地衣对南京石刻文物侵蚀现象的研究

目前、地衣对石刻文物形成的微观喀斯特侵蚀作用,已经引起了地衣学家和地理学家的关注。本文阐述了南京石刻文物上的地衣种类和侵蚀程度;介绍了地衣生物侵蚀的化学和物理机理;提出了保护南京石刻文物的建议。 地衣是藻类和菌物共生形成的一类特殊的原植体生物。其对外界逆境有着巨大的忍耐能力,生命力顽强,因此,地衣的分布十分广泛。从地球两极到赤道丛林;从平原海岸到高山荒漠都有地衣的踪迹。地衣能在树皮、土表、岩石、墙壁甚至金属玻璃等基物上生长。然而.每一种地衣对其着生的基物种类生态条件十分敏感,它们只在适合的小生境中生长。有些生长在石灰岩等碳酸盐岩表面的地衣是喜钙性地衣,这些地衣是生物微观喀斯特侵蚀过程的一个重要营力。

Optimization of Expression Conditions for Immunodominant Membrane Protein Gene of Phytoplasmas in E.coli

[Objective] This study aimed to increase the expression level of immun- odominant membrane protein gene （Imp） of phytoplasmas in E. coil BL21 （DE3）. [Method] On the basis of orthogonal experiment, effects of different culture conditions on recombinant bacteria E. coil BL21-pET-28a（＋）-Imp were investigated. Based on the obtained optimal culture condition, effects of different induction conditions on the ex- pression level of Imp protein were explored. The expression level of Imp fusion pro- tein was analyzed by using SDS-PAGE and Gene Tools software. [Result] The re- sults showed that the optimal conditions for culture were at 37℃, pH 7.0, with liq- uid volume of 20% and oscillation speed of 200 r/min, for induction were at 37℃ for 6 h, with initial OD600 of about 1.5 and IPTG final concentration of 0.1 mmol/L. [Conclusion] The expression level of Imp achieved 70.98 mg/L under the optimal conditions. Optimized conditions for expression of Imp fusion protein in E. coil were determined.

Plants regenerated from mesophyll protoplasts of white mulberry

Morus alba(white mulberry) mesophyll protoplasts were isolated from leaves of 30-45 day old sterile shoots,with protoplast yields of 2.5 x 107 g-1/F.W. after purification. The protoplasts were cultured in a modified K8P liquid medium containing 0.2 mg/L 2,4-D(2,4- Dichlorophe-noxy acetic acid), 1 mg/L NAA(Naphthyl acetic acid) and 0.5 mg/L BA(6-benzylaminopurine). A low plating density (5 x 104/ml) proved to be favourable to the division of protoplast-derived cells. The first divisioll occurred 4 days after culture, and the division frequency reached 24% at 10 days. A number of cell colonies and microcalli formed in 6 weeks. The microcalli were transferred onto MSB medium with 0.5 mg/L NAA and 0.5 mg/L BA for further proliferation. Shoot formation was initiated when the calli of 3-4 mm in size were transferred onto MSB differentiation medium with 0.1 mg/L NAA and 1 mg/L BA. The frequency of shoot formation was 35%. The shoots of 4-5 cm in height were excised from the callus and rooted on half strength MS medium with 0.5 mg/L IBA and 0.1 mg/L BA. After transplantation into pots, the regenerated plants grew vigorously in the phytotron.

Production of Somatic Hybrid Plants Between Two Types of Wheat Protoplasts and the Protoplasts of Haynaldia villosa

小麦 (TriticumaestivumL .)济南 177的两种原生质体 ,一种来自快速生长的悬浮细胞 ,它们因长期继代而丧失分化能力 ,其染色体只有 2n =2 4～ 2 8;另一种来自可以再生的愈伤组织 ,其原生质体不能持续分裂。它们中任一种与UV照射过的簇毛麦原生质体融合均不能再生植株。然而当它们混合在一起作为受体时 ,能够获得再生绿色植株。细胞核基因和胞质基因的分析证明这些绿色植株是杂种。以上事实说明这两种原生质体在融合时存在某些互补的关系 ,讨论了这种融合方式的可能作用及重要性。

Responses of Phytolith in Guinea Grass(Leymus chinensis) Leaves to Simulated Warming,Nitrogen Deposition and Elevated CO_2 Concentration in Songnen Grassland,Northeast China

Deposited in plant cells and their intercellular space,phytoliths,a special form of silica,could be used to determine information on plant structure and physiology especially their size and content.With the hypothesis that phytolith in plant would change under variable climate and environment,the dominant plant species in Songnen grassland,guinea grass(Leymus chinensis),was treated by an open-top chamber(OTC) to elevate CO2 concentration,infrared heaters,and artificial nitrogen(N) addition for three years from 2006–2008.Phytoliths were extracted by wet-ashing method and analyzed by variance analysis and so on.We found that the responses to elevated CO2 are complicated,and warming is positive while N addition is negative to the deposition of phytoliths in L.chinensis leaves.Especially,warming could reduce the negative impact of N addition on phytolith in L.chinensis.The short cell's taxonomic in graminea is significant because of no disappearance with simulated environmental changes.The phytolith originated in the long cell and plant intercellular space are more sensitive to elevated CO2 concentration,warming,and N addition,and could become some new indicators for environmental changes.In conclusion,different phytolith types have various responses to simulated warming,N addition and elevated CO2 concentration.

Plant regeneration from cultured protoplasts of a glutinous rice

Young embryos of rice (Oryza saliva L. subsp. japonica var. Guo-xiang No.l) were cultured on MS agar medium(2,4-D 2 mg/l). Calli were formed and subcultured on N6 agar medium (2,4-D 2 mg/l). After selection, the small, grainy and pale yellowish cell clusters with dense cytoplasm were used in protoplast preparation. Isolated protoplasts were cultured in N6 medium (2,4-D 1 mg/l, 6-BA 0.2 mg/l)1 with agarose block culture method. The protoplasts grew, divided and formed calli. After inducing differentiation, the regenerated mature plants were obtained.

Dual function of Arabidopsis A TAF1 in abiotic and biotic stress responses

NAC family genes encode plant-specific transcription factors involved in diverse biological processes. In this study, the Arabidopsis NAC gene ATAF1 was found to be induced by drought, high-salinity, abscisic acid （ABA）, methyl jasmonate, mechanical wounding, and Botrytis cinerea infection. Significant induction of ATAF1 was found in an ABA-deficient mutant aba2 subjected to drought or high salinity, revealing an ABA-independent mechanism of expression. Arabidopsis ATAFl-overexpression lines displayed many altered phenotypes, including dwarfism and short primary roots. Furthermore, in vivo experiments indicate that ATAF1 is a bonafide regulator modulating plant responses to many abiotic stresses and necrotrophic-pathogen infection. Overexpression of ATAF1 in Arabidopsis increased plant sensitivity to ABA, salt, and oxidative stresses. Especially, ATAF1 overexpression plants, but not mutant lines, showed remarkably enhanced plant tolerance to drought. Additionally, ATAF1 overexpression enhanced plant susceptibility to the necrotrophic pathogen B. cinerea, but did not alter disease symptoms caused by avirulent or virulent strains of P. syringae pv tomato DC3000. Transgenic plants overexpressing ATAF1 were hypersensitive to oxidative stress, suggesting that reactive oxygen intermediates may be related to ATAFl-mediated signaling in response to both pathogen and abiotic stresses.

Initial Screening of 10 Plant Essential Oils in Vitro Antibacterial Activity Against Blueberry Pathogens

In order to develop natural antistaling agent for blueberries preservation,the antibacterial activities of 10 kinds of plant essential oils were analyzed by oxford-cup test and tube dilution method,and their inhibitory abilities to two kinds of representative Gram bacteria which are Escherichia coli and Staphylococcus aureus,and three kinds of harmful fungi in blueberries,involving Alternaria alternata,Penicillium digitatum and Botrytis cinerea,were tested.The results showed that 7 kinds of essential oils can inhibit the three fungi,among which cinnamon oil,clove oil,anise oil and thyme oil have strong fungi static efficacy.Cinnamon oil and thyme oil can effectively inhibit the Gram-positive bacterium(Staphylococcus aureus);cinnamon oil and masson pine oil are strongly inhibitory to Gram-negative bacterium(E.coli).Cinnamon oil has broad-spectrum ability to inhibit fungi,Gram-negative and positive bacteria,with a minimum inhibitory concentration(MIC)ranging from 0.0391 to 0.1560 L/mL.With strong inhibition effects on fungi,cinnamon oil can be used as a compound base oil and mixed with other essential oils to retain the freshness of blueberries,thus achieving better antibacterial and anti-corrosion effects.

CD28/B7-MEDIATED COSTIMULATION IS REQUIRED FOR PARATHYROID GLAND ALLOGRAFT REJECTION IN RATS

The activation of T cells to differentiate and to proliferate is an essential step in the immune response to antigen, especially in cell mediated acute allograft rejection. Besides the interaction of CD3/TCR complex with Ag/MHC complex presented on antigen presenting cells, a complete T cell activation and proliferation requires a second costimulatory signal. The interaction of CD28/CTLA 4 and B7 is a major costimulatory pathway for T Cell activation. Inhibition of this pathway results in development of antigen specific unresponsiveness and clonal anergy.In present study,the biologic function of anti CD28 monoclonal antibody and its Fab fragment were investigated in vitro and in vivo.The results indicate that mAbCD28 and its Fab fragments could promote the functional recovery of allografts and prolong the graft survival,but could not reverse the acute rejection or induce transplantation tolerance in the rat PTG allograft model. We also found that peripheral TNF α level and NK cell activity were suppressed in the presence of mAbCD28 and its Fab fragments for a relatively long time after PTG transplantation.

Plant regeneration from protoplasts of hydroxyprolineresistant cell line in Onobrychis viciaefolia

An efficient protocol for plant regeneration from protoplasts of hydroxyproline(HYP)resistant cell line of Onoblychis viciaefolia was established. In SH medium supplemented with 1 mg/L 2, 4-dichlorophenoxy-acetic acid (2,4-D), 0.5 mg/L kinetin (KT) and 0.2 mg/L naphthalene acetic acid (NAA), the division frequency of protoplastderived cells reached uP to over 60 %, and microcalli were obtained in 5-6 wk. Upon transferring them on agar solidified MS medium plus 2 mg/L indole-3-acetic acid (IAA), shoots were induced. After cultivating them on MS medium with or without IAA, roots were regenerated.Chromosome number of all protoplast-regenerated plants examined were normal (2n=28). The protoplast-derived calli and plants grew vigorously on the medium containing 10 mmol/L HYP.

Proteomic study of three component interactions: plant, pathogens and antagonistic fungi

The molecular factors involved in the three-way interaction between plant, pathogenic fungi and antagonistic/biocontrol fungi, such as Trichoderma, are still poorly understood, even if they represent a matter of interest for improving crop management and developing new strategies for plant diseases control. The aim of this work is to investigate the components involved in this interaction and, for this purpose, a proteomic approach was used. 2-D maps of the protein extracts from the single components in various interactions between plants (potato, bean, tobacco or tomato), pathogens (Botrytis cinerea, Rhizoctonia solani or Pythium ultimum) and biocontrol fungi (Trichoderma atroviride strain P1 or Trichoderma harzianum strain T22) were obtained. The proteome of each partner was collected separately and extracted by acetone precipitation in presence of trichloroacetic acid and a reducing agent (DTT). The extracted proteins were separated by isoelectrofocusing (IEF), using IPG (Immobilized pH gradient) strips, followed by SDS-PAGE. In order to improve resolution the separations were performed both on wide than narrow pH range and on different gel lengths. Differential spots were noted in the proteome of the three-way interaction when compared to each single component. These were further characterized by mass spectrometry and in silico analysis with the aim of identifying and cloning the relative genes. During the in vitro interaction of T. harzianum strain T22 with tomato and the culture filtrate or cell walls of pathogens, the spot number was higher than in the presence of pathogen biomass. In terms of Trichoderma differential proteins displayed on 2D gels, the most important changes were obtained in the presence of P. ultimum . During the in vivo interaction with tomato, the antagonist proteome changed much more in presence of soilborne fungi R. solani and P. ultimum than with the foliar fungus B. cinerea, both in terms of total and increased or novel spots. In silico analysis of some of those spots revealed homology with intracellular enzymes (GTPases, hydrolases) and with stress-related proteins (heat shock proteins HSP70, bacteriocin cloacin). Specific proteins in the plant proteome, i.e. pathogenesis-related proteins, have been identified during the in vivo interaction of bean with R. solani and T. atroviride strain P1. This is in agreement with the demonstrated ability of these beneficial fungi to induce plant systemic disease resistance by activating expression of defence-related genes. Proteins extracted from T. atrovride strain P1 which were analysed by mass spectrometry, revealed some interesting homologies with a fungal hydrophobin of Pleurotus ostreatus and an ABC transporter of Ralstonia metallidurans. These could represent molecular factors involved in the antagonistic mechanisms of Trichoderma and play a role in the three-way interaction with the plant and other microbes.

Comparative Toxicity of Selected Insecticides to Phytoplasma Transmitted Leafhopper Cicadulina bipunctata （Melichar）

Leafhopper Cicadulina bipunctata is represented the main insect as a pathogen for phytoplasma disease occurring by insect-transmitted plant viruses in date palm orchards. Therefore, it is important to investigate the potential effect of some insecticides against such insect. The adults of leafhopper C. bipunctata were collected from date palm orchards in Alhasa, Eastern province, Saudi Arabia. Three insecticides from different classes--beta-cyfluthrin （pyrethroids）, imidacloprid （neonicotinoids） and abamectin （natural compounds）--have been evaluated in vivo against adults C. bipunctata. This stage was exposed to residual film of various concentrations of each insecticide on transparent plastic cups using a Potter precision laboratory spray tower. Bioassay test showed that both beta-cyfluthrin and imidacloprid caused 100% mortality by 500 ppm at 24 h after treatment, whereas abamectin gave the same mortality by 50 ppm at the same time. Toxicity values revealed that abameetin was the most potent insecticide compared with beta-cyfluthrin and imidacloprid, where the lethal concentrations LC50 and LC95 were 24.58 ppm and 116.73 ppm at 3 h after treatment, respectively. Therefore, abamectin can be a possible candidate to be applied on date palm or ground grass by the Ministry of Agriculture after successful field experiments.

Alteration in Biochemical Response in Sesamum indicum upon Different Plant-Pathogen Interactions

Sesamum, an important oil yielding crop suffers a huge loss in its yield due to attack of large number of fungal pathogens. In semi-arid regions Sesamum is mainly affected by two major plant-pathogenic fungus viz. Macrophomina phaseolina and Fusarium oxysporum. The aim of the study was to analyze the metabolic alterations in Sesamum after infection with both pathogens. This accomplished by individually by （the word estimating is not quantitative） the levels of total phenolic compounds and the activities of phenylalanine ammonia lyase （PAL） of one week old plants. The PAL showed high activity in infected plants, revealing the active phase in the synthesis of secondary metabolites in the Sesamum plant after infection. As a consequence, in infected plants the contents of polyphenols along with salicylic acid （SA） considerably exceeded when compared to control plants. This in vivo study of M. phaseolina and F. oxysporum infection reveals the differences of resistance levels in sesame against these two pathogens. These results provide important information regarding the plant-pathogen interactions and also forfor Sesamum improvement programs seeking the adaptation to diverse range of fungal attack along with adverse environmental factors.

Use of random amplified polymorphic DNA （RAPD） analysis to detect jujube witches＇ broom phytoplasmas

Jujube witches＇ broom is a devastating disease of Ziziphusjujube that occurs in various jujube regions of China. Nucleic acid extracted from midribs of samples collected from three jujube varieties （＂Suanzao＂, ＂Lajiaozao＂ and ＂Langzao＂） from symptomatic and asymptomatic shoots were tested by random amplified polymorphic DNA analyses. Using 13 different 10 and 11-bp random primers the amplification of jujube DNA was achieved from all the samples; AMI4 primer provided amplification of specific DNA fragments of about 400 bp, only from samples collected from symptomatic plants. No genetic variations in these varieties were identified using the other 11 arbitrary primers; only with primer AL07 it was possible to differentiate ＂Langzao＂ from the other two varieties tested. All the experiments were repeated 2 times and the results were consistent. Compared with PCR analyses with phytoplasma-specific primers, RAPD techniques resulted to be an alternative rapid and sensitive method for detecting jujube phytoplasmas presence in different jujube varieties.

The keratin intermediate filament-like system in maize protoplasts

The application of Penman's method of cell fractionation to plant protoplasts leads to our finding of keratin intermediate filament(IF)-like system in maize protoplasts,which was identified by using immunogold labelling with monoclonal antibody of cytokeratin from animal cells.Many gold particles were found to be bound on filaments,linked by 3 nm filaments.After further digestion and extraction with DNase I and ammonium sulphate.IF-like framework-lamina-nuclear matrix system was shown under electron microscope.That IF system exists in plant protoplasts just like in animal cells,and their main component is keratin-like protein.

Evaluation of Endophytic Bacteria for Plant Growth Promotion and Pathogen Suppression Traits in Saccharum officinarum

Endophytes are beneficial microbes that are capable of promoting growth, besides protecting colonized plants against plant pathogens. These microbes are of either bacterial, fungal or actinomycetes in plants. In the study, the endophytic bacteria isolated from sugarcane with their characterization related to plant growth promotion and pathogen suppression have been reported. Roots, shoots and leaves of rooted tissue culture plantlets of sugarcane cultivars of 87A298 and 2009A107 were excised aseptically and isolated endophytic bacterial strains. The strains were identified using 16S rRNA gene sequence based homology. Molecular characterization of these strains was carried out for presence of antimicrobial genes. The results showed that the endophytes isolated from sugarcane tissue culture plantlets were of the genera Bacillus （B. amyloliquefaciens, B. subtilis, B. cereus, B. safensis, B. siamensis, B. aryabhattai, B. flexus and B. velezensis） and Paenibacillus pabuli. There were three antimicrobial peptides （AMPs） producing genes of bacilysin, bacillomycin and fengycin in B. amyloliquefaciens （SE1, SE7）, B. siamensis （SE4, SE16）, B. subtilis （SE2, SE3） and B. velezensis （SE15）. The biochemical characterization assays showed that some of these strains could produce hydrogen cyanide （HCN）, protease, cellulase and indole acetic acid （IAA）. Few strains （SE1 and SE4） were phosphate solubilizers, whereas nine isolates were found to be diazotrophs. Most of the bacterial isolates were found antagonistic to Fusarium sacchari, the sugarcane wilt pathogen under in vitro conditions. Overall, the results suggested the scope and potentiality of sugarcane endophytic bacteria, isolated from tissue culture plantlets, in promoting plant growth and suppression of sugarcane pathogen.

Optimization the Cell Wall Degrading Enzymes and Technique for Isolation of Protoplasts in Potato

Plasma membrane of plant cells is surrounded by cellulose wall and adjacent cells are joined together by a thick pectin rich matrix. Separation of plant cells and removal of the cell wall experimentally, by either a mechanical or an enzymatic process, results in the production ofprotoplast. Protoplasts are useful tools to study the uptake and transport ofmacromolecules and production of somatic hybrids. Protoplasts can be obtained from all types of actively growing young and healthy tissues. The most convenient and widely used source of plant protoplasts is leaf. Juvenile seedling tissues, cotyledons are other alternative tissues most frequently used for protoplasts isolation. All the environmental and genotypic factors, which affect the cell wall thickenings and compactness indirectly, influence the number of protoplasts recovered. Protoplasts are isolated by two methods, mechanical and enzymatic. The enzyme mixture solution of celluiose/macerozyme is used to digest the cell wall. The critical factors affecting the obtaning ofprotoplasts are the kinds of cell wall degrading enzymes, the physiological state of plant leaves, the type of osmotic stabilizers and the composition of reaction solution. With the improvement of technique and enzyme combination rate, the yield of collected protoplasts will be increased higher.

Clustering and Expression Analysis of Chitinases in Maize and Rice

Chitinases play an important role in regulating plant growth and development, especially defending themselves from fungal pathogens. It is important to do the biological analyses in crops. In this study, the result showed that the chitinases were distributed into the whole genome in rice, and nearly the whole genome in maize expect for Chromosome 9. The clustering results showed that one out of three chitinases from maize and rice belonged to new groups, which were separated from those in the conformed Classes I-VII. The identification of most amino acid sequences was very low among the chitinases from rice and/or maize. It was inferred that the chitinases with different functions were relatively stable during plant evolution. The relationship of chitinases expression between leaf blade and anther was positively significant in maize, but not significant in rice. Additionally, the ratio of chitinases with up- or down-regulated expression in sensitive maize under Fusarium moniliforme inoculation was different from that in sensitive rice under Magnaporthe grisea inoculation. It might be result from different tissues infected by different fungi. The number of chitinases from resistant maize was less than that from sensitive maize, which inferred that the resistant pathways on F. moniliforme should be not only chitin induced Pathogen-associated molecular PTI （patterns-triggered immunity） pathway, but also might include other PTI pathways that improve tolerance to F. moniliforme. The analysis of expression pattern of chitinases from maize and rice under fungi inoculation will be contributed into further research on the defense mechanism of fungi in crops.

Adoptive transfer of T cells transduced with a chimeric antigen receptor to treat relapsed or refractory acute leukemia: efficacy and feasibility of immunotherapy approaches

Treatment outcomes of acute leukemia(AL) have not improved over the past several decades and relapse rates remain high despite the availability of aggressive therapies. Conventional relapsed leukemia treatment includes second allogeneic hematopoietic stem cell transplantation(allo-HSCT) and donor lymphocyte infusion(DLI), which in most cases mediate, at best, a modest graft-versus-leukemia effect, although their clinical efficacy is still limited. Although allo-HSCT following myeloablative conditioning is a curative treatment option for younger patients with acute myeloid leukemia(AML) in a first complete remission(CR), allo-HSCT as a clinical treatment is usually limited because of treatment-related toxicity. The overall DLI remission rate is only 15%–42% and 2-year overall survival(OS) is approximately 15%–20%, with a high(40%–60%) incidence of DLI-related graft-versus-host disease(GVHD). Therefore, development of new, targeted treatment strategies for relapsed and refractory AL patients is ongoing. Adoptive transfer of T cells with genetically engineered chimeric antigen receptors(CARs) is an encouraging approach for treating hematological malignancies. These T cells are capable of selectively recognizing tumor-associated antigens and may overcome many limitations of conventional therapies, inducing remission in patients with chemotherapy-refractory or relapsed AL. In this review, we aimed to highlight the current understanding of this promising treatment modality, discussing its adverse effects and efficacy.

The role of soil-borne fungi in driving the coexistence of Pinus massoniana and Lithocarpus glaber in a subtropical forest via plant-soil feedback

Aims Plant–soil feedback(PSF)is a key mechanism that can facilitate tree species coexistence and diversity.Substantial evidence suggests that species-specific soil-borne pathogens around adult trees limit the performance of home(conspecific)seedlings relative to foreign(heterospecific)seedlings.However,the underlying mechanism remains largely elusive.Methods Here,we conducted a reciprocal transplant pot experiment using seedlings and from two tree species,Pinus massoniana and Lithocarpus glaber that are dominant and coexist in a subtropical,evergreen,broad-leaf forest in Gutianshan,Zhejiang Province of eastern China.We examined how seedlings from the two tree species responded to soils originating from underneath their own versus the other tree species,using a full-factorial design.Additionally,we added a fungicide(benomyl)to half of the pots to evaluate the role of soil-borne fungi on seedling growth.Important Findings We found that the seedlings from L.glaber grew better in soils that were collected from beneath the canopy of P.massoniana,while seedling growth of P.massioniana was not affected by soil origin.The addition of fungicide benomyl resulted in a shift towards more positive PSF effects for L.glaber,indicating that L.glaber seedlings performed better in their own soils than in soils from P.massoniana in the absence of fungi.Our findings highlight the importance of soil-borne pathogenic and ectomycorrhizal fungi in driving PSF,and indicate that PSF may promote the coexistence of two subtropical tree species by reducing the performance of L.glaber in own soils.