共查询到20条相似文献，搜索用时 328 毫秒
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Pamela Paparu Thomas Dubois Danny Coyne Altus Viljoen 《Physiological and Molecular Plant Pathology》2007,71(4-6):149-157
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Tika B. Adhikari Boovaraghan Balaji Jill Breeden Stephen B. Goodwin 《Physiological and Molecular Plant Pathology》2007,71(1-3):55-68
Large-scale cDNA-AFLP profiling identified numerous genes with increased expression during the resistance response of wheat to the Septoria tritici blotch fungus, Mycosphaerella graminicola. To test whether these genes were associated with resistance responses, primers were designed for the 14 that were most strongly up-regulated, and their levels of expression were measured at 12 time points from 0 to 27 days after inoculation (DAI) in two resistant and two susceptible cultivars of wheat by real-time quantitative polymerase chain reaction. None of these genes was expressed constitutively in the resistant wheat cultivars. Instead, infection of wheat by M. graminicola induced changes in expression of each gene in both resistant and susceptible cultivars over time. The four genes chitinase, phenylalanine ammonia lyase, pathogenesis-related protein PR-1, and peroxidase were induced from about 10- to 60-fold at early stages (3 h–1 DAI) during the incompatible interactions but were not expressed at later time points. Nine other genes (ATPase, brassinosteroid-6-oxidase, peptidylprolyl isomerase, peroxidase 2, 40S ribosomal protein, ADP-glucose pyrophosphorylase, putative protease inhibitor, methionine sulfoxide reductase, and an RNase S-like protein precursor) had bimodal patterns with both early (1–3 DAI) and late (12–24 DAI) peaks of expression in at least one of the resistant cultivars, but low if any induction in the two susceptible cultivars. The remaining gene (a serine carboxypeptidase) had a trimodal pattern of expression in the resistant cultivar Tadinia. These results indicate that the resistance response of wheat to M. graminicola is not completed during the first 24 h after contact with the pathogen, as thought previously, but instead can extend into the period from 18 to 24 DAI when fungal growth increases dramatically in compatible interactions. Many of these genes have a possible function in signal transduction or possibly as regulatory elements. Expression of the PR-1 gene at 12 h after inoculation was much higher in resistant compared to susceptible recombinant-inbred lines (RILs) segregating for the Stb4 and Stb8 genes for resistance. Therefore, analysis of gene expression could provide a faster method for separating resistant from susceptible lines in research programs. Significant differential expression patterns of the defense-related genes between the resistant and susceptible wheat cultivars and RILs after inoculation with M. graminicola suggest that these genes may play a major role in the resistance mechanisms of wheat. 相似文献
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染色质重塑因子INO80是一类由多亚基构成的遗传学调控因子，调控多种DNA代谢，在基因的表达中发挥着重要的调控功能。但其在苹果树腐烂病菌（Valsa mali）中是否存在及其生物学功能并不清楚，为此，本研究从病菌基因组中分析鉴定到INO80的一个亚基基因Vmles4，利用qRT-PCR技术分析了Vmles4在病菌侵染过程中的表达模式，利用Double-joint PCR技术和PEG介导的原生质体转化方法进行了基因敲除，然后对3个突变体的营养生长及致病力进行测定和分析，并对病菌的非核糖体肽合成酶基因VmNRPS12及VmNRPS14在突变体中的表达进行定量分析。结果表明：Vmles4在侵染初期的表达显著上调，接种后6 h上调表达6.2倍。敲除突变体的生长速率平均降低28%且菌丝生长稀疏，在富士苹果品种（Malus domestic cv. Fuji）叶片和枝条上的致病力分别降低到22.5%和27.5%，VmNRPS12及VmNRPS14基因在Vmles4突变体侵染苹果枝条24 h后的表达量分别下调86.5%和50%；综上所述，Vmles4正调控腐烂病菌的营养生长、致病力以及次级代谢合成酶基因VmNRPS12和VmNRPS14的表达。 相似文献
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从向日葵转录组测序结果中获得了3个对盐胁迫有响应的谷胱甘肽-S-转移酶（GST，EC2.5.1.18）GST基因，构建了系统进化树并进行分析，得知这3个基因属于Tau型GST，并将它们命名为HaGSTU26（HanXRQChr04g0127901）、HaGSTU8（HanXRQChr06g0177581）、HaGSTU27（HanXRQChr10g0316331），然后以向日葵Sk02R为试验材料，克隆这3个基因，并进行了不同组织和不同胁迫条件下的表达分析。序列分析表明：HaGSTU26基因组为1674bp，CDS（编码蛋白序列）长666bp，编码221个氨基酸，由2个外显子和1个内含子组成；HaGSTU8基因组为2271bp，CDS长654bp，编码217个氨基酸，由2个外显子和1个内含子组成； HaGSTU27基因组为663bp，CDS长663bp，编码220个氨基酸,由1个外显子组成。实时荧光定量PCR分析表明：向日葵HaGSTU26、HaGSTU8、HaGSTU27基因在不同组织（根、幼叶、成熟叶、茎、幼茎、苞叶）中表达量不同，其中，HaGSTU26基因和HaGSTU27基因在根中表达量最高，而HaGSTU8基因在苞叶中表达量最高，但这3个基因均在成熟茎中的表达量最低。在不同胁迫条件下，测定这3个基因在向日葵幼苗中的表达量，结果表明在盐及ABA胁迫下，基因表达量均随着处理时间的增加而呈现先增加后下降的趋势。其中，在盐胁迫下，HaGSTU26基因在12 h后相对表达量最高，HaGSTU8及HaGSTU27基因表达量在3h后相对表达量最高。在ABA胁迫后，HaGSTU26及HaGSTU27基因表达量在12 h后相对表达量最高，HaGSTU8在24 h后相对表达量最高。在冷胁迫下，HaGSTU26和HaGSTU27基因上调表达,它们分别在3、24 h后相对表达量最高，HaGSTU8基因下调表达，其相对表达量随处理时间的延长呈现逐渐减少的趋势。在热胁迫条件下，这3个基因的相对表达量随着胁迫时间的延长而增加,均在24 h后表达量最高。以上结果说明这3个基因对不同非生物胁迫（盐、ABA、冷、热胁迫）均有响应。 相似文献
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Chestnut blight has commonly been regarded as a phloem disease due to conspicuous stem cankers that result from infection by the fungal pathogen Cryphonectria (Endothia) parasitica. Stomatal conductance (gs), transpiration rate (E) and leaf water potential were measured throughout the day on leaves distal to naturally-occurring virulent (sunken bark with abundant stromata) or hypovirulent (swollen bark lacking stromata) cankers and cankers induced by inoculation with virulent or hypovirulent strains of C. parasitica. Relative to control stems, hydraulic conductivity (Kh), gs and E were reduced significantly (α = 0·05) for both natural virulent cankers, and cankers that were induced by a virulent strain. These effects were less pronounced for both natural and induced hypovirulent cankers. Isolation experiments revealed that the percentage of xylem tissue chips yielding C. parasitica was greater for virulent than for hypovirulent cankers. The data provide evidence that the localized presence of C. parasitica in cankers of American chestnut results in stomatal closure, possibly as a direct result of xylem dysfunction. 相似文献
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James E. Rookes David M. Cahill 《European journal of plant pathology / European Foundation for Plant Pathology》2003,109(1):83-94
Arabidopsis thaliana ecotype Columbia-0 was transformed with a green fluorescent protein (GFP) gene under control of a phenylalanine ammonia-lyase (PAL) promoter. PAL is a key enzyme of the phenylpropanoid pathway and is induced to high levels during plant stress. Constitutive expression of PAL1 promoter-controlled GFP occurred in vascular tissues within stems, leaves and roots and in developing flowers. PAL1 promoter–GFP expression was examined in leaves of transgenic plants subjected to an abiotic elicitor, mechanical wounding or to inoculation with the pathogens Pseudomonas syringae pv. tomato or Peronospora parasitica. Wounding of leaves and treatment with an abiotic elicitor and compatible interactions produced low to moderate levels of GFP. However, in incompatible interactions there were high levels of GFP produced. In incompatible interactions, the intensity of GFP fluorescence was similar to that produced in transgenic plants expressing GFP driven by the CaMV promoter. The bright green fluorescence produced in live cells and tissues was readily visualised using conventional fluorescence microscopy and was quantified using spectroflourometry. This is the first report of the use of GFP as a reporter of defence gene activation against pathogens. It has several advantages over other reporter genes including real time analysis of gene expression and visualisation of defence gene activation in a non-invasive manner. 相似文献
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抗坏血酸过氧化物酶（Ascorbate peroxidase, APX）是植物活性氧代谢中重要的抗氧化酶之一,在植物抵抗氧化胁迫方面发挥重要作用。利用生物信息学方法对芹菜基因组中的APX基因家族成员进行鉴定和分析,并通过实时荧光定量PCR（quantitative real\|time PCR, qRT-PCR）验证分析AgAPXs在高温胁迫下的表达情况,为开展芹菜APX基因参与高温胁迫调控机制提供依据。结果表明：芹菜基因组中共有9个APX基因,随机分布在5个染色体上,并出现了基因片段复制现象;大多数基因被定位在细胞质中。系统发育分析表明,AgAPX基因家族可分为3个亚族,同一亚族中的成员具有相似的基因结构和基序。启动子顺式元件分析表明,大多数AgAPX基因含有多种与生长发育、植物激素和逆境胁迫相关的顺式元件。高温胁迫下,芹菜APX活性提高。qRT-PCR分析表明,AgAPXs在不同时间的高温处理下表达具有显著差异,并与转录组表达丰度相一致,AgAPX2、AgAPX3、AgAPX4、AgAPX5、AgAPX7的表达量和APX活性具有显著相关性,推测AgAPXs可能参与了芹菜抵御高温的调控过程。本研究初步鉴定并提供了芹菜APX基因家族成员信息,为今后进一步探索芹菜APX基因功能提供了重要的研究基础。 相似文献
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为明确沃尔巴克氏体Wolbachia对果蝇神经行为影响的分子机制,采取转录组测序技术对感染沃尔巴克氏体和未感染的黑腹果蝇Drosophila melanogaster头部样本进行转录组测序、组装、注释,筛选感染沃尔巴克氏体wMel和未感染黑腹果蝇头部转录组间的差异表达基因,并选择差异表达基因中差异倍数较大或与神经行为相关的基因进行qPCR验证。结果表明,感染沃尔巴克氏体wMel和未感染黑腹果蝇头部差异表达基因有679个（差异倍数≥2,P<0.05）,其中,由于感染沃尔巴克氏体wMel而上调表达的基因有566个,下调表达的基因有113个。GO功能注释分析显示,差异表达基因与代谢过程、催化和结合功能相关。KEGG通路注释分析发现,差异表达基因主要富集在蛋白消化与吸收、内分泌、神经活性配体-受体互作以及激素合成等通路中。从差异表达基因中筛选出11个基因进行qPCR验证,有9个基因的表达趋势与RNA测序结果一致。表明沃尔巴克氏体可广泛影响果蝇头部基因的表达水平,暗示可能由此影响宿主的神经行为。 相似文献
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H. Ishihara G. Ponciano J. E. Leach S. Tsuyumu 《Physiological and Molecular Plant Pathology》2003,63(6):329-338
The phytopathogens Xanthomonas oryzae pathovar (pv.) oryzae and Xanthomonas axonopodis pv. citri each contain several avrBs3/pthA family genes. Structural features of these genes important for avirulence and/or virulence functions include a central region of multiple direct repeats and three nuclear localization signals (NLSs) and an acidic activation domain (AAD) at the 3′ end. To identify other regions critical to function in the 3′ ends of these genes, we constructed several chimeras using apl1 and apl2 from X. axonopodis pv. citri and avrXa10 and avrXa7 from X. oryzae pv. oryzae and evaluated their functions by inoculation to citrus and rice. The apl1 and avrXa7 genes are major virulence determinants in citrus and rice, respectively, while the contributions of apl2 and avrXa10 to virulence are negligible or not measurable. Constructs that contained a 417 bp HincII-SphI fragment from the 3′ end of apl1 in combination with the repeats from avrXa7, avrXa10, and apl1 caused a canker phenotype on citrus. Interchange of the HincII-SphI fragment between avrXa7 and avrXa10 abolishes avrXa7 avirulence function and reduces its virulence but it does not affect avrXa10 avirulence function in rice. avrXa7 caused a hypersensitive response (HR) in citrus and replacement of it's 3′ end with that of apl1 resulted in loss of canker and induction of HR. Thus, the HincII-SphI fragment of the avrBs3/pthA gene family is important for avirulence and virulence functions in two different plant species, Oryza sativa and Citrus natsudaidai HAYATA. 相似文献
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Tuija Pehkonen Janne Koskimki Kaisu Riihinen Anna Maria Pirttil Anja Hohtola Laura Jaakola Anne Tolvanen 《Physiological and Molecular Plant Pathology》2008,72(4-6):146-150
An inoculation method for Exobasidium splendidum and Exobasidium vaccinii was developed on the dwarf shrub Vaccinium vitis-idaea. Using inoculated ramets, we investigated whether there are differences between V. vitis-idaea populations in the susceptibility to Exobasidium infections and whether the defence reaction of V. vitis-idaea is visible at a molecular level. Sixteen V. vitis-idaea clones from four populations were propagated in tissue cultures and the ramets were inoculated with E. splendidum or E. vaccinii fungi. The expression of three flavonoid biosynthetic genes (chalcone synthase, dihydroflavonol 4-reductase and anthocyanidin synthase) and the accumulation of flavonoids and hydroxycinnamic acids were determined in response to E. splendidum infection. A pathogenesis-related (PR 4) gene was isolated and its expression was studied in host ramet leaves. To our knowledge, this was the first successful artificial infection reported with E. splendidum. Disease frequencies of the inoculated ramets were between 32% and 47% for E. splendidum and 33% for E. vaccinii, but below 10% in uninoculated control ramets. There were no differences in disease frequencies between V. vitis-idaea populations. Both symptomatic leaves and healthy leaves of diseased ramets showed activation of flavonoid biosynthesis at the gene level, whereas expression of PR 4 was observed only in symptomatic leaves. The increase of flavonoid biosynthesis in healthy leaves of diseased ramets may represent a general response to stress or a role in defence against the pathogen E. splendidium. Ability of V. vitis-idaea to defend chemically against Exobasidium fungi and the heterogeneity of genotypes, age, size, and growth rates in host plant populations might be reasons for the low infection incidence of Exobasidia in nature. 相似文献
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为明确毁灭炭疽菌Colletotrichum destructivum诱抗蛋白诱导烟草的抗病性及其作用,采用喷雾、摩擦接种方法及RT-PCR技术研究了诱抗蛋白的预防保护作用,以及烟草悬浮细胞经诱导后过氧化物酶(POD)、多酚氧化酶(PPO)、苯丙氨酸解氨酶(PAL)活性及脯氨酸(Pro)含量和病程相关基因表达的变化。结果表明,接种3、5和7 d后,该诱抗蛋白对烟草炭疽病的诱抗效果分别为58.00%、48.99%和49.65%,对烟草白粉病的诱抗效果分别为83.26%、80.76%和78.60%,并可以抑制烟草普通花叶病毒的复制及在寄主体内的扩增;经诱抗蛋白处理后,烟草悬浮细胞POD、PPO、PAL活性及Pro含量明显提高;诱抗蛋白能够诱导烟草病程相关蛋白基因PR-1a、PR-1b以及抗病信号传导途径关键基因NPR1的表达。表明毁灭炭疽菌诱抗蛋白可诱导烟草产生抗病性,可能与烟草悬浮细胞中POD、PAL、PPO的活性及Pro的含量提高以及相关病程基因表达有关。 相似文献
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为提升齐整小核菌Sclerotium rolfsii菌株SC64作为生物除草剂的应用潜力，解析植物对其的防御机制，通过比较6种生态型拟南芥Arabidopsis thaliana(Col-0、Ms-0、Gr-1、Se-0、Tu-0和Wa-1)被菌株SC64侵染后病理特征、茎秆木质素水平以及抗病相关基因表达的差异，筛选出抗性最高和抗性最弱的典型生态型拟南芥，通过施加0.1 mmol/L外源水杨酸来验证其在拟南芥防御菌株SC64侵染过程中对木质素代谢及病理的调节作用，并比较分析6种生态型拟南芥水杨酸上游调控通路基因MPK4启动子区域的甲基化差异。结果显示，6种生态拟南芥中Col-0的木质素化程度最高，被菌株SC64侵染时木质素代谢通路基因CAD4和PAL3表达上调最显著，与其抗病能力最强相吻合，而Ms-0的病理表型和抗病能力最弱。外源水杨酸预处理使具典型抗性的生态型拟南芥Col-0受菌株SC64侵染后发病程度加重，木质素化程度减弱，同时木质素代谢通路基因MYB46、LAC17、PAL3和CAD4被菌株SC64侵染后的表达上调程度均显著减弱。另外，6种生态型拟南芥MPK4基因启动子区域CHH... 相似文献
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J. -L. Peng H. -S. Dong H. -P. Dong T. P. Delaney J. M. Bonasera S. V. Beer 《Physiological and Molecular Plant Pathology》2003,62(6):317-326
Plants sprayed with harpin, a bacterial protein that induces hypersensitive cell death (HCD), develop systemic acquired resistance (SAR) without macroscopic necrosis. HCD sometimes accompanies the development of resistance conferred by resistance (R) genes. In Arabidopsis, some R genes require one or both of the signalling components NDR1 and EDS1 for function. This study addresses whether HCD, NDR1 and EDS1 are required for induction of SAR by harpin. When Arabidopsis and tobacco leaves were sprayed with harpin, microscopic hypersensitive response (micro-HR) lesions developed. Systemic expression of PR genes and the development of resistance were accompanied by micro-HR, except in the ndr1-1 mutant, in which harpin induced micro-HR without the development of resistance or expression of the PR-1 gene. Cell death and resistance did not occur following treatment with harpin in plants that could not accumulate salicylic acid. Harpin also failed to induce resistance in Arabidopsis eds1-1 mutants. Therefore, harpin-induced resistance seems to develop concomitantly with cell death and resistance requires NDR1 and EDS1. 相似文献
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为明确南方根结线虫Meloidogyne incognita效应蛋白MiV901在其寄生过程中的生物学功能,通过构建MiV901基因的植物表达载体,利用根癌农杆菌Agrobacterium tumefaciens介导的花序浸染法将其转化拟南芥Arabidopsis thaliana,并采用室内人工接种法测定转基因植株对灰葡萄孢 Botrytis cinerea侵染及南方根结线虫寄生的影响。结果显示：经Southern blot检测,MiV901基因以不同的拷贝数插入到转基因拟南芥株系901-6、901-8和901-12的基因组中,且qPCR检测结果证实 MiV901基因能够正常表达。3个转基因拟南芥株系901-6、901-8和901-12叶部接种灰葡萄孢3 d后,叶片上形成的病斑平均直径分别为1.00、1.06、1.05 cm,比野生型对照扩大了9.9%~16.5%。相比野生型对照,转基因拟南芥株系901-12、901-6和901-8接种南方根结线虫2龄幼虫后根系上产生了更多的雌虫和卵块,雌虫数分别显著增加了45.4%、34.4%和23.7%,卵块数分别显著增加了51.2%、 46.3%和31.7%。表明异源表达MiV901基因能够抑制植物免疫,增加拟南芥对灰葡萄孢和南方根结线虫侵染的敏感性。 相似文献
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为明确自主分离的生防菌株寡雄腐霉Pythium oligandrum GAQ1对辣椒疫病的生防效果及其防御机制,通过平板拮抗和盆栽防效试验测定寡雄腐霉菌株GAQ1对辣椒疫霉Phytophthora capsici菌丝的拮抗作用、对辣椒疫病的防效和对辣椒的促生效果,同时应用实时荧光定量PCR技术检测菌株GAQ1处理后辣椒抗性基因表达的变化。结果表明,寡雄腐霉菌株GAQ1的菌丝可以缠绕并吸附寄生在辣椒疫霉菌丝表面或穿入菌丝体内,使辣椒疫霉菌丝细胞死亡;菌株GAQ1发酵液处理辣椒离体叶片再接种辣椒疫霉后产生的病斑直径较对照组显著减少,离体防效为30.79%;接种菌株GAQ1菌丝球后,辣椒疫病的病情指数较对照组显著降低,盆栽防效达69.16%;经菌株GAQ1处理辣椒后可诱导相关抗性基因PR1、WRKY40、WRKY53、ACCO和GST的相对表达量出现不同程度的升高,说明菌株GAQ1可诱导辣椒植株产生不同程度的防御系统应答。菌株GAQ1对辣椒具有良好的促生效果,处理后第5周其株高、株重及根重分别较对照组提高10.11%、33.23%和24.72%,其叶片中叶绿素a、叶绿素b及类胡萝卜素的含量分... 相似文献