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1.
丛枝菌根(arbuscular mycorrhizal,AM)真菌能与植物根系建立共生体提高植物抗病性。植物激素茉莉酸(jasmonic acid,JA)参与AM的形成,介导AM真菌诱导的植物抗病性。目前,关于AM真菌诱导的植物抗病性内容较为丰富,但是关于JA介导的AM真菌诱导的植物抗病性却有待进一步研究。本文首先总结了JA对AM形成和AM对植物内源JA积累的影响;其次介绍了AM真菌对植物抗病性影响及诱导机制;最后从诱导形成防御结构、提高酶活性及合成防御蛋白、诱导次生代谢物质合成、诱导调控信号分子、JA与其他激素相互作用五个方面探讨了JA在AM真菌诱导抗病性中的作用,并对本领域的研究方向进行展望,以期为植物病害防治和菌根研究提供可借鉴的思路。  相似文献   

2.
通过对毛乌素沙地草木樨(Melilotus suaveolens)、胡枝子(Leapedeza bicolor)和沙打旺(Astragalus adsurgens)等3种豆科植物根际土壤样品和根样的采集和分析,研究了3种植物根际AM真菌的群落组成和生态分布.试验结果表明,在已分离出的3属28种AM真菌中,球囊霉属(Glomus)种类占绝对优势;3种豆科植物都有较高的AM真菌定殖率和孢子密度,但不同种之间或同一种植物在不同样地之间的AM真菌种类和分布差异显著.AM真菌泡囊定殖率和总定殖率与土壤速效N有显著负相关,其定殖强度可能主要取决于宿主植物和AM真菌的相互选择性.  相似文献   

3.
为明确丛枝菌根(arbuscular mycorrhizal,AM)真菌对加拿大一枝黄花Solidago canadensis与本地菌根植物和非菌根植物种间竞争格局的调控作用,采用温室盆栽试验,通过接种摩西球囊霉Glomus mosseae(GM)、根内球囊霉G. intraradices(GI)及其混合菌种(GM+GI)3种处理,分析AM真菌对加拿大一枝黄花与本地菌根植物玉米Zea mays和非菌根植物油菜Brassica campestris种间作用的影响。结果表明:与对照相比,接种AM真菌均显著提高了加拿大一枝黄花和玉米的菌根侵染率,菌根侵染率为13.720%~50.015%,且前者的菌根侵染率明显高于后者。单独种植时,与对照相比,接种AM真菌尤其是接种混合菌种显著提高了加拿大一枝黄花的株高、叶片数和总干重。在加拿大一枝黄花与玉米混合种植时,与单独种植相比,加拿大一枝黄花的株高、叶片数、根长和总干重均较低;同时,与对照相比,接种AM真菌显著提高了玉米的相对竞争强度而对加拿大一枝黄花的相对竞争强度没有显著影响。在加拿大一枝黄花和油菜混合种植时,与对照相比,接种AM真菌则显著提高了加拿大一枝黄花的株高、叶片数、净光合速率和总干重;同时,接种AM真菌促进了入侵种的竞争优势而抑制了非菌根植物油菜的生长。说明加拿大一枝黄花与本地种的竞争格局受到与之混生物种的菌根依赖性强度以及AM真菌的种类差异影响。  相似文献   

4.
为探明新疆常见的 2 种建群植物胡杨(Populus euphratica)和骆驼刺(Alhagi sparsifolia)丛枝菌根真菌的侵染状况、群落的种类和分布,在塔里木河中游和昌吉老龙河下游的胡杨林分别采集了 13 个土壤和根系样,在骆驼刺根周围分别采集了 8 个土壤和根系样,对土样中丛枝菌根真菌的种类和根系菌根的侵染状况进行了分析.结果表明:胡杨根周围 AM 真菌的优势种为缩球囊霉(Glomus constrictum)、大果球囊霉(G.macrocarpum)、沙荒球囊霉(G.deserticola)、透光球囊霉(G.diaphanum)和象牙白球囊霉(G.eburneum).骆驼刺根周围 AM 真菌的优势种为沾屑多样孢囊霉(Diversispora spurcum)、摩西球囊霉(G.mosseae)和聚丛球囊霉(G.aggregatum).胡杨根系侵染频度和侵染强度分别可达80%和100%,骆驼剌根系侵染频度和侵染强度分别达65%和90%.说明胡杨和骆驼刺是丛枝菌根依赖性很强的植物,且丛枝菌根真菌的多样性也十分丰富.  相似文献   

5.
丛枝菌根(Arbuscular mycorrhizas,AM)真菌是土壤生态系统中广泛分布的优秀微生物资源,是具有重要经济价值的药用植物。本文基于人工培育条件下对中药材红花(Carthamus tinctorius)分别进行摩西球囊霉(Glomus mosseae)、根内球囊霉(Glomus intraradices)和混合菌(G. mosseae,Glomus etunicatum,Glomus microagregatum,Glomus caledonium,Glomus cladoideum和G. intraradices) 3种AM真菌接种处理,并以接种等量灭活菌种作为对照组处理。采用高效液相色谱法测定不同采摘时期红花绒中羟基红花黄色素A和山奈素含量的变化。结果表明:与对照组相比,AM真菌接种处理显著促进了红花生物量的积累,且AM真菌混合接种效果显著高于AM真菌单接种;在次生代谢产物合成方面,AM真菌接种处理以及不同采摘期的红花中羟基红花黄色素A和山奈素的含量差异不显著。表明AM真菌虽能促进红花的生长,但不影响羟基红花黄色素A和山奈素的合成。  相似文献   

6.
为了探明干旱环境下AM真菌形态结构及其生态适应性,2009年7月在内蒙古和河北农牧交错带选取4个样地,采集沙棘(Hippophae rhamnoides L.)根围土壤样品,利用光学显微镜和扫描电镜对分离的AM真菌进行分类鉴定。共分离鉴定3属17种AM真菌,其中球囊霉属(Glomus)11种,无梗囊霉属(Acaulospora)5种,盾巨孢囊霉属(Scutellospora)1种。沙棘AM真菌孢子具有体积小、颜色深、孢壁厚,整体形态不饱满等特征,表现出对干旱荒漠环境的生态适应性。扫描电镜下,不同属种孢子表面纹饰特征差异明显,可作为AM真菌属种分类的参考依据。  相似文献   

7.
AM真菌与西瓜枯萎病关系初探   总被引:31,自引:4,他引:27  
 在温室盆栽条件下研究了丛枝菌根(Arbuscular Mycorrhiza,AM)真菌Gigaspora rosea Nicol.& Schenck、Glomusmosseae(Nicol.& Gerd.) Gerdemann & Trappe和Glomus versiforme(Karsten) Berch与西瓜枯萎病菌(Fusariumoxysporum f. sp. niveum)的关系。结果表明,接种AM真菌能促进西瓜植株的生长发育,增加植株干重;显著减少根内和根围土壤中镰刀菌群体数量及其对根系的侵染率;降低枯萎病发病率和病情指数,从而减轻西瓜枯萎病的危害。接种F.oxysporum f. sp. niveum能降低AM真菌对西瓜的侵染率,并且AM真菌与镰刀菌的不同接种时间和顺序影响西瓜枯萎病的发生发展,证实AM真菌与镰刀菌存在竞争关系。另外,AM真菌对西瓜高感枯萎病品种的防治效果优于抗病品种,说明高感品种对菌根的依赖性较大。  相似文献   

8.
2004年7~12月在关中盆地西部,每月分别从0~10、10~20、20~30和30~40 cm 4个土层采集树莓根际土样,系统研究树莓根际AM真菌时空分布和土壤因子之间的相关性。结果表明,树莓能与AM真菌形成良好的共生关系。AM真菌的最高定殖率并不伴随有最大孢子密度,最高定殖率发生在9月,达86%,而最大孢子密度出现在11月,平均密度为14个/g土。土壤碱解氮与孢子密度呈极显著负相关,土壤有机质与孢子密度呈显著负相关,土壤pH与菌丝定殖率呈显著负相关,与泡囊定殖率呈极显著负相关。在检测和评估土壤生态状况和植物形成菌根的能力等方面,宿主植物根际AM真菌的孢子密度和AM真菌不同结构的定殖程度是十分有用的指标。  相似文献   

9.
通过从分布于山西、陕西和内蒙古三省区12个样地中的柠条锦鸡儿(Caragana korshinskii)根围采集土样和根样,系统研究了柠条锦鸡儿AM真菌种类组成和生态分布.试验结果表明,在已分离鉴定出的12种AM真菌中,球囊霉属(Glomus)6种,无梗囊霉属(Acaulospora)3种,巨孢囊霉属(Gigaspora)1种,盾巨孢囊霉属(Scutellospora)2种,而摩西球囊霉(Glomus mosseae)和缩球囊霉(Glomus constrictum)是优势菌种. AM真菌能与柠条锦鸡儿形成良好的共生结构,AM真菌平均总定殖率59.98%,平均孢子密度为830.59个/100 g土.不同采样地之间的AM真菌种类和分布差异显著.孢子密度与菌丝和总定殖率呈显著正相关;孢子密度与土壤速效N呈极显著正相关,丛枝定殖率与土壤有机质呈显著正相关,总定殖率和菌丝定殖率与土壤pH呈极显著正相关.  相似文献   

10.
为探索丛枝菌根(arbuscular mycorrhiza,AM)真菌与植食性昆虫的相互作用,将摩西管柄囊霉(Funneliformis mosseae BEG167,Fm)、根内球囊霉(Glomus intraradices BEG141,Gi)和地表球囊霉(Glomus versiforme Berch,Gv)3种AM真菌以及甜菜夜蛾Spodoptera exigua分别接种至花生和番茄上,通过测定AM真菌的侵染定殖和甜菜夜蛾的生长发育指标分析AM真菌与甜菜夜蛾的相互作用。结果显示,甜菜夜蛾取食菌根花生植株后,Fm、Gv和Gi的侵染率和泡囊数均有增加,侵染率分别是未取食的1.15、1.10和1.11倍,而Fm的泡囊数增加最显著,是未取食的1.27倍。在菌根番茄植株上,Fm和Gv的侵染率显著增加,分别是未取食的1.24倍和1.94倍,Fm、Gv和Gi的泡囊数均显著增加,分别是未取食的1.50、1.98和1.42倍。甜菜夜蛾取食菌根花生和菌根番茄植株后,幼虫存活率下降,幼虫历期和蛹期明显延长;Fm对其影响最显著,甜菜夜蛾在花生上的存活率、幼虫历期和蛹期分别为26.67%、26.78 d和10.67 d,在番茄上分别为35.52%、24.33 d和10.39 d,与取食非菌根植株处理差异显著。表明甜菜夜蛾能在一定程度上促进AM真菌的侵染和定殖,而AM真菌能抑制甜菜夜蛾的生长和发育,但其影响因AM真菌种类而不同。  相似文献   

11.
Arbuscular mycorrhiza (AM) colonization led to a decrease in the severity of fusarium wilt disease caused by Fusarium oxysporum f. sp. lycopersici in tomato plants. The involvement of two plant defense hormones, namely methyl jasmonate (MeJA) and salicylic acid (SA), in the expression of mycorrhiza induced resistance (MIR) against this vascular pathogen was studied in the AM colonized and non-colonized (controls) plants. Activity of lipoxygenase (LOX), which plays a role in jasmonic acid (JA) biosynthesis, as well as levels of methyl jasmonate (MeJA) increased in AM colonized plants as compared to controls, but did not show any further changes in response to F. oxysporum inoculation. On the other hand, activity of phenylalanine ammonia lyase (PAL), which is an enzyme from salicylic acid (SA) biosynthetic pathway, as well as SA levels, increased in both controls and AM colonized plants in response to application of F. oxysporum spores. Hence the JA and not the SA signalling pathway appeared to play a role in the expression of MIR against this vascular pathogen. The resistance observed in AM colonized plants was completely compromised when plants were treated with the JA biosynthesis inhibitor salicylhydroxamic acid (SHAM). This confirmed that the AM-induced increase in JA levels was involved in the expression of resistance toward F. oxysporum. The SA response gene pathogenesis-related 1 (PR1) showed an increased expression in response to F. oxysporum infection in SHAM treated AM colonized plants as compared to plants that were not treated with this JA inhibitor. This suggested the possibility that JA inhibited SA responses, at least in the roots. AM colonization therefore appeared to prime plants for improved tolerance against the vascular pathogen F. oxysporum, which was mediated through the JA signalling pathway.  相似文献   

12.
The root-knot nematode, Meloidogyne incognita, is among the most damaging agricultural pests, particularly to tomato. The mutualistic endophytes Fusarium oxysporum strain Fo162 (Fo162) and Rhizobium etli strain G12 (G12) have been shown to systemically induce resistance toward M. incognita. By using triple-split-root tomato plants, spatially separated but simultaneous inoculation of both endophytes did not lead to additive reductions in M. incognita infection. More importantly, spatially separated inoculation of Fo162 and G12 led to a reduction in Fo162 root colonization of 35 and 39% when G12 was inoculated on a separate root section of the same plant in two independent experiments. In an additional split-root experiment, spatial separation of Fo162 and G12 resulted in a reduction of Fo162 root colonization of approximately 50% over the water controls in two independent experiments. The results suggested that the suppressive activity of G12 on Fo162 and M. incognita is possibly related to the induction of specific plant defense mechanisms. Thus, although Fo162 and G12 have the ability to systemically repress M. incognita infection in tomato, they can be considered incompatible biocontrol agents when both organisms are present simultaneously on the same root system.  相似文献   

13.
When the biocontrol agent Pythium oligandrum (PO) colonizes the rhizosphere, it suppresses bacterial wilt disease in tomato (Solanum lycopersicum cv. Micro‐Tom) caused by Ralstonia solanacearum, and a homogenate of its mycelia exhibits elicitor activity, inducing an ethylene (ET)‐dependent defence response in Micro‐Tom. Since salicylic acid (SA) and jasmonic acid (JA) play an important role in plant defence responses to pathogens, the involvement of SA‐ and JA‐dependent signal transduction pathways in resistance to R. solanacearum was investigated in tomato roots treated with a mycelial homogenate of PO. Bacterial wilt disease was also suppressed in tomato cv. Moneymaker treated with the PO homogenate. However, the SA‐inducible PR‐1(P6) gene was not up‐regulated in either Micro‐Tom or Moneymaker. SA did not accumulate in homogenate‐treated roots in comparison with distilled water‐treated controls, even 24 h after inoculation. Induced resistance against R. solanacearum was not compromised in SA‐non‐accumulating NahG transgenic plants treated with the PO homogenate. On the other hand, the expression of the JA‐responsive gene for the basic PR‐6 protein was induced in both tomato cultivars treated with the PO homogenate. Furthermore, quantitative disease assays showed that the induced resistance against R. solanacearum was compromized in PO homogenate‐treated jai1‐1 mutant plants defective in JA signalling. These results indicated that the JA‐dependent signalling pathway is required for PO‐induced resistance against R. solanacearum in tomato.  相似文献   

14.
Recent evidence suggests that nitric oxide (NO) signaling plays an important role in plant–pathogen interactions and that aconitase is a major target of NO. In the present study on the signaling role of NO in the elicitation of defense responses in peach fruit against Monilinia fructicola and subsequent effect on brown rot disease, 15 μM NO solution induced disease resistance in harvested peaches. As a potentiated elicitor, NO induced high levels of endogenous NO and superoxide (O2 ?), hydrogen peroxide (H2O2), and NADPH oxidase and Ca2+-ATPase activity in the fruit. Aconitase activity in peach fruit was inhibited by NO. Activity of partially purified aconitase was inhibited in vitro by sodium nitroprusside (SNP) and H2O2; however, the inhibition could be relieved by carboxy-2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl 3-oxide (cPTIO) or catalase (CAT), indicating that the defense response and signals induced by NO transduction depend on aconitase and conditions leading to elevated levels of NO; otherwise, H2O2 would inactivate aconitase directly in fruit. Treatment with NO resulted in salicylic acid (SA) accumulating during storage. Higher levels of jasmonic acid (JA) were detected in NO-treated fruit 48 h after the treatment. But after NO was removed, the level of SA and JA were lower than in the control. The results suggest that exogenous NO enhances resistance of harvested peach fruit against the fungus by inducing signals such as endogenous NO, reactive oxygen species (ROS), SA and JA and by inhibiting aconitase activity.  相似文献   

15.
[目的]明确在多种植物病原物和植物激素处理下,辣椒CaRKNIF2基因的诱导表达特性,分析CaRKNIF2基因的抗根结线虫功能.[方法]以辣椒‘HDA149’为试材,分别接种南方根结线虫毒性群体、烟草花叶病毒(TMV)、辣椒青枯病菌、辣椒疫霉病菌以及信号分子水杨酸(SA)和茉莉酸甲酯(MeJA),实时荧光定量PCR分析了辣椒CaRKNIF2基因的诱导表达模式和特征;构建了含CaRKNIF2基因片段的RNAi载体,通过烟草脆裂病毒介导的基因沉默(VIGS)同源沉默辣椒CaRKNIF2基因,来评价CaRKNIF2基因沉默的辣椒植株对线虫侵染的应答效应.[结果]信号分子MeJA抑制CaRKNIF2的表达,但TMV、辣椒青枯病菌、辣椒疫霉病菌以及信号分子水杨酸(SA)能快速而显著地诱导CaRKNIF2的表达,而毒性南方根结线虫对CaRKNIF2的表达则基本无影响;CaRKNIF2基因沉默的辣椒植株接种非毒性南方根结线虫后根部卵块数明显增加.[结论]这些结果为进一步解析CaRKNIF2的调控功能提供了重要的证据.  相似文献   

16.
Desert ephemeral plants play an important role in desert ecosystem.Soil water availability is considered as the major restrictive factor limiting the growth of ephemeral plants.Moreover,arbuscular mycorrhizal fungi(AM fungi) are widely reported to improve the growth of desert ephemerals.The present study aimed to test the hypothesis of that AM fungi could alleviate drought stress of desert ephemeral Plantago minuta,and AM fungal functions reduced with the improvement of soil water content.A pot experiment was carried out with three levels of soil water contents(4.5%,9.0%,and 15.8%(w/w)),and three AM inoculation treatments(Glomus mosseae,Glomus etunicatum and non-inoculation).The results indicate that mycorrhizal colonization rate decreased with the increase of soil water availability.Inoculation improved plant growth and N,P and K acquisition in both shoots and roots regardless water treatments.When comparing the two fungi,plants inoculated with G.mosseae performed better than those inoculated with G.etunicatum in terms of plant growth and nutrient acquisition.These results showed that ameliorative soil water did not suppress arbuscular mycorrhizal fungal functions in improving growth and nutrient acquisition of desert ephemeral Plantago minuta.  相似文献   

17.
葡萄感染霜霉病菌后几种信号物质的变化   总被引:1,自引:0,他引:1  
以3个抗病性不同的酿酒葡萄品种(‘西拉’‘霞多丽’‘赤霞珠’)叶片为材料,检测霜霉病菌侵染后几种病原相关信号物质,如脱落酸(ABA)、过氧化氢(H2O2)、一氧化氮(NO)、茉莉酸(JA)和乙烯(ETH)等的变化,以探讨葡萄抵御霜霉病菌的信号转导机制。结果表明,H2O2和NO是葡萄感应霜霉病菌的早期信号分子,且抗性较强的品种‘西拉’的变化最为明显;JA和ABA是抗性较差品种‘赤霞珠’应答霜霉病的信号组分。而3个抗性不同葡萄品种的乙烯变化无明显差别。推测H2O2、NO、JA和ABA均参与了葡萄对霜霉病菌的防御反应,但不同品种间信号转导组分可能存在差异。  相似文献   

18.
 红灰链霉菌Streptomyces rubrogriseus HDZ-9-47分离自根结线虫的卵,它既可寄生南方根结线虫,又可产生具杀线虫活性的代谢产物。本研究通过田间试验评价了HDZ-9-47发酵液对南方根结线虫的防治效果,以及对番茄产量和品质的影响;并测定了施用HDZ-9-47对番茄根部几种防御酶的影响。结果表明,在番茄移栽90 d后,穴施HDZ-9-47发酵液处理的防效达61.5%,并且促进番茄增产17.9%,增加了番茄果实中可溶性糖的含量,但对番茄茎粗无显著影响。此外,施用HDZ-9-47发酵液可提高番茄根部多酚氧化酶(PPO)、过氧化物酶(POD)、苯丙氨酸解氨酶(PAL)和超氧化物歧化酶(SOD)的活性,进而诱导番茄产生抗性。  相似文献   

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