植物β-半乳糖苷酶

β-半乳糖苷酶是一个与细胞壁降解相关的酶,广泛分布于植物组织中,参与一系列的生理生化过程,如植物的花粉发育、果实成熟及生长过程中多糖的裂解。目前,已从多种植物中分离到β-半乳糖苷酶基因。β-半乳糖苷酶基因属于多基因家族,随着研究的深入,其不同水平的转录本在不同植物的不同组织中被发现。但目前β-半乳糖苷酶在植物发育中确切的作用机制尚不明确。现介绍目前这一领域内细胞与分子生物学方面的研究进展,并结合所在课题组的研究结果进行相关探讨,为进一步研究β-半乳糖苷酶在植物中的作用机制提供新的线索。     

The influence of genetics on future crop production strategies: from traits to genes, and genes to traits

This paper discusses how a genetical approach to plant physiology can contribute to research underpinning the production of new crop varieties. It highlights the interactions between genetics and plant breeding and how the current advances in genetics and the new science of genomics can contribute to our understanding of the genetical control of key agronomic traits ‐ the process of ‘translating’ traits to identified and mapped genes. Advances in genomics, such as the sequencing of whole genomes and expressed sequence tags, are producing information on genes and gene structures, but without knowing their function. A great deal more biology will be necessary to translate gene structure to function ‐ the process of translating genes to traits. Combining these ‘forward’ and ‘reverse’ genetic approaches will allow us to get comprehensive knowledge of the biology of agronomic traits at the physiological, biochemical and molecular levels, so that the ‘circuitry’ of our crop plants can be elucidated. This will enable plant breeders to manipulate crop phenotype using marker‐assisted breeding or genetic engineering approaches with a precision not previously possible.     

mRNA降解在植物发育以及抗性反应中的作用

植物mRNA的降解对于维持其生化和细胞学的功能都是必需的,而且这种降解要根据植物发育和外界环境的变化进行及时的调整。与酵母和哺乳动物相比,人们对植物mRNA的降解机制了解较少。对近几年来该领域的研究进展进行总结,包括参与植物mRNA降解的酶类和基因芯片技术的应用,以及mRNA降解的生物学意义等。     

Mitochondrial involvement in bladder function and dysfunction

Benign bladder pathology resulting from prostatic hypertrophy or other causes is a significant problem associated with ageing in humans. This condition is characterized by increased bladder mass, decreased urinary flow rate, decreased compliance, and these and other changes in bladder function often subject patients to increased risk of urinary tract infection. While the physiologic attributes of benign bladder pathology have been extensively described in humans and in various animal model systems, the biochemical and molecular genetic bases for that pathology have only recently been investigated in detail. Studies demonstrate that mitochondrial energy production and utilization are severely impaired in bladder smooth muscle during benign bladder disease, and to a large extent this realization has provided a rational basis for understanding the characteristic alterations in urinary flow and compliance in bladder tissue. Recent investigations targeting the detailed molecular basis for impaired mitochondrial function in the disease have shown that performance of the organellar genetic system, and to a large extent that of relevant portions of the nuclear genetic system as well, is severely aberrant in bladder tissue. In this article, we discuss the physiologic aspects of benign bladder disease, summarize biochemical evidence for the altered mitochondrial energy metabolism that appears to underlie bladder pathology, review the structure and function of the mitochondrial genetic system, and discuss molecular genetic studies of that system which have begun to provide a mechanistic explanation for the biochemical and physiological abnormalities that characterize the disease. We also discuss areas for further research which will be critically important in increasing our understanding of the detailed causes of benign bladder pathology.     

中国植物发育生物学若干重要领域的研究回顾

植物发育是指从种子萌发经过营养生长、开花与花器官发育、受精结果形成新一代的有序过程。每一个时期具有复杂的代谢和基因表达与调控网络。过去的数 10年中我国在该领域的研究取得了许多重要的进展 ,特别是近 10年来发育生物学已经从以往的以描述为主要特征发展到在分子水平上阐明发育控制的机理。花器官的发育研究是发育生物学研究最具突破性的领域 ,开花和营养器官的发育已经成为新的研究热点。本文按照植物发育的时间顺序 ,回顾了我国发育生物学若干重要领域的重要研究进展 ,并展望了基因组时代给发育生物学研究带来的新的机遇和研究平台     

中国植物发育生物学若干重要领域的研究回顾

植物发育是指从种子萌发经过营养生长、开花与花器官发育、受精结果形成新一代的有序过程.每一个时期具有复杂的代谢和基因表达与调控网络.过去的数10年中我国在该领域的研究取得了许多重要的进展,特别是近10年来发育生物学已经从以往的以描述为主要特征发展到在分子水平上阐明发育控制的机理.花器官的发育研究是发育生物学研究最具突破性的领域,开花和营养器官的发育已经成为新的研究热点.本文按照植物发育的时间顺序,回顾了我国发育生物学若干重要领域的重要研究进展,并展望了基因组时代给发育生物学研究带来的新的机遇和研究平台.     

Population genetics of fungal diseases of plants

Although parasitism is one of the most common lifestyles among eukaryotes, population genetics on parasites lag for behind those on free-living organisms. Yet, the advent of molecular markers offers great tools for studying important processes, such as dispersal, mating systems, adaptation to host and speciation. Here we highlight some studies that used molecular markers to address questions about the population genetics of fungal (including oomycetes) plant pathogens. We conclude that population genetics approaches have provided tremendous insights into the biology of a few fungal parasites and warrant more wide use in phytopathology. However, theoretical advances are badly needed to best apply the existing methods. Fungi are of prime interest not only because they are major parasites of plants and animals, but they also constitute tractable and highly useful models for understanding evolutionary processes. We hope that the emerging field of fungal evolution will attract more evolutionary biologists in the near future.     

Adaptive mechanisms of medicinal plants along altitude gradient: contribution of proteomics

Medicinal plants are a rich source of secondary metabolites extensively used in traditional health care systems. High altitude biodiversity encompasses the diversified and valuable medicinal plant species. The extreme environmental conditions of high altitude region viz. fluctuating temperatures, high UV radiation, salinity, low oxygen concentration, and high wind velocity limits the plant growth and distribution. Yet, how medicinal plants respond to these extreme conditions is not sufficiently understood. Therefore, addressing plant acclimation to different stresses presents an opportunity to unravel adaptive mechanism of medicinal plants along altitude gradient. This article reviews the recently published research that highlights the major role of proteins in plant adaptation to extreme environmental conditions. In the last few decades, climate change has made a profound impact on high altitude plants. Stress conditions alter cellular homeostasis of plants. With the advent of proteomics, it has become evident that stresses induce changes in proteome by synthesis/expression of novel stress responsive proteins. These proteins constitute a highly organized, complex network that leads to changes in the molecular, biochemical, physiological, and morphological responses of plants. Herein, we comprehensively discuss the proteomics of medicinal plants and its role in adaptation along altitude gradient. This review aims to provide impetus to current research in medicinal plants ranging from developmental to stress biology and to generate basis for genetic engineers and plant breeders to produce next-generation medicinal plants.     

Consideration of the taxonomy and biodiversity of Australian ectomycorrhizal fungi

Mycorrhiza management in forestry must be predicated on an understanding of fungal biology and ecology. A fundamental building block of the biology and ecology of any organism is accurate identification and an understanding of its relationship to other organisms. The taxonomy of the larger fungi has been largely based on morphological classification of sexual structures but now Taxonomy routinely incorporates mating studies, and biochemical and molecular data. Taxonomy may not revolutionize theories on mycorrhiza but can clarify some of the inconsistencies due to misrepresentation or over-generalizations and inappropriate conclusions drawn from studies with inaccurately identified fungi. To illustrate this, we discuss and example where incorrect fungal names were repeatedly erroneously applied in morphological and physiological research reports on this fungus, e.g. Laccaria laccata. In this case subsequent taxonomic study revealed the reason for the conflicting research results reported for this fungus. We discuss the status of identifying the ectomycorrhizal fungi in various forest communities in Australia and the relationships of this process to assessing their use in forestry. Recent intensive efforts to collect, isolate and identify Australian ectomycorrhizal fungi have revealed an enormous and unique species diversity, e.g., for truffle-like fungi, over 2000 collections from the last five years alone have yielded 2 new families, 24 new genera, and about 184 new species. Nearly 95% of the described and undescribed fungi from Australia are novel, with some 22 genera and 3 families endemic. In most cases the current systematic knowledge of mycorrhizal fungi is inadequate to support clear framework for Australian taxa. This reflects the traditional Northern Hemisphere view of the world, the uniqueness of the Australian fungal flora, and how poorly it is known. For example, the genus Hymenogaster had been widely acknowledged as the most reduced member of the Cortinariaceae. However recent work on Hymenogaster species from the Southern Hemisphere has offered a number of alternative affinities to various species. We also discuss the role proper identification of the organisms involved plays in understanding the ecosystem. Emphasis should be placed on how species diversity equates with physiological and genetic diversity and how a sound taxonomic understanding of species and their systematic position is essential to properly manage them. Accurate taxonomic information will continue to be required as the basis for assessing the role of ectomycorrhizal fungi in sustained ecological development. Of particular significance is the role of ectomycorrhizal fungi in maintenance of plant diversity in natural ecosystems and those disturbed by management. In conclusion, we present some key research areas involving the use of taxonomy that need priority attention.     

代谢组及其在真菌研究中的应用

代谢组学是利用现代分析化学手段对一定条件下生物体内小分子代谢产物（初级和次级代谢产物）定性及定量,从而揭示生命现象及其内在规律的学科。相对于基因组、转录组和蛋白质组,代谢组是一定条件下生物学过程完成后的最终代谢产物的集合,因而是各种组学研究中最接近表型的一种组学,可以直接动态地反映出细胞的生理生化过程,从而有效地检测和发现特定的生化途径,准确地解释生理或者病理现象。代谢组学作为系统生物学中基因组学、转录组学以及蛋白质组学三大组学的延伸和补充,是目前的研究热点之一。目前代谢组学在真菌领域的研究得到日益重视和发展。本文首先从历史发展和技术路线简述了代谢组学的发展历程和常见的代谢组学研究方法。接着从真菌的分类鉴定、生物膜研究、代谢途径、代谢工程、天然产物发现与植物互作这6个方面介绍了代谢组学在真菌研究领域的应用。     

Two Distinct Pathways for Targeting Proteins from the Cytoplasm to the Vacuole/Lysosome

Stress conditions lead to a variety of physiological responses at the cellular level. Autophagy is an essential process used by animal, plant, and fungal cells that allows for both recycling of macromolecular constituents under conditions of nutrient limitation and remodeling the intracellular structure for cell differentiation. To elucidate the molecular basis of autophagic protein transport to the vacuole/lysosome, we have undertaken a morphological and biochemical analysis of this pathway in yeast.     

植物落花落果的分子机理研究进展

落花落果是花、果实、种子从母体脱落的一种普遍存在的自然现象。发生器官脱落的区域为离区(abscission zone,AZ)。离区分化形成离层,离层与脱落息息相关。离层的发育和功能行使是多酶、多激素、多基因参与调控的复杂而精确的过程。落花落果不仅是作物栽培和育种中的典型农艺性状,而且是植物器官脱落的主要形式之一。减少植物落花落果或控制某些植物适度落花落果,提高作物和果蔬类植物的产量和品质,是人类在作物驯化上努力的目标。该文基于前人对植物器官脱落的生理生化和分子生物学机制的研究,主要从植物落花落果的细胞学基础、生理生化机制、遗传学规律、分子生物学和相关基因定位、转录组分析方面阐述落花落果分子机理,重点从落花落果的分子生物学和相关基因定位两个方面进行剖析落花落果的作用机制,以便为作物遗传育种研究提供理论指导。     

植物与病原真菌互作机制研究进展

植物与病原真菌之间的互作是当今植物病理学研究的热点问题之一,相关的研究有望为植物抗病机制的解析和抗病品种的选育奠定理论基础。我们从形态、细胞、生理生化和分子等水平综述了植物与病原真菌互作机制的研究进展。     

Phytomonas: Trypanosomatids Adapted to Plant Environments

Over 100 years after trypanosomatids were first discovered in plant tissues, Phytomonas parasites have now been isolated across the globe from members of 24 different plant families. Most identified species have not been associated with any plant pathology and to date only two species are definitively known to cause plant disease. These diseases (wilt of palm and coffee phloem necrosis) are problematic in areas of South America where they threaten the economies of developing countries. In contrast to their mammalian infective relatives, our knowledge of the biology of Phytomonas parasites and how they interact with their plant hosts is limited. This review draws together a century of research into plant trypanosomatids, from the first isolations and experimental infections to the recent publication of the first Phytomonas genomes. The availability of genomic data for these plant parasites opens a new avenue for comparative investigations into trypanosomatid biology and provides fresh insight into how this important group of parasites have adapted to survive in a spectrum of hosts from crocodiles to coconuts.     

Prospects for improving nitrogen use efficiency: Insights given by 15N-labelling experiments

In higher plants, recent advances in plant molecular genetics, combined with modern physiological and biochemical studies, have expanded our understanding of the regulatory mechanisms controlling the primary steps of inorganic nitrogen assimilation and the subsequent biochemical pathways involved in nitrogen supply and recycling for higher plant metabolism, growth and development. In this presentation, we describe improvements in our understanding of the molecular controls of nitrogen assimilation through the use of transgenic plants and the study of genetic variability in model and crop species. To illustrate this research programme, the physiological impact of modified gene expression, using either transgenic plants or different genotypes, was studied using ¹⁵N-labelling experiments in order to monitor the influx of nitrate or ammonia and its subsequent incorporation into amino acids.