植物生理学论文..
植物生理学与生物化学研究论文

植物生理学与生物化学研究论文在植物生理学与生物化学研究领域,大量的论文被发表和研究,为我们深入了解植物的生理和生物化学过程提供了重要的依据。
本文将就植物生理学与生物化学领域的一些研究进展进行论述,以期能够更好地了解植物的生理和生物化学特征。
一、光合作用及植物繁殖光合作用是植物生理学和生物化学研究中的重要内容之一。
光合作用是植物利用光能将二氧化碳与水转化为有机物质和氧气的过程。
其中,光合色素和酶是光合作用中的两个关键因素。
光合色素包括叶绿素、类胡萝卜素等,它们能够吸收不同波长的光线,从而将光能转化为化学能。
而酶则能够促进光合作用的进行,起到催化剂的作用。
除了光合作用外,植物的繁殖也是植物生理学和生物化学研究的热点之一。
植物的繁殖方式多种多样,包括性繁殖和无性繁殖等。
性繁殖通过花的开放、授粉、受精等过程,形成种子并完成繁殖。
而无性繁殖则是植物通过植物体的其他结构(如茎、根等)进行繁殖,不需要花的开放和授粉。
二、植物代谢与物质运输植物代谢与物质运输是植物生理学和生物化学研究中的另一个重要内容。
植物代谢包括物质的吸收、转运、分解以及合成等过程。
植物通过根系吸收土壤中的水和养分,通过叶片进行光合作用和呼吸作用,并通过根茎进行物质的转运。
植物的代谢过程涉及到多种生物化学反应和代谢途径,如氮循环、葡萄糖代谢等。
物质运输是指植物体内物质的传递过程,也是植物生理学和生物化学研究的重要内容之一。
植物体内物质的运输主要通过细胞间连通的组织——维管束进行。
维管束包括导管和木质部,导管主要负责水分和养分的输送,而木质部则起到支持植物体的作用。
三、激素与植物发育激素在植物生理学和生物化学研究中扮演着重要的角色。
激素能够调节植物的生长、发育和生理过程。
植物体内存在多种类型的激素,如生长素、赤霉素、脱落酸等。
这些激素可以促进或抑制植物的生长和发育,从而适应环境的变化。
激素与植物发育之间存在复杂的相互作用关系。
例如,生长素可以促进植物的细胞伸长和分裂,而赤霉素则可以抑制细胞伸长和促进细胞分裂。
苹果酸论文

《植物生理学》课程论文题目:苹果酸在与植物生命活动中的重要性摘要:苹果酸对植物的生长起到的作用以及相应的生理反应,植物体内的苹果酸对植物的养分吸收有着重要作用及苹果酸对各类植物的影响。
关键字:苹果酸代谢产物碳循环气孔水势膜电位一.什么是苹果酸【品名】:苹果酸【学名】:“L--羟基丁二酸”Hydrozybutanedioic acid【英文名】:Malic Acid【分子式】:C4H6O5[结构式]:HOOCCHOHCH2COOH【CAS号】:97-67-6【分子量】:134.09【性状】:白色结晶体或结晶状粉末,有较强的吸湿性,易溶于水、乙醇。
有特殊愉快的酸味二.苹果酸的主要功能以及作用A、由于苹果酸在物质代谢途径中所处的特殊位置,可直接参与人体代谢,被人体直接吸收,实现短时间内向肌体提供能量,消除疲劳,起到抗疲劳、迅速恢复体力的作用利用苹果酸的抗疲劳、护肝、肾、心脏作用可以开发保健饮料。
B、代谢的正常运行可以使各种营养物质顺利分解,促进食物在人体内吸收代谢,低热量,可有效地防止肥胖,可以起到减肥的作用。
C、在药物中添加苹果酸可增加其稳定性,促进药物在人体的吸收、扩散;复合氨基酸输液生产中就是利用L—苹果酸这一功能而用它来调节pH值的,同时作为混合氨基酸输液组分之一,可提高氨基酸利用率,用于治疗尿毒症、高血压等和减少抗癌药物对正常细胞的侵害,用于癌症放、化疗后的辅助药物,用于烧伤治疗可以促进伤口愈合。
D、 L—苹果酸可以促进氨代谢,降低血氨浓度,对肝脏有保护作用,是治疗肝功能不全、肝衰竭、肝癌尤其是肝功能障碍导致的高血氨症的良药。
E、 L—苹果酸作为治疗心脏病基础液成分之一,用于K+、Mg2+的补充,保持心肌的能量代谢,对心肌梗塞的缺血性心肌层起到保护作用。
F、 L—苹果酸是乳酸钙注射液的稳定剂,也可作为抗癌药的前体及用作动物生长促进剂。
G、抗牙垢,苹果酸具有酸度大、味道柔和、香味独特及苹果酸的腐蚀破坏作用比较弱,相应的牙釉质磨损体积损失较小,有不损害口腔和牙齿等特点。
植物生理学论文--低温对植物光合作用的影响.

167940010 张东芳
Abstract
• Photosynthesis in warm-climate plants is substantially reduced after chilling. Tropical and subtropical species offer the opportunity to study the effects of low temperature on photosynthetic processes undisguised by the myriad of protective responses observed in temperate species. In this article, we highlight the primary components of photosynthesis that are affected by a short chill, in both the dark and the light, and discuss what is known of the mechanisms involved. Recent work implicates impaired redox and circadian regulation among other processes. • 在低温处理的情况下,热带植物的光合作用效率大幅降低。 热带和亚热带的物种为我们研究低温对各物种光合作用过 程的影响提供一个机会。在这篇文章中,我们强调由一个 短暂的低温处理和黑暗或光照的组合影响的光合作用,并 讨论什么是已知参与的机制。最近的研究发现其中包括氧 化还原受损和昼夜调控。
Keywபைடு நூலகம்rds/关键字
• Low temperature; Photoinhibition; Oxidative stress; Carbon reduction cycle; Circadian rhythm • 低温;光抑制;氧化应激;减碳循环;昼夜节律
专题小论文撰写提高植物生理学教学质量的实践与思考

按照教学资源介绍 、 知识导入 、 重点问题归纳 、 难点问 题剖析和实践提高五个教学环节完成《 管理学基础》 的教 学过程 , 能达到开始设定的教学 目标 , 学生有所收获。 但在 实际教学 中, 也存在学生对辅导老师的导学思路不能很好 地贯彻的问题 , 影响了教学效果。分析原 因主要是学生 自 主学习能力差 , 对案例教学 的意义认识不够。针对问题我 们提出以下措施 , 期待着在以后 的教学中加以改进。 1 . 加强对学生的启发和引导 。通过学 习时间管理 、 有 效整合利用学习资源 、 制定个别学 习计划 、 寻求帮助加强 协作等策略培养学生的 自主学习能力 。 2 . 各种教学方式 的灵活运用 。针对不同的教学内容分 别采取面授辅导课、 网上教学 、 网上讨论等教学方法 。 3 . 正确认识案例教学与理论教学 的关系。案例教学是 对理论教学的延伸和深化 , 但是案例毕竟不是企业 的实际 情况 ,所以教学过程中要特别强调管理理论的系统学习 , 学生在扎实的理论基础上 , 通过案例教学真正有所提高。
的高低直接影响后续专业课程 内容 的理解和应用 。 随着科
作为人类的一种基本实践活动 ,管理有其基本理论 , 掌握这些管理知识 , 是管理者开展工作 的基本保证 , 也是 管理者与上级 、 同事和谐相处 , 实现职业 目标的保证。 但这 些概念原理和方法必须结合组织 的实际情况来运用 , 这一 点管理学同其他科学不 同,比如背熟了制 图所有规则 , 就
【 教师观点 】
专题小论 文撰 写提 高植 物生理学教学质量 的实践 与思考
熊辉 岩 , 韦梅琴
( 青海大学 农牧学院, 青海 西宁 8 1 0 0 1 6 )
摘要 : 为适 应植 物 生 理 学教 学 内容 和 深度 日益 增加 的 形 势 , 为取 得 良好 的教 学效 果 , 通过 学生 专题 小论 文撰 写的 实践
植物生理学及其作用与解释 Plant Physiology 英语作文论文

植物生理学其作用与解析Plant PhysiologyIts role and explanation What is Plant PhysiologyPlant physiology describes the physiology and functioning of the plants. It is a sub-discipline of botany. It primarily describes the key processes such as the respiration, photosynthesis, hormone functions, nutrition, nastic movements, tropisms, parthenogenesis, phototropism and circadian rhythms. It also deals with the topics including seed germination, environmental stress physiology, stomata function and dormancy. Besides, the subject is closely connected to the fields such as plantmorphology, phytochemistry, plant ecology, biophysics, genetics, molecular biology and cell biology.In order to understand the plant way of life, knowing the structure and functioning of is crucial. Plant Physiology provides information on how the plants survive. Therefore, studying the subject is necessary to get a deeper insight into the plants.Role of Plant Physiology in Knowledge DevelopmentPlant physiology focuses on studying every internal activity of the plant. The key physical and chemical processes are analyzed in the subject. It also covers the activities of different scale of time and size. In other words, molecularinteractions such as photosynthesis, internal diffusion of minerals, water and nutrients are studies as part of the subject. Along with with it, the large scale activities such as seasonality, plant development, reproductive control and dormancy.Role of Plant PhysiologyNow we will tell you about the subjects that plays a key role to develop knowledge in the following areas—Phytochemistry or Plant Chemistry in plant physiology:It is one of the key knowledge areas in the domain. The plants require producing a number of chemical compounds for survival andfunctioning. Many of these compounds are unique in nature as those are not found in other organisms. The photosynthesis process needs a generation of different enzymes, pigments and other compounds to be completed. The plants are unable to move. So, chemical compounds are generated for defense also. The compounds are generated by categories such as pathogens, herbivores. In most of the cases, the toxins are produced. Additionally, the smelling and foul-tasting chemicals are also produced by the plants for self-defense. There are some chemicals which give protection against diseases. Survival at the time of drought is crucial for the plants. The chemical compounds are useful for this purpose as well.Dormancy can be described as a period during which growth and development in an organismstop completely. During this time, the metabolic activity minimizes. As an effect, the organism becomes able to save energy. The environmental conditions influence the dormancy period significantly. Dormancy is an important part of the plant life-cycle. Chemical compounds are necessary for preparing the plant for the period. Attracting pollinators is another crucial activity for the plant. It keeps the reproduction works uninterruptedly. The chemicals play a key role in this case also. These compounds attract the herbivores and pollinators for spreading the ripe seeds. The discussion indicates that studying Phytochemistry is essential for getting an idea on the chemical processes at the different stages of the lifecycle.Cellular Processes:The subject aims at developing knowledge in the domain of chemical and biological processes in the cells. The cells of a plant show a number of attributes. These attributes are different from those of the animal cells. Due to the unique attributes, the plant cells respond and behave differently than the animals.For example, the walls of the plant cell are more rigid. So, these walls influence the shape of cells. Mobility and flexibility of the plants are also limited by the walls. Presence of the chlorophyll is another unique feature of these cells.It is a chemical compound which makes interactions with the light. On the basis of interactions, the plants become able to create their own nutrients. This is a distinctive feature of them. other animals cannot create nutrientsfor themselves. The plants in this regard are completely independent. It states that the subject is effective to create an understanding of the unique processes within the plant cells.Cellular Interactions:The plant cells, organs and tissues interact in a unique manner. Different cells are designated to perform different duties. Those have special physical and chemical abilities for performing the tasks. For example, the rhizoids and the roots play a key role in holding the plant. These parts also play a crucial role in acquiring minerals from the soil. The leaf is another important part of the plant. The leaves create the necessary nutrients at the presence of light. The minerals collected by the roots and the rhizoids are transferred to the leaves. The nutrients whichare manufactured in the leaves are then sent to the roots. Such transportation tasks are performed in several ways. For example, the vascular tissues are a major part of the process. It reflects that the subject gives importance to understanding the processes using which the plants liveEnvironmental InteractionAbove all, the plants interact with the environment in several ways. The study on the physiological attributes of the plants also helps in developing the knowledge of how these plants interact with the environment. The plants respond to different types of environment condition in a different manner. The subject gives importance to gaining knowledge on how the responses change with the environmentalconditions. The subject gives importance to discussing how the plants get stressed due to water loss. The alternations in air chemistry are also reviewed as part of the subject. The way of functioning in a plant changes with the crowding. Such changes also occur due to the chemical, genetic and physical factors. The subject also discusses how the functioning of plants is influenced by different factors.Role of plant physiology in AgricultureThe study of plant physiology is important in agriculture. It is the science and art of how plants are cultivated. Agriculture is the base of the development of human civilization. The works related to farming of domesticated species generate food surpluses which make people able to live in cities. The modernagriculture deals with plant breeding, agronomy and agrochemicals such as the use of the fertilizers and the pesticides. The technological developments have changed the conventional agricultural processes significantly. The technological developments have increased the number of crops. Along with it, the technological tools caused environmental and economic changes.The modern agricultural practices are also shaped by depletion of aquifers, global warming, deforestation, use of growth hormones and antibiotics. Increase demand for Genetically modified organisms is another key trend in agriculture. The products in the agricultural industry are broadly categorized as fibres, foods, raw materials and fuels. The food productsobtained from the agricultural industry are classified as vegetables, cereals, oil and fruit.The knowledge of the physiological factors associated with the plants is essential for conducting the agricultural works effectively. Crop physiology is an important part of the subject. It deals with investigating different processes in the plants. The key areas of focus in the domain of Crop physiology are —the activities which drive growth in the plants, the development processes and the production of crop plants in an economic manner.This area of the subject includes both the basic and applied research to determine the functionalities of the crop plants. The basic researches in the crop physiology give importance to developing knowledge in the area.The applied researches, on the contrary, give importance to solving practical problems. However, the crop physiology studies the plants and plant communities as a whole. This is because the processes which control the production. The area also gives importance to studying how the plants interact with the environment.The key areas related to the crop physiology are—Plant Breeding:Crop alteration is a widely used practiced in agriculture. Altering crops with the help of breeding practice brings changes in the genetic structure of a plant. It helps the farmers in the development of the crops which possess morebeneficial attributes. As an effect, these crops become more suitable for society. The larger fruits or seeds are an example in this case as those products are more economical. Production of the drought-tolerance crops is another useful application. Such crops can be produced in harsh environmental condition. The recent developments in crop physiology and plant breeding enabling the farmers to produce pest-resistant crops. Such products have a lower risk of getting damaged. As an effect, the losses in agriculture reducesSignificant Advancements in Plant BreedingThe plant breeding domain has experienced several new advancements. These advancements are based on the studies done by Gregor Mendel, in the area of plant physiology.His works developed knowledge of recessive and dominant alleles. The findings were ignored for several years. Later, the same findings provided plant breeders with a better understanding of breeding technique and genetics. The widely used crop breeding development includes the use of techniques which enable the farmers to choose a plant with persevered traits. The other developments in the domain include cross-pollination, self-pollination along with the use of the molecular techniques for modifying the organism genetically.Domestication of PlantsDomestication is another important practice in the domain of agriculture. It helps to enhance disease resistance. It also increases the tolerance to the drought. Additionally,domestication leads to make harvesting easier. Taste of the crops improves which is another benefit of the domestication. Finally, domestication increases the nutritional value of the food. It is another benefit of the domestication.The knowledge on crop physiology also helps the farmers to understand the effects of variation in farming techniques such as pest control using the chemicals, use of fertilizers and controlling growth using the chemicals. The variation in the crop is also observed due to the changes in climate and genetics.Genetic Engineering of PlantsStudying the physiological feature of plants is necessary to determine the effects of geneticengineering. Genetically modified organisms (GMO) are organisms which posses modified genes. The genetic engineering techniques are used for altering the genetic materials It is also known as the recombinant DNA technology. These techniques are often used to develop new crops. The other benefits of genetically modified crops are higher nutritional value, increased level of durability, a higher level of resistance to the virus and insect.Development of Herbicide-resistant SeedDevelopment of Herbicide-resistant Seed is another instance of the genetic engineering and its applications on the domain of physiological studies of plants. When the gene is modified in the seeds, the plants become able to tolerate a higher level of exposure to herbicides.Controlling weed is one of the crucial activities in farming. By using the modified seeds, the farmers become able to g produce a crop which can tolerate the herbicides. Therefore, controlling the weed in the fields becomes easier.Development of Insect-Resistant CropsGenetic engineering techniques are used to develop insect resistant crops. These crops are modified using the gene found in the soil bacteriumBacillus thuringiensis (Bt). These crops generate a toxin for the insects. In this way, the attacks of the insects are prevented.Coping with Global WarmingGlobal warming is one of the key issues in the current agricultural systems. Both global warming and agricultural practices are interrelated to each other. Global warming impacts on agriculture by bringing changes in average temperatures. The pattern of rainfall also changes with global warming. With the changing nature of the global climate, weather extremes are being observed more frequently. For example, incidents like heat waves and storms are being observed in a frequent manner. The change in weather also brings changes in the natural pests and diseases. The level of ground-level ozone concentrations along with the atmospheric carbon dioxide is changing with the climate. It indicates that the plants are being exposed to harsher weather in the modern days.The exposure to extreme weather is impacting the crops in different ways. The nutritional quality of the crops is being changed due to the adverse impacts of weather. Global warming is leading to the rise of sea level. As an effect, crop production in the low-altitude countries is being affected. Global warming might cause food insecurity in some areas. Under these circumstances, understanding the plant physiology is especially necessary to develop strategies for protecting the crops.Role in HorticultureHorticulture is another area which is closely related to the plant physiology. It is defined as the study which includes the culture of plants. The horticulture primarily focuses on producing food and materials for the purpose of beauty andcomfort. The key areas of focus in the domain of horticulture are– the restoration of the landscape, conservation of plants, management of soil, designing the garden and the landscape, development and maintenance of the garden.Key areas of HorticultureThe primary activities in Horticulture can be classified in the following manner—Pomology:It deals with fruit culture. The activities in Pomology mainly include the production of pome fruits such as pear, apple and quince. It also includes the production of stone fruits such as cherry, peach, nectarine, plum and apricot. Production on small fruits such as raspberry,blueberry, grape and strawberry falls under the domain of Pomology. Finally, the production of nut tree fruits is also one of the notable activities in the field of Pomology.Vegetable ProductionIt is the activity which deals with the culture of food crops. The crops are obtained from vegetable plants. Different parts of the vegetable plants are used as the product. Such parts include fruits, roots, and seeds.Floriculture:It is a domain that deals with the growing of flowers. The domain also focuses on growing the bedding plants, potted plants, bulbs and floral design.Environmental Horticulture:It is the domain which deals with nursery production of woody plants and herbaceous. The domain also emphasizes on managing and designing the landscape.Postharvest PhysiologyThis area of horticulture deals with harvest the crops, handling and storing those. The crops which are managed as part of the domain include fruits, flowers, and vegetables.The key difference between agriculture and horticulture is the scale of production. Agriculture aims at the production of the crop at a large scale. On the contrary, horticulture emphasizes producing a crop at a smaller scale.However, in both the domains, having knowledge of the physiology of plants is equally important. In horticulture, application of skills, knowledge and technology is needed producing the plants which meet the food-related and non-food requirements. The knowledge of the physiological attributes of the plants is required for cultivation and propagation purpose.The application of knowledge aims at the improvement of the growth rate of the plants, increasing the yields, improving the quality and enhancing the nutritional value. In horticulture, the presence of the insects can damage the plants. Similarly, plants can also be damaged due to diseases. The knowledge of physiology plays a crucial role to prevent such attacks. It indicates that knowledge is also useful for developing strategies to cope with the damage.。
植物生理学论文综述

海南大学植物生理学论文题目:光合作用与农业论文综述学号:20110203310001姓名:陈邓伟年级:2011级学院:园艺园林学院系别:园艺专业:园艺(花卉与景观设计方向)指导教师:黄绵佳完成日期:2013年 6 月15 日光合作用与农业论文综述陈邓伟(海南大学园艺园林学院海口 570228)【摘要】光合作用被誉为是地球上最重要的化学反应, 没有光合作用就不可能有人类社会的产生和发展。
我国是一个农业大国、粮食问题始终是我国的首要问题。
我国人均耕地少,因此提高农业粮食单产是关键。
光合作用是作物产量形成的物质基础,所以光合作用对农业生产和粮食产量有着十分重要的意义。
本文考察了光合作用与农业生产以及粮食产量的相关论文并做了综述,讨论归纳了光合作用与农业生产的关系以及如何充分利用太阳能进行光合作用、如何提高光合作用效率的问题,总结概述了光合作用在农业生产上的应用。
【关键词】光合作用;农业生产;综述光合作用是自然界中的一个十分重要的物质同化过程。
植物通过光合作用制造的有机物, 可供地球上所有异养生物之用。
作为人类的粮食、油料、蔬菜、水果等, 以及作为家畜饲料的有机物均是植物的光合产物。
此外, 人类生活所需的木材、纤维、棉、麻、橡胶以及糖等也是植物的光合产物。
由此可见, 光合作用与人类的生活, 特别是与农业生产具有密切的关系。
可以说, 光合作用是农业生产的基础, 农作物的产量和质量均取决于光合作用的状况。
一、光合作用与农业生产的关系(一)、作物光能利用率与光合作用效率提高光能利用率就是通过植物光合作用将照射到单位土地面积上的太阳能尽可能多地用于把环境中的无机物同化成植物体中的有机物。
计算这些有机物中所含的能量占此时期内照射到有关土地面积上的太阳能的比例, 即为该土地面积上植物的光能利用率(赵育民等2007)。
20世纪60年代初, 殷宏章先生到农村调研后, 对如何提高作物群体光能利用作了系统分析, 可以说是很有意义的科技创新(殷宏章等1959)。
开展农业院校植物生理学课外学习活动,提高学生综合能力[论文]
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开展农业院校植物生理学课外学习活动,提高学生的综合能力“植物生理学”等专业基础课具有理论性强、发展快和与生产联系紧密等特点,仅靠课堂教学难以满足复合型和创新型人才培养的需要。
以课堂教育引导为起点,以课外主题活动为渠道,以团队合作为组织形式,在提高学生的学习积极性,培养学生的理论联系实践能力、团结协作能力、写作能力、口头表达能力和应变能力等方面进行了实践和探索。
植物生理学课外学习活动专业素质综合能力植物生理学是高等农业院校农学、植保、园艺、蔬菜、种子和生物技术等植物生产类专业的重要专业基础课程,与农作物高产优质抗逆生产、设施农业建设、生态环境保护、药用植物栽培和食品贮藏加工等领域密切相关,具有理论性强、发展快、知识点多、需要大量记忆、与生产联系紧密等特点。
其教学质量直接影响到学生对后续专业课程的学习,在素质和能力的综合培养方面起重要作用。
目前,在教学内容速增、学时紧缩的情况下,教师必须加强学生课外学习能力的培养,改革传统的考核模式,以满足人才培养的需要。
一、加强课外学习的必要性和紧迫性课堂教学是传授知识培养能力的主要环节,但传统的课堂教学和考核模式难以圆满解决以下几个问题:第一,专业基础课的专业特性。
目前,专业基础课教学现状基本上是不同专业授课内容基本相同,考试试题相同,与专业联系不够紧密,在教学过程中没有充分体现出专业基础课其“基础”与“专业”的桥梁作用。
该教学和考核模式往往导致学生的专业学习目的和目标不够明确,不利于学生的学习兴趣、社会责任感和实践应用能力的培养。
第二,学生创新能力的培养。
对学生的学习评价主要依据是对课本理论知识的掌握程度,导致许多学生靠上课记笔记、考前背试题,临时突击就能过关甚至取得好成绩,主动学习和探究的精神不足,不能及时了解学科最新进展。
第三,学生团队精神的培养。
以个人为考核对象的传统考核模式,虽培养了学生独立学习思考的习惯,但不利于学生团队协助意识及能力的培养。
第四,学生表达能力的培养。
植物生理学论文多种因素与植物抗旱性的关系研究综述

高级植物营养学课程论文姓名:张伟汉学号:15720567 __________ 专业:植物营养学班级:15 级七班多种因素与植物抗旱性的关系研究综述摘要:水分作用植物各个阶段的生长发育和植物各种生理代谢过程,是植物成活与生长的重要限制因素之一。
干旱则严重影响植物的生长发育,所以植物自身的抗旱性至关重要。
文章从营养元素,植物激素,植物自身内部和外部等多种因素与植物抗旱性的关系进行综述,以期为植物抗旱性研究工作提供参考。
关键词:抗旱性;营养元素;植物激素目前全球公认的焦点性环境问题之一就是水资源短缺, 我国人均占有水资源量(2300m3)仅为世界人量的1/4,是世界上最缺水国家之一,且大部分地区属亚洲季风区, 干旱灾害具有普遍性、区域性、季节性和持续性的特点,旱灾十分严重[1]。
水资源缺乏不仅会影响植物的产量和观赏性状, 严重时还会造成植株的死亡。
提高植物的抗旱能力已经成为现代植物研究工作中急需解决的关键问题之一。
而影响植物抗旱性的原因多种多样,本文综述了部分植物抗旱性影响因素的研究进展,为生化调控植物的抗旱性提供参考。
1. 生长物质1.1 乙烯利国内学者通过叶片喷施乙烯利,研究其对玉米和甘蔗等农作物抗旱性的影响,揭示出乙烯利作用于植物抗旱性的复杂性。
乙烯利对植物抗旱性的影响和许多因素相关,例如,不同植物种和品种对乙烯利处理敏感程度不同。
乙烯利对植物抗旱性的影响因其处理方式的不同而不同,目前应用乙烯利主要有2种处理方式:乙烯利叶片喷施和乙烯利浸种处理。
综述目前已经取得的研究成果,展望未来研究的趋势,可以为今后乙烯利提高植物抗旱性研究提供一定的借鉴。
[2]此外,植物所处的生长发育阶段不同,干旱胁迫程度不同,乙烯利的处理浓度不同,对抗旱性的影响也不同。
1.1.1 喷施乙烯利对植物抗旱性的影响刘剑锋等[3]报道,400mg • L-1浓度的乙烯利叶片喷施处理可以提高玉米 (出苗后Id)的抗旱性,并加速其干旱胁迫后的复水恢复过程。
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题目:紫杉醇课程名称:《植物生理学》学院:林学院专业:水土保持与荒漠化防治班级:水保122学生姓名:徐永服指导教师:江龙2014年5月摘要紫杉醇是红豆杉属植物中的一种复杂的次生代谢产物,也是目前所了解的惟一种可以促进微管聚合和稳定已聚合微管的药物。
同位素示踪表明,紫杉醇只结合到聚合的微管上,不与未聚合的微管蛋白二聚体反应。
细胞接触紫杉醇后会在细胞内积累大量的微管,这些微管的积累干扰了细胞的各种功能,特别是使细胞分裂停止于有丝分裂期,阻断了细胞的正常分裂。
目录1简介 (1)2发现缘由 (3)提取方法 (3)4功用作用 (4)5药理毒理 (4)6药代动力学 (4)7适应症 (4)8用法用量 (5)9不良反应 (5)10禁忌症 (6)11注意事项 (6)12孕妇及哺乳期妇女用药 (6)13药物相互作用 (6)14药物过量 (6)15规格 (6)16贮藏 (7)17分离方法 (7)1简介【药物名称】紫杉醇【结构式】【药物别名】泰素,TAXOL,紫素,特素【英文名称】 Paclitaxel【说明】注射液:每支30mg(5ml)。
【性状】本品为无色或淡黄色澄明粘稠液体。
【化学名称】5β,20-环氧-1,2α,4,7β,10β,13α-六羟基紫杉烷-11-烯-9-酮-4,10-二乙酸酯-2-苯甲酸酯-13[(2’R,3’S)-N-苯甲酰-3-苯基异丝氨酸酯]【分子式】C47H51NO14【分子量】853.92【CA S NO】33069-62-4【产品来源】为红豆杉科植物红豆杉的干燥根、枝叶以及树皮。
【规格含量】99.6%【物理性质】白色结晶体粉末。
无臭,无味。
不溶于水,易溶于氯仿、丙酮等有机溶剂。
【鉴别】a.红外吸收:红外光谱图中的主要吸收带与对照品一致。
b.HPLC鉴别:在含量检测中,检测制备的色谱图中主峰的保留时间与标准制备色谱图中主峰的保留时间一致。
【纯度】99-100%,以无水无溶剂的干燥品计.【有关物质】相关物质总≤2.0%有机挥发性杂质:符合美国药典 (USP)和中国药典(CP)有机挥发性杂质要求.【比旋度】[α]20 D=-49.0°~55.0°(10mg/mL的甲醇溶液),以无水无溶剂的干燥品计。
【水分】≤4.0%【炽灼残渣】≤0.2%。
【重金属】≤0.002%【微生物限量】≤100cfu/g paclitaxel;符合对金黄色葡萄状菌、绿脓杆菌、沙门氏菌、人肠杆菌的无菌试验要求。
【细菌内毒素】≤4.0%USPEU/mg paclitaxel【简述】紫杉醇最早由太平洋红豆杉Taxus brevifolia的树皮中分离提取的新型抗癌植物药,1992年12月29日,美国FDA批准紫杉醇上市,美国BMS公司,商品名Taxol,用于治疗卵巢癌。
紫杉醇的特点是广谱抗癌。
对肺癌、食管癌、膀胱癌、头颈部癌、黑色素瘤、结肠癌和HIV引起的卡波济肉瘤也有效【1】。
紫杉醇(Paclitaxel,商品名为Tax01)分子式为C47H5lNOl4,是1963年美国化学家Wall等首先从短叶红豆杉(Taxus brevifolia)树皮中分离出来的具有独特抗癌活性的二萜类化合物,命名为紫杉醇,1971年利用X射线确定了它的结构,紫杉醇为针状结晶,具有高度的亲脂性,不溶于水(在水中溶解度为0.006 mg/mL) ,不溶于石油醚,可溶于甲醇、乙醇、乙酸乙酯、二氯甲烷等有机溶剂。
与糖结合成苷后的水溶性大大提高,紫杉醇分子中虽有含氮取代基,但氮原子处于酰胺状态,邻近又有吸电子基,故不显碱性而为中性化合物。
紫杉醇对酸相对稳定(pH4-8范围内),碱性条件很快分解【9】。
紫杉醇在植物体内的含量相当低,目前公认含量最高的短叶红豆杉树皮中也仅含0.069%,资源很匮乏。
由于美国、加拿大等国家对红豆杉立法保护,药源地转向了中国等国家。
在中国,80%的红豆杉集中在云南,而且云南红豆杉的紫杉醇含量最高。
从1992年到2001年,将近10年时间,云南红豆杉遭到了毁灭性的破坏,分布在滇西横断山区中的300多万棵红豆杉,绝大部分被剥了皮(有调查数据认为是92.5%),已慢慢死去。
2发现缘由1963年美国化学家瓦尼(M.C. Wani)和沃尔(Monre E. Wall)首次从一种生长在美国西部大森林中称谓太平洋杉(Pacific Yew)树皮和木材中分离到了紫杉醇的粗提物。
在筛选实验中,Wani和 Wall发现紫杉醇粗提物对离体培养的鼠肿瘤细胞有很高活性,并开始分离这种活性成份。
由于该活性成份在植物中含量极低,直到1971年,他们才同杜克(Duke)大学的化学教授姆克法尔(Andr e T. McPhail)合作,通过x-射线分析确定了该活性成份的化学结构——一种四环二萜化合物,并把它命名为紫杉醇(taxol)。
3提取方法紫杉醇主要存在于太平洋紫杉树的内皮中,在干的内皮中紫杉醇的含量仅为0.01%~0. 03%。
提取IKg紫杉醇需要从2000~3000棵树上剥取9000Kg的内皮,而治疗一名患者需要生长100年的紫杉树5~6棵。
太平洋紫杉是一种生长缓慢稀有的树种,利用它的树皮来生产紫杉醇会对生态环境造成严重破坏。
因此,必须想办法从其他的途径得到紫杉醇【10】。
研究发现,从幼树的针叶和树皮中也能提取紫杉醇,美国国立癌症研究所已经与一家公司合作实施大规模种植紫杉幼树的研究开发项目,使紫杉醇的来源困难有所改善。
另外可用生物植株平种改良提高植物中药物含量——例如:红豆杉是东北红豆杉和欧洲红豆杉的天然杂交种,其枝叶中的紫杉醇量较高。
曼地亚红豆杉是美国学者发现的一种天然杂交品种,其母本为东北红豆杉,父本为欧洲红豆杉。
曼地亚红豆杉适应性强,生长速度快,不仅树皮中含有紫杉醇,而且枝叶中紫杉醇的量为0.017%~0.051%,甚至有高达0.069%的报道。
由于紫杉醇的量极低,且其提取中含有大量的植物蜡、色素和树胶等杂质,特别是其中共存许多与紫杉醇分子结构和理化性质极其相近的紫杉烷系列化合物,给紫杉醇的分离纯化工作带来了很大的障碍。
世界上通常的纯化方法都是将液液萃取、色谱分离和重结晶等手段有机结合,并反复多次使用色谱手段。
从植物中提取紫杉醇的前期纯化来说,局部沉淀法是一个简单而有效地方法,该方法所用溶剂最少,但获得的紫杉醇的纯度和产量比较高。
4功用作用通过Ⅱ-Ⅲ临床研究,紫杉醇主要适用于卵巢癌和乳腺癌,对肺癌、大肠癌、黑色素瘤、头颈部癌、淋巴瘤、脑瘤也都有一定疗效。
5药理毒理本品是新型抗微管药物,通过促进微管蛋白聚合抑制解聚,保持微管蛋白稳定,抑制细胞有丝分裂。
体外实验证明紫杉醇具有显著的放射增敏作用,可能是使细胞中止于对放疗敏感的G2和M期。
6药代动力学静脉给予紫杉醇,药物血浆浓度呈双相曲线。
本品蛋白结合率89%~98%,紫杉醇在肝脏代谢。
紫杉醇主要在肝脏代谢,随胆汁进入肠道,经粪便排出体外(> 90%)。
经肾清除只占总清除的1%~8%,肾功能不全者一般紫杉醇在肝肾功能不全的病人体内代谢尚不明确。
7适应症卵巢癌和乳腺癌及NSCLC的一线和二线治疗。
头颈癌、食管癌,精原细胞瘤,复发非何金氏淋巴瘤等。
8用法用量为了预防发生过敏反应,在紫杉醇治疗前12小时口服地塞米松10mg,治疗前,6小时再囗服地塞米松10mg,治疗前30~60分钟给予苯海拉明肌注20mg,静注西咪替丁300mg或雷尼替丁50mg。
单药剂量为135~200mg/m2,在G-CSF支持下,剂量可达250mg/m2。
将紫杉醇用生理盐水或5%葡萄糖盐水稀释,静滴3小时。
联合用药剂量为135~175mg/m2,3~4周重复。
一般临床使用紫杉醇的程序如下:1.先询问病人有无过敏史,并查看白细胞及血小板的数据。
有过敏史者及白细胞/血小板低下者应慎用。
2.由于此药可引起过敏反应,在给药12小时和6小时前服用地塞米松20mg,给药前30~60分钟给予苯海拉明50mg口服及西咪替丁300mg静脉注射。
3.常用紫杉醇的剂量为135~175mg/m2,应先将注射液加于生理盐水或5%葡萄糖液500~1000ml中,需用玻璃瓶或聚乙烯输液器,应用特制的胶管及0.2 2μm的微孔膜滤过。
4.滴注开始后每15分钟应测血压、心率、呼吸一次,注意有无过敏反应。
5.一般滴注3小时。
6.注药后每周应检查血像至少2次,3~4周后视情况可再重复。
本品可与顺铂、卡铂、异环磷酰胺、氟尿嘧啶、阿霉素、VP-16等联合应用,血像低下时应用G-CSF,或紫杉醇加G-CSF预防给药。
9不良反应1、过敏反应:发生率为39%,其中严重过敏反应发生率为2%。
多数为1型变态反应,表现为支气管痉挛性呼吸困难,荨麻疹和低血压。
几乎所有的反应发生在用药后最初的10分钟。
2、骨髓抑制:为主要剂量限制性毒性,表现为中性粒细胞减少,血小板降低少见,一般发生在用药后8~10日。
严重中性粒细胞发生率为47%,严重的血小板降低发生率为5%。
贫血较常见。
3、神经毒性:周围神经病变发生率为62%,最常见的表现为轻度麻木和感觉异常,严重的神经毒性发生率为6%。
4、心血管毒性:可有低血压和无症状的短时间心动过缓。
肌肉关节疼痛:发生率为55%,发生于四肢关节,发生率和严重程度呈剂量依赖性。
5、胃肠道反应:恶心,呕吐,腹泻和黏膜炎发生率分别为59%,43%和39%,一般为轻和中度。
6、肝脏毒性:为ALT,AST和AKP升高。
7、脱发:发生率为80%。
8、局部反应:输注药物的静脉和药物外渗局部的炎症。
10禁忌症对聚氧乙基代蓖麻油过敏者。
禁用于中性白细胞低于1500/MM者。
11注意事项1.血液学毒性:为限制剂量提高的主要因素,一般在白细胞低于1500/mm3时应辅助应用G-CSF,血小板低于30,000/mm3时应输成分血。
2.过敏反应:除了预处理外,如只有轻微症状如面潮红、皮肤反应、心率略快、血压稍降可不必停药,可将滴速减慢。
但如出现严重反应如血压低、血管神经性水肿、呼吸困难、全身寻麻疹,应停药并给以适当处理。
有严重过敏的病人下次不宜再次应用紫杉醇治疗。
3.神经系统:最常见为指趾麻木。
有约4%的病人,特别是高剂量时可出现明显的感觉和运动障碍及腱反射减低。
曾有个别报告在滴注时发生癫痫大发作。
4.心血管:一过性心动过速和低血压较常见,一般不需处理。
但在滴注的第一小时应严密观察,以后除有严重传导阻滞的病人不必每小时观察一次。
5.关节和肌肉:半数左右的病人在用药后2~3天会感到关节和肌肉疼痛,与所用剂量相关。
一般在几天内恢复。
在给予G-CSF的病人肌肉痛会加重。
6.肝胆系统:由于紫杉醇大部由胆汁中排出,对有肝胆疾病的病人应谨慎观察。
在数千例的资料中约8%的病人有胆红素升高,23%的病人碱性磷酸酶升高,18%有谷草转氨酶升高。