Age-related resistance to Pseudomonas syringae pv. tomato is associated with the transition to flowering in Arabidopsis and is effective against Peronospora parasitica     

C. Rusterucci  Z. Zhao  K. Haines  D. Mellersh  M. Neumann  R.K. Cameron   《Physiological and Molecular Plant Pathology》2005,66(6):120

As plants mature it has been observed that some become more resistant to normally virulent pathogens. The ability to manifest the Age-Related Resistance (ARR) response in Arabidopsis to Pseudomonas syringae pathovars tomato (Pst) coincided with the transition to flowering in plants both delayed and accelerated in the transition to flowering. ARR was also associated with a change in PR-1 gene expression, such that young plants expressed PR-1 abundantly at 3 days post inoculation (dpi) while mature plants expressed much less. The Arabidopsis ARR response requires SA accumulation via isochorismate synthase (ICS1) [24]. ICS1 was expressed one dpi with virulent and avirulent Pst in both young and mature plants. The ARR response was also effective versus avirulent Pst providing an additional 4-fold limitation in bacterial growth. Arabidopsis ARR was found to be ineffective against two necrotrophs, Erwinia carotovora subspecies carotovora (bacterium) and Botrytis cinerea (fungus) and one obligate biotroph, Erysiphe cichoracearum (fungus). However, mature wild type, SA-deficient sid2 and NahG plants supported little growth of the obligate biotrophic oomycete, Peronospora parasitica. Therefore ARR to P. parasitica appears to be SA-independent, however the level of ARR resistance was somewhat reduced in these mutants in some experiments. Thus, there may be numerous defence pathways that contribute to adult plant resistance in Arabidopsis.  相似文献   

大白菜软腐病菌游动性突变体在大白菜体内增殖扩展研究     

宋从凤  潘小玫  陆萍  王金生 《植物病理学报》2002,32(2):165-169

 用培养皿滤纸吸附测定法和不伤根土壤拌菌处理及针刺接种法,测定了大白菜软腐病菌游动性突变体进入大白菜体内、并在其中侵染定殖和扩展的特性。结果表明,游动性丧失和增强的突变体都可以通过种子萌发和主动接触进入大白菜体内、并可以在体内有短期的繁殖,但菌量远低于野生菌。大白菜叶片接种实验说明,这两种突变体也都可以进行短距离扩展,但扩展距离和菌的繁殖量低于野生菌。  相似文献   

Phenotypic and genetic characterization of Erwinia carotovora from mulberry (Morus spp.)     

S. T. Seo  N. Furuya  C. K. Lim  Y. Takanami  K. Tsuchiya † 《Plant pathology》2003,52(2):140-146

Phenotypic and genetic characteristics of nine bacterial strains isolated from mulberry ( Morus spp.), which were originally described as Erwinia carotovora ssp. carotovora (Ecc), were investigated. Based on the results of biochemical tests, these bacterial strains were divided into two different types, type 1 and type 2. Two strains of type 1 were similar to Ecc, whereas seven strains of type 2 were distinct from Ecc. A polyphasic study that included serological assay, specific PCR assay for E. carotovora ssp. atroseptica (Eca), PCR-RFLP of a pectate lyase ( pel ) gene and RAPD-PCR was performed on the type 2 strains, and the data were compared with those of related E. carotovora subspecies. The results of serological and specific PCR assays for Eca showed that the type 2 strains were distinct from Eca. In RFLP analysis of the pel gene using Sau 3AI, the type 2 strains showed a unique RFLP pattern. On the basis of RAPD analysis, similarity of RAPD patterns within the type 2 strains was very high. A unique RAPD fragment was isolated from the type 2 strains and used as a probe for Southern hybridization. This probe hybridized only with PCR products from the type 2 strains. Based on phenotypic, serological and genetic characteristics, the type 2 strains isolated from mulberry may belong to a distinct E. carotovora subspecies other than Eca or Ecc.  相似文献   

Relationship between potato seed tuber contamination by Erwinia carotovora ssp. atroseptica, blackleg disease development and progeny tuber contamination     

I. K. Toth†  L. Sullivan  J. L. Brierley  A. O. Avrova  L. J. Hyman  M. Holeva  L. Broadfoot  M. C. M. Pérombelon  J. McNicol 《Plant pathology》2003,52(2):119-126

  相似文献   

Homolog of FlhDC, a master regulator for flagellum synthesis: required for pathogenicity in Erwinia carotovora subsp. carotovora     

Hiroyuki Matsumoto  Masahiro Umehara  Hironobu Muroi  Yoshimasa Yoshitake  Shinji Tsuyumu 《Journal of General Plant Pathology》2003,69(3):189-193

 Erwinia carotovora subsp. carotovora (Ecc) is a causal agent of soft-rot diseases in a wide variety of plants. Here, we have isolated nonmotile mutants in Ecc by in vivo insertional mutagenesis using a transposon Tn5. The sequence disrupted by the Tn5 insertion in YMU1 and YMU5 mutants was highly homologous to that of flhC and flhD genes, respectively. They are involved in the initiation of the expression of flagellum-related genes in many gram-negative bacteria such as Escherichia coli and Salmonella. With electron microscopy, the flhC and the flhD homolog mutants were shown to be aflagellate. Furthermore, the virulence of these mutants was greatly reduced in Chinese cabbage and potato compared to that of the parental strain. These results suggest that flagellar formation is required for the pathogenicity of Ecc. Received: November 5, 2002 / Accepted: December 2, 2002 Acknowledgments This research was supported in part by Grant-in-Aid (12052210) and by a grant from the Ministry of Education, Culture, Sports, Science, and Technology of Japan (13073).  相似文献   

菌株Bacillus sp.CLb芽孢漆酶对染料、模拟染料废水脱色的研究     

李凡姝  刘海洋  范丽莉  王天女  戴绍军  赵敏  汪春蕾 《安徽农业科学》2014,(15):4569-4572

[目的]研究芽孢杆菌菌株CLb的芽孢漆酶在介体的互作下对不同类型的染料及模拟染料废水的脱色效果。[方法]制备芽孢粗酶液,在介体的互作下,测定具有漆酶活性的粗酶液对活性亮蓝、活性黑、靛红和结晶紫的脱色效果,筛选出对染料脱色有促进作用的漆酶介体,并且研究芽孢漆酶在不同pH条件下对染料和模拟染料废水脱色的影响。[结果]菌株CLb的芽孢漆酶在无介体参与下只能使活性亮蓝和结晶紫脱色。在介体乙酰丁香酮（ACE）的作用下,芽孢漆酶对4种染料的脱色率均超过70%。在pH 7.0条件下,芽孢漆酶浓度为44.74 U/L和介体ACE浓度为1 mmol/L时对模拟染料废水的脱色效果最好,6 h脱色率超过80%。在介体乙酰丁香酮存在,pH 7.0的条件下,菌株CLb的芽孢漆酶对合成染料脱色效率高于pH 9.0时的脱色率。[结论]在介体乙酰丁香酮的存在下,芽孢漆酶对染料和模拟染料废水均具有较好的脱色效果。  相似文献   

大白菜软腐病苗期抗性及其与成株期抗性的关系   总被引：4，自引：0，他引：4  

张学君  张斌 《华北农学报》1995,10(3):80-83

对６６个大白菜品种苗期抗性的测定结果表明，不同品种对细菌根系侵入和潜伏侵染的抗性存在显著差别；同一品种幼苗对侵入侵染的抗性与对潜伏侵染的抗性间没有相关性。幼苗期的组织含菌量与成株的田间软腐病发病程度有一定的相关性。并初步建立了大白菜对软腐病苗期抗性的鉴定方法。  相似文献   

A morphological approach to understanding preferential flow using image analysis with dye tracers and X-ray Computed Tomography   总被引：1，自引：0，他引：1  

Sacha J. Mooney  Catherine Morris 《CATENA》2008

A key problem facing soil physics and hydropedology at present is some of the standard theories of water flow in soils do not fully reflect the processes at the pore scale, and thus, cannot be adequately used for prediction. As such, examination of soil structure is vital for hydropedologists. Realisation that solutes move preferentially through soil into groundwaters has meant research in this area has increased in importance. This paper describes a multi-scale approach to analyse transport mechanisms using visualisation techniques. Chloride and Brilliant Blue tracers were applied to undisturbed soil cores to examine the physical and morphological properties associated with preferential flow in a range of soil types. Following collection of serial digital images, it was possible to examine and quantify the nature of active water flow mechanisms in terms of both dye-stained pathways and spatial distribution of dye concentration, using image analysis. Preferential flow linked to water potential and soil structural discontinuity was observed in all but the coarsest textured soil which conformed to uniform flow theory. A high level of variability in flow patterns was noted between the soil types. Such information as to how a soil dynamically re-wets is key for hydropedologists involved in applications such as pollution modelling. This is especially significant when considering a wetting mechanism, such as preferential flow, that cannot be adequately described by conventional soil physics.  相似文献   

opaque-2玉米近等基因系的构建与赖氨酸含量快速检测   总被引：2，自引：0，他引：2  

陈岩  宋丽雅  周志强  张德贵  颜娜  张世煌  李新海  郝转芳  翁建峰  白丽  李明顺 《作物学报》2013,39(9):1530-1537

我国高赖氨酸玉米种质资源狭窄,opaque-2(o2)突变基因能大幅提高玉米赖氨酸含量,通过分子标记辅助选择构建o2玉米近等基因系并检测其赖氨酸含量具有重要意义。其中,要解决的两个关键问题是如何准确地将不同供体的o2突变基因导入受体系和如何快速地检测导入系的赖氨酸含量。本研究利用O2基因内紧密连锁的SSR共显性标记引物phi057检测玉米供体和受体自交系的多态性,利用其特异性和共显性构建o2近等基因系;参考已有研究,改进染料结合(DBL)法,测定18组构建成功的o2近等基因系的赖氨酸含量。结果表明,不仅在不同供体(CA339和山东2548)之间存在多态性,而且在不同受体系间也存在多态性,利用phi057能够成功地将不同供体的o2突变基因导入受体系,构建o2近等基因系;改进的DBL法分析表明,不同受体系赖氨酸含量变化较大,不同背景的受体系导入o2突变基因后赖氨酸含量增加的幅度差异也较大;普通玉米自交系间赖氨酸含量为0.223%~0.368%,构建成功的不同o2近等基因系间,赖氨酸含量为0.373%~0.527%,与受体亲本相比,赖氨酸增加幅度最低为13%,最高为74%。分析表明,phi057能准确筛选导入o2突变基因的受体系,结合改进的DBL法能快速地选择赖氨酸含量高的玉米。  相似文献   

A 9-year monitoring study of diseases on potato seed tubers imported to Israel     

Leah Tsror  A. Nachmias  Orly Erlich  M. Aharon  M. C. M. Pérombelon 《Phytoparasitica》1993,21(4):321-328

Potato seed tubers are imported annually to Israel from northern Europe. Although the seed is registered as certified, a survey carried out over a 9-year period indicated that most lots were affected by latent or active bacterial and fungal infections. Latent infection byErwinia carotovora subsp.atroseptica, the causal agent of blackleg, at a level of 10³ cells/g peel, was present in 30% of the lots in most years. Black scurf caused byRhizoctonia solani was present in 20–70% of the imported lots, with a moderate to high level of infection in all years except 1985. In contrast, although many lots were affected by powdery scab, common scab, and Fusarium dry rot in most years, disease incidence within lots was generally low. The gangrene pathogen (Phoma exigua) was rarely detected. The survey findings are of marked importance, due to the extensive use of soil fumigation in Israeli agriculture.  相似文献