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1.
印度梨形孢诱导烟草对黑胫病的抗性及其机理的初步研究   总被引:2,自引:0,他引:2  
印度梨形孢(Piriformospora indica)是分离自印度塔尔沙漠的植物根系内生真菌,能够诱导多种植物对生物和非生物逆境产生抗性,目前已作为一种模式真菌用于内生真菌与植物互作关系的研究。为了研究印度梨形孢对烟草(Nicotiana tobacum)抗黑胫病的影响,本研究采用烟草疫霉菌(Phytophthora parasitica var.nicotianae)分别接种根部有印度梨形孢定殖与未定殖的烟草,观察接种后根部有印度梨形孢定殖与未定殖的烟草发病情况,测定抗病相关防御酶苯丙氨酸解氨酶(PAL)、过氧化物酶(POD)、多酚氧化酶(PPO)的活性变化及抗病相关基因的表达量,并通过平皿对峙试验研究印度梨形孢对烟草疫霉菌生长的影响。结果表明,接种烟草疫霉菌后,根部有印度梨形孢定殖的烟草发病严重度要显著低于对照;接种烟草疫霉菌后第1~10 d,根部有印度梨形孢定殖的烟草叶片中防御酶PAL、POD和PPO活性高于对照,在第1 d,PAL活性是对照烟草的3.99倍,在第2 d,POD活性是对照烟草的1.5倍,在第4 d,PPO活性是对照烟草的2.66倍;实时荧光定量PCR(Real-time quantitative PCR,q RT-PCR)结果显示,接种烟草疫霉菌后第6~96 h,根部有印度梨形孢定殖的烟草叶片中抗病相关基因PR1b、P450-2、hrs203J、Nm IMSP和P450-1的表达量高于对照;在第12 h,PR1b、P450-2、hrs203J的表达量分别是对照烟草的3.8、15.7和3.1倍,在第48 h,Nm IMSP的表达量是对照烟草的2.6倍,在第72 h,P450-1的表达量是对照烟草的1.5倍;平皿对峙试验结果显示印度梨形孢对烟草疫霉菌的生长没有抑制、重寄生作用。研究结果表明,印度梨形孢可显著提高烟草对黑胫病的抗性,对黑胫病的抗性不是通过印度梨形孢分泌的抗菌物质实现的,是与烟草中抗病相关基因表达量的上升、防御酶活性的提高有关。本研究初步揭示了印度梨形孢诱导烟草抗黑胫病的相关机理,为进一步深入研究烟草黑胫病的生物防治及其机理提供基础资料。  相似文献   

2.
水稻白叶枯病菌蛋白质激发子HarpinXoo诱导植物的防卫反应   总被引:17,自引:0,他引:17  
摘要:含质粒pHRF4的表达菌株BLHR4在培养基中经IPTG诱导,16 h Harpin表达接近最高量。用不同浓度的HarpinXoo喷雾处理烟草(Nicotiana tabacum L.)、油菜(Brassica campestris L.)和番茄(Lycopersicon esculentum Mill.),对烟草花叶病毒(TMV)、油菜菌核病(Sclerotinia sclerotiorum (lib.) de Bary)和番茄灰霉病(Botrytis cinerea Pers.)均表现较好的诱导抗病效果。以浓度为100μg/mL的HarpinXoo处理烟草后,分别测定叶片中与防卫反应相关的一些生理指标的变化,结果表明,处理叶片中苯丙氨酸解氨酶(PAL)、过氧化物酶(PO)和多酚氧化酶(PPO)活性都有不同程度的增强。三种酶活性高峰分别在处理后24、12和3 h出现,分别比清水对照增加110.1%、211.2%和273.0%;同时,两个病程相关蛋白(pathogenesis-related protein,PR)基因PR-1b和PR-1a在HarpinXoo处理24 h后被诱导显著表达,36 h时达到最高表达水平。这表明HarpinXoo与HarpinEa一样能够诱导烟草不同抗病信号通路的启动,从而使植株获得抗病性。  相似文献   

3.
激发子隐地蛋白基因介导的烟草抗病性研究   总被引:3,自引:0,他引:3  
摘要:从隐地疫霉(Phytophthora cryptogea)中克隆cryptogein(Crypt)激发子基因。针对病原菌侵染和Crypt基因的特点,选用能在根、茎、叶等的表皮细胞中特异性表达的、弱组成型并受病原菌诱导的水稻(Oryza sativa )苯丙氨酸解氨酶基因(PAL)的启动子;同时为了使表达的cryptogein蛋白能分泌到细胞外,更好地与植物细胞膜受体互作,在Crypt基因前还融合了病程相关蛋白PR1b的信号肽; 然后将此融合基因构建于植物表达载体CHF3中。通过根癌农杆菌(Agrobacterium tumefancens)介导的叶盘转化法转入烟草(Nicotiana tabacum )。经卡那霉素抗性筛选获22株再生植株,PCR检测都为阳性,部分植株的Southern杂交结果表明,Crypt基因已以低拷贝(1~2个)整合到烟草基因组中。抗病性测定结果表明,转化植株对烟草黑胫病菌(P. parasitica var. nicotianae )、赤星病菌(Alternaria alternata )和野火病菌(Pseudomonas syringae pv. tabaci )的抗性均有提高。  相似文献   

4.
室内研究了广东省稻瘟病菌优势生理小种之一ZC13(菌株为97-151a)的菌丝细胞胞壁激发子(cell wall elicitor,CWE)诱导玉米体内几种病害防御酶活性的变化。结果表明:各玉米品种幼苗经激发子处理后,其过氧化物酶(POD)、苯丙氨酸解氨酶(PAL)、多酚氧化酶(PPO)和过氧化氢酶(CAT)活性均明显高于对照和未经激发子处理而直接接种病菌的幼苗,从而证实了该激发子能诱导玉米对玉米小斑病(Helminokosporicum turcicum)产生一定抗病性。  相似文献   

5.
为探究富士和嘎啦对外源水杨酸的生理响应机制,采用叶片喷雾法,测定外源水杨酸(SA)对苹果叶片中丙二醛(MDA)含量、防御酶活性及病程相关蛋白(PR)基因表达的影响。结果表明,0.2mmol·L~(-1)SA处理后,富士和嘎啦叶片中MDA含量变幅较小且均与对照无显著差异;SA处理显著提高了叶片中过氧化氢酶(CAT)、多酚氧化酶(PPO)、过氧化物酶(POD)和苯丙氨酸解氨酶(PAL)活性,富士和嘎啦叶片中各酶活性峰值分别是对照的1.31倍~2.06倍和1.16倍~3.13倍。SA诱导后苹果叶片中PR5和PR8的表达明显上调,富士于处理后第3天基因表达量达到高峰,而嘎啦于处理后第1天基因表达量最高。研究表明,外源SA可提高苹果叶片中防御酶活性并诱导PR基因上调表达,但富士和嘎啦中酶活性水平和持续时间及PR基因的应答反应存在差异。本研究为利用植物诱导抗病性防治苹果叶部病害提供了科学依据。  相似文献   

6.
为明确黄芪根瘤象取食胁迫对黄芪叶片主要防御酶活性的影响及对黄芪药效物质的可能影响,以黄芪根瘤象及其寄主膜荚黄芪为试验材料,测定了不同取食诱导时间的苯丙氨酸解氨酶(PAL)、过氧化物酶(POD)和多酚氧化酶(PPO)活性变化.结果表明,取食24、48、72 h后,叶片PAL和POD的活性均显著增加;取食24 h后PPO活...  相似文献   

7.
植物激活蛋白Ap36在苏云金芽胞杆菌的表达及抗病作用   总被引:1,自引:0,他引:1  
以含有植物激活蛋白(Activator protein)基因ap36的质粒pMYE为摸板,设计一对特异引物,通过PCR反应扩增出激活蛋白基因开放读码框序列,使用XbaI和SphI双切PCR产物,插入到用这两酶双切的pBMB982-304质粒slh motif的下游,构建重组表达质粒pBMB0588,转化苏云金芽胞杆菌无质粒突变株BMB171。结果表明,目标蛋白以融合蛋白的形式成功表达。为探讨表达植物激活蛋白的重组菌是否能够诱导植物获得抗性,用重组菌在28℃培养24小时发酵液原液处理番茄幼苗和土豆片。结果显示,发酵液处理90min后,番茄叶片过氧化物酶(POD)和脯氨酸含量较对照分别提高了57.14%和131.59%;4d后苯丙氨酸解氨酶(PAL)含量较对照也有所提高;经重组菌发酵液处理的马铃薯片,对马铃薯软腐病表现出很强的抗病性。  相似文献   

8.
张亮  盛浩  袁红  赵兰凤  李华兴 《土壤》2018,50(5):1056-1060
本文采用实时荧光定量PCR技术对荧光假单胞菌PEF-5#18诱导番茄系统性抗性(ISR)的作用机理进行了研究,包括了诱导进程中番茄根系病程蛋白基因PRs族、GR等重要防卫基因以及乙烯、水杨酸、茉莉酸等诱导信号调控路径的关键基因的表达情况。结果表明,尖孢镰刀菌Forl和荧光假单胞菌PEF-5#18对番茄植株分别具有SAR和ISR诱导抗性能力,而在"Forl-番茄-PEF-5#18"互作模式下,番茄植株受诱导所产生的抗性则受到SAR和ISR共同作用的影响;与对照相比,Forl或荧光假单胞菌PEF-5#18均能诱导番茄病情蛋白基因PRs (PR1、PR4、PR5、PR6)与GR、POX、PAL等相关防卫基因的表达进行上调,而相关受诱导基因的表达程度与动态变化则与所诱导的SAR和ISR抗性反应类型以及诱导时间有关;此外,对于调控路径的分析结果显示出尖孢镰刀菌Forl对番茄SAR诱导抗性主要依赖于水杨酸路径进行调控,而荧光假单胞菌PEF-5#18对番茄ISR诱导抗性则主要依赖于茉莉酸和乙烯路径来调控。  相似文献   

9.
氯化钾对玉米茎腐病抗性反应中酚类物质代谢的影响   总被引:2,自引:1,他引:1  
采用田间试验,比较人工接种禾谷镰刀菌(Fusarium graminearum)后,不同氯化钾处理对玉米酚类物质代谢的影响,揭示氯化钾提高作物抗病过程中的酚类物质代谢机理。结果表明,诱导接菌加速了玉米对K+的吸收,且施用氯化钾可以提高接菌后玉米茎髓中苯丙氨酸解氨酶(PAL)的诱导活性,加速多酚氧化酶(PPO)活性的升高,提高过氧化物酶(POD)活性的峰值。此外,施钾还有利于增加茎髓中固有木质素的含量,增加诱导产生的木质素和总酚的积累量。说明钾素可以通过调节酚类物质的代谢,增强次生代谢能力,提高玉米对茎腐病的抗性。  相似文献   

10.
为探讨He-Ne激光和增强UV-B辐射对小麦幼苗多酚代谢相关酶活性的影响,利用5 mW·mm-2的He-Ne激光和增强UV-B(10.08 kJ·m-2·d-2)辐射处理"晋麦8号"小麦幼苗,分别在不同时段测定苯丙氨酸解氨酶(PAL)、多酚氧化酶(PPO)及过氧化物酶(POD)的活性.结果表明,增强UV-B辐射使小麦幼苗叶片PAL活性升高,PPO与POD活性降低,且随处理天数的增加,不同处理组小麦幼苗叶片PAL、PPO、POD活性间具有一定相关性.长期增强UV-B辐射,导致多酚类物质的代谢速度降低甚至停止,自由基不能被及时清除,生物膜破坏:经过一定剂量的He-Ne激光辐照可修复增强UV-B辐射对小麦幼苗叶片多酚类物质代谢的损伤.  相似文献   

11.
The combined effects of natamycin (NA) and pure oxygen (PO) treatment on microbial and physicochemical characteristics of button mushroom ( Agaricus bisporus ) stored at 4 ± 1 °C for 16 days was investigated. Mushroom respiration rate, weight loss, firmness, color, percent open caps, total soluble solids, microbial and activities of polyphenol oxidase (PPO), phenylalanine ammonia lyase (PAL), and peroxidase (POD) were measured. The results indicate that treatment with natamycin + pure oxygen (NAPO) maintained tissue firmness, inhibited increase of respiration rate, delayed browning and cap opening, and reduced microorganism counts of yeasts and molds compared to control treatment. The efficiency was better than that of NA or PO treatment. Furthermore, NAPO inhibited the activities of PPO, PAL, and POD throughout the storage period. Our study suggests that NAPO treatment has the potential to improve the quality of button mushroom and extend the shelf life.  相似文献   

12.
为了探讨减压贮藏延缓采后去壳黄甜竹笋木质化和褐变的效果及其作用机制,本试验以黄甜竹笋为试验材料,笋剥壳后于温度6 ±1℃、相对湿度80%~85%、55 kPa减压环境下贮藏10 d,测定其品质指标、竹笋木质化和褐变关键酶的活性和相关基因的相对表达量。结果表明,减压贮藏(中后期)显著抑制了黄甜竹笋基部切面的褐变(P<0.05),显著延缓了黄甜竹笋的呼吸速率、电导率、硬度,以及丙二醛、纤维素和木质素含量的上升(P<0.05),同时也显著抑制了苯丙氨酸解氨酶(PAL)、过氧化物酶(POD)、肉桂醇脱氢酶(CAD)、多酚氧化酶(PPO)的活性及其编码基因的相对表达量(P<0.05)。本研究结果为减压贮藏在黄甜竹笋采后保鲜的应用提供了理论依据。  相似文献   

13.
Sheath blight caused by Rhizoctonia solani is a major disease of rice worldwide. Silicon (Si) can enhance rice resistance to sheath blight, but the relation with phenolic metabolism is poorly known. Two rice cultivars with different levels of resistance to R. solani (resistant Teqing and susceptible Ningjing 1) were studied to determine the effects of Si on disease intensity (rated from 0 to 9) and the involvement of phenolic compounds in disease resistance. Variation in the concentrations of phenolics (including total soluble phenolics, flavonoids, and lignin) and in the activities of defense‐related enzymes polyphenoloxidase (PPO) and phenylalanine ammonia‐lyase (PAL) in rice leaf sheaths was investigated. The results show that Si application reduced sheath‐blight disease ratings of Ningjing 1 and Teqing by 2.96 and 0.65, respectively. In uninoculated plants, Si application alone had no significant effects on the concentrations of phenolic compounds or on the activities of PPO and PAL. In inoculated plants, Si application increased phenolics concentrations and PPO and PAL activities only in the susceptible cultivar Ningjing 1. We conclude that Si‐induced enhancement of phenolic metabolism contributed to the improved resistance of rice to sheath blight in the sensitive cultivar.  相似文献   

14.
为探讨伞形花内酯处理对猕猴桃果实采后灰霉病的控制效应,本试验研究了伞形花内酯对灰霉菌孢子和生长的影响,以及对美味猕猴桃徐香损伤接种灰霉菌后果实病害发展、抗病相关酶活性和抗性物质的影响。结果表明,离体条件下,0.5和1.0 mg·mL-1伞形花内酯能够显著抑制灰霉菌孢子的萌发和生长;0.5 和1.0 mg·mL-1伞形花内酯处理能够抑制损伤接种灰霉菌猕猴桃果实病斑的扩张,显著提高果肉几丁质酶(CHT)、β-1,3 葡聚糖酶(GLU)、苯丙氨酸解氨酶(PAL)、4-香豆酰辅酶A连接酶(4CL)、过氧化物酶(POD)和多酚氧化酶(PPO)的活性,提高果实贮藏后期总酚、类黄酮和木质素的含量,因而诱导了猕猴桃采后果实对灰霉病的抗性。本研究为应用外源伞形花内酯控制猕猴桃采后果实灰霉病害提供了理论依据。  相似文献   

15.
The effect of the treatment of chitosan at various concentrations (0.01%, 0.05%, 0.1%, 0.5%, and 1%) upon sweet basil (Ocimum basilicum L.) before seeding and transplanting was investigated in aspects of the amount of phenolic and terpenic compounds, antioxidant activity, and growth of the basil, as well as the phenylalanine ammonia lyase (PAL) activity. The total amount of the phenolic and terpenic compounds increased after the chitosan treatment. Especially, the amounts of rosmarinic acid (RA) and eugenol increased 2.5 times and 2 times, respectively, by 0.1% and 0.5% chitosan treatment. Due to the significant induction of phenolic compounds, especially RA, the corresponding antioxidant activity assayed by the DPPH (2,2-diphenyl-1-picrylhydrazyl) free radical scavenging test increased at least 3.5-fold. Also, the activity of PAL, a key regulatory enzyme for the phenylpropanoid pathway, increased 32 times by 0.5% chitosan solution. Moreover, after the elicitor chitosan treatment, the growth in terms of the weight and height of the sweet basil significantly increased about 17% and 12%, respectively. Our study demonstrates that an elicitor such as chitosan can effectively induce phytochemicals in plants, which might be another alternative and effective means instead of genetic modification.  相似文献   

16.
A series of biochemical parameters, including the concentration of total ascorbic acid (ASA(tot)) and the activities of phenylalanine ammonia lyase (PAL), polyphenol oxidase (PPO), and peroxidases (PODs), was investigated during cold storage (72 h at 4 degrees C in the dark) in fresh-cut (minimally processed) leaves of two lettuce (Lactuca sativa L. var. acephala) cultivars differing in the susceptibility to tissue browning: Green Salade Bowl (GSB), susceptible, and Red Salade Bowl (RSB), resistant. The two cultivars showed differences also at the biochemical level. The content in ASA(tot) increased in RSB, as a consequence of increased DHA concentration; conversely, ASA(tot) diminished in GSB, in which ASA was not detectable after 72 h of storage, thus suggesting a disappearance of ascorbate (both ASA and DHA) into nonactive forms. The antioxidant capacity (as determined by using FRAP analysis) decreased significantly during storage in RSB, while a strong increase was observed in GSB. PAL activity increased soon after processing reaching a maximum by 3 h, then it declined to a relatively constant value in RSB, while in GSB it showed a tendency to decrease in the first few hours from harvest and processing. POD activity, at least for chlorogenic acid, increased significantly during storage only in GSB.  相似文献   

17.
采用土培的方法,研究土壤中钙、氮含量对番茄接种枯萎病病原菌后其体内有效钙含量、干物质重及番茄抗病指标变化的影响。结果表明,接种病原菌后各处理番茄病情指数、叶片组织苯丙氨酸解氨酶(PAL)、多酚氧化酶(PPO)、过氧化物酶(POD)和过氧化氢酶(CAT)活性、丙二醛(MDA)和细胞膜透性均显著提高,以土壤有效钙为241.36 mg·kg-1、碱解氮为553.63 mg·kg-1条件下番茄有效钙含量及干物质重较高,病情指数较低、4种防御酶活性增加幅度较大且峰值较高,丙二醛和细胞膜透性较低,氮含量随土壤碱解氮的增加而增加。因此,在土壤碱解氮过多处理中施入适量钙肥可以缓解其对番茄抗枯萎病的抑制作用,提高钙素有效性,使番茄具有较高抗枯萎病能力。  相似文献   

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