Effects of phosphate solubilization and phytohormone production of Trichoderma asperellum Q1 on promoting cucumber growth under salt stress

Salinity is one of the major abiotic stresses limiting crop growth and yield.This study investigated the underlying mechanisms of Trichoderma asperellum Q1 in promoting cucumber growth under salt stress, including the abilities of the strain to solubilize phosphate and to produce phytohormone.The results showed that T.asperellum Q1 could solubilize inorganic or organic phosphate and the activities of phosphatases and phytase could be detected in the culture supernatant.In hydroponic experiments, the growth of cucumber seedlings was increased in the hydroponic system treated by culture filtrate of strain Q1 with tricalcium phosphate or calcium phytate under salt stress.This strain also exhibited the ability to produce indole acetic acid(IAA), gibberellic acid(GA) and abscisic acid(ABA) in liquid medium without any inducers.The levels of those three phytohormones in cucumber seedling leaves also increased after inoculated with this strain, along with increased root growth and root activities of the plant.These results demonstrated the mechanisms of T.asperellum Q1 in alleviating the suppression effect of salt stress involving the change of phytohormone levels in cucumber plant and its ability of phosphate solubilization.     

一株促生拮抗木霉菌的鉴定

从采集的植物根际土壤中分离到一株对黄瓜具有拮抗作用的木霉菌LT19,该菌能够促进黄瓜幼苗的生长,并具有溶磷、产嗜铁素、IAA及ACC脱氨酶的能力,显示了该菌在防治作物病害以及促进作物生长方面潜在的应用价值。根据形态特征与ITS序列分析,将其鉴定为棘孢木霉(Trichoderma asperellum)。     

Evaluating effective Trichoderma isolates for biocontrol of Rhizoctonia solani causing root rot of Vigna unguiculata

The highly diverse genus Trichoderma has provided many formulations that are alternatives to the chemical pesticides in agriculture. The present study was undertaken to investigate the biocontrol potential of eight Trichoderma species, T. atrobrunneum, T. guizhouense, T. paratroviride, T. pyramidale, T. rufobrunneum, T. simmonsii, T. thermophilum and T. viridulum, against the phytopathogenic fungus Rhizoctonia solani. Trichoderma isolates were first evaluated in vitro by dual culture tests for their antagonism, mycoparasitic ability and antifungal activity against R. solani. Their growth promoting potential was further assessed in relation to phosphate solubilization, indole acetic acid and siderophore production. Five of the isolates were selected and evaluated for their abilities to prompt plant growth and to control R. solani infecting Vigna unguiculata(cowpea) seedlings in vivo. Two most effective isolates, T. guizhouense 9185 and T. simmonsii 8702, significantly(P0.05) reduced the disease severity incidences(36.6 and 45.0%, respectively) and promoted plant growth, which have good prospects for application.     

黄腐酸对番茄幼苗适应低磷胁迫的生理调控作用

【目的】磷是植物生长发育的关键元素之一,缺磷会严重影响作物的产量和质量。黄腐酸作为一种天然有机物,在促进植物生长的同时还能提高植物的抗逆能力。开展黄腐酸对番茄幼苗适应低磷胁迫生理调控作用研究,明确黄腐酸对番茄适应低磷胁迫的生理调控机制,对黄腐酸缓解番茄“遗传学缺磷”的概念和机理做出合理解释。【方法】采用Hogland营养液水培方式,以番茄‘金棚1号’为供试品种,待番茄幼苗长到三叶一心时移到水培盆中缓苗7 d,外源添加不同浓度（0、0.04、0.08、0.12、0.16和0.20 g·L^-1）黄腐酸,研究其对低磷胁迫（10 μmol·L^-1）下番茄幼苗生长、根系发育、光合作用性能、磷素吸收和分配、有机酸积累和分泌等生理过程的影响。【结果】低磷胁迫下,随着黄腐酸施用量的增加,番茄幼苗的各项生理指标基本呈现先增后降趋势。当黄腐酸的施用浓度为0.08 g·L^-1时,显著提高根冠比;增加叶绿素含量,提高叶片光合作用性能;提高番茄不同组织中磷素积累、分配和转运;提高磷转运相关基因（PT1和PHO1）的表达,其中PT1能促进番茄幼苗根系向环境中吸收磷酸盐缓解低磷胁迫;PHO1能促进磷酸盐由根系向茎叶分配从而有效缓解地上部缺磷。黄腐酸能提高根系有机酸（草酸、苹果酸、柠檬酸、琥珀酸和酒石酸）积累,降低根系中无氧呼吸产物乳酸和乙酸含量,促进质子泵基因（HA1）的表达,促进根系泌酸,这种生理代谢变化有利于将环境中难溶性的磷转变为可溶性的磷,并促进植物根系对磷素吸收;增强生长发育相关转录因子（GRAS1）表达,降低叶片花青素积累。【结论】通过低磷胁迫下添加一定浓度的黄腐酸可明显改善番茄幼苗地上部生长及根系发育,可在一定程度上缓解植物的缺磷症状。     

棘孢木霉分泌蛋白和效应子的预测及分析

棘孢木霉(Trichoderma asperellum)作为一种生防菌,在植物病害的防控中具备较高的开发以及利用价值.根据棘孢木霉CBS 433.97菌株全基因组测序获得的12557个蛋白序列,利用SignalP、TargetP、TMHMM、WoLF PSORT和big-PI Predictor生物信息学软件和预测程序...     

Mechanisms involved in biocontrol and plant induced resistance by richoderma. asperellum (T. harzianum T-203)

Growing awareness of the environmental damage caused by the use of chemical substances for plant disease control in agriculture has raised the need to study biological alternatives, such as activating the defense response of plant crops by inducers not toxic to the environment. Trichoderma spp. are effective biocontrol agents for a number of soilborne pathogens, and are also known for their ability to enhance plant growth and to induce systemic resistance (ISR) in plants. In our laborator…     

低分子量有机酸对石灰性潮土磷吸附与解吸的影响

采用磷的平衡吸附与解吸方法，模拟缺磷胁迫条件下植物根系分泌的有机酸种类和数量，研究了草酸、柠檬酸、苹果酸、酒石酸、乙酸5种有机酸对石灰性潮土磷吸附的影响，并以作用能力较强的草酸为代表，研究了有机酸对石灰性潮土磷吸附和解吸的影响。结果表明：（1）中性条件下供试有机酸均能不同程度的降低石灰性潮土对磷的吸附，作用强弱依次为草酸、柠檬酸＞苹果酸、酒石酸＞乙酸。（2）有机酸使土壤对磷吸附的降低效应随着有机酸浓度和有机酸与磷浓度比的增加而增加。（3）石灰性潮土在草酸体系中所吸附的磷容易被中性盐解吸，有机酸对土壤吸附磷的解吸有一定的促进作用。     

拮抗木霉菌的生防机制研究进展

从拮抗木霉菌的抑茵作用机理、诱导抗病性、促进植物生长等方面对木霉菌生防机制的研究进行了综述,并对其应用前景进行了概括。从生防功能的多样性来看,木霉菌是一种理想的生防菌株和难得的生防资源。     

植物酸性磷酸酶的研究进展

酸性磷酸酶是植物体和土壤中普遍存在的一种非常重要的水解酶,其活性高低与植物体和土壤中的磷素丰缺状况有着密切的联系.低磷胁迫能够诱导植物体内和根系分泌的酸性磷酸酶活性显著增加,并且酸性磷酸酶活性的增加能够促进有机磷的水解,因此,研究植物酸性磷酸酶及其在磷胁迫条件时诱导分泌的机理对于植物磷营养性状的遗传改良、挖掘土壤有机磷资源、缓解世界磷矿资源短缺矛盾以及减少环境污染等方面都具有重要的现实意义.本文从磷胁迫条件下植物体内和根际酸性磷酸酶活性变化、根系分泌机理以及酸性磷酸酶与土壤有机磷有效性等方面进行综述.     

草酸青霉和棘孢木霉对青枯劳尔氏菌的生防效果

  目的  探究自主筛选获得的2株生防菌棘孢木霉Trichoderma asperellum QZ2与草酸青霉Penicillium oxalicum QZ8对青枯劳尔氏菌Ralstonia solanacearum(简称青枯菌)的生防效果。  方法  以青枯菌作为靶标菌,通过平板培养法、生长曲线法测定2株生防菌及其发酵液对青枯菌生长的抑制作用;通过土培试验、基于稀释涂布法测定生防菌在土壤中对青枯菌的抑制效果。  结果  平板对峙培养试验发现:棘孢木霉QZ2和草酸青霉QZ8对青枯菌有显著的抑制作用(P＜0.05),抑制率分别达80.9%和45.9%;棘孢木霉QZ2与草酸青霉QZ8生防菌高温灭菌发酵液对平板培养青枯菌,同样呈显著的抑制作用(P＜0.05),抑制率分别达33.3%和34.8%。无菌滤膜处理的未高温灭菌2株生防菌发酵液的青枯菌液培养结果表明:其D(600)显著小于未添加生防菌发酵液的对照D(600)(P＜0.05),且棘孢青霉QZ8抑制效果好于草酸木霉QZ2。土壤培养结果显示:2株生防菌处理的土壤中青枯菌的活菌数量显著低于未添加生防菌的对照(P＜0.05)。  结论  棘孢木霉QZ2和草酸青霉QZ8对青枯菌均有显著的抑制效果,可作为番茄Lycopersicon esculentum青枯病的潜在生防菌。图5表2参32     

优良植物根际促生菌的筛选及其生物学特性

为获得能应用于环保微生物肥料中性状优良的植物根际促生菌,根据菌株的固氮、溶磷和解钾能力,经过初筛和复筛从不同土壤样本中分离得到1株芽孢杆菌(Bacillus velezensis)(LPL-410.7)。全基因组分析结果显示,该菌株基因组的大小为3 907 842 bp, GC含量为46.66%,可编码3 743个基因/蛋白;生物信息学注释结果显示,LPL-410.7中与促进植物生长相关的功能基因59个,参与次级代谢产物的合成、辅酶运输和代谢、氨基酸运输与代谢等通路途径。进一步的菌株特性试验结果显示,LPL-410.7能够分泌蛋白酶及纤维素酶,并能产生相对表达量为51.78%的铁载体;采用酶联免疫吸附法检测到该菌株亦能产生植物激素吲哚乙酸、赤霉素和细胞分裂素;LPL-410.7在pH 3～10和盐质量浓度为0～15 g/L时均能存活;菌株自凝集性达到88.77%,且具有较强的自由基清除能力。全基因组分析结果与菌株解有机磷、产生促生抗病相关物质(铁载体、吲哚乙酸、纤维素酶和蛋白酶)的实际功能相符合。综合评定,贝莱斯芽孢杆菌LPL-410.7是一株优良的植物根际促生菌,具有很好的开发利用价...     

有机酸对不同磷源施入土壤后速效磷变化的影响

采用室内无菌培养方法,模拟缺磷胁迫条件下植物根系分泌的有机酸种类和数量,研究草酸、 柠檬酸、苹果酸、酒石酸、腐殖酸5种有机酸对不同磷源施入土壤后速效磷动态变化的影响。结果表 明:不同磷源施入土壤后都会使土壤中速效磷含量增加,而后随时间的推移,速效磷含量迅速下降, 大约30-45d后趋于稳定;供试有机酸均能增加土壤速效磷含量,能明显减弱速效磷含量随时间而降 低的趋势,使得土壤速效磷含量在较长的一段时间内保持较高的水平;有机酸对石灰性潮土速效磷 动态变化影响能力因有机酸种类和性质的不同而不同,其作用能力大小顺序为:草酸、腐殖酸>柠檬 酸、苹果酸>酒石酸。     

Use of Hypocrea jecorina (anamorph Trichoderma reesei) as a model system for Trichoderma biocontrol of Pythium blight identifies new targets for genetic strain improvement

Biocontrol by Trichoderma has been studied mainly with selected isolates of T. harzianum, T. atroviride and T. asperellum, which are members of sections Pachybasium and Trichoderma. In contrast, species from section Longibrachiatum have only rarely been studied. On the other hand, one taxon from this section-Hypocrea jecorina (anamorph: Trichoderma reesei)-has been widely used for the production of cellulolytic and hemicellulolytic enzymes and recombinant proteins. As far as T…     

Screening of Trichoderma strains tolerant to benzimidazole

The screening of isolates and the assay of biocontrol mechanisms of Trichoderma were studied systematically in laboratory and greenhouse in vivo. The proteins tolerant to benzimidazole in Trichoderma strains were purified, and their physical and chemical properties were detected. Compared their biological activities in vitro and vivo in greenhouse, nine biocontrol strains (including Ty-10-2,LTR-2,Tj-5-1,Tj-5-4,Ty-11-1,Tj-11-3,Ty-11-3,Tj-3-3-2,Tj-3-3-4) were screened. These bioco…     

小盐芥耐盐机制的研究进展

盐胁迫是世界上大多数国家和地区在农业生产上一直存在的问题,极大地威胁着植物的生长发育和世界各国的农业生产。在盐胁迫条件下,植物产生了一系列的生理生化变化,包括：细胞质膜解体,活性氧增多,光合作用受到抑制以及代谢有毒物质的积累等,甚至是植株的死亡。理解盐胁迫对植物生理生化代谢的影响,有利于改善植物生长条件,提高农作物的产量和品质,也为遗传工程提供有力证据。小盐芥是与模式植物拟南芥亲缘关系较近的极端耐盐植物,是研究植物耐受非生物胁迫逆境机理的理想材料。该文根据近年来该领域已有的研究成果阐述了小盐芥耐盐机制方面的研究进展。     

酸性条件下Al3+对苜蓿根瘤菌溶磷和分泌生长素能力的影响

采用溶磷圈和Salkowski比色法,对酸性条件下铝对耐酸性能极优的两种根瘤菌溶磷和分泌生长素能力的影响进行了研究.结果表明,两种根瘤菌都具有较强的溶磷和分泌生长素的能力,且溶解无机磷的能力更强.在铝毒胁迫下,两菌株均表现出了一定的耐受性,随着铝离子浓度的增加,铝对溶磷和分泌生长素的能力抑制作用增强,相同条件下,菌株S...     

木霉菌REMI转化子解磷筛选及其解磷效果分析

[目的]为了获得具有防病和解磷双重功能的木霉菌REMI转化子。[方法]从康氏木霉菌(Trichoderma koningii)T30及其60株REMI(限制性内切酶介导的基因整合技术)转化子中筛选出3株解磷作用较好的转化子,并研究不同碳、氮源对转化子TK!46解磷作用的影响。[结果]结果表明,碳源对转化子解磷能力影响较小,而氮源的作用较大,其中转化子在解磷过程中最适氮源是氨态氮。[结论]该研究为研制多功能木霉剂奠定了基础,但完全揭示木霉菌解磷机理仍需进一步研究。     

黄瓜根际促生真菌的筛选及促生效应研究

[目的]筛选黄瓜根际促生真菌,并探索其促生效应。[方法]以解磷、产IAA和拮抗黄瓜枯萎病菌能力为筛选标准测定初筛菌株的多项促生能力;通过种子萌发和盆栽试验测定菌株对黄瓜的促生效应;通过形态鉴定和r DNA-ITS序列分析对促生菌株进行分类学鉴定。[结果]从连作黄瓜根际土壤中分离到1株同时具解磷、产IAA和拮抗黄瓜枯萎的真菌,该菌株孢子悬浮液能有效促进黄瓜种子萌发和幼苗生长。形态学和分类学鉴定结果显示该菌株为哈茨木霉(Trichoderma harzianum)。[结论]所筛选的促生真菌能有效改善黄瓜连作障碍,为开发研制黄瓜专型促生制剂提供良好的种质资源。     

碱活化载镁橘皮生物炭除磷后对土壤的改良作用

改性生物炭作为一种新型环保材料常被用于污水吸附除磷,然而吸附除磷后的改性生物炭若不妥善处理可能会对环境造成二次污染。为促进吸附除磷后生物炭的资源化、无害化利用,本研究将吸附除磷后的载镁橘皮生物炭(KMg-BC/P)用于土壤改良及大豆栽培。结果表明:添加适量的KMg-BC/P能显著提高土壤的pH、有机质含量、阳离子交换量、有效磷含量、总磷含量、磷素的释放量以及持水能力;同时增加土壤中高效磷源和缓效磷源的含量,提高土壤碱性磷酸酶活性,促进无机磷和低活性有机磷向高活性有机磷转化;此外其还能促进土壤中细菌的生长繁殖,同时降低真菌的数量和多样性。用KMg-BC/P改良后的土壤种植大豆能促进大豆的生长,使大豆的发芽率、植株高度、根长、叶片数量、大豆植株鲜质量和茎粗均优于对照组。因此,KMg-BC/P具有作为土壤改良剂的潜力。     

Prospects for the use of strains of the genus Trichoderma to obtain vermicomposts with fungicides and growth-stimulating properties

The addition of the Trichoderma asperellum MG-97 strain and of a biological product Trichodermin-M based on it enables the reduction in terms of composting of organic wastes. As a result of composting, one observes an increase in the biomass of worms with a high proportion of mature individuals in comparison with the control. The obtained biopreparation has increased fungicide and plant growth-stimulating properties.