A Dynamic Equation for Plant Interaction and Application to Yield-density-time Relations

On p. 527 the legend for Table 2 should read: TABLE 2. Measured and simulated dry matter production (g m^–2)of Wimmera ryegrass. Data from Donald (1951) and sentence 7 in the text should read: Measured yields (averaged over four replicates and convertedto g m^–2), simulated yields and estimated parameters aregiven in Table 3. On p. 528 the legends for Tables 4 and 5 should read: TABLE 4. Measured and simulated dry matter production (g m^–2)of maize. Data from Tetio-Kagho and Gardner (1988) TABLE 5. Measured and simulated dry matter production (g m^–2)of lucerne. Data from Jarvis (1962), averages of four replicates,planted at two different dates in two successive years and sentence 1 should read: The maximum biomass production (A) of 113 g m^–2 of f.wt.corresponds with 6.3 g m^–2 of dry matter.     

A New Functional Equation Analogous to CAUCHT-PEXIDER Functional Equation and its Application

The CAUCHY-PEXIDER functional equation H (x±y)=F(x) G(y) is generalized to the form H ((x^c±y^c)^1/c) = F(x) G(y), c≠0, assuming the function H(x) possesses a measurable majorant on a set of positive measure. The result is used to obtain a characterization of WEIBULL distribution. This functional equation is generalized to functions of vector variables.     

A Generalized Simplest Equation Method and Its Application to the Boussinesq-Burgers Equation

In this paper, a generalized simplest equation method is proposed to seek exact solutions of nonlinear evolution equations (NLEEs). In the method, we chose a solution expression with a variable coefficient and a variable coefficient ordinary differential auxiliary equation. This method can yield a Bäcklund transformation between NLEEs and a related constraint equation. By dealing with the constraint equation, we can derive infinite number of exact solutions for NLEEs. These solutions include the traveling wave solutions, non-traveling wave solutions, multi-soliton solutions, rational solutions, and other types of solutions. As applications, we obtained wide classes of exact solutions for the Boussinesq-Burgers equation by using the generalized simplest equation method.     

A Diagram for the Description of Water Relations in Plant Cells and Organs

A diagram is described which is based on the ideal relationshipbetween osmotic potential and volume as defined by Boyle's andVan't Hoff's laws. The new graphical presentation differs fromthe related earlier one by Hammel and co-workers in the choiceof relative water content (RWC), a term depending on the volumechanges of the vacuole, as the reciprocally plotted variable.The diagram is well suited for didactic purposes and may haveadvantages for the analysis of experimental data.     

植物病毒载体在植病互作研究中的应用

在植物与病原菌互作的研究中,植物抗性基因和病原菌无毒基因的研究是两个重要的热点。利用植物病毒沉默载体构建的VIGS(Virus Induced Gene Silencing)体系研究植物的防御机制;利用植物病毒表达载体克隆和研究病原菌的无毒基因,将使我们更深刻地理解植物和病原菌互作的分子机理,最终为培育番茄白粉病持久抗性品种打下理论基础。对植物病毒载体的研究进行了综述并就我们承担的课题进行了讨论。     

Photosynthetic CO2 Uptake and Whole Plant Growth as Related to Plant Water Relations

Morphological features of arid region plant life forms are described and interpreted as adaptations to drought although this cannot be easily quantified. Functional adaptations, however, can be measured, and using the annual crop plant Vigna unguiculata (L.) Walp. responses to drought are described at the leaf and the whole plant level. In the first step of this analysis theoretical criteria are developed to define optimal water use. In the second step experimental data are used to test to what extent Vigna follows a theoretically optimal regulation of water and carbon relations. The analysis indicates that the ecological adaptation of regulatory processes may be quantified at a functional level.     

压力探针技术在植物水分关系研究中的运用

压力探针（pressure probe）技术最初设计时用于测定巨型藻类细胞的膨压,后来转到对高等植物细胞的膨压及其他水分关系参数的测定,现在已发展成为植物生理学和生态学研究中的一种多用途技术。它可以在细胞原位测定水分及溶质跨膜运输及分布情况。能够在不离体的植物中测定水通道的活性。新近发展的木质部压力探针是惟一可以直接测定导管或管胞中负压的技术。文章介绍该技术基本原理及其在植物水分生理学研究中的应用。     

植物病原真菌黑色素与致病性关系的研究进展

黑色素是一类生物聚合分子的总称,不同来源的黑色素种类不同,其中报道较多的是DOPA黑色素和DHN黑色素。DOPA黑色素和DHN黑色素具有相似的理化性质但其合成底物和途径不同。DHN黑色素在植物病原直菌中广泛存在,与病原菌致病能力密切相关。病原菌侵染寄主时黑色素沉积存附着胞细胞壁的内层,防止了形成膨压的溶质渗透到细胞外,产生很大的机械压力,保证病原菌侵入寄主。结合作者的研究结果综述了黑色素的种类、性质及黑色素与病原菌致病性关系等方面的研究进展。     

The Need for Simple Dynamic Equations to Describe Plant Competition

A dynamic single-equation model for plant interaction is comparedwith the competition mechanism implicit in larger simulationmodels. When light is the limiting factor, both mechanisms canbe written in the same mathematical form containing a ‘drivingforce’ and a restriction factor. In the single-equationmodel the driving force is derived directly from the RGR ofa competition-free plant. In more comprehensive models, detailedinformation on the growth of plant organs has to be generatedby submodels. When factors other than light are limiting growth, the representationof competition in crop simulation models is complex; the single-equationmodel has the same form irrespective of which factor is limitinggrowth. It is argued that simple dynamic models should be developedfor complex processes. Plant competition, dynamic model     

植物激素信号间的相互作用(综述)

本文从植物激素信号转导过程中特殊基因的鉴定、植物激素信号间、激素与糖之间的相互作用,以及激素对种子萌发和发育的影响等方面,概述近年来植物激素信号间相互作用的研究进展。     

Native Plant and Microbial Contributions to a Negative Plant-Plant Interaction

A number of hypotheses have been suggested to explain why invasive exotic plants dramatically increase their abundance upon transport to a new range. The novel weapons hypothesis argues that phytotoxins secreted by roots of an exotic plant are more effective against naïve resident competitors in the range being invaded. The common reed Phragmites australis has a diverse population structure including invasive populations that are noxious weeds in North America. P. australis exudes the common phenolic gallic acid, which restricts the growth of native plants. However, the pathway for free gallic acid production in soils colonized by P. australis requires further elucidation. Here, we show that exotic, invasive P. australis contain elevated levels of polymeric gallotannin relative to native, noninvasive P. australis. We hypothesized that polymeric gallotannin can be attacked by tannase, an enzymatic activity produced by native plant and microbial community members, to release gallic acid in the rhizosphere and exacerbate the noxiousness of P. australis. Native plants and microbes were found to produce high levels of tannase while invasive P. australis produced very little tannase. These results suggest that both invasive and native species participate in signaling events that initiate the execution of allelopathy potentially linking native plant and microbial biochemistry to the invasive traits of an exotic species.Invasive weeds are a major source of agricultural costs due to reduced productivity and the labor expended for weed control. In addition, the extensive use of herbicides to control weed populations has undesirable environmental consequences. Therefore, understanding mechanisms that facilitate exotic plant dispersal and displacement of natives in new ranges is critical to predicting and controlling invasions and may yield insights into the ecological processes that govern homeostasis and perturbation in natural plant communities.Phragmites australis (Cav.) Trin ex. Steud. (common reed) has been present in the United States for at least 10,000 years as a major component of mixed tidal wetland plant communities (Saltonstall, 2002). However, over the past 200 years its distribution and abundance has expanded rapidly and it is now considered one of the most aggressive invasive species in marsh communities in North America. Chloroplast DNA analysis has shown that 13 native North American Phragmites haplotypes exist, while invasive populations possess a single chloroplast DNA haplotype (M) that is also widespread in Europe and Asia (Saltonstall, 2002). These data are supported by nuclear microsatellite DNA analysis (Saltonstall, 2003) and morphological differences that distinguish native, noninvasive from exotic, invasive Phragmites in North America (Saltonstall et al., 2004). When grown under the same conditions, exotic Phragmites has significantly higher aboveground and belowground biomass than native Phragmites (Vasquez et al., 2005; Saltonstall and Stevenson, 2007), and this pattern is typically observed under field conditions as well although exceptions exist (League et al., 2006; Meadows and Saltonstall, 2007). Unfortunately today, only remnant native P. australis populations remain along the Atlantic Coast of North America, indicating the near total displacement of native populations by exotic P. australis.Various hypotheses have been forwarded to explain the rapid invasion of P. australis, of which human activities, stress regimes, and hydrologic disturbances have received the greatest attention (Chambers et al., 1999). Compared to invasion in terrestrial ecosystems, invasiveness in marsh communities is less well documented and it is still not clear how environmental factors relate to the establishment of specific dominant marsh species. Although allelopathy has been superficially suggested as the main displacing mechanism in P. australis (Kaneta and Sugiyama, 1972; Drifmeyer and Zieman, 1979), there has been minimal success in characterizing the responsible allelochemical. Interestingly, three triterpenoids (β-amacin, taraxerol, and taraxerone) and a flavone (tricin) have been identified from aerial portions of P. australis (Kaneta and Sugiyama, 1972; Drifmeyer and Zieman, 1979). Regrettably, none of these identified chemicals were tested for possible allelopathic activity.Previously, we showed that a root exudate component of P. australis roots inhibits seedling growth, and that production of the exudates is higher in the invasive P. australis haplotype (Rudrappa et al., 2007). The active fraction of this exudate was found to be composed of gallic acid (3,4,5-trihydroxybenzoic acid). Gallic acid is toxic to a variety of weeds, crop plant species, and the model plant species Arabidopsis (Arabidopsis thaliana; Rudrappa et al., 2007; Rudrappa and Bais, 2008). Our published results also show the persistence of gallic acid in soil extracts from P. australis-invaded fields, which validates our in vitro results and strongly supports the idea that P. australis'' invasive behavior may partly be due to the exudation of gallic acid in the soil/marsh (Rudrappa et al., 2007). Our studies concur with the earlier established reports of phytotoxicity and persistence of gallic acid in soil (Weidenhamer and Romeo, 2004).Biochemically, the transition from simple galloylglucoses to complex gallotannins is marked by addition of further galloyl moieties to the pentagalloylglucose (Niemetz and Gross, 2005). It is now known that free gallic acid is released from complexed gallotannins by simple hydrolysis reactions, wherein a tannase activity breaks gallate ester to form free gallic acid, ellagic acid, and Glc (Mahoney and Molyneux, 2004). Treatment of fungal tannase from Aspergillus flavus results in hydrolysis of pellicle-localized gallotannin to form gallic acid, and ellagic acid as two phenolic components (Mahoney and Molyneux, 2004). As gallic acid is often complexed as gallotannins (Niemetz and Gross, 2005), we speculated that plant- or microbial-derived tannase may facilitate free gallic acid release in salt marsh soils.Aside from allelopathy, invasive plants may deleteriously affect interactions between rhizospheric microbial communities and native plant species (Klironomos, 2002; Wardle et al., 2004; Callaway et al., 2008) to promote their expansion in new ranges. One specific example is the disruption of interactions between native species and their arbuscular mycorhizae, upon which the native species rely for nutrient acquisition (Stinson et al., 2006). Another recent study suggests that the recruitment or establishment of an altered soil microbial community may negatively impact the ability of native species to survive in the same soils (Batten et al., 2008). Evidences suggest that soil biota have several effects on the success of invasive plants and the interactions are based in part on the biochemistry, i.e. novel biochemical weapons (Callaway and Ridenour, 2004). However, to our knowledge, no previous studies have directly tested whether P. australis or any other exotic plant may exploit the biochemical potential of native plant and microbial communities to release a phytotoxin (gallic acid) from a relatively benign precursor (gallotannin) in the rhizosphere. This report presents evidence that links native plant and microbial biochemistry to the invasive traits of an exotic species.     

The Arrhenius Equation as a Model for Explaining Plant Responses to Temperature and Water Stresses

The Arrhenius equation describes the response of biologicalprocesses to temperature. This study was conducted to examinethe applicability of the Arrhenius equation to whole plant processesand to explore the application of the Arrhenius equation asa basis for characterizing plant responses to water stress.Rates of growth of leaf area and shoot dry mass of spring wheatseedlings were measured at combinations of five soil water potentials(–0.03, –0.06, –0.10, –0.17 and –0.25MPa) and seven root temperatures (12, 14, 17, 22, 27, 29 and32 C). A non-linear least square procedure was used to fitthe modified Arrhenius equation to experimental observations.Adequate distribution of experimental observations with respectto temperature reduces the uncertainties in parameter evaluations.The standard error of the estimate of optimum temperature forleaf area growth increased from 1.4 C to 6.3 C when one ofthe data points was omitted. The optimum temperature and theenthalpy of denaturalization of enzyme systems were independentof soil water potential. A linear relation was found betweenthe rate constant and the activation energy: The Arrhenius equation was modified using this linear relation,leaving the activation energy as the only parameter affectedby water stress. The activation energy increased linearly assoil water potential decreased, with slopes of –27.18 10₃ and –28.09 10₂ K MPa^–1 for the rates ofgrowth of leaf area and shoot dry mass, respectively. Theseslopes could be used as indicators of the sensitivity of plantprocesses to water stress. Temperature, water, plants, Arrhenius equation     

A Single Equation to Quantify the Hierarchy in Plant Size Induced by Competition Within Monocultures

The following empirical model: Ra(i) = r(1+ln(w(i)/wm)Kn)(1–(w(i)/W))(1–(y/Y)) which is based on the logistic growth equation, is developedto describe the growth of differently sized individuals withinplant communities. The model is tested against extensive setsof carrot (Daucus carota L.) and red beet (Beta vulgaris L.)data and is shown to fit well. The model was used to predictindividual plant weights in independent data. The agreementsbetween observed and predicted weights were often close butsome systematic deviations did occur. Thus, a single equationdescribed most of the complex interactions that occurred withinmonocultures of annual crop plants. Carrot, Daucus carota L., red beet, Beta vulgaris L., model, growth, variation     

A Dynamic Model for Plant Growth: Validation Study Under Changing Temperatures

A dynamic simulation model to describe vegetative growth ofplants, for which some functions and parameter values have beenestimated previously by optimization search techniques and numericalexperimentation based on data from constant temperature experiments,is validated under conditions of changing temperatures. To testthe predictive capacity of the model, dry matter accumulationin the leaves, stems, and roots of tobacco plants (Nicotianatabacum L.) was measured at 2- or 3-day intervals during a 5-weekperiod when temperatures in controlled-environment rooms wereprogrammed for changes at weekly and daily intervals and inascending or descending sequences within a range of 14 to 34°C. Simulations of dry matter accumulation and distributionwere carried out using the programmed changes for experimentaltemperatures and compared with the measured values. The agreementbetween measured and predicted values was close and indicatesthat the temperature-dependent functional forms derived fromconstant-temperature experiments are adequate for modellingplant growth responses to conditions of changing temperatureswith switching intervals as short as 1 day. Nicotiana tabacum, tobacco, translocation, partitioning, root growth, shoot growth     

GFP及其在植物学研究中的应用

绿色荧光蛋白 (ｇｒｅｅｎｆｌｕｏｒｅｓｃｅｎｔｐｒｏｔｅｉｎ ,ＧＦＰ)是来源于多管水母属 (Ａｅｑｕｏｒｅａｖｉｃｔｏｒｉａ)体内的一种天然发光蛋白 ,在植物体内不需任何底物和外源辅助因子的参与就能显现 ,本文就ＧＦＰ的基因在植物基因工程和分子生物学研究中的应用作一概述。1 .ＧＦＰ及其特性ＧＦＰ由ｇｆｐ基因编码 ,具有 2 38个氨基酸残基的多肽单体 ,分子量约为 2 7ｋＤ。ＧＦＰ有两个吸收峰 ,最大吸收峰在 395ｎｍ处 ,在475ｎｍ处还有一个吸收峰 ,前者由紫外光激发 ,后者由蓝光激发。发射光谱也具有两个峰值 ,一个为 5 0 9…     

芸薹素与其他植物激素相互作用的研究进展

芸薹素是植物中发现的固醇类激素,对植物的生长和发育等起着非常重要的作用,而这些重要的生理功能通常又需要通过与其它植物激素的相互作用.主要对芸薹素与其他植物激素之间相互作用的研究进展进行了综述.     

A New Formulation of the Logistic Growth Equation and Its Application to Leaf Area Growth

A formulation of the logistic growth equation in terms of twodifferential equations is proposed; this permits the asymptoteto depend upon conditions during the growth period such as substratesupply (irradiance) and temperature. The application of themodel to leaf area growth is outlined, and it is shown how observedresponses of mature leaf area to irradiance and temperaturemay be simulated. Logistic, leaf area, model     

食草动物与植物的相互关系

动植物相互作用是决定动植物群落结构的重要因素[50 ] 。动物从多方面和多层次影响植物 ,最后都反映到植物群落结构的变化。而变化的植物群落又从各方面影响动物的生理、行为、种群特征、分布、种间关系等方面 ,最终反映到动物群落水平层次的改变 ,所以对动物群落与植物群落关系及机理的研究是个内容十分丰富的重要领域。1　食草动物的牧食作用对植物的影响食草动物的牧食作用 ,常使植物形态和结构发生变化 ,如导致植株的“矮化”或“匍匐化”,增加剌结构和机械结构 ,以抵御进一步被牧食[42 ] 。一定强度的牧食会加速植物光合作用强度 ,从而…     

加性基因效应与分子标记回归方程的关系

控制数量性状的基因作用历来是遗传学工作者所关注的重要课题．本文对以正交表形式表现的共显性动物分子标记资料,根据加性效应基因控制的数量性状遗传模型配合了动物分子标记回归方程通式．结果表明：对以正交表形式表现的加性效应基因共显性分子标记资料配合的分子标记回归方程,可对加性等位基因的相对作用差加以估计,并可作为育种的依据．