目前研究最热门的作用靶点之一.FtsZ是一高度保守的蛋白质,在大多数原核细胞的细胞分裂中发挥着关键作用,本文回顾了细菌分裂蛋白的结构特点及其生物学功能,并综述了以FtsZ为靶点的抗菌药物研究的进展.