枇杷LFY同源基因植物表达载体构建及其功能分析

为研究枇杷LFY同源基因的功能,构建了含枇杷LFY同源基因ejLFY的植物表达载体pBI121-ejLFY,并转入到农杆菌GV3101中。利用花序侵染法将该基因导入拟南芥,经抗性筛选、PCR检测表明获得了25个转化株系。与对照相比,大部分转基因植株明显早花,成花时间可提早1周左右,莲座叶数目减少2-3片;部分植株侧生花序全部转变成单独的花,从莲座叶中抽出的花枝也全部转变为单独的花;少量转化株系花器官异常,不能形成种子。这表明枇杷LFY同源基因在其成花过程中起重要作用,为了解枇杷的成花分子机制奠定了基础。     

multifit: an R function for multi-scale analysis in landscape ecology

Context

Multi-scale analyses are a common approach in landscape ecology. Their aim is to find the appropriate spatial scale for a particular landscape attribute in order to perform a correct interpretation of results and conclusions.

Objectives

I present an R function that performs statistical analysis relating a biological response with a landscape attribute at a set of specified spatial scales and extracts the statistical strength of the models through a specified criterion index. Also, it draws a plot with the value of these indexes, allowing the user to choose the most appropriate spatial scale. This paper introduces the usage of multifit and demonstrates its functionality through a case study.

Conclusions

The spatial scale at which ecologists conduct studies may change study outcomes and conclusions. Because of this, landscape ecologists commonly conduct multi-scale studies in order to establish an appropriate spatial scale for particular biological or ecological responses. The tool presented here allows ecologists to simultaneously run several statistical models for a response variable and a specified set of spatial scales, automating the process of multi-scale analysis.

     

杧果MiCO基因的克隆与表达模式分析

【目的】克隆杧果(Mangifera indica L.)MiCO基因并探讨其表达模式,为深入研究该基因的功能奠定基础。【方法】根据从杧果转录组测序数据中获得一个MiCO基因全长序列信息,设计基因全长引物,克隆具有不同开花习性的‘四季杧’和‘紫花杧’2个品种的MiCO基因全长序列,对其序列进行生物信息学分析,并利用荧光定量PCR技术对MiCO基因在杧果不同组织以及年周期的表达情况进行分析。【结果】序列分析显示,2个杧果品种的MiCO基因c DNA全长均为1 150 bp,都包含1个966 bp的开放阅读框,编码322个氨基酸,等电点为5.8,‘四季杧’品种的MiCO蛋白分子质量为35.30 ku,‘紫花杧’品种的MiCO蛋白分子质量为35.22 ku;MiCO基因编码的蛋白具有典型的CO同源蛋白结构,包括B-box1、B-box2和CCT结构域;系统进化树表明,杧果MiCO蛋白属于第一类CO蛋白,与拟南芥(Arabidopsis thaliana)At COL4相似性最高而聚类到一起。基因表达分析表明,MiCO基因在杧果不同组织中均表达,但不同组织的表达水平存在差异。年周期表达分析表明,MiCO基因在杧果成花转变期高度表达,而且在来年的5—6月还存在一个小的表达高峰期,但2个品种不同组织中MiCO基因表达存在差异。【结论】克隆获得杧果MiCO基因全长序列,发现2个具有不同开花习性的杧果品种的MiCO基因核苷酸和氨基酸序列高度同源,只存在少许差异。MiCO基因在杧果成花转变期高度表达,说明MiCO基因与杧果成花关系密切。     

基于RNAi和蛋白质组学研究胶孢炭疽菌CgCDC2基因的功能

【目的】CDC2是调控细胞周期的主要因子之一,对植物病原菌的生长发育有着重要作用,但目前还未有胶孢炭疽菌CDC2蛋白生物学功能方面的研究。本试验的目的是获得胶孢炭疽菌(Colletotrichum gloeosporioides)CgCDC2的RNAi突变体菌株,并分析CgCDC2基因的功能。【方法】利用RNAi技术和PEG介导法获得CgCDC2的RNAi突变体菌株,通过表型分析、TMT蛋白质组学分析和酶活性测定来确定该基因的生物学功能。【结果】通过PCR扩增获得CgCDC2基因,编码一个326个氨基酸的蛋白,其RNAi突变体菌株与野生型相比,生长速率减缓、分生孢子产量显著下降、对H_2O_2敏感性增强,PG、PL蛋白质含量、基因相对表达量和酶活性均显著降低,致病力减弱。【结论】CgCDC2参与调控胶孢炭疽菌的生长,分生孢子产量,氧化应激反应以及PG、PL的酶活性,从而降低病原菌的致病力。     

The FAST technique: a simplified Agrobacterium-based transformation method for transient gene expression analysis in seedlings of Arabidopsis and other plant species

Background  

Plant genome sequencing has resulted in the identification of a large number of uncharacterized genes. To investigate these unknown gene functions, several transient transformation systems have been developed as quick and convenient alternatives to the lengthy transgenic assay. These transient assays include biolistic bombardment, protoplast transfection and Agrobacterium-mediated transient transformation, each having advantages and disadvantages depending on the research purposes.     

桃脂氧合酶基因家族生物信息学及其表达特性分析

【目的】脂氧合酶(lipoxygenase;LOX;linoleate oxygen oxidoreductase;EC1.13.11.12)作为一种重要的酶,广泛参与植物生长、发育、成熟、衰老及植物抗逆过程,因其重要作用一直是国内外研究的重点和热点。研究利用生物信息学方法对桃LOX基因家族进行发掘和预测,以期为桃LOX家族基因鉴定和功能分析提供基础信息,并在分子水平上为桃品种改良及采后保鲜提供明确的候选基因。【方法】采用生物信息学方法研究了桃LOX基因家族成员数目、系统进化关系、假定蛋白质结构及分类,运用q RT-PCR技术研究LOX基因家族在桃特异组织中的表达模式。【结果】桃LOX基因家族包含13个假定蛋白,9-LOX和13-LOX类型分别有6个成员,另外存在1个特殊类型,与苹果具有相似性;桃LOX蛋白氨基酸序列一致性在33.76%~90.84%;13个LOX家族成员绝大多数是两性氨基酸,9-LOX类型的6个家族成员的理论等电点都小于7,13-LOX类型各等电点没有规律;13个蛋白质的二级结构除ppa017962m外以无规则卷曲为主要构成元件;染色体定位分析表明,LOX家族基因并非平均分布在桃的8条染色体上,其中6号染色体上桃LOX基因分布最多,ppa017962m未定位在任何特异染色体上;q RT-PCR的组织特异性表达结果表明,LOX基因家族主要在果实和茎中的相对表达量较高。【结论】分离并鉴定了13个桃LOX家族基因,其不均匀地分布在桃染色体上;多数桃LOX基因主要在果实和茎部表达;ppa001634m、ppa001082m、ppa001216m、ppa001016m、ppa017962m在果实中的表达量最高,可能参与调控桃果实衰老软化过程。     

Vacant lots: An underexplored resource for ecological and social benefits in cities

Vacant lots make up a large proportion of urban land and are of interest to many stakeholder groups. While they are often viewed as dangerous or unsightly, they can be an economic, social, and ecological resource. Here we present a literature review focused on restoring biodiversity in vacant lots, emphasizing the intersection of human and wildlife needs. We focus on the benefits, challenges, and processes of restoration in vacant lots and synthesize ecological, social, and economic information across these domains. We suggest that fast, inexpensive restoration techniques could be implemented in vacant lots and would be well suited to increasing greenspace in low-income areas. Furthermore, we emphasize that land managers, ecologists, sociologists, urban planners, and local communities must work together to conceptualize, carry out, and monitor restoration projects, as these projects are often characterized by disparate goals and insufficient follow-up. Vacant lot restoration is best addressed by an interdisciplinary approach that combines economic, social, and environmental needs and concerns into a holistic urban land use paradigm.     

荔枝多酚氧化酶基因启动子克隆与功能分析

【目的】获得多酚氧化酶(PPO)基因启动子序列并初步分析其功能,为进一步研究PPO基因表达规律及应用PPO基因启动子提供基础。【方法】通过TAIL-PCR和接头PCR方法相结合获得荔枝PPO基因启动子序列并进行生物信息学分析,序列缺失结合瞬时表达法分析核心启动子调控元件。【结果】从‘妃子笑’荔枝基因组中克隆获得了1048bp的荔枝PPO基因启动子序列,含有多种顺式作用元件。不同长度的启动子序列均能驱动GUS基因在‘妃子笑’、‘无核’和‘紫娘喜’荔枝叶片和果皮中表达,但都不能驱动GUS基因在‘妃子笑’和‘紫娘喜’荔枝种子中表达。【结论】获得了荔枝PPO基因启动子序列并获得了其调控基因表达的部分规律。     

The function of Hoxa-10 gene in the reproductive system

Hoxa gene plays an essential role in the generation and development of the human female reproductive system. This gene is expressed in the Mullerian duct and the adult female reproductive system. Expression of Hoxa10 dramatically increased during the midsecretory phase of the menstrual cycle, corresponding to the time of implantation. Female mice lacking Hoxa10 have a uterine factor defect that results in death of the preimplantation embryo and failure of implantation. These results suggest Hoxa10 may have an important function in implantation. Hoxa10 - deficient males exhibit cryptorchidism that lead to male infertility.     

用于多基因表达检测的猕猴桃macroarray阵列

基因阵列是开展高通量功能基因组学研究的有效手段之一。对适用于多年生果树猕猴桃的macroarray阵列进行了探索,构建了含有42个基因的macroarray阵列,与α-32P标记的cDNA探针杂交产生清晰信号,有效分辨了不同基因或基因家族不同成员的表达差异。DNase处理可去除基因组DNA污染,提高结果准确性。     

Zonal lacunarity analysis: a new spatial analysis tool for geographic information systems

Landscape Ecology - Lacunarity as a scale-dependent measure of spatial heterogeneity has received great attention in landscape ecology. Most lacunarity measures have been obtained from greyscale or...     

Universal endogenous gene controls for bisulphite conversion in analysis of plant DNA methylation

Background

Protein extraction is a frequent procedure in biological research. For preparation of plant cell extracts, plant materials usually have to be ground and homogenized to physically break the robust cell wall, but this step is laborious and time-consuming when a large number of samples are handled at once.

Results

We developed a chemical method for lysing Arabidopsis cells without grinding. In this method, plants are boiled for just 10 minutes in a solution containing a Ca²⁺ chelator and detergent. Cell extracts prepared by this method were suitable for SDS-PAGE and immunoblot analysis. This method was also applicable to genomic DNA extraction for PCR analysis. Our method was applied to many other plant species, and worked well for some of them.

Conclusions

Our method is rapid and economical, and allows many samples to be prepared simultaneously for protein analysis. Our method is useful not only for Arabidopsis research but also research on certain other species.     

中国野生葡萄病原菌诱导响应VqSAP基因的克隆及表达分析

【目的】为了验证SAP基因在葡萄抗病防御机制中的作用,【方法】在前期通过抑制消减杂交技术(SSH)获得中国野生葡萄毛葡萄株系‘商-24’衰老相关蛋白(SAP)基因EST序列的基础上,采用RT-PCR从毛葡萄‘商-24’中分离到SAP基因cDNA序列,并通过实时定量PCR和半定量PCR分析了SAP基因的表达特异性。【结果】序列分析表明该基因具有完整的的开放阅读框,序列长度为819 bp,编码272个氨基酸残基,相对分子质量为30.56 ku,等电点为8.78,将其命名为VqSAP。多重比较结果显示VqSAP基因与油棕、玉米、萱草、拟南芥、水稻等植物SAP基因的同源性为65%~74%。实时定量结果表明,在白粉菌诱导初期,抗病的毛葡萄株系‘商-24’和感病的华东葡萄株系‘湖南-1’VqSAP基因表达量均升高,这可能是因为它参与了病原菌诱导的细胞程序性死亡过程。水杨酸(SA)、茉莉酸甲酯(MeJA)、乙烯(Eth)处理表明衰老相关蛋白基因表达受激素分子调节,但在抗病和感病株系中基因的表达量有所差异。在嫩叶、嫩茎、花、果皮、卷须等不同葡萄组织中的表达表明VqSAP基因的表达具有空间差异性。【结论】这些结果暗示着VqSAP的表达响应病原菌侵染并受生物胁迫相关激素的调控,很有可能在葡萄防御病原菌侵染的机制中发挥重要作用。     

Central-place analysis and modeling of landscape-scale resource use in an East African agropastoral system

Most spatial models of grazing assume a global search; that is, the entire paddock or landscape is available to grazers. These `unconstrained' models characterize landscape patches based on absolute properties (i.e., without regard for how individual grazers are situated within them). In most of East Africa cattle are herded and must start and end each day's grazing at their enclosure. Thus, global search is not a realistic assumption. This implies that the relative location of a patch may be more important than its absolute properties because its quality depends not only on the properties of the patch itself, but also on its location relative to home and to water. Using data from 73 full-day herd follows among a group of agropastoralists in western Tanzania, I build and test an unconstrained model and compare its analytical utility and predictive power to a `central-place' model that defines the landscape relative to herders' homes (the central place) and dry season water. The central-place model provides analytical insights into the grazing system that are not apparent when using an unconstrained model, and it explains more of the variance in grazing intensity. Because many types of resources are collected around a focal point, central-place models should have wide applicability for analyzing and modeling many kinds of resource use, particularly in the developing world.     

Fast-track applications: The potential for direct delivery of proteins and nucleic acids to plant cells for the discovery of gene function

In animal systems, several methods exist for the direct delivery of nucleic acids and proteins into cells for functional analysis. Until recently, these methods have not been applied to plant systems. Now, however, several preliminary reports suggest that both nucleic acids and proteins can also be delivered into plant cells by very simple, direct application. This promises to open the way for high-throughput screening for gene function in a range of plant species.     

Post-fire resource redistribution and fertility island dynamics in shrub encroached desert grasslands: a modeling approach

A common form of land degradation in desert grasslands is associated with the relatively rapid encroachment of woody plants, a process that has important implications on ecosystem structure and function, as well as on the soil hydrological and biogeochemical properties. Until recently this grassland to shrubland transition was thought to be highly irreversible. However recent studies have shown that at the early stages of shrub encroachment in desert grasslands, there exists a very dynamic shrub–grass transition state with enough grass connectivity between the shrub islands to allow for fire spread. In this state fire could play a major role in determining the dominance of grasses and their recovery from the effects of overgrazing. Using a spatially explicit cellular automata model, we show how the patch-scale feedbacks between fires and soil erosion affects resource redistribution and vegetation dynamics in a mixed grass–shrub plant community at landscape to regional scales. The results of this study indicate that at its early stages, the grassland-to-shrubland transition can be reversible and that the feedbacks between fire and soil erosion processes may play a major role in determining the reversibility of the system.     

我国杏种质资源研究及利用

综述了国内外近5年来在杏起源演化、资源评价、种质创新及遗传育种等方面研究进展,并着重介绍了杏的砧木资源、鲜食资源、加工资源及观赏资源等优异种质资源。