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几丁质酶是一种分解N-乙酰氨基葡萄糖分子的糖苷酶。在高等植物中，几丁质酶虽然普遍存在，但迄今未发现其底物的存在。据研究，几丁质酶在植物抗病机制中起重要作用。近年来，通过对橡胶胶乳中几丁质酶的研究，认识到它不仅是橡胶树防御病原微生物的抗病系统的重要组成部分，而且还参加了胶乳的凝固过程，与橡胶树的排胶及产量具有密切的关系。文章概述了几丁质酶研究的现状及最新进展，介绍了橡胶树胶乳中几丁质酶的理化性质、生理学功能、在细胞中的定位及其调控。 相似文献
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多基因转化是基因工程研究热点之一。本研究应用DNA重组技术,将两个抗病机制不同,抗菌谱较广的抗病基因(天麻抗真菌蛋白GAFP和兔防御素NP1基因)构建在一个植物表达载体pBin35SGAFP-NP1上,两者具有各自的CaMV35S启动子和Nos终止子。通过根癌农杆菌介导,采用叶盘法转化烟草,PCR和PCR-Southern分析证明已将NP1和GAFP基因整合到烟草基因组中。离体抑菌实验表明转基因植株对真菌和细菌表现出一定的抗性。以上结果表明通过该表达载体进行遗传转化可获得含双价抗病基因植物,并能有效表达,提高转基因植物抗病能力。 相似文献
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反义磷脂酶Dγ基因与几丁质酶基因转化美洲黑杨G2 总被引：5，自引：1，他引：4
建立美洲黑杨G2组培再生体系,确立美洲黑杨G2分化最适宜培养基和生根培养基.然后分别进行卡那霉素和潮霉素敏感性试验,利用叶盘法依次将反义磷脂酶Dγ(Anti-PLDγ)基因和几丁质酶(CH5B)基因转入美洲黑杨G2中.首先转入反义磷脂酶Dγ基因,经诱导不定芽及生根阶段卡那霉素(选择性抗生素)连续筛选,获得了21株卡那霉素抗性植株.抗性植株经PCR及PCR-Southern杂交检测,有13株均呈阳性,证明Anti-PLDγ基因成功整合到美洲黑杨G2基因组中.耐盐性试验表明,4株转基因植株抗NaCl能力比对照都有不同程度提高.选择4号株系继续转入几丁质酶基因,通过潮霉素(选择性抗生素)筛选不定芽及诱导生根获6株潮霉素抗性植株,经PCR及PCR-Southern杂交检测,6株均呈阳性,证明CH5B基因成功整合到美洲黑杨G2基因组中.由于CH5B基因与报告基因GUS处于同一开放阅读框(ORF)内,因此通过GUS基因的组织化学染色分析,证明了6株转化植株几丁质酶基因均获得正常表达. 相似文献
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蜡梅几丁质酶基因的克隆与原核表达 总被引：2，自引：1，他引：1
在构建好蜡梅花cDNA文库并进行EST分析基础上,通过随机克隆测序,得到1个蜡梅几丁质酶的cDNA基因,命名为Cpchia(GenBank登录号:FJ749130).Cpchia cDNA全长为1 184 bp,开放阅读框为954 bp,编码317个氨基酸,其结构包括信号肽、几丁质结合域、可变交联区、催化区,无C端延伸区,为Class Ⅰ b型胞外几丁质酶,属于几丁质酶第19家族.将Cpchia克隆到原核表达载体pET-28a(+),在大肠杆菌BL21细胞中以包涵体形式表达融合蛋白,利用透析法获得复性蛋白,其几丁质酶活性经DNS法检测达到200 U·mL~(-1).酶活性和稳定性分析表明,试验条件下,pH 7.0有利于酶的稳定和活性发挥,40 ℃活性最高,在0 ℃低温下也有较高活性.上述结果说明,分离的Cpchia基因编码蛋白具有几丁质酶活性,而且可能与蜡梅花的抗寒性形成有关. 相似文献
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从自然环境中,筛选出了高效降解几丁质的菌株,同时也具有广谱的杀虫潜能的菌株,为植物病虫害的防治提供一个新思路。以武汉沙湖边的水样为材料,经过富集培养、初筛和复筛后,筛选到一株高效降解几丁质的菌株,并对菌株进行生理生化和16srDNA鉴定,同时测定了产生的几丁质酶的活力,探讨了菌的发酵液对真菌的拮抗作用和毒杀秀丽隐杆线虫作用。从水样中筛选到一株能够在pH7和pH11的1%胶体几丁质平板上有明显水解圈的菌株,经生理生化和16srDNA鉴定,该菌为粘质沙雷氏菌,命名为MEW06。经摇瓶培养后,测得该菌株发酵上清液的几丁质酶活力可达75U/mL。该菌能抑制苹果轮纹菌和草莓灰霉真菌的生长,并能毒杀秀丽隐杆线虫。MEW06菌株能分泌高活性的几丁质酶,该酶具有广谱的pH值作用范围,同时具有杀菌杀虫作用,因此在植物生物防治方面有很好的应用前景。 相似文献
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利用转基因技术将多种抗病基因共同转入毛白杨中以提高其抗性,从而获得毛白杨抗病新品种是目前解决杨树真菌病害的主要研究方向之一。本研究通过根癌农杆菌介导的二次遗传转化,将来源于球孢白僵菌几丁质酶基因Bbchit1转入过量表达无色花色素还原酶基因LAR3转基因毛白杨中,实时定量PCR显示Bbchit1与LAR3均能有效表达,离体抗病试验显示Bbchit1+LAR3共表达转基因毛白杨细胞粗提液对杨树叶枯病菌具有明显抑制作用,进一步将叶枯病菌接种在转基因和非转基因毛白杨叶片上培养30天,转基因植株的感病面积均低于非转基因植株且Bbchit1+LAR3共表达转基因株系抗病效果更明显。上述抗病试验结果表明:LAR3和Bbchit1在杨树中共表达可提高其对叶枯病的抗性。 相似文献
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Korean spruce(Picea koraiensis Sieb. El Zucc.)is one of the main afforestation species in northern China.Seedling quality is a critical factor at planting time. To test whether the synergistic growth enhancement of Scotch pine(P. sylvestris var. mongolica) seedlings brought by the plant beneficial fungus Trichoderma virens(J.H. Mill., Giddens and A.A. Foster) Arx and ectomycorrhizal fungus(Suillus luteus(L.) Roussel.) can also benefit Korean spruce seedlings, we examined the effects of S. luteus and T. virens on the growth of P. koraiensis seedlings and drought resistance of P. sylvestris var. mongolica in peat soils. The two fungi were added to sterilized peat soil in pots, and the plants were grown for 4 months. Seedling growth and physiological variables, including mycorrhizal colonization rate of roots,biomass, and chlorophyll content, were examined. The colonization rate of the mycorrhizal fungus on P. koraiensis exceeded 65 %, and the synergism between S. luteus and T.virens enhanced most of the variables for P. koraiensis seedlings after inoculation with S. luteus then 30 days later with T. virens as in our published results for seedlings of P.sylvestris var. mongolica. When seedlings of P. sylvestris var. mongolica were inoculated with this sequence, they became more drought tolerant. T. virens also induced S.luteus to produce-1,3-glucanase and chitinase. This inoculation sequence at planting can thus improve the quality of P. sylvestris var. mongolica and P. koraiensis seedlings and substantiates our previous results. 相似文献
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We studied the defense reactions of 33-year-old susceptible and resistant clones of Norway spruce (Picea abies (L.) Karst.) to the major root-rot fungus Heterobasidion annosum (Fr.) Bref. and determined if tissue cultures can be used as a model system for studying defense responses of mature trees at the molecular level. Quantitative PCR analysis of genomic DNA obtained from samples taken at different times along the lesion length in living bark indicated that the fungus was present in higher amounts and extended further into the host tissue in the susceptible clone than in the resistant clone. In protein extracts from the same lesion samples, there were differences in temporal and spatial changes in host chitinase isoform profiles between the resistant and susceptible clones. Host chitinase isoforms with pI values approximately 4.8, 4.4 and 3.7 increased more during the first 7 days after wounding and inoculation and extended further along the lesion length in the resistant clone than in the susceptible clone. These results suggest that the time from wounding and infection to induction of defense-related expression is shorter in the resistant clone indicating a more efficient host defense response than in the susceptible clone. Tissue cultures from the same clones were not resistant to H. annosum and showed no difference in the timing of the increase in chitinase isoforms in response to the pathogen. However, tissue cultures from both clones showed an increase in chitinase isoforms within 6 to 24 h past inoculation, indicating that increased chitinase expression in response to the pathogen is part of a general defense response common to both mature clones and tissue cultures. 相似文献
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S. Xenopoulos 《Forest Pathology》1982,12(6):316-326
Chestnut blight in Greece occurred since its beginning in a mild form, causing superficial cankers with callus formation, a low production of pycnidia and very slow distribution, even though the strain of this fungus has shown to be virulent. It was concluded that this mild form of the disease is due to a combination of resistance of the chestnut trees and unfavourable local climatic conditions for the development of the fungus. 相似文献
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本研究以木材蓝变生物控制菌康氏木霉(6111-ET)为供试菌株进行胞外几丁质酶纯化和特性的研究.将液态PDA培养基中的康氏木霉(Trichoderma koningii)置于恒温播床(200 r/min,28℃)培养10天.培养滤液经过硫酸铵分级沉淀、Q-HP强阴离子交换柱层析、Phenyl-Sepharose疏水层析... 相似文献
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系统研究了碳源、氮源、温度、起始pH值、培养基装量和接种量等因素对绿粘帚霉(Gliocladium virens)F051产几丁质酶的影响。结果表明,碳、氮源分别为麦芽糖和酵母粉最好,并通过正交试验法优化了发酵条件。优化后的产酶条件为:温度为28℃,pH值7,瓶装量为100 ml,每100 ml接种1 ml孢悬液,且碳源和氮源的量分别为1.5%和0.2%。从时间对菌丝生长和几丁质酶活的影响来看,培养第4天酶活便达到最高。在此基础上探索了几丁质对病原菌细胞壁的作用,结果显示,该几丁质酶粗酶液对3种病原真菌细胞壁有一定的降解效果,使病原真菌出现细胞壁变薄、断裂,质壁分离,原生质空泡等现象。 相似文献
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The fungus Brunchorstia pinea Karst. v. H. is found to be consistentlyassociated with early stages of dieback disease in a numberof pine species. Inoculation of buds with conidial suspensions of the funguscauses typical disease symptoms to develop. The proportion ofsuccessful inoculations depends on the time of year, the locationof the tree, and its physiological condition. Vigorous treesare able to avoid infection, while weaker trees are very susceptibleto attack. It is suggested that though infection depends on low host resistance,Brunchorstia must be considered a primary pathogen since inall probability trees would survive and produce a crop wereit not for the activities of the fungus. 相似文献
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Nilmara P. Caires Pollyane S. Hermenegildo Lúcio M. S. Guimares Reginaldo G. Mafia Edival . V. Zauza Norton Borges Júnior Jorge L. Badel Acelino C. Alfenas 《Forest Pathology》2019,49(4)
Dieback caused by Erwinia psidii is currently one of the most important emerging diseases in eucalypt plantations in Brazil. However, little is known in terms of the host range of this pathogen or the potential sources of resistance against the disease it causes. In this study, we inoculated plants of species from nine families to gain insight into the host range of E. psidii. Plants of all inoculated species of Myrtaceae except Acca sellowiana exhibited disease symptoms and therefore represent potential hosts for the pathogen under natural conditions. In addition, the response of four Corymbia species, 29 Eucalyptus species and three interspecific Eucalyptus hybrids to inoculation with E. psidii was evaluated. All Corymbia henryi, Corymbia maculata, Eucalyptus thozetiana, Eucalyptus cloeziana, Eucalyptus viminalis, Eucalyptus dalrympleana and Eucalyptus pilularis plants were highly resistant to the pathogen, whereas differential disease resistance was observed in the other species. This study provides important information on sources of resistance to Erwinia psidii with potential use in the development of clones with enhanced resistance in eucalypt species of economic importance. 相似文献
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This paper reports a successful transformation of chitinase gene into Populus simonii×P. nigra by Agrobacterium-mediated means. For reducing adventitious buds,the optimal concentration of kanamycin was 40 mg·L~ -1 . Up to 700 mg·L~ -1 of Cefazolin Sodium had no obvious effect on differentiation of leaves. About 20-day-old leaf disc explants were pre-cultured for 3-4 d,then immersed in Agrobacterium suspension for infection for 6-15 min,then co-cultured on non-selection culture medium for 3 d in the dark at ... 相似文献
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In recent years, a considerable number of studies have harnessed the power of genomics to decipher the role of pathogenesis‐related (PR) proteins in plant defence against various biotic and abiotic stresses. Chitinases are PR antifungal proteins expressed constitutively at low levels in plants and induced during biotic pressures and are demonstrated to be involved in the plant defence responses. Remarkable induction of chitinase enzymes by various abiotic agents (salicylic acid, jasmonic acid, ethylene and ozone) and biotic components (pathogens, insect pest, fungal cell wall components and oligosaccharides) is well demonstrated in plants. Several reviews on plant chitinase expression during host–pathogen interaction are available for annual species, whilst reports of their expression in tree species are limited to a few woody perennials: Populus, Pinus, Picea, Eucalyptus, Castanea and Pseudotsuga. The aim of this paper is to review the induction of chitinase during various stresses and developmental processes in forest tree species. 相似文献