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1.
Romana Gaderer Netta L Lamdan Alexa Frischmann Michael Sulyok Rudolf Krska Benjamin A Horwitz Verena Seidl-Seiboth 《BMC microbiology》2015,15(1)
Background
The proteins Sm1 and Sm2 from the biocontrol fungus Trichoderma virens belong to the cerato-platanin protein family. Members of this family are small, secreted proteins that are abundantly produced by filamentous fungi with all types of life-styles. Some species of the fungal genus Trichoderma are considered as biocontrol fungi because they are mycoparasites and are also able to directly interact with plants, thereby stimulating plant defense responses. It was previously shown that the cerato-platanin protein Sm1 from T. virens - and to a lesser extent its homologue Epl1 from Trichoderma atroviride - induce plant defense responses. The plant protection potential of other members of the cerato-platanin protein family in Trichoderma, however, has not yet been investigated.Results
In order to analyze the function of the cerato-platanin protein Sm2, sm1 and sm2 knockout strains were generated and characterized. The effect of the lack of Sm1 and Sm2 in T. virens on inducing systemic resistance in maize seedlings, challenged with the plant pathogen Cochliobolus heterostrophus, was tested. These plant experiments were also performed with T. atroviride epl1 and epl2 knockout strains. In our plant-pathogen system T. virens was a more effective plant protectant than T. atroviride and the results with both Trichoderma species showed concordantly that the level of plant protection was more strongly reduced in plants treated with the sm2/epl2 knockout strains than with sm1/epl1 knockout strains.Conclusions
Although the cerato-platanin genes sm1/epl1 are more abundantly expressed than sm2/epl2 during fungal growth, Sm2/Epl2 are, interestingly, more important than Sm1/Epl1 for the promotion of plant protection conferred by Trichoderma in the maize-C. heterostrophus pathosystem.Electronic supplementary material
The online version of this article (doi:10.1186/s12866-014-0333-0) contains supplementary material, which is available to authorized users. 相似文献2.
Netta-Li Lamdan Samer Shalaby Tamar Ziv Charles M. Kenerley Benjamin A. Horwitz 《Molecular & cellular proteomics : MCP》2015,14(4):1054-1063
Trichoderma virens is a biocontrol agent used in agriculture to antagonize pathogens of crop plants. In addition to direct mycoparasitism of soil-borne fungal pathogens, T. virens interacts with roots. This interaction induces systemic resistance (ISR), which reduces disease in above-ground parts of the plant. In the molecular dialog between fungus and plant leading to ISR, proteins secreted by T. virens provide signals. Only a few such proteins have been characterized previously. To study the secretome, proteins were characterized from hydroponic culture systems with T. virens alone or with maize seedlings, and combined with a bioassay for ISR in maize leaves infected by the pathogen Cochliobolus heterostrophus. The secreted protein fraction from coculture of maize roots and T. virens (Tv+M) was found to have a higher ISR activity than from T. virens grown alone (Tv). A total of 280 fungal proteins were identified, 66 showing significant differences in abundance between the two conditions: 32 were higher in Tv+M and 34 were higher in Tv. Among the 34 found in higher abundance in Tv and negatively regulated by roots were 13 SSCPs (small, secreted, cysteine rich proteins), known to be important in the molecular dialog between plants and fungi. The role of four SSCPs in ISR was studied by gene knockout. All four knockout lines showed better ISR activity than WT without affecting colonization of maize roots. Furthermore, the secreted protein fraction from each of the mutant lines showed improved ISR activity compared with WT. These SSCPs, apparently, act as negative effectors reducing the defense levels in the plant and may be important for the fine tuning of ISR by Trichoderma. The down-regulation of SSCPs in interaction with plant roots implies a revision of the current model for the Trichoderma-plant symbiosis and its induction of resistance to pathogens.Fungi belonging to the genus Trichoderma are used as biocontrol agents in agriculture. In addition to direct antagonism of soil-borne pathogens, these fungi intimately interact with plant roots, and are thus considered rhizosphere-competent (1). The interaction is, in general, a beneficial one, promoting plant growth as well as inducing systemic resistance (ISR)1 to pathogens (2–6). The elicitation of defense response in the leaves of plants whose roots are colonized with Trichoderma enhances the plant''s resistance to foliar pathogens. This clear potential for application in agriculture is already beginning to be realized (7–9).Secreted proteins are central to the molecular dialog between fungi and their plant hosts. Recent studies addressed, for example, the molecular basis for mutualistic interactions between soil fungi and plants in mycorrhizae, a fungus-root symbiosis of widespread importance for nutrient acquisition. Specific secreted proteins were found to have targets in the plant (10, 11). The Trichoderma-root mutualism is distinct from these well-studied mycorrhizal symbioses, but some of the principles may be shared. Proteomic studies on several Trichoderma species have been reviewed (12). These studies employed total protein extracts from Trichoderma interacting with plants, or the three-way Trichoderma-plant-pathogen interaction (13, 14), and led to the identification of some secreted proteins expressed during the interaction with plant and fungal hosts. Indeed, the first studies of secreted proteins demonstrated an abundant Trichoderma secreted protein, belonging to the ceratoplatanins, which are a fungal family of secreted elicitors and toxins. This protein, Sm1 (in T. virens)/Epl1 (in T. atroviride (15–20) was shown to elicit ISR. The ceratoplatanin Sm1/Epl1 also belongs to a larger class of fungal proteins defined as SSCPs or SSPs: small, secreted (cysteine rich) proteins (21–23). There are no sequence motifs or domains common to the members of the entire SSCP class. Within the wide definition, though, there are subfamilies of proteins that do share sequence homology, for example the ceratoplatanin family to which Sm1 belongs.A bioinformatic survey of the SSCPs encoded in the genomes of three Trichoderma species, T. virens (Tv), T. atrovirde (Ta), and T. reesei (Tr) revealed several hundred candidate SSCPs in each species (24). Approximately half of the SSCPs from each species have homologs in the same and/or in the other two species, whereas the other half are unique and do not share homology in or between the species. This diversity between the three species suggests that SSCPs are evolving rapidly.Given the known importance of Sm1, and the wide host range of Trichoderma species, it seemed likely that many SSCPs might be involved in the Trichoderma-root interaction. Secreted proteins (with emphasis on SSCPs), whose abundance changes in response to association with plant roots, may function in the fungal-plant molecular dialog. To test the hypothesis that the abundance of specific SSCPs and other secreted proteins is regulated by the interaction with plant roots, we compared the secretome of Trichoderma alone to the secretome of Trichoderma cocultured with the roots of maize seedlings. Functional experiments using knock out mutants in the genes encoding some of the regulated SSCPs were carried out in order to shed light on their role in the molecular interaction between the plant and the fungus. 相似文献
3.
Kubicek CP Herrera-Estrella A Seidl-Seiboth V Martinez DA Druzhinina IS Thon M Zeilinger S Casas-Flores S Horwitz BA Mukherjee PK Mukherjee M Kredics L Alcaraz LD Aerts A Antal Z Atanasova L Cervantes-Badillo MG Challacombe J Chertkov O McCluskey K Coulpier F Deshpande N von Döhren H Ebbole DJ Esquivel-Naranjo EU Fekete E Flipphi M Glaser F Gómez-Rodríguez EY Gruber S Han C Henrissat B Hermosa R Hernández-Oñate M Karaffa L Kosti I Le Crom S Lindquist E Lucas S Lübeck M Lübeck PS Margeot A 《Genome biology》2011,12(4):R40
Background
Mycoparasitism, a lifestyle where one fungus is parasitic on another fungus, has special relevance when the prey is a plant pathogen, providing a strategy for biological control of pests for plant protection. Probably, the most studied biocontrol agents are species of the genus Hypocrea/Trichoderma.Results
Here we report an analysis of the genome sequences of the two biocontrol species Trichoderma atroviride (teleomorph Hypocrea atroviridis) and Trichoderma virens (formerly Gliocladium virens, teleomorph Hypocrea virens), and a comparison with Trichoderma reesei (teleomorph Hypocrea jecorina). These three Trichoderma species display a remarkable conservation of gene order (78 to 96%), and a lack of active mobile elements probably due to repeat-induced point mutation. Several gene families are expanded in the two mycoparasitic species relative to T. reesei or other ascomycetes, and are overrepresented in non-syntenic genome regions. A phylogenetic analysis shows that T. reesei and T. virens are derived relative to T. atroviride. The mycoparasitism-specific genes thus arose in a common Trichoderma ancestor but were subsequently lost in T. reesei.Conclusions
The data offer a better understanding of mycoparasitism, and thus enforce the development of improved biocontrol strains for efficient and environmentally friendly protection of plants. 相似文献4.
5.
Background
Plant sucrose transporter activities were shown to respond to changes in the extracellular pH and redox status, and oxidizing compounds like glutathione (GSSG) or H2O2 were reported to effect the subcellular targeting of these proteins. We hypothesized that changes in both parameters might be used to modulate the activities of competing sucrose transporters at a plant/pathogen interface. We, therefore, compared the effects of redox-active compounds and of extracellular pH on the sucrose transporters UmSRT1 and ZmSUT1 known to compete for extracellular sucrose in the Ustilago maydis (corn smut)/Zea mays (maize) pathosystem.Methodology/Principal Findings
We present functional analyses of the U. maydis sucrose transporter UmSRT1 and of the plant sucrose transporters ZmSUT1 and StSUT1 in Saccharomyces cerevisiae or in Xenopus laevis oocytes in the presence of different extracellular pH-values and redox systems, and study the possible effects of these treatments on the subcellular targeting. We observed an inverse regulation of host and pathogen sucrose transporters by changes in the apoplastic pH. Under none of the conditions analyzed, we could confirm the reported effects of redox-active compounds.Conclusions/Significance
Our data suggest that changes in the extracellular pH but not of the extracellular redox status might be used to oppositely adjust the transport activities of plant and fungal sucrose transporters at the host/pathogen interface. 相似文献6.
Background
Two major mycoparasitic lineages, the family Hypocreaceae and the genus Tolypocladium, exist within the fungal order, Hypocreales. Peptaibiotics are a group of secondary metabolites almost exclusively described from Trichoderma species of Hypocreaceae. Peptaibiotics are produced by nonribosomal peptide synthetases (NRPSs) and have antibiotic and antifungal activities. Tolypocladium species are mainly truffle parasites, but a few species are insect pathogens.Results
The draft genome sequence of the truffle parasite Tolypocladium ophioglossoides was generated and numerous secondary metabolite clusters were discovered, many of which have no known putative product. However, three large peptaibiotic gene clusters were identified using phylogenetic analyses. Peptaibiotic genes are absent from the predominantly plant and insect pathogenic lineages of Hypocreales, and are therefore exclusive to the largely mycoparasitic lineages. Using NRPS adenylation domain phylogenies and reconciliation of the domain tree with the organismal phylogeny, it is demonstrated that the distribution of these domains is likely not the product of horizontal gene transfer between mycoparasitic lineages, but represents independent losses in insect pathogenic lineages. Peptaibiotic genes are less conserved between species of Tolypocladium and are the product of complex patterns of lineage sorting and module duplication. In contrast, these genes are more conserved within the genus Trichoderma and consistent with diversification through speciation.Conclusions
Peptaibiotic NRPS genes are restricted to mycoparasitic lineages of Hypocreales, based on current sampling. Phylogenomics and comparative genomics can provide insights into the evolution of secondary metabolite genes, their distribution across a broader range of taxa, and their possible function related to host specificity.Electronic supplementary material
The online version of this article (doi:10.1186/s12864-015-1777-9) contains supplementary material, which is available to authorized users. 相似文献7.
8.
Molecular cloning, characterization and expression analysis of two members of the Pht1 family of phosphate transporters in Glycine max 总被引:2,自引:0,他引:2
Background
Phosphorus is one of the macronutrients essential for plant growth and development. The acquisition and translocation of phosphate are pivotal processes of plant growth. In a large number of plants, phosphate uptake by roots and translocation within the plant are presumed to occur via a phosphate/proton cotransport mechanism.Principal Findings
We cloned two cDNAs from soybean (Glycine max), GmPT1 and GmPT2, which show homology to the phosphate/proton cotransporter PHO84 from the budding yeast Saccharomyces cerevisiae. The amino acid sequence of the products predicted from GmPT1 and GmPT2 share 61% and 63% identity, respectively, with the PHO84 in amino acid sequence. The deduced structure of the encoded proteins revealed 12 membrane-spanning domains with a central hydrophilic region. The molecular mass values are ∼58.7 kDa for GmPT1 and ∼58.6 kDa for GmPT2. Transiently expressed GFP–protein fusions provide direct evidence that the two Pi transporters are located in the plasma membrane. Uptake of radioactive orthophosphate by the yeast mutant MB192 showed that GmPT1 and GmPT2 are dependent on pH and uptake is reduced by the addition of uncouplers of oxidative phosphorylation. The K m for phosphate uptake by GmPT1 and GmPT2 is 6.65 mM and 6.63 mM, respectively. A quantitative real time RT-PCR assay indicated that these two genes are expressed in the roots and shoots of seedlings whether they are phosphate-deficient or not. Deficiency of phosphorus caused a slight change of the expression levels of GmPT1 and GmPT2.Conclusions
The results of our experiments show that the two phosphate transporters have low affinity and the corresponding genes are constitutively expressed. Thereby, the two phosphate transporters can perform translocation of phosphate within the plant. 相似文献9.
10.
Michael H Perlin Joelle Amselem Eric Fontanillas Su San Toh Zehua Chen Jonathan Goldberg Sebastien Duplessis Bernard Henrissat Sarah Young Qiandong Zeng Gabriela Aguileta Elsa Petit Helene Badouin Jared Andrews Dominique Razeeq Toni Gabaldón Hadi Quesneville Tatiana Giraud Michael E. Hood David J. Schultz Christina A. Cuomo 《BMC genomics》2015,16(1)
11.
Background
Plants within the Orobanchaceae are an agriculturally important group of parasites that attack economically important crops to obtain water and nutrients from their hosts. Despite their agricultural importance, molecular mechanisms of the parasitism are poorly understood.Methodology/Principal Findings
We developed transient and stable transformation systems for Phtheirospermum japonicum, a facultative parasitic plant in the Orobanchaceae. The transformation protocol was established by a combination of sonication and acetosyringone treatments using the hairy-root-inducing bacterium, Agrobacterium rhizogenes and young seedlings. Transgenic hairy roots of P. japonicum were obtained from cotyledons 2 to 3 weeks after A. rhizogenes inoculation. The presence and the expression of transgenes in P. japonicum were verified by genomic PCR, Southern blot and RT-PCR methods. Transgenic roots derived from A. rhizogenes-mediated transformation were able to develop haustoria on rice and maize roots. Transgenic roots also formed apparently competent haustoria in response to 2,6-dimethoxy-1,4-benzoquinone (DMBQ), a haustorium-inducing chemical. Using this system, we introduced a reporter gene with a Cyclin B1 promoter into P. japonicum, and visualized cell division during haustorium formation.Conclusions
We provide an easy and efficient method for hairy-root transformation of P. japonicum. Transgenic marker analysis revealed that cell divisions during haustorium development occur 24 h after DMBQ treatment. The protocols described here will allow functional analysis of genes involved in plant parasitism. 相似文献12.
Silicon modifies root anatomy, and uptake and subcellular distribution of cadmium in young maize plants 总被引:2,自引:0,他引:2
Background and Aims
Silicon (Si) has been shown to ameliorate the negative influence of cadmium (Cd) on plant growth and development. However, the mechanism of this phenomenon is not fully understood. Here we describe the effect of Si on growth, and uptake and subcellular distribution of Cd in maize plants in relation to the development of root tissues.Methods
Young maize plants (Zea mays) were cultivated for 10 d hydroponically with 5 or 50 µm Cd and/or 5 mm Si. Growth parameters and the concentrations of Cd and Si were determined in root and shoot by atomic absorption spectrometry or inductively coupled plasma mass spectroscopy. The development of apoplasmic barriers (Casparian bands and suberin lamellae) and vascular tissues in roots were analysed, and the influence of Si on apoplasmic and symplasmic distribution of 109Cd applied at 34 nm was investigated between root and shoot.Key Results
Si stimulated the growth of young maize plants exposed to Cd and influenced the development of Casparian bands and suberin lamellae as well as vascular tissues in root. Si did not affect the distribution of apoplasmic and symplasmic Cd in maize roots, but considerably decreased symplasmic and increased apoplasmic concentration of Cd in maize shoots.Conclusions
Differences in Cd uptake of roots and shoots are probably related to the development of apoplasmic barriers and maturation of vascular tissues in roots. Alleviation of Cd toxicity by Si might be attributed to enhanced binding of Cd to the apoplasmic fraction in maize shoots. 相似文献13.
14.
15.
Phylogenetic analyses provide the first insights into the evolution of OVATE family proteins in land plants 总被引:1,自引:0,他引:1
Di Liu Wei Sun Yaowu Yuan Ning Zhang Alice Hayward Yongliang Liu Ying Wang 《Annals of botany》2014,113(7):1219-1233
Background and Aims
The OVATE gene encodes a nuclear-localized regulatory protein belonging to a distinct family of plant-specific proteins known as the OVATE family proteins (OFPs). OVATE was first identified as a key regulator of fruit shape in tomato, with nonsense mutants displaying pear-shaped fruits. However, the role of OFPs in plant development has been poorly characterized.Methods
Public databases were searched and a total of 265 putative OVATE protein sequences were identified from 13 sequenced plant genomes that represent the major evolutionary lineages of land plants. A phylogenetic analysis was conducted based on the alignment of the conserved OVATE domain from these 13 selected plant genomes. The expression patterns of tomato SlOFP genes were analysed via quantitative real-time PCR. The pattern of OVATE gene duplication resulting in the expansion of the gene family was determined in arabidopsis, rice and tomato.Key Results
Genes for OFPs were found to be present in all the sampled land plant genomes, including the early-diverged lineages, mosses and lycophytes. Phylogenetic analysis based on the amino acid sequences of the conserved OVATE domain defined 11 sub-groups of OFPs in angiosperms. Different evolutionary mechanisms are proposed for OVATE family evolution, namely conserved evolution and divergent expansion. Characterization of the AtOFP family in arabidopsis, the OsOFP family in rice and the SlOFP family in tomato provided further details regarding the evolutionary framework and revealed a major contribution of tandem and segmental duplications towards expansion of the OVATE gene family.Conclusions
This first genome-wide survey on OFPs provides new insights into the evolution of the OVATE protein family and establishes a solid base for future functional genomics studies on this important but poorly characterized regulatory protein family in plants. 相似文献16.
17.
Yordem BK Conte SS Ma JF Yokosho K Vasques KA Gopalsamy SN Walker EL 《Annals of botany》2011,108(5):821-833
Background and Aims
Brachypodium distachyon is a temperate grass with a small stature, rapid life cycle and completely sequenced genome that has great promise as a model system to study grass-specific traits for crop improvement. Under iron (Fe)-deficient conditions, grasses synthesize and secrete Fe(III)-chelating agents called phytosiderophores (PS). In Zea mays, Yellow Stripe1 (ZmYS1) is the transporter responsible for the uptake of Fe(III)–PS complexes from the soil. Some members of the family of related proteins called Yellow Stripe-Like (YSL) have roles in internal Fe translocation of plants, while the function of other members remains uninvestigated. The aim of this study is to establish brachypodium as a model system to study Fe homeostasis in grasses, identify YSL proteins in brachypodium and maize, and analyse their expression profiles in brachypodium in response to Fe deficiency.Methods
The YSL family of proteins in brachypodium and maize were identified based on sequence similarity to ZmYS1. Expression patterns of the brachypodium YSL genes (BdYSL genes) were determined by quantitative RT–PCR under Fe-deficient and Fe-sufficient conditions. The types of PS secreted, and secretion pattern of PS in brachypodium were analysed by high-performance liquid chromatography.Key Results
Eighteen YSL family members in maize and 19 members in brachypodium were identified. Phylogenetic analysis revealed that some YSLs group into a grass-specific clade. The Fe status of the plant can regulate expression of brachypodium YSL genes in both shoots and roots. 3-Hydroxy-2′-deoxymugineic acid (HDMA) is the dominant type of PS secreted by brachypodium, and its secretion is diurnally regulated.Conclusions
PS secretion by brachypodium parallels that of related crop species such as barley and wheat. A single grass species-specific YSL clade is present, and expression of the BdYSL members of this clade could not be detected in shoots or roots, suggesting grass-specific functions in reproductive tissues. Finally, the Fe-responsive expression profiles of several YSLs suggest roles in Fe homeostasis. 相似文献18.
19.