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NAC(NAM/ATAF/CUC)基因家族是广泛分布于陆生植物的一类转录因子,在植物生长发育和胁迫应答的调控中发挥重要作用。本文对该基因家族在木薯抗细菌性萎蔫病方面的作用机制进行了初步研究。采用RT-PCR技术从木薯cDNA中克隆了MeNAC29和MeNAC30基因,并采用qRT-PCR技术对抗、感种质受木薯萎蔫病菌(Xanthomonas axonopodispv.manihotis,Xam)侵染后2个基因的表达变化进行了定量分析。结果表明,2个基因均含有3个外显子和2个内含子,且均有保守的NAM结构域。MeNAC29基因的开放阅读框全长888 nt,编码295 aa。MeNAC30基因的开放阅读框全长870 nt,编码289 aa。接种木薯萎蔫病菌后,抗病种质中MeNAC29和MeNAC30基因的表达量显著高于感病品种,表明这2个基因参与了木薯对细菌性萎蔫病菌的抗性反应。 相似文献
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细菌性萎蔫病是世界范围内木薯种植中的重要病害,也是中国木薯种植中为害最严重的病害。前期研究发现铜基杀菌剂对国内木薯细菌性萎蔫病防效欠佳,随即开展了病菌抗铜性评价及抗铜相关基因簇的分子分析工作。评价了42个不同来源病原菌菌株对硫酸铜的抗性,发现其抑菌最低有效浓度均在1.35~1.75 mmol/L之间。通过和已报道黄单胞菌类抗铜相关基因的比对分析,发现来自广西的菌株GX11携带有cop TAB和Xme RSA2个抗铜基因簇。对来自南美州、非洲和亚洲67个菌株的基因组序列分析发现绝大多数菌株均带有这2个基因簇,聚类分析发现相关基因在菌株之间具高度的同源性。 相似文献
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采用平板试验,通过生长速率法分析木薯根系分泌物及其土壤浸出液对橡胶树白根病病菌及棒孢霉落叶病病菌的化感效果,为判断胶园林下种植木薯的可行性提供理论依据。结果表明:(1)木薯根系分泌物对橡胶树白根病和棒孢霉落叶病病菌均表现为化感促进效果,但在任一处理时间,不同浓度间对白根病病菌的化感效果与对照均未达显著差异,而对棒孢霉落叶病病菌的化感效果呈现明显的剂量效应,浓度达40 mg/mL时,化感促进效果与对照达到显著水平。(2)木薯根系分泌物的任一浓度,对橡胶树白根病和棒孢霉落叶病病菌的化感效果,在不同处理天数间均未达到显著水平。(3)木薯土壤浸出液对橡胶树白根病和棒孢霉落叶病病菌均呈现化感促进效果,且存在明显的剂量效应;对橡胶树白根病病菌,处理后2 d,达到显著化感效果所需浸出液浓度至少为40 mg/mL,处理后3 d和处理后4 d,达到显著化感效果所需浸出液浓度至少为8 mg/mL;对棒孢霉落叶病病菌,在任一处理时间达到显著化感效果的浸出液浓度均至少为200 mg/mL。(4)土壤浸出液小于8 mg/mL时,3个处理时间之间的橡胶树白根病病菌化感效果无显著差异,当浓度达到40 mg/mL时,处理后2 d的化感促进效果显著大于处理后3 d和4 d;4种土壤浸出液的任一浓度,对橡胶树棒孢霉落叶病病菌的化感效果在不同处理时间之间均未达到显著差异。所以说,幼龄胶园间作木薯会在一定程度上促进橡胶树棒孢霉落叶病和白根病的发生。 相似文献
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国内橡胶树多主棒孢Cassiicolin毒素多样性及致病性分析 总被引:1,自引:0,他引:1
由多主棒孢引起的棒孢霉落叶病是橡胶树的主要叶部病害,cassiicolin毒素是病菌的主要致病因子。本研究通过ITS序列分析对供试多主棒孢菌株进行了准确鉴定,利用cassiicolin毒素不同亚型编码基因特异引物对不同地理来源和寄主来源的49个多主棒孢菌株毒素类型进行了分析,并利用生物萎蔫法对不同亚型毒素进行了致病性分析。结果显示,78%供试菌株含有cassiicolin基因,其中Cas2亚型有10个菌株,Cas5亚型有28个菌株,其它为Cas0型(未检测到cassiicolin毒素基因)。含有Cas5亚型的菌株均来源于橡胶树,并且为橡胶树上的优势群体;Cas2亚型菌株则来源于橡胶树、黄瓜、番木瓜和木薯等不同作物;Cas2和Cas5毒素对不同橡胶树品种的致病性存在明显差异。 相似文献
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由多主棒孢(Corynespora cassiicola)引起的橡胶树棒孢霉落叶病已成为影响天然橡胶产量的主要限制因素。本实验对从我国海南、云南和广西等地分离得到的17个橡胶树多主棒孢病菌菌株进行了致病性测定,获得强致病力菌株HC-10。分别用该菌株菌丝体接种鉴定、粗毒素叶片穿刺接种和叶片萎蔫生物鉴定等3种方法对我国选育的45个巴西橡胶树品种进行抗病性评价。结果表明,不同橡胶树品种对棒孢霉落叶病的抗性水平存在明显差异。在供试的45个品种中,不同抗性评价方法的鉴定结果基本一致,抗病品种占13.3%~17.8%;轻感病品种占66.7%~73.4%;易感病品种占11.1%~17.8%。 相似文献
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10种无机盐对橡胶树多主棒孢病菌的抑菌作用及对粗毒素的钝化 总被引:1,自引:0,他引:1
以橡胶树棒孢霉落叶病病原菌及其产生的粗毒素为供试材料,研究了10种无机盐对多主棒孢菌株菌丝生长、分生孢子萌发的抑制作用和对其粗毒素的钝化作用。结果表明:CuSO4.5H2O、FeCl3和FeSO4.6H2O在2~5mg/mL浓度范围内对多主棒孢病菌菌丝生长及其孢子萌发都有很强抑制作用,菌丝生长抑制率为100%,孢子萌发率为0。KMnO4在0.5~5 mg/mL浓度范围内能够完全抑制孢子的萌发,而1~5 mg/mL浓度范围内却促进菌丝的生长。KMnO4和FeCl3在浓度为0.5 mg/mL时对该毒素均有很强的钝化作用,萎蔫指数分别为2.04%和3.97%。 相似文献
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不同来源橡胶树多主棒孢病菌致病性及基础生物学特性的比较 总被引:5,自引:0,他引:5
对已在我国海南、云南、广西等省区橡胶树上发生为害的3株多主棒孢病菌(Corynespora cmssiicola)和来自印度的橡胶树多主棒孢病菌进行了致病性及基础生物学特性的比较研究.结果表明,印度HCcYD01菌株的致病力最强;基础生物学特性测定结果表明,参试的3株国内菌株与印度菌株问除分生孢子大小、孢子萌发和致死温度相似外,在菌落形态、最适培养基、光照条件、碳氮源利用、最适生长温度和pH等方面存在一定差异.由多主棒孢引起的橡胶树棒孢霉落叶病业已成为影响天然橡胶产量的主要限制因素,本研究旨在了解我国橡胶树棒孢霉落叶病的最初发病病原,为该病发生规律的研究及防控措施的制定提供理论依据. 相似文献
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茶园土壤高活性氨化菌的筛选鉴定及特性研究 总被引:1,自引:0,他引:1
经过菌株富集培养、分离纯化等一系列步骤,从山东茶园土壤中分离出33株氨化细菌菌株。经过活性比较和菌株分类,从中选出3株不同种属的高活性菌株。通过对其进行形态特征、生理生化指标的测定及16 S rDNA测序,初步鉴定菌株SNT3属于芽孢杆菌属,菌株SNT6属于微小杆菌属,菌株SNT33属于不动杆菌属。同时对菌株的生长环境以及氨化活性进行了初步研究。结果表明:菌株SNT3、SNT6和SNT33适宜的pH依次为5~8.5、6~8.5、5~7;3株菌株的最适宜生长温度为35℃;在氨化能力方面,菌株SNT3高于菌株SNT6、SNT33。 相似文献
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Cassava is a vital crop in Africa and represents the main food crop in Central African Republic (CAR). CAR has recently faced large reductions in cassava yields that have led to a surge in market prices. To better understand the causes of the reduction in yield, we identified biotic constraints to cassava production by means of a large-scale plant epidemiological survey conducted in 2007 and 2008. Standard protocols were used for the assessment of the major cassava pests and diseases. Cassava mosaic disease (CMD) was shown to be the most serious constraint to cassava in CAR, with symptoms observed at all localities surveyed. CMD is distributed throughout the country, with an average incidence of 85%. Importantly, 94% of diseased plants had cutting-derived CMD infection suggesting that farmers mostly use virus-infected cuttings for planting. PCR amplification and direct sequencing of partial fragments of the Rep ORF revealed that the causal agents of CMD in CAR are African cassava mosaic virus (ACMV) and the Uganda strain of East African cassava mosaic virus (EACMV-UG). We also demonstrated that 58% of CMD samples present mixed infections (ACMV and EACMV-UG) and that these samples had significantly higher symptom severities. Our results suggest that mixed infection and synergism between CMGs, could be an important feature in the yield reduction of cassava plants in CAR, similar to the other severe CMD epidemics reported in East Africa. 相似文献
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Siv Kristin Prestegard Svein Rune Erga Pia Steinrücken Svein Are Mj?s Gjert Knutsen Jens Rohloff 《Marine drugs》2016,14(1)
We have searched for special characteristics in growth, protein expression, fatty acids and volatile organic compounds (VOCs) in a local Phaeodactylum tricornutum Bohlin strain (Bergen Marine Biobank), by comparing it with a common accession strain (CCAP). Differences in growth and expressed proteins were detected between the BMB strain and the CCAP strain, and the BMB strain reached the highest cell densities under the given growth conditions. Fatty acid (FA) analyses showed highest relative eicosapentaenoic acid (EPA) levels in the exponential phase (25.73% and 28.31%), and highest levels of palmitoleic acid (16:1 n-7) in the stationary phase (46.36% and 43.66%) in the BMB and CCAP strain, respectively. The most striking finding of the VOCs analyses was the relatively high levels of ectocarpene, 6-((1E)-butenyl)-1,4-cycloheptadiene, hormosirene, and desmarestene and structurally related compounds, which were exclusively detected in the BMB strain. Many of the VOCs detected in the CCAP and, in particular, in the BMB strain have been reported as antimicrobial agents. We suggest that the array of pheromones and antimicrobial substances could be part of an allelopathic strategy of the BMB strain, dominated by oval cells, thus reflecting the benthic life stage of this morphological form. These findings show the potential for bioactive metabolites in the BMB strain. 相似文献
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枯草芽孢杆菌CS16抑菌活性与胞外产物成分分析 总被引:3,自引:0,他引:3
通过测定枯草芽孢杆菌CS16菌株的抑菌活性,对其胞外代谢物活性与成分进行分析,以期开发有效的生防菌剂.结果表明:CS16菌株对多株植物病原真菌具有明显的抑制作用,对病原细菌的抑菌作用相对较弱;CS16发酵液中羧甲基纤维素酶、淀粉酶和木聚糖酶活力分别为509.58 U/mL、7 198.71 U/mL和1 853.68 U/mL;其发酵液经酸沉淀所得粗提物可明显抑制香蕉枯萎病菌丝生长,最小抑菌浓度为0.062 5 mg/mL;利用反相硅胶柱、Sephadex LH-20凝胶柱和正相硅胶柱分离纯化获得较纯的抑菌物质,经薄层层析和HPLC定性分析,初步认为其胞外抑菌物质中含有Iturin A. 相似文献
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Marion Navarri Camille Jégou Laurence Meslet-Cladière Benjamin Brillet Georges Barbier Ga?tan Burgaud Yannick Fleury 《Marine drugs》2016,14(3)
The evolving global threat of antimicrobial resistance requires a deep renewal of the antibiotic arsenal including the isolation and characterization of new drugs. Underexplored marine ecosystems may represent an untapped reservoir of novel bioactive molecules. Deep-sea fungi isolated from a record-depth sediment core of almost 2000 m below the seafloor were investigated for antimicrobial activities. This antimicrobial screening, using 16 microbial targets, revealed 33% of filamentous fungi synthesizing bioactive compounds with activities against pathogenic bacteria and fungi. Interestingly, occurrence of antimicrobial producing isolates was well correlated with the complexity of the habitat (in term of microbial richness), as higher antimicrobial activities were obtained at specific layers of the sediment core. It clearly highlights complex deep-sea habitats as chemical battlefields where synthesis of numerous bioactive compounds appears critical for microbial competition. The six most promising deep subseafloor fungal isolates were selected for the production and extraction of bioactive compounds. Depending on the fungal isolates, antimicrobial compounds were only biosynthesized in semi-liquid or solid-state conditions as no antimicrobial activities were ever detected using liquid fermentation. An exception was made for one fungal isolate, and the extraction procedure designed to extract amphipathic compounds was successful and highlighted the amphiphilic profile of the bioactive metabolites. 相似文献