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关键词： Obligate seeder   Plant population structure   Resprouter   Bud bank   Heat shock experiment  

摘要： Fire is an important factor in several ecosystems, affecting plant population biology. Campos grasslands are under constant influence of disturbance, mostly grazing and fire. However, few studies evaluated the effect of fire on plant population biology of grassland species. Therefore, we aim to analyze the effect of fire on the population biology of four species, from different functional groups and regeneration strategies: Chaptalia runcinata (forb, resprouter, absence of belowground organ), Vernonia flexuosa (forb, resprouter, presence of rhizophore), Eupatorium ligulaefolium (shrub, resprouter, presence of xylopodium) and Heterothalamus psiadioides (shrub, obligate seeder). Seven plots were established in different sites in southern Brazil: frequently burned (FB) and excluded from fire since 6 years (E). All plots were subjected to controlled burns during summer. Before experiments, populations were sampled. Further observations were carried out after 90 and after 360 days of fire experiments. In addition, we counted the number of seedlings and resprouters recruited after fire. Heat shock experiments were conducted with two species (H. psiadioides and V. flexuosa), as well as the study of the bud bank of the following species: E. ligulaefolium and V. flexuosa. The obligate seeder species had all individuals killed by fire and established only after 1 year. Resprouters, however, showed new stems immediately after fire. E. ligulaefolium and V. flexuosa showed only vegetative regeneration from belowground organs and more individuals in excluded sites 1 year after the fire. The bud bank of E. ligulaefolium tended to be larger in excluded sites, whilst V. flexuosa showed an opposite result. High temperatures did not enhance nor kill seeds from both studied species. Vegetative regeneration was the most important strategy for all studied species, except for H. psiadioides, the obligate seeder species. Fire thus, plays an important role on population structure and demogr

关键词： Aloe sect. Lomatophyllum   antimicrobial activity   anthraquinones   genetic diversity   Mascarene Islands  

摘要： Introduction - Aloe tormentorii, A. purpurea and A. macra are used as multipurpose folk medicines in Reunion and Mauritius Islands and are mistaken for the introduced Aloe vera. Objective - To compare the phytochemical, antimicrobial and DNA profiles of Aloe endemic to Mauritius and Reunion with the profiles of A. vera. Methodology - Leaf extracts of these Aloe species were analysed using standard phytochemical screening techniques, TLC and by HPLC. These extracts were also assayed for antimicrobial activity using microdilution techniques. Genetic diversity was studied using RAPD markers. Results - Phytochemical and antimicrobial assays and RAPD analysis showed that Mascarene Aloe species were very different from A. vero. Conclusion - This study is the first report highlighting the differences between Aloe sp.p from Mascarene and Aloe vera at the metabolic and genomic level. Copyright (C) 2010 John Wiley & Sons, Ltd.

关键词： 植物   发育生物学   实验  

ISBN: (纸本)9787307082373

摘要： 本书系统介绍了植物发育生物学研究的常规方法和技术，重点介绍了有关分子生物学研究方法和技术，涉及植物开花、传粉、受精、胚胎发育及植株形成等不同发育阶段的细胞和分子机理。

关键词： 植物生物学   教学改革   教学手段  

摘要： 本文探讨了植物生物学教学改革的必要性和进行改革的主要方法,对植物生物学的教学内容、教学模式以及教学手段进行了一系列改革,提高学生的创新意识和自主学习能力,以培养适应社会需要的具备较高专业知识素养和创新精神的人才。

关键词： Post-translational modifications   Proteome   Proteomics   Mass spectrometry   Plant   Affinity purification  

摘要： Post-translational modifications (PTMs) are involved in the regulation of a wide range of biological processes, and affect e.g. protein structure, activity and stability. Several hundred PTMs have been described in the literature, but relatively few have been studied using mass spectrometry and proteomics. In general, methods for PTM characterization are developed to study yeast and mammalian biology and later adopted to investigate plants. Our point of view is that it is advantageous to enrich for PTMs on the peptide level as part of a quantitative proteomics strategy to not only identify the PTM, but also to determine the functional relevance in the context of regulation, response to abiotic stress etc. Protein phosphorylation is the only PTM that has been studied extensively at the proteome wide level in plants using mass spectrometry based methods. We review phosphoproteomics studies in plants and discuss the redox mediated PTMs (S-nitrosylation, tyrosine nitration and S-glutathionylation), ubiquitylation, SUMOylation, and glycosylation, including GPI anchors, and the quantitative proteomics methods that are used to study these modification in plants. Where appropriate we contrast the methods to those used for mammalian PTM characterization. (C) 2010 Elsevier B.V. All rights reserved.

关键词： 移植物抗宿主病   CD+4CD+25调节T细胞   异基因造血干细胞移植  

摘要： CD＋4CD＋25调节T（Treg）细胞具有免疫无能性和免疫抑制性两大功能特征,是抑制性T细胞的一种亚群.能抑制效应细胞CD＋4T细胞和CD＋8T细胞的活化与增殖,从而有效抑制免疫系统对外来器官产生的排异反应,减轻了造血干细胞移植（HSCT）术后移植物抗宿主病（GVHD）,而且不影响移植物抗白血病（GVL）效应,从而在移植免疫耐受中发挥重要的作用.

关键词： 问题化教学设计   自主探究   合作学习  

摘要： 本文以＂绿色植物通过光合作用制造有机物＂为例,探讨如何将问题化教学设计应用于生物学探究课上。阐述了教师如何设计有效问题来引导学生高效并自主的学习、探究,以达到变被动为主动学习、开发智力、活跃思维的目的,以激发学生的学习兴趣。

关键词： WRKY转录因子   抗病   衰老   损伤   生长发育   非生物逆境  

摘要： WRKY转录因子是近年来在植物中发现的N端含有WRKYGQK高度保守氨基酸序列的转录因子,主要包括三个大类。WRKY通过调节启动子中含W-box元件的调节基因或功能基因的表达,参与了植物的各种防卫反应以及植物的衰老,并调节植物的生长发育。论述了植物WRKY转录因子的分子生物学功能。

关键词： 被子植物   受精   雄配子   雌配子  

摘要： 被子植物有性生殖中,受精始终占有中心位置。受精是一系列精巧有序的发育事态,是十分复杂的自然过程。本文主要对被子植物花粉的发育、胚囊的发育以及精子和卵细胞发生的受精过程进行概述。

关键词： 繁殖生物学   繁育系统   传粉生物学   濒危植物   克隆植物   入侵植物  

摘要： 植物繁殖生物学是研究与植物繁殖有关的特征与过程的科学。本文综述了植物繁殖生物学的主要研究内容,概述了植物繁殖生物学的主要研究方向,主要包括植物繁育系统、传粉生物学研究,并总结了濒危植物、克隆植物、入侵植物繁殖生物学的研究进展,初步揭示了繁殖生物学的研究意义。