Irreversible Electrical Breakdown of Malignant Tumor Cell Under Steep Pulsed Electric Fields

The basic characteristic of electric field is that the substance in the field is in operation by the stress. Under steep pulsed electric fields, there is strong distribution of electric fields on the inside and outside surfaces of cell membrane. In virtue of the difference of the permittivity among membrane, cytoplasm and extracellular medium, there must be the electric field stress on the surface of the membrane. The calculation results showe that cell membrane is stressed from two directions of cytoplasm and extracellular medium under external electric fields. The stress on tumor cell membrane is greatly larger than normal cell membrane, so the tumor cell is more sensitive than normal cell. Tumor cell membrane certainly will be destroyed by electric field stress, then its survival environment and germ plasm will be injured and accordingly the cell will be damaged.     

小麦类发芽素蛋白3启动子序列(登录号:AY864922)

In germinating wheat embryos, gl-OXO accumulation is localized in cell wall. It has been confirmed that this enzyme locally provides H2O2 to catalyze peroxide-mediated cross-linking of cell wall components in terminal cellular differentiation and plays an important role in enabling cells to retain their meristematic and organogenic capacity. Using tail-PCR and DNA sequencing techniques, we isolated Germin-like Protein 3 promoter sequence（l 654 bp）, from common wheat cultivar （yumai 18） genome. No GGGCGGG sequence exiting in promoter implies that germin-like protein 3 is not “house-keeping” protein. The presence of TGTCTC, an auxin response element and localizing at upstream -258, indicates that this promoter is auxin-inducible. The TATA box situates in upstream -27- -32 and 5＇-UTR consists of 95 bp.     

玉米BADH基因的克隆与序列分析

Betaine was accumulated as a nontoxic and protective osmolyte in water-dificit and salt-stressed plants. Betaine aldehyde dehydrogenase for glycine betaine synthesis is an important enzyme. The BADH gene of Maize was cloned by RT-PCR and RACE. The gene is 1 762 bp in length, including an open reading frame of 1 515 bp.Its nucleotide sequence shares 95% with the the partial cDNA of BADHI from Sorghum bicolor. Its deduced amino acid sequence contains the conserved domain sequence “VTLELGGKSP“ of ALDH, and a tripeptide SKL at its C-terminal, a signal targetting to the microbodies. The phylogenetic tree of 20 BADHs was constructed,which corresponds to the classical botanical division of plant, the BADH of maize is closest to the one of Oryza Sativa.     

Role of RGD-mediate Adhesion in Signal Transduction of Plant Resistance

During the period of the primary contact time,there are series of recognition between the Fungal pathogens and the plant cell,which include physical and biochemical recognition.The results affect the infection directly.In the process of penetrating plant cell walls,there is not only an emzymolysis to plant cell wall,but also a mechanical squeeze to the cell wall.The latter almost trigger cell-associated defense response,such as extracellular hydrogen peroxide generation and callose doposition The complete cell wall-related defence response will be induced by mechanical signal and chemical signal together.Being to with the mammalian cell,in plant cell wall intergrin-like proteins have response to perceive the mechanical signal,which is via RGD(Arg-Gly-Asp)motif,and the plasma membrane-cell wall adhesion is required for expression of plant defense responses during fungal penetration.     

Brief Study on Physiological Effects of Sound Field on Actinidia Chinensis Callus

Insight into the relationship between plant cell (tissue) and physical stimulation is a focus of biomechanics. In this study, several important plant physiological indexes of Actinidia chinensis callus in sound field including the content of soluble proteins, the activity of SOD, the activity of IAA oxidase and the penetrability of cell membrane, were measured. Some information is got about stress effect through the study and try to explore its mechanism. From the result of experiment,we found that there were a great similarity of stress effect on sound field between Actinidia chinensis and Gerbera Jamesonii acrocarpous , a kind of herbage plant, which had been studied in our lab before. That is to say, the sound field also has dual effect on woody plant. It can enhance or inhibit the growth and development of Actinidia chinensis callus along with the sound field frequency ,and the moderate frequency of sound field acting on the callus could promote callus growth. A conclusion is drawn that the optimal stimulation of sound field are 100 dB and 1 000 Hz. Under the conditions, the sound field can distinctly enhance the growth of Actinidia chinensis callus Whereas, it is not very easy to explore the detail mechanism of environmental stress effects on plant. This paper discussed the mechanism of sound field stress on plant from the level of cell and molecule.     

Some Issues about the Recycling Liquid Sludge Water from Water Treatment Plant

The liquid sludge water is produced from coagulation/filtration units and filtration operation of water treatment plant. The utilization of liquid sludge water from water treatment plant is an efficient way to save water resource. The potential problems in recycling the liquid sludge water are discussed in this paper from the aspects of its biological, physical and chemical properties. The microbiological safety of filtered water can be improved by recycling the liquid sludge water after coagulation and sedimentation or membrane filtration pretreatment. The status of utilization of the liquid sludge water at home and abroad is presented as well.     

Application of Low Intensity Ultrasound to Biotechnology

Application of low intensity ultrasonic waves to the biotechnology is one of new and hot research fields. The physical mechanisms of ultrasound mainly include the effects of mass transfer ,heating and cavitation. Many researchers found that low intensity ultrasonic waves could accelerate the interacton of substrate and help reactant to enter the active center of enzyme and production to leave center; it could also alter the permeability of membrane and enhance the transfer of mass, and so promote the production of beneficial matter and the absorption of drug to cells; in addition ,it could raise the efficiency of cell metabolism and the growth of cells; so low intensity ultrasonic waves can be used in enzyme engineering, fermentation engineering, cell engineering and biological therapeutics of Neoplasm. In this paper, we reviewed the application of low intensity ultrasound to biotechnology at home and abroad.     

Cloning and Function Characteristic of GhDWF 4,an Ortholog of Arabidopsis DWF 4 from Upland Cotton (Gossypium hirsutum L.)

As one of the longest cells characterized in plant kingdom,cotton fibers were regarded as an ideal material for studying plant cell growth and development.In recent years,several reports revealed that brassinosteroids (BRs) play an important role in the growth and development of cotton fiber.To further investigate the effect of BRs on fiber cell development and illuminate the mechanism of BRs action,we cloned GhDWF4,an ortholog of Arabidopsis DWF4 from upland cotton (Gossypium hirsuturn L.).     

Functional Investigation of a Cotton Fiber HOX Gene

Most of the plant homeodomain-containing proteins play important roles in regulating cell differentiation and organ development,and Arabidopsis GLABRA2 (GL2),a member of the class IV homeodomain-Leucine zipper (HD-ZIP) proteins,is a trichome and non-root hair cell regulator.We have analyzed several cotton homeodomain-containing proteins that belong to the class IV HD-ZIP family.One of them,GaHOX1,shows a high sequence identity to Arabidopsis GL2 (95% in the homeodomain and 64% overall).     

GhDET2,a Steroid 5alpha-reductase,Plays an Important Role in Cotton Fiber Cell Initiation and Elongation

Cotton (Gossypium hirsutum L.) fibers,one of the most important natural raw materials for the textile industry,are highly elongated trichomes from epidermal cells of cotton ovules.Among the longest plant cells ever characterized,cotton fiber is an ideal system for studying plant cell elongation.Brassinosteroids (BRs),a class of steroidal phytohormone,play an important role in plant cell division and elongation.     

硅对盐胁迫下黄瓜幼苗根系质膜、液泡膜酶活性的影响

研究硅对盐胁迫下黄瓜幼苗生长及根细胞质膜H^＋-ATPase、液泡膜H^＋-ATPase、H^＋-PPase和Ca^2＋-ATPase活性的影响。结果表明：盐胁迫严重抑制黄瓜幼苗生长,根细胞质膜H^＋-ATPase、液泡膜H^＋-ATPase、H^＋-PPase和Ca^2＋-ATPase活性明显降低。硅处理明显提高盐胁迫黄瓜根液泡膜H^＋-ATPase、H^＋-PPase、Ca^2＋-ATPase活性,一定程度上维持了液泡膜质子泵活性,有效地防御了细胞质酸化,这可能是硅提高黄瓜耐盐性的一个重要因素。     

渗透胁迫对白三叶幼苗根系离子分泌和质膜ATP酶活性的影响

用PEG－6000渗透胁迫处理,白三叶根系质膜透性升高,抗旱品种‘海发’增幅小于不抗旱品种‘瑞文德’。根系分泌物中K+、Ca2+、H+的含量变化与根系质膜透性的变化一致。水分胁迫早期,白三叶根系PM H＋-ATPase活性升高,胁迫时间延长,不抗旱品种‘瑞文德’的PM H＋-ATPase酶活性下降,但抗旱品种‘海发’的酶活性一直较高。PM Ca2+-ATPase酶的活性与PM H＋-ATPase酶表现一致。     

水稻质膜H+-ATPase基因对拟南芥遗传转化及其抗盐性分析

RT-PCR扩增得水稻质膜H -ATPase全长cDNA(PM-H -ATPase),构建了植物表达载体获得质粒pBI121-PM-H -ATPase,农杆菌介导、真空渗入法转化PM-H -ATPase基因入拟南芥,得35株T1代卡那抗性植株.抗性植株PCR分析表明,抗性植株整合了目的基因.Northern杂交分析进一步表明T3代转基因拟南芥表达了目的基因.抗盐(NaHCO3和NaC1)性分析表明:转基因植株的耐盐能力明显高于野生型;盐碱胁迫下转基因植株开花优先于野生型植株.     

盐胁迫及La3+对不同耐盐性水稻根中抗氧化酶及质膜H+-ATPase的影响

用盐敏感的武运粳8号和强耐盐的韭菜青两个粳稻品种,比较了盐胁迫条件下根中抗氧化酶类和质膜H＋-ATPase活性的变化以及La^3＋对其变化的影响。结果表明,两个品种根中SOD和APX活性无显著区别,但耐盐品种的CAT和POD活性强于盐敏感品种。盐胁迫不同程度地提高了两者抗氧化酶活性。La^3＋对其影响最显著的差异出现在高盐条件下（200-300mmolL^-1NaCl）,对耐盐品种添加La^3＋可以提高上述4种酶的活力,而对盐敏感品种,La^3＋的作用不明显。对盐敏感品种,盐胁迫导致其质膜H＋-ATPase活性持续下降,添加La^3＋明显提高其H＋-ATPase活性,而对耐盐品种,盐胁迫导致其质膜H＋-ATPase活性呈现先降后升的趋势,La^3＋对其活性影响不大。进一步分析表明,上述H＋-ATPase活性变化及La^3＋对其影响均发生在转录水平上。据此推测,以上2个品种可能具有完全不同的盐胁迫响应机制。     

液泡膜质子泵与植物耐盐相关性研究

土壤盐渍化是一个世界性的资源问题和生态问题,盐分胁迫几乎会影响植物所有重要的生命活动,造成植物的减产或其他不利影响.液泡膜质子泵(H~+-ATPase和H~+-PPase)在植物细胞的跨膜物质转运、胞内pH值平衡等诸多生理活性方面都发挥关键作用.因此,在植物对环境胁迫的响应过程中,液泡膜质子泵活性的调节对植物的耐盐性具有重要意义.本文结合植物液泡膜H~+-ATPase和H~+-PPase的分子结构、生理功能及其在盐胁迫下调节机理的研究结果,阐述了植物液泡膜质子泵的生理功能与植物耐盐性的相关性,并对其仍未解决的问题进行了展望.     

光敏核不育水稻农垦58S花粉败育过程中Ca2+-ATPase的变化

运用电镜细胞化学技术(铅盐沉淀法),对长日照条件下光敏核不育水稻农垦58S和可育株系58N花药发育的不同时期进行了Ca²⁺-ATPase定位研究。结果表明,Ca²⁺-ATPase颗粒在可育与不育水稻的花药壁、花粉及药隔中的出现时间和数量具有明显差异。可育花药在花粉母细胞时期,药壁细胞内出现Ca²⁺-ATPase颗粒,至单核花粉后期,解体的绒毡层细胞和乌氏体表面分布大量的Ca²⁺-ATPase颗粒;与可育材料相比,不育花药在花粉发育的同时期,Ca²⁺-ATPase颗粒在药壁各层细胞内不仅出现的时间滞后,且分布的数量较少,到二核花粉时期(花粉已畸形空瘪),药壁表皮细胞的液泡膜上、绒毡层细胞质中及乌氏体表面才出现明显的Ca²⁺-ATPase颗粒。可育花粉单核早期,花粉细胞内线粒体膜上有少量的Ca²⁺-ATPase分布;单核花粉中期,花粉外壁上有少量的Ca²⁺-ATPase分布;到单核花粉后期,Ca²⁺-ATPase颗粒大量分布在花粉外壁、内壁及细胞质膜和细胞核中。而不育花粉在单核花粉发育中都未见Ca²⁺-ATPase的分布,到花粉败育空瘪时才出现明显的Ca²⁺-ATPase颗粒,但数量较可育花粉同期同部位少。可育花药药隔细胞中Ca²⁺-ATPase在花粉母细胞减数分裂期就有分布,而不育花药到单核花粉早期药隔中才有少量的Ca²⁺-ATPase分布。由此推测,水稻不育系在其花粉发育中,由于细胞壁和质膜上Ca²⁺-ATPase颗粒出现时间滞后和数量减少影响到细胞膜钙泵将Ca²⁺由胞质向胞外转运的功能,致使胞质内Ca²⁺过多积累,导致花粉败育。     

铝胁迫对花生根尖线粒体膜生理特性的影响

线粒体在植物生命活动中发挥重要作用,以花生为材料,研究了在铝胁迫条件下,花生根尖细胞线粒体膜生理变化。结果表明,通过根长试验、苏木精染色和根尖铝离子含量测定,筛选到耐铝品种LH11,铝敏感品种R1549。铝胁迫后,两个品种根尖线粒体MDA含量增加,R1549的MDA含量均高于LH11,在处理浓度是20 μmol L^-1和100 μmol L^-1时,两品种的MDA含量差异显著,但在400 μmol L^-1时,差异不显著;两品种根尖线粒体Ca²⁺-ATP酶活性和Ca²⁺含量呈下降趋势,且随铝溶液浓度增加而加快,R1549的线粒体Ca²⁺含量下降较LH11快;随处理铝溶液浓度增加,线粒体光密度持续下降,MPT不断增大,ΔΨ_m明显降低,线粒体中Cyt c/a减少,R1549较LH11下降更明显。试验结果说明在较高铝浓度胁迫下,两品种线粒体透性转换孔开放,膜透性增加,跨线粒体膜Ca²⁺转运系统活性降低,使胞质Ca²⁺超载,细胞色素C释放到细胞质中,诱导根尖细胞发生程序性死亡,从而抑制根生长;在低铝浓度下,与铝敏感品种相比,耐铝品种吸收铝少,脂质过氧化水平低,线粒体膜Ca²⁺-ATPase活性、MPTP和ΔΨ_m调控能力强,不易发生PCD,从而表现出较强的耐铝能力。     

植物吸收、转移镉相关的转运蛋白CAXs和HMAs的研究进展

为探究植物对镉耐性的分子机理研究,提供植物蛋白转运重金属理论基础。本文分别归纳了CAX_S和HMAs的结构和功能及其对植物生长的影响,以及协同作用下解毒重金属的机制。CAXs在提高植物修复潜力和强化植物营养有重要作用,主要参与二价阳离子向膜内的转运,决定植物体内Ca²⁺的浓度,在重金属胁迫下参与重金属离子的转运和解毒。其运行与质膜、液泡膜HMAs产生的电化学H⁺梯度相关,通过在细胞质膜两侧建立电势梯度差,为CAXs转运物质提供了必不可少的能量支持。但CAXs和HMAs的协同作用机理有待加强研究,建议进行CAXs、HMAs蛋白活性测定、基因分离的鉴定,研究CAXs、HMAs蛋白之间的相互关系,为将来基因工程修复重金属污染的土壤提供可能性。     

干旱胁迫下一氧化氮对小麦离体根尖离子吸收的影响

为阐明干旱胁迫下一氧化氮(NO)对植物的保护机制,利用干旱敏感性不同的3个小麦(Triticum aestivum L.)品种的离体根尖,比较了NO对干旱胁迫的响应及其对离子吸收的影响。在干旱胁迫下, 耐旱品种陇春8139根尖中大量产生NO, K⁺和Ca²⁺被大量吸收, 而Cl^-1被排出体外, 质膜H⁺-ATPase活性升高; 而干旱敏感品种甘麦8和定西24的根尖中NO、离子含量和质膜H⁺-ATPase活性的变化呈相反趋势。NO供体硝普纳(SNP)处理使3个品种根尖中的K⁺和Ca²⁺含量增加,Cl^-1含量下降,并能提高质膜H⁺-ATPase活力;NOS抑制剂N^ω-nitro-L-arginine(LNNA)和NO清除剂2-phenyl-4,4,5,5-tetramethyl-imidazoline-1-oxyl- 3-oxide(PTIO)能够逆转这一效果。Na⁺含量在所有处理下都没有明显变化。试验结果证明,NO能够通过调节质膜H⁺-ATPase活力影响植物对离子的选择吸收,从而提高耐旱性。     

干旱胁迫下一氧化氮对小麦离体根尖离子吸收的影响

为阐明干旱胁迫下一氧化氮(NO)对植物的保护机制,利用干旱敏感性不同的3个小麦(Triticum aestivum L.)品种的离体根尖,比较了NO对干旱胁迫的响应及其对离子吸收的影响。在干旱胁迫下, 耐旱品种陇春8139根尖中大量产生NO, K⁺和Ca²⁺被大量吸收, 而Cl^-1被排出体外, 质膜H⁺-ATPase活性升高; 而干旱敏感品种甘麦8和定西24的根尖中NO、离子含量和质膜H⁺-ATPase活性的变化呈相反趋势。NO供体硝普纳(SNP)处理使3个品种根尖中的K⁺和Ca²⁺含量增加,Cl^-1含量下降,并能提高质膜H⁺-ATPase活力;NOS抑制剂N^ω-nitro-L-arginine(LNNA)和NO清除剂2-phenyl-4,4,5,5-tetramethyl-imidazoline-1-oxyl- 3-oxide(PTIO)能够逆转这一效果。Na⁺含量在所有处理下都没有明显变化。试验结果证明,NO能够通过调节质膜H⁺-ATPase活力影响植物对离子的选择吸收,从而提高耐旱性。