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Sample records for fusarium wilt pathogen

  1. Fusarium wilt of lentil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fusarium wilt of lentil is caused by the soil borne fungus Fusaium oxysporum f. sp. lentis. The pathogen is widespread. The disease shows symptoms of wilting, and stunted plants. Other symptoms include wilting of top leaves resemble water deficiency, shrinking and curling of leaves from the lower...

  2. Fusarium Wilt of Banana.

    PubMed

    Ploetz, Randy C

    2015-12-01

    Banana (Musa spp.) is one of the world's most important fruits. In 2011, 145 million metric tons, worth an estimated $44 billion, were produced in over 130 countries. Fusarium wilt (also known as Panama disease) is one of the most destructive diseases of this crop. It devastated the 'Gros Michel'-based export trades before the mid-1900s, and threatens the Cavendish cultivars that were used to replace it; in total, the latter cultivars are now responsible for approximately 45% of all production. An overview of the disease and its causal agent, Fusarium oxysporum f. sp. cubense, is presented below. Despite a substantial positive literature on biological, chemical, or cultural measures, management is largely restricted to excluding F. oxysporum f. sp. cubense from noninfested areas and using resistant cultivars where the pathogen has established. Resistance to Fusarium wilt is poor in several breeding targets, including important dessert and cooking cultivars. Better resistance to this and other diseases is needed. The history and impact of Fusarium wilt is summarized with an emphasis on tropical race 4 (TR4), a 'Cavendish'-killing variant of the pathogen that has spread dramatically in the Eastern Hemisphere. PMID:26057187

  3. Fusarium verticillioides: A new cotton wilt pathogen in Uzbekistan

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An increase in wilt has been observed in cotton fields in Uzbekistan. This prompted us to conduct a survey of Uzbek cotton fields for wilt over a five year period beginning in 2007. Twenty-four regions with different soil types and ecologies were screened. In 9 regions, over 45% of the plants dem...

  4. Fusarium Wilt of Orchids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fusarium wilt of orchids is highly destructive and economically limiting to the production of quality orchids that has steadily increased in many production facilities. Important crops such as phalaenopsis, cattleyas, and oncidiums appear to be especially susceptible to certain Fusarium species. Fu...

  5. Race 3, a new race of Fusarium oxysporum f. sp. niveum, the watermelon Fusarium wilt pathogen

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Three races (0, 1, and 2) of Fusarium oxysporum f. sp. niveum (FON) have been described in watermelon. Two FON isolates collected in Maryland along with reference isolates of each of races 0, 1, and 2 were tested for pathogenicity, host range and vegetative compatibility. Race was determined on 8 di...

  6. Role of fusaric acid in the virulence of cotton wilt pathogen Fusarium Oxysporum f. sp. Vasinfectum

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fusaric acid is a potent phytotoxin to cotton. It has also long been implicated in the pathogenesis of Fusarium wilt for a number of plant species including cotton, tomato, watermelon, and flax. The Australian biotype isolates of Fusarium oxysporum f. sp. vasinfectum (Fov) produce copious amount of ...

  7. Fusarium wilt in seedless watermelons

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fusarium wilt of watermelon [Citrullus lanatus (Thunb.) Matsum. & Nakai], caused by Fusarium oxysporum f. sp. niveum (E.F. Sm.) Snyd. & Hans., was first reported in the United States in 1894. Historically, Fusarium wilt has been the greatest yield-limiting disease of watermelon worldwide. The stat...

  8. Resistance to Fusarium wilt in chickpea

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fusarium wilt of chickpea, caused by the fungal pathogen Fusarium oxysporum f. sp. ciceris (Foc), is a destructive disease and is distributed in almost all chickpea producing regions of the world. Foc has eight physiological races designated as 0, 1A, 1B/C, 2, 3, 4, 5 and 6. The races are different...

  9. Genome and Transcriptome Analysis of the Fungal Pathogen Fusarium oxysporum f. sp. cubense Causing Banana Vascular Wilt Disease

    PubMed Central

    Zeng, Huicai; Fan, Dingding; Zhu, Yabin; Feng, Yue; Wang, Guofen; Peng, Chunfang; Jiang, Xuanting; Zhou, Dajie; Ni, Peixiang; Liang, Changcong; Liu, Lei; Wang, Jun; Mao, Chao

    2014-01-01

    Background The asexual fungus Fusarium oxysporum f. sp. cubense (Foc) causing vascular wilt disease is one of the most devastating pathogens of banana (Musa spp.). To understand the molecular underpinning of pathogenicity in Foc, the genomes and transcriptomes of two Foc isolates were sequenced. Methodology/Principal Findings Genome analysis revealed that the genome structures of race 1 and race 4 isolates were highly syntenic with those of F. oxysporum f. sp. lycopersici strain Fol4287. A large number of putative virulence associated genes were identified in both Foc genomes, including genes putatively involved in root attachment, cell degradation, detoxification of toxin, transport, secondary metabolites biosynthesis and signal transductions. Importantly, relative to the Foc race 1 isolate (Foc1), the Foc race 4 isolate (Foc4) has evolved with some expanded gene families of transporters and transcription factors for transport of toxins and nutrients that may facilitate its ability to adapt to host environments and contribute to pathogenicity to banana. Transcriptome analysis disclosed a significant difference in transcriptional responses between Foc1 and Foc4 at 48 h post inoculation to the banana ‘Brazil’ in comparison with the vegetative growth stage. Of particular note, more virulence-associated genes were up regulated in Foc4 than in Foc1. Several signaling pathways like the mitogen-activated protein kinase Fmk1 mediated invasion growth pathway, the FGA1-mediated G protein signaling pathway and a pathogenicity associated two-component system were activated in Foc4 rather than in Foc1. Together, these differences in gene content and transcription response between Foc1 and Foc4 might account for variation in their virulence during infection of the banana variety ‘Brazil’. Conclusions/Significance Foc genome sequences will facilitate us to identify pathogenicity mechanism involved in the banana vascular wilt disease development. These will thus advance us develop effective methods for managing the banana vascular wilt disease, including improvement of disease resistance in banana. PMID:24743270

  10. First Report on Fusarium Wilt of Zucchini Caused by Fusarium oxysporum, in Korea

    PubMed Central

    Choi, In-Young; Kim, Ju-Hee; Lee, Wang-Hyu; Park, Ji-Hyun

    2015-01-01

    Fusarium wilt of zucchini in Jeonju, Korea, was first noticed in May 2013. Symptoms included wilting of the foliage, drying and withering of older leaves, and stunting of plants. Infected plants eventually died during growth. Based on morphological characteristics and phylogenetic analyses of the molecular markers (internal transcribed spacer rDNA and translation elongation factor 1α), the fungus was identified as Fusarium oxysporum. Pathogenicity of a representative isolate was demonstrated via artificial inoculation, and it satisfied Koch's postulates. To our knowledge, this is the first report of F. oxysporum causing wilt of zucchini in Korea. PMID:26190927

  11. First Report on Fusarium Wilt of Zucchini Caused by Fusarium oxysporum, in Korea.

    PubMed

    Choi, In-Young; Kim, Ju-Hee; Lee, Wang-Hyu; Park, Ji-Hyun; Shin, Hyeon-Dong

    2015-06-01

    Fusarium wilt of zucchini in Jeonju, Korea, was first noticed in May 2013. Symptoms included wilting of the foliage, drying and withering of older leaves, and stunting of plants. Infected plants eventually died during growth. Based on morphological characteristics and phylogenetic analyses of the molecular markers (internal transcribed spacer rDNA and translation elongation factor 1α), the fungus was identified as Fusarium oxysporum. Pathogenicity of a representative isolate was demonstrated via artificial inoculation, and it satisfied Koch's postulates. To our knowledge, this is the first report of F. oxysporum causing wilt of zucchini in Korea. PMID:26190927

  12. In Search of Markers Linked to Fusarium Wilt Race 1 Resistance in Watermelon

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fusarium wilt in watermelon, caused by the fungus Fusarium oxysporum f. sp. niveum (FON), is responsible for severe economic losses and is one of the most important soilborne pathogens limiting watermelon production in many areas of the world. FON, which attacks the vasculature system of watermelon...

  13. Discovery of Fusarium wilt race 4 resistance in cotton

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fusarium wilt [Fusarium oxysporum f.sp. vasinfectum (FOV) Atk. Sny & Hans)] is a soil-inhabiting fungus that can survive for long periods in the absence of a host, making it impractical to eradicate from infested fields. This cotton host specific forms of the fungus is comprised of different genotyp...

  14. Population structure and dynamics among fusarium oxysprium isolates causing wilt of cotton

    Technology Transfer Automated Retrieval System (TEKTRAN)

    From 1992 to 2015 nearly 3,000 isolates of Fusarium species from wilted cotton plants, seed, or cotton field soils were tested for pathogenesis using root-dip, stem-puncture, and soil-infestation assays. The greatest numbers of pathogens were identified by the root-dip assay. These were divided in...

  15. Genome Sequence of Fusarium oxysporum f. sp. melonis, a fungus causing wilt disease on melon

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This manuscript reports the genome sequence of F. oxysporum f. sp. melonis, a fungal pathogen that causes Fusarium wilt disease on melon (Cucumis melo). The project is part of a large comparative study designed to explore the genetic composition and evolutionary origin of this group of horizontally ...

  16. Genome sequence of Fusarium oxysporum f. sp. melonis, a fungus causing wilt disease on melon

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This manuscript reports the genome sequence of F. oxysporum f. sp. melonis, a fungal pathogen that causes Fusarium wilt disease on melon (Cucumis melo). The project is part of a large comparative study designed to explore the genetic composition and evolutionary origin of this group of horizontally ...

  17. Cross Pathogenicity of Fusarium oxysporum f. sp. betae on Sugar Beet and Common Bean

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fusarium wilt, also known as Fusarium yellows, is caused by the fungus Fusarium oxysporum. Fusarium oxysporum is a vascular pathogen with a broad host range including common bean (Phaseolus vulgaris L.) and sugar beet (Beta vulgaris L.) with formae speciales (f. sp.) defined by the ability to cause ...

  18. Production of anti-fungal volatiles by non-pathogenic Fusarium oxysporum and its efficacy in suppression of verticillium wilt of cotton

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aims: The study aimed to identify volatile organic compounds (VOCs) produced by the non-pathogenic Fusarium oxysporum (Fo) strain CanR-46, and to determine the anti-fungal spectrum and the control efficacy of the Fo-VOCs. Methods: The Fo-VOCs were identified by GC-MS. The antifungal activity of the...

  19. Control of Fusarium wilt in banana with Chinese leek

    PubMed Central

    Huang, Y.H.; Wang, R.C.; Li, C. H.; Zuo, C.W.; Wei, Y. R.; Zhang, L.; Yi, G.J.

    2012-01-01

    The inhibitory effects of Chinese leek(Allium tuberosum) on Fusarium oxysporum f. sp. cubense (Foc) and on Fusarium wilt incidence were studied in order to identify a potential efficient way to control the disease. Adopting the rotation system of Chinese leek-banana reduced the Fusarium wilt incidence and disease severity index by 88 %-97 % and 91 %-96 %, respectively, improved the crop value by 36 %-86 %, in an area heavily infested by Foc between 2007 and 2009. As a result of inoculation in the greenhouse, Chinese leek treatment reduced disease incidence and the disease severity index by 58 % and 62 %, respectively in the variety Baxi (AAA) and by 79 % and 81 %, respectively in the variety Guangfen NO.1 (ABB). Crude extracts of Chinese leek completely inhibited the growth of Foc race 4 on Petri dishes, suppressed the proliferation of the spores by 91 % and caused 87 % spore mortality. The findings of this study suggest that Chinese leek has the potential to inhibit Foc growth and Fusarium wilt incidence. This potential may be developed into an environmentally friendly treatment to control Fusarium wilt of banana. PMID:23144534

  20. Controlling fusarium wilt of California strawberries by anaerobic soil disinfestation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In the 2014-15 season, the ASD-treated berry acreage exceeded 1,000 acres in California; more than doubled from the previous season. Fusarium wilt an emerging lethal disease of strawberries in California, can also be controlled by ASD. However, a study has shown that higher soil temperatures are n...

  1. Environmental Influences on Pigeonpea-Fusarium udum Interactions and Stability of Genotypes to Fusarium Wilt

    PubMed Central

    Sharma, Mamta; Ghosh, Raju; Telangre, Rameshwar; Rathore, Abhishek; Saifulla, Muhammad; Mahalinga, Dayananda M.; Saxena, Deep R.; Jain, Yogendra K.

    2016-01-01

    Fusarium wilt (Fusarium udum Butler) is an important biotic constraint to pigeonpea (Cajanus cajan L.) production worldwide. Breeding for fusarium wilt resistance continues to be an integral part of genetic improvement of pigeonpea. Therefore, the study was aimed at identifying and validating resistant genotypes to fusarium wilt and determining the magnitude of genotype × environment (G × E) interactions through multi-environment and multi-year screening. A total of 976 genotypes including germplasm and breeding lines were screened against wilt using wilt sick plot at Patancheru, India. Ninety two genotypes resistant to wilt were tested for a further two years using wilt sick plot at Patancheru. A Pigeonpea Wilt Nursery (PWN) comprising of 29 genotypes was then established. PWN was evaluated at nine locations representing different agro-climatic zones of India for wilt resistance during two crop seasons 2007/08 and 2008/09. Genotypes (G), environment (E), and G × E interactions were examined by biplot which partitioned the main effect into G, E, and G × E interactions with significant levels (p ≤ 0.001) being obtained for wilt incidence. The genotype contributed 36.51% of resistance variation followed by the environment (29.32%). A GGE biplot integrated with a boxplot and multiple comparison tests enabled us to identify seven stable genotypes (ICPL 20109, ICPL 20096, ICPL 20115, ICPL 20116, ICPL 20102, ICPL 20106, and ICPL 20094) based on their performance across diverse environments. These genotypes have broad based resistance and can be exploited in pigeonpea breeding programs. PMID:27014287

  2. Environmental Influences on Pigeonpea-Fusarium udum Interactions and Stability of Genotypes to Fusarium Wilt.

    PubMed

    Sharma, Mamta; Ghosh, Raju; Telangre, Rameshwar; Rathore, Abhishek; Saifulla, Muhammad; Mahalinga, Dayananda M; Saxena, Deep R; Jain, Yogendra K

    2016-01-01

    Fusarium wilt (Fusarium udum Butler) is an important biotic constraint to pigeonpea (Cajanus cajan L.) production worldwide. Breeding for fusarium wilt resistance continues to be an integral part of genetic improvement of pigeonpea. Therefore, the study was aimed at identifying and validating resistant genotypes to fusarium wilt and determining the magnitude of genotype × environment (G × E) interactions through multi-environment and multi-year screening. A total of 976 genotypes including germplasm and breeding lines were screened against wilt using wilt sick plot at Patancheru, India. Ninety two genotypes resistant to wilt were tested for a further two years using wilt sick plot at Patancheru. A Pigeonpea Wilt Nursery (PWN) comprising of 29 genotypes was then established. PWN was evaluated at nine locations representing different agro-climatic zones of India for wilt resistance during two crop seasons 2007/08 and 2008/09. Genotypes (G), environment (E), and G × E interactions were examined by biplot which partitioned the main effect into G, E, and G × E interactions with significant levels (p ≤ 0.001) being obtained for wilt incidence. The genotype contributed 36.51% of resistance variation followed by the environment (29.32%). A GGE biplot integrated with a boxplot and multiple comparison tests enabled us to identify seven stable genotypes (ICPL 20109, ICPL 20096, ICPL 20115, ICPL 20116, ICPL 20102, ICPL 20106, and ICPL 20094) based on their performance across diverse environments. These genotypes have broad based resistance and can be exploited in pigeonpea breeding programs. PMID:27014287

  3. Suppression of Fusarium wilt by combining green compost and Trichoderma hamatum.

    PubMed

    Heremans, B; Demeulenaere, S; Haesaert, G

    2005-01-01

    Fusarium wilts, caused by the fungus Fusarium oxysporum, are important diseases of horticultural and agricultural crops and lead to significant yield losses. The pathogen infects the roots and colonizes the vascular tissue, leading to wilting and finally death of the plant. The objective of this study was to investigate the efficacy of amendment of green compost and a Trichoderma hamatum strain against Fusarium wilt of radish. The substrate effects and the effect of a Trichoderma strain were tested in a potting soil bioassay. The tested composts lowered the disease level and had a positive influence on the plant yield (fresh weight and dry weight). Nothwithstanding, only a small dosis effect of the amendment was observed. In the presence of the tested Trichoderma hamatum strain no significant lower disease level was observed. Furthermore, a minor effect on plant yield (fresh weight and dry weight) was observed compared to the amendment with only green compost. Maybe the pathogenic Fusarium oxysporum strain and the Trichoderma strain competed for nutrients, iron could be a limiting factor. One possible approach to improve biological control may be the application of combinations of biocontrol agents. PMID:16637174

  4. A major locus for fusarium wilt race 4 resistance identified in Gossypium Hirsutum Acala NemX using an interspecific progeny with g barbadense

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fusarium wilt, caused by the soil-borne pathogen Fusarium oxysporum f. sp. vasinfectum race 4 (FOV4), is a vascular disease of cotton (Gossypium spp.) which causes plant injury and yield loss in most Pima (G. barbadense L.) and Acala or Upland (G. hirsutum L.) cultivars without co-infection with roo...

  5. Effects of Varying Environmental Conditions on Biological Control of Fusarium Wilt of Tomato by Nonpathogenic Fusarium spp.

    PubMed

    Larkin, Robert P; Fravel, Deborah R

    2002-11-01

    ABSTRACT The influence of varying environmental and cropping conditions including temperature, light, soil type, pathogen isolate and race, and cultivar of tomato on biological control of Fusarium wilt of tomato by isolates of nonpathogenic Fusarium oxysporum (CS-20 and CS-24) and F. solani (CS-1) was evaluated in greenhouse and growth chamber experiments. Liquid spore suspensions (10(6)/ml) of the biocontrol isolates were applied to soilless potting mix at the time of tomato seeding, and the seedlings were transplanted into pathogen-infested field soil 2 weeks later. Temperature regimes ranging from 22 to 32 degrees C significantly affected disease development and plant physiological parameters. Biocontrol isolate CS-20 significantly reduced disease at all temperature regimes tested, yielding reductions of disease incidence of 59 to 100% relative to pathogen control treatments. Isolates CS-24 and CS-1 reduced disease incidence in the greenhouse and at high temperatures, but were less effective at the optimum temperature for disease development (27 degrees C). Growing plants under shade (50% of full light) versus full light affected some plant growth parameters, but did not affect the efficacy of biocontrol of any of the three bio-control isolates. Isolate CS-20 effectively reduced disease incidence (56 to 79% reduction) in four different field soils varying in texture (sandy to clayey) and organic matter content (0 to 3.2%). Isolate CS-1 reduced disease in the sandy and loamy soils (49 to 66% reduction), but was not effective in a heavy clay soil. Both CS-1 and CS-20 were equally effective against all three races of the pathogen, as well as multiple isolates of each race (48 to 66% reduction in disease incidence). Both isolates, CS-1 and CS-20, were equally effective in reducing disease incidence (66 to 80% reduction) by pathogenic races 1, 2, and 3 on eight different tomato cultivars containing varying levels of inherent resistance to Fusarium wilt (susceptible, resistant to race 1, or resistant to races 1 and 2). These results demonstrate that both these Fusarium isolates, and particularly CS-20, can effectively reduce Fusarium wilt disease of tomato under a variety of environmental conditions and have potential for further development. PMID:18944240

  6. Expression of rice thaumatin-like protein gene in transgenic banana plants enhances resistance to fusarium wilt.

    PubMed

    Mahdavi, F; Sariah, M; Maziah, M

    2012-02-01

    The possibility of controlling Fusarium wilt--caused by Fusarium oxysporum sp. cubensec (race 4)--was investigated by genetic engineering of banana plants for constitutive expression of rice thaumatin-like protein (tlp) gene. Transgene was introduced to cauliflower-like bodies' cluster, induced from meristemic parts of male inflorescences, using particle bombardment with plasmid carrying a rice tlp gene driving by the CaMV 35S promoter. Hygromycin B was used as the selection reagent. The presence and integration of rice tlp gene in genomic DNA confirmed by PCR and Southern blot analyses. RT-PCR revealed the expression of transgene in leaf and root tissues in transformants. Bioassay of transgenic banana plants challenged with Fusarium wilt pathogen showed that expression of TLP enhanced resistance to F. oxysporum sp. cubensec (race 4) compared to control plants. PMID:22183565

  7. Elite-upland cotton germplasm-pool assessment of Fusarium wilt resistance in California

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Host-plant resistance is currently the most economic and effective strategy for managing Fusarium wilt [Fusarium oxysporum f. sp. vasinfectum (FOV)] disease. Over the past nine years, a new race of Fusarium (FOV race 4) has increasingly impacted cotton (Gossypium spp.) in production fields in the Sa...

  8. [Effects of root exudates from cucumber and squash on fusarium wilt occurrence].

    PubMed

    Huang, Ben-Li; Xu, Yun-Dong; Wu, Ye; Zhang, Shun-Qi; Chen, Xue-Hao

    2007-03-01

    With the root exudates of two cucumber varieties Jinyan 4 (susceptible variety) and Jinchun 4 (resistant variety) and of black seed squash variety as test materials, this paper studied their effects and action mechanisms on the occurrence of Fusarium wilt on Jinyan 4. The results showed that the occurrence of Fusarium wilt was earlier when treated with the root exudates of Jinyan 4, and the infection rate was significantly higher at 15 days after inoculation, but nearly the same as the control at 20 days after inoculation. On the contrary, the infection rate was significantly lower than the control when treated with the root exudates of Jinchun 4. The plant height and fresh mass of Jinyan 4 treated with its own root exudates were lower than those of the control, and the root vigor decreased but conductance increased. No significant effect was observed in the plant height and fresh mass of Jinyan 4 treated with the root exudates of Jinchun 4 and black seed squash. It could be concluded that the root exudates of susceptible cucumber variety stimulated the growth of Fusarium oxysporum pathogen, while those of resistance cucumber variety and black seed squash were in adverse. PMID:17552193

  9. The Role of Pathogen-Secreted Proteins in Fungal Vascular Wilt Diseases

    PubMed Central

    de Sain, Mara; Rep, Martijn

    2015-01-01

    A limited number of fungi can cause wilting disease in plants through colonization of the vascular system, the most well-known being Verticillium dahliae and Fusarium oxysporum. Like all pathogenic microorganisms, vascular wilt fungi secrete proteins during host colonization. Whole-genome sequencing and proteomics screens have identified many of these proteins, including small, usually cysteine-rich proteins, necrosis-inducing proteins and enzymes. Gene deletion experiments have provided evidence that some of these proteins are required for pathogenicity, while the role of other secreted proteins remains enigmatic. On the other hand, the plant immune system can recognize some secreted proteins or their actions, resulting in disease resistance. We give an overview of proteins currently known to be secreted by vascular wilt fungi and discuss their role in pathogenicity and plant immunity. PMID:26473835

  10. The Role of Pathogen-Secreted Proteins in Fungal Vascular Wilt Diseases.

    PubMed

    de Sain, Mara; Rep, Martijn

    2015-01-01

    A limited number of fungi can cause wilting disease in plants through colonization of the vascular system, the most well-known being Verticillium dahliae and Fusarium oxysporum. Like all pathogenic microorganisms, vascular wilt fungi secrete proteins during host colonization. Whole-genome sequencing and proteomics screens have identified many of these proteins, including small, usually cysteine-rich proteins, necrosis-inducing proteins and enzymes. Gene deletion experiments have provided evidence that some of these proteins are required for pathogenicity, while the role of other secreted proteins remains enigmatic. On the other hand, the plant immune system can recognize some secreted proteins or their actions, resulting in disease resistance. We give an overview of proteins currently known to be secreted by vascular wilt fungi and discuss their role in pathogenicity and plant immunity. PMID:26473835

  11. First report of Fusarium wilt caused by Fusarium oxysporum f. sp. niveum Race 2 in Georgia watermelon

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Watermelon [Citrullus lanatus (Thunb.) Matsum. & Nakai] is the number one specialty crop grown in Georgia, a state that ranks fourth nationally in watermelon production. In the last five years, Fusarium wilt caused by Fusarium oxysporum f. sp. niveum (Fon), has been the greatest yield-limiting dise...

  12. Biocontrol of Fusarium wilt disease in cucumber with improvement of growth and mineral uptake using some antagonistic formulations.

    PubMed

    Moharam, Moustafa H A; Negim, Osama O

    2012-01-01

    Fusarium wilt disease in Cucumber (Cucumis sativus L.) is widespread, responsible for serious economic losses. Amongst totally 15 isolates of Fusarium spp., obtained from different localities of Sohag governorate, Egypt, only the identified isolates as F. oxysporum were pathogenic on cucumber Denmark Beta-Alpha cv. and caused wilt symptoms. Totally 22 isolates of Trichoderma spp., B. subtilis and Pseudomonas spp., were obtained from rhizosphere of cucumber and some available commercial formulations and then tested for antagonistic activity against F. oxysporum (FO5) in vitro. The highest inhibitory effect on growth of FO5 was observed by isolate Trichodex of T. harzianum (89.29%) followed by Th4 of T. harzianum, Serenade and MBI 600 of B. subtilis, PS3 of Pseudomonas spp., and Treico and Tv2 of T. viride. Pot experiments were performed to investigate the effects of formulated antagonists as seed treatment on Fusarium wilt incidence, growth and mineral uptake of cucumber. Results showed that all tested formulations significantly reduced percent of wilted plants and disease severity, and improved plant growth by increasing length of shoot and root, fresh and dry weight of shoot and root system, and number of leaves and flowers per plant compared with untreated control. They also significantly increased nutrient contents of plant shoot including N, P, K, Ca, Fe, Mn, Cu, and Zn. Magnesium content in shoot slightly not significantly increased. Formulation of Trichodex was the most effective ones followed by Serenade, Th4 and PS3. PMID:23878960

  13. Constitutive expression of a novel antimicrobial protein, Hcm1, confers resistance to both Verticillium and Fusarium wilts in cotton.

    PubMed

    Zhang, Zhiyuan; Zhao, Jun; Ding, Lingyun; Zou, Lifang; Li, Yurong; Chen, Gongyou; Zhang, Tianzhen

    2016-01-01

    Fusarium and Verticillium wilts, two of the most important diseases in cotton, pose serious threats to cotton production. Here we introduced a novel antimicrobial protein Hcm1, which comprised harpin protein from Xanthomonas oryzae pv. oryzicola (Xoc), and the chimeric protein, cecropin A-melittin, into cotton. The transgenic cotton lines with stable Hcm1 expression showed a higher resistance to Verticillium and Fusarium wilts both in greenhouse and field trials compared to controls. Hcm1 enabled the transgenic cotton to produced a microscopic hypersensitive response (micro-HR), reactive oxygen species (ROS) burst, and caused the activation of pathogenesis-related (PR) genes in response to biotic stress, indicating that the transgenic cotton was in a primed state and ready to protect the host from pathogenic infection. Simultaneously, Hcm1 protein inhibited the growth of Verticillium dahliae (V. dahliae) and Fusarium oxysporum (F. oxysporum) in vitro. The spread of fungal biomass was also inhibited in vivo since the V. dahliae biomass was decreased dramatically in transgenic cotton plants after inoculation with V. dahliae. Together, these results demonstrate that Hcm1 could activate innate immunity and inhibit the growth of V. dahliae and F. oxysporum to protect cotton against Verticillium and Fusarium wilts. PMID:26856318

  14. Constitutive expression of a novel antimicrobial protein, Hcm1, confers resistance to both Verticillium and Fusarium wilts in cotton

    PubMed Central

    Zhang, Zhiyuan; Zhao, Jun; Ding, Lingyun; Zou, Lifang; Li, Yurong; Chen, Gongyou; Zhang, Tianzhen

    2016-01-01

    Fusarium and Verticillium wilts, two of the most important diseases in cotton, pose serious threats to cotton production. Here we introduced a novel antimicrobial protein Hcm1, which comprised harpin protein from Xanthomonas oryzae pv. oryzicola (Xoc), and the chimeric protein, cecropin A-melittin, into cotton. The transgenic cotton lines with stable Hcm1 expression showed a higher resistance to Verticillium and Fusarium wilts both in greenhouse and field trials compared to controls. Hcm1 enabled the transgenic cotton to produced a microscopic hypersensitive response (micro-HR), reactive oxygen species (ROS) burst, and caused the activation of pathogenesis-related (PR) genes in response to biotic stress, indicating that the transgenic cotton was in a primed state and ready to protect the host from pathogenic infection. Simultaneously, Hcm1 protein inhibited the growth of Verticillium dahliae (V. dahliae) and Fusarium oxysporum (F. oxysporum) in vitro. The spread of fungal biomass was also inhibited in vivo since the V. dahliae biomass was decreased dramatically in transgenic cotton plants after inoculation with V. dahliae. Together, these results demonstrate that Hcm1 could activate innate immunity and inhibit the growth of V. dahliae and F. oxysporum to protect cotton against Verticillium and Fusarium wilts. PMID:26856318

  15. Comparative Genomics Yields Insights into Niche Adaptation of Plant Vascular Wilt Pathogens

    PubMed Central

    Klosterman, Steven J.; Subbarao, Krishna V.; Kang, Seogchan; Veronese, Paola; Gold, Scott E.; Thomma, Bart P. H. J.; Chen, Zehua; Henrissat, Bernard; Lee, Yong-Hwan; Park, Jongsun; Garcia-Pedrajas, Maria D.; Barbara, Dez J.; Anchieta, Amy; de Jonge, Ronnie; Santhanam, Parthasarathy; Maruthachalam, Karunakaran; Atallah, Zahi; Amyotte, Stefan G.; Paz, Zahi; Inderbitzin, Patrik; Hayes, Ryan J.; Heiman, David I.; Young, Sarah; Zeng, Qiandong; Engels, Reinhard; Galagan, James; Cuomo, Christina A.; Dobinson, Katherine F.; Ma, Li-Jun

    2011-01-01

    The vascular wilt fungi Verticillium dahliae and V. albo-atrum infect over 200 plant species, causing billions of dollars in annual crop losses. The characteristic wilt symptoms are a result of colonization and proliferation of the pathogens in the xylem vessels, which undergo fluctuations in osmolarity. To gain insights into the mechanisms that confer the organisms' pathogenicity and enable them to proliferate in the unique ecological niche of the plant vascular system, we sequenced the genomes of V. dahliae and V. albo-atrum and compared them to each other, and to the genome of Fusarium oxysporum, another fungal wilt pathogen. Our analyses identified a set of proteins that are shared among all three wilt pathogens, and present in few other fungal species. One of these is a homolog of a bacterial glucosyltransferase that synthesizes virulence-related osmoregulated periplasmic glucans in bacteria. Pathogenicity tests of the corresponding V. dahliae glucosyltransferase gene deletion mutants indicate that the gene is required for full virulence in the Australian tobacco species Nicotiana benthamiana. Compared to other fungi, the two sequenced Verticillium genomes encode more pectin-degrading enzymes and other carbohydrate-active enzymes, suggesting an extraordinary capacity to degrade plant pectin barricades. The high level of synteny between the two Verticillium assemblies highlighted four flexible genomic islands in V. dahliae that are enriched for transposable elements, and contain duplicated genes and genes that are important in signaling/transcriptional regulation and iron/lipid metabolism. Coupled with an enhanced capacity to degrade plant materials, these genomic islands may contribute to the expanded genetic diversity and virulence of V. dahliae, the primary causal agent of Verticillium wilts. Significantly, our study reveals insights into the genetic mechanisms of niche adaptation of fungal wilt pathogens, advances our understanding of the evolution and development of their pathogenesis, and sheds light on potential avenues for the development of novel disease management strategies to combat destructive wilt diseases. PMID:21829347

  16. Analyses of Fusarium wilt race 3 resistance in upland cotton (Gossypium hirsutum L.)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In Uzbekistan, the most northern cotton country, as well as in many others worldwide, Fusarium wilt [Fusarium oxysporum f.sp. vasinfectum (FOV) Atk. Sny & Hans] represents a serious threat to cotton (Gossypium spp.) production. At least eight genotypes of FOV, called races, have been described. Thes...

  17. Study on Fusarium wilt disease (F. oxysporum vasinfectum) in Upland cotton (G. hirsutum)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In Uzbekistan, Upland cotton (Gossypium hirsutum L.) has been increasingly affected by the Fusarium wilt disease [Fusarium oxysporum vasinfectum (FOV)] during the last couple of years. This disease significantly reduces cotton yields. A highly virulent strain of FOV (No. 316) has been isolated from ...

  18. Inheritance and QTL mapping of Fusarium wilt race 4 resistance in cotton

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Diseases such as Fusarium wilt [Fusarium oxysporum f.sp. vasinfectum (FOV) Atk. Sny & Hans)] represent expanding threats to cotton production. Integrating disease resistance into high-yielding, high-fiber quality cotton (Gossypium spp.) cultivars is one of the most important objectives in cotton bre...

  19. A major quantitative trait locus is associated with Fusarium Wilt Race 1 resistance in watermelon

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fusarium wilt is a major disease of watermelon caused by the soil-borne fungus Fusarium oxysporum Schlechtend.:Fr. f. sp. niveum (E.F. Sm.) W.C. Snyder & H.N. Hans (Fon). A genetic population of 186 F3 families (24 plants in each family) exhibited continuous segregation for Fon race 1 response. Geno...

  20. Impact of five cover crop green manures and Actinovate on Fusarium Wilt of watermelon

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Triploid watermelon cultivars are grown on more than 2,023 ha in Maryland and in Delaware. Triploid watermelons have little host resistance to Fusarium wilt of watermelon (Fusarium oxysporum f. sp. niveum). The effects of four different fall-planted cover crops that were tilled in the spring as gree...

  1. Mapping Fusarium wilt race 1 resistance genes in cotton by inheritance, QTL, and sequencing composition

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Host-plant resistance is highly effective in limiting yield loss in cotton (Gossypium spp.) from Fusarium wilt [Fusarium oxysporum f.sp. vasinfectum (FOV) Atk. Sny & Hans]. In this study, we conducted a comprehensive analysis of gene action in cotton governing FOV race 1 resistance by applying molec...

  2. Apoptosis-related genes confer resistance to Fusarium wilt in transgenic 'Lady Finger' bananas.

    PubMed

    Paul, Jean-Yves; Becker, Douglas K; Dickman, Martin B; Harding, Robert M; Khanna, Harjeet K; Dale, James L

    2011-12-01

    Fusarium wilt, caused by Fusarium oxysporum f. sp. cubense (Foc), is one of the most devastating diseases of banana (Musa spp.). Apart from resistant cultivars, there are no effective control measures for the disease. We investigated whether the transgenic expression of apoptosis-inhibition-related genes in banana could be used to confer disease resistance. Embryogenic cell suspensions of the banana cultivar, 'Lady Finger', were stably transformed with animal genes that negatively regulate apoptosis, namely Bcl-xL, Ced-9 and Bcl-2 3' UTR, and independently transformed plant lines were regenerated for testing. Following a 12-week exposure to Foc race 1 in small-plant glasshouse bioassays, seven transgenic lines (2 × Bcl-xL, 3 × Ced-9 and 2 × Bcl-2 3' UTR) showed significantly less internal and external disease symptoms than the wild-type susceptible 'Lady Finger' banana plants used as positive controls. Of these, one Bcl-2 3' UTR line showed resistance that was equivalent to that of wild-type Cavendish bananas that were included as resistant negative controls. Further, the resistance of this line continued for 23-week postinoculation at which time the experiment was terminated. Using TUNEL assays, Foc race 1 was shown to induce apoptosis-like features in the roots of wild-type 'Lady Finger' plants consistent with a necrotrophic phase in the life cycle of this pathogen. This was further supported by the observed reduction in these effects in the roots of the resistant Bcl-2 3' UTR-transgenic line. This is the first report on the generation of transgenic banana plants with resistance to Fusarium wilt. PMID:21819535

  3. Microbial and biochemical basis of a Fusarium wilt-suppressive soil.

    PubMed

    Cha, Jae-Yul; Han, Sangjo; Hong, Hee-Jeon; Cho, Hyunji; Kim, Daran; Kwon, Youngho; Kwon, Soon-Kyeong; Crüsemann, Max; Bok Lee, Yong; Kim, Jihyun F; Giaever, Guri; Nislow, Corey; Moore, Bradley S; Thomashow, Linda S; Weller, David M; Kwak, Youn-Sig

    2016-01-01

    Crops lack genetic resistance to most necrotrophic pathogens. To compensate for this disadvantage, plants recruit antagonistic members of the soil microbiome to defend their roots against pathogens and other pests. The best examples of this microbially based defense of roots are observed in disease-suppressive soils in which suppressiveness is induced by continuously growing crops that are susceptible to a pathogen, but the molecular basis of most is poorly understood. Here we report the microbial characterization of a Korean soil with specific suppressiveness to Fusarium wilt of strawberry. In this soil, an attack on strawberry roots by Fusarium oxysporum results in a response by microbial defenders, of which members of the Actinobacteria appear to have a key role. We also identify Streptomyces genes responsible for the ribosomal synthesis of a novel heat-stable antifungal thiopeptide antibiotic inhibitory to F. oxysporum and the antibiotic's mode of action against fungal cell wall biosynthesis. Both classical- and community-oriented approaches were required to dissect this suppressive soil from the field to the molecular level, and the results highlight the role of natural antibiotics as weapons in the microbial warfare in the rhizosphere that is integral to plant health, vigor and development. PMID:26057845

  4. Physiology of host-pathogen interaction in wilt diseases of cotton in relation to pathogen management

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Verticillium and Fusarium wilts are important vascular wilt diseases of cotton that significantly reduce cotton yields and negatively impact fiber quality. In spite of intense efforts to control these diseases, yield losses persist and in the US alone were estimated to be about 133 and 28 thousand b...

  5. Antifungal potential of some higher plants against Fusarium udum causing wilt disease of Cajanus cajan.

    PubMed

    Singh, R; Rai, B

    2000-01-01

    The fungitoxic effects of different plant extracts on Fusarium udum, which causes wilt disease of Cajanus cajan in vitro and in vivo, were examined. The complete arrest of the radial growth of the pathogen occurred at a 10% concentration of leaf extract from Adenocallyma alliaceum. A leaf extract of Citrus medica, a root extract of Asparagus adscendens, rhizome extracts of Curcuma longa and Zingiber officinale, and a bulb extract of Allium sativum inhibited up to 100% growth at higher concentrations. A. alliaceum controlled the disease up to 100% by amending its 4% powder in unsterilized soil and 2% in sterilized soil. The population of F. udum was found to be markedly reduced following treatments with plant powders. PMID:10955831

  6. Development of molecular map and identification of QTLs linked to Fusarium wilt resistance in chickpea.

    PubMed

    Jingade, Pavankumar; Ravikumar, R L

    2015-12-01

    A number of genetic maps for Fusarium wilt resistance in chickpea have been reported in earlier studies, however QTLs identified for Fusarium wilt resistance were unstable. Hence, the present study aims to map novel molecular markers and to identify QTLs for Fusarium wilt resistance in chickpea. An intraspecific linkage map of chickpea (Cicer arietinum L.) was constructed using F10-F11 recombinant inbred lines (RILs) derived from a cross between K850 and WR315 segregating for H2 locus. A set of 31 polymorphic simple sequence repeat (SSR) markers obtained by screening 300 SSRs and were used for genotyping. The linkage map had four linkage groups and coverage of 690 cM with a marker density of 5.72 cM. The RILs were screened for their wilt reaction across two seasons in wilt sick plot at International Crop Research Institute for Semi-Arid Tropics (ICRISAT), Hyderabad, India. Five major quantitative trait loci (QTLs) were detected in both seasons for late wilting (60 days after sowing). A stable QTL (GSSR 18-TC14801) for wilt resistance was identified in both the seasons, and the QTL explained a variance of 69.80 and 60.80% in 2007 and 2008 rabi respectively. PMID:26690528

  7. Predictive factors for the suppression of fusarium wilt of tomato in plant growth media.

    PubMed

    Borrero, Celia; Trillas, M Isabel; Ordovás, José; Tello, Julio C; Avilés, Manuel

    2004-10-01

    ABSTRACT Fusarium wilts are economically important diseases for which there are no effective chemical control measures. However, biological control and fertility management are becoming efficient alternatives for controlling this disease. Growth media formulated with composts that are able to suppress Fusarium wilt of tomato provide a control system that integrates both strategies. The aim of this study was to predict Fusarium wilt suppression of growth media using abiotic and biotic variables. Grape marc compost was the most effective medium used to suppress Fusarium wilt. Cork compost was intermediate, and light peat and expanded vermiculite were the most conducive growth media. The growth media evaluated were in a pH range of 6.26 to 7.97. Both composts had high beta-glucosidase activity. When pH and beta-glucosidase activity were taken into account as predictive variables, more than 91% of the variation in severity of Fusarium wilt was explained. This relationship illustrates the effect of nutrient availability and the degree of microbiostasis, two key factors in this pathosystem. Microbial populations involved in suppressiveness were cellulolytic and oligotrophic actinomycetes, fungi, and the ratios cellulolytic actinomycetes/cellulolytic bacteria, oligotrophic bacteria/copiotrophic bacteria, and oligotrophic actinomycetes/oligotrophic bacteria. Based on community level physiological profiles, different community structures were evident among growth media evaluated. PMID:18943798

  8. User-friendly markers linked to Fusarium wilt race 1 resistance Fw gene for marker-assisted selection in pea

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fusarium wilt is one of the most widespread diseases of pea. Resistance to Fusarium wilt race 1 was reported as a single gene, Fw, located on linkage group III. The previously reported AFLP and RAPD markers linked to Fw have limited usage in marker-assisted selection due to their map distance and l...

  9. Race 3, a new and highly virulent race of Fusarium oxysporum f. sp. niveum causing Fusarium wilt in watermelon

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Three races (0, 1, and 2) of Fusarium oxysporum f. sp. niveum have been previously described in watermelon (Citrullus lanatus) based on their ability to cause disease on differential watermelon genotypes. Four isolates of F. oxysporum f. sp. niveum collected from wilted watermelon plants or infeste...

  10. Stem nematode-fusarium wilt complex in alfalfa as related to irrigation management at harvest time.

    PubMed

    Griffin, G D

    1992-06-01

    A high moisture level in the top 10 cm of soil at time of cutting of alfalfa increased the incidence of plant mortality and Fusarium wilt in soil infested with Ditylenchus dipsaci and Fusarium oxysporum f. sp. medicaginis in greenhouse and field microplot studies. Ranger alfalfa, susceptible to both D. dipsaci and F. oxysporum f. sp. medicaginis, was less persistent than Moapa 69 (nematode susceptible and Fusarium wilt resistant) and Lahontan alfalfa (nematode resistant with low Fusarium wilt resistance). In the greenhouse, the persistence of Ranger, Moapa 69, and Lahontan alfalfa plants was 46%, 64%, and 67% respectively, in nematode + fungus infested soil at high soil moisture at time of cutting. This compared to 74%, 84%, and 73% persistence of Ranger, Moapa 69, and Lahontan, respectively, at low soil moisture at time of cutting. Shoot weights as a percentage of uninoculated controls at the high soil moisture level were 38%, 40%, and 71% for Ranger, Moapa 69, and Lahontan, respectively. Low soil moisture at time of cutting negated the effect D. dipsaci on plant persistence and growth of subsequent cuttings, and reduced Fusarium wilt of plants in the nematode-fungus treatment; shoot weights were 75%, 90%, and 74% of uninoculated controls for Ranger, Moapa 69, and Lahontan. Similar results were obtained in the field microplot study, and stand persistence and shoot weights were less in nematode + fungus-infested soil at the high soil-moisture level (early irrigation) than at the low soil-moisture level (late irrigation). PMID:19283002

  11. The tomato xylem sap protein XSP10 is required for full susceptibility to Fusarium wilt disease.

    PubMed

    Krasikov, Vladimir; Dekker, Henk L; Rep, Martijn; Takken, Frank L W

    2011-01-01

    XSP10 is an abundant 10 kDa protein found in the xylem sap of tomato. The protein displays structural similarity to plant lipid transfer proteins (LTPs). LTPs are involved in various physiological processes, including disease resistance, and some are able to bind and transfer diverse lipid molecules. XSP10 abundance in xylem sap declines upon infection with Fusarium oxysporum f. sp. lycopersici (Fol), implying involvement of XSP10 in the plant-pathogen interaction. Here, the biochemical characterization of XSP10 with respect to fatty acid-binding properties is reported; a weak but significant binding to saturated fatty acids was found. Furthermore, XSP10-silenced tomato plants were engineered and it was found that these plants exhibited reduced disease symptom development upon infection with a virulent strain of Fol. Interestingly, the reduced symptoms observed did not correlate with an altered expression profile for known reporter genes of plant defence (PR-1 and WIPI). This work demonstrates that XSP10 has lipid-binding properties and is required for full susceptibility of tomato to Fusarium wilt. PMID:20974736

  12. Mapping Fusarium wilt race 1 resistance genes in cotton by inheritance, QTL and sequencing composition.

    PubMed

    Ulloa, Mauricio; Wang, Congli; Hutmacher, Robert B; Wright, Steven D; Davis, R Michael; Saski, Christopher A; Roberts, Philip A

    2011-07-01

    Knowledge of the inheritance of disease resistance and genomic regions housing resistance (R) genes is essential to prevent expanding pathogen threats such as Fusarium wilt [Fusarium oxysporum f.sp. vasinfectum (FOV) Atk. Sny & Hans] in cotton (Gossypium spp.). We conducted a comprehensive study combining conventional inheritance, genetic and quantitative trait loci (QTL) mapping, QTL marker-sequence composition, and genome sequencing to examine the distribution, structure and organization of disease R genes to race 1 of FOV in the cotton genome. Molecular markers were applied to F(2) and recombinant inbred line (RIL) interspecific mapping populations from the crosses Pima-S7 (G. barbadense L.) × 'Acala NemX' (G. hirsutum L.) and Upland TM-1 (G. hirsutum) × Pima 3-79 (G. barbadense), respectively. Three greenhouse tests and one field test were used to obtain sequential estimates of severity index (DSI) of leaves, and vascular stem and root staining (VRS). A single resistance gene model was observed for the F(2) population based on inheritance of phenotypes. However, additional inheritance analyses and QTL mapping indicated gene interactions and inheritance from nine cotton chromosomes, with major QTLs detected on five chromosomes [Fov1-C06, Fov1-C08, (Fov1-C11 ( 1 ) and Fov1-C11 ( 2)) , Fov1-C16 and Fov1-C19 loci], explaining 8-31% of the DSI or VRS variation. The Fov1-C16 QTL locus identified in the F(2) and in the RIL populations had a significant role in conferring FOV race 1 resistance in different cotton backgrounds. Identified molecular markers may have important potential for breeding effective FOV race 1 resistance into elite cultivars by marker-assisted selection. Reconciliation between genetic and physical mapping of gene annotations from marker-DNA and new DNA sequences of BAC clones tagged with the resistance-associated QTLs revealed defenses genes induced upon pathogen infection and gene regions rich in disease-response elements, respectively. These offer candidate gene targets for Fusarium wilt resistance response in cotton and other host plants. PMID:21533837

  13. Effect of pseudobactin 358 production by Pseudomonas putida WCS358 on suppression of fusarium wilt of carnations by nonpathogenic Fusarium oxysporum Fo47.

    PubMed Central

    Lemanceau, P; Bakker, P A; De Kogel, W J; Alabouvette, C; Schippers, B

    1992-01-01

    Nonpathogenic Fusarium oxysporum Fo47b10 combined with Pseudomonas putida WCS358 efficiently suppressed fusarium wilt of carnations grown in soilless culture. This suppression was significantly higher than that obtained by inoculation of either antagonistic microorganism alone. The increased suppression obtained by Fo47b10 combined with WCS358 only occurred when Fo47b10 was introduced at a density high enough (at least 10 times higher than that of the pathogen) to be efficient on its own. P. putida WCS358 had no effect on disease severity when inoculated on its own but significantly improved the control achieved with nonpathogenic F. oxysporum Fo47b10. In contrast, a siderophore-negative mutant of WCS358 had no effect on disease severity even in the presence of Fo47b10. Since the densities of both bacterial strains at the root level were similar, the difference between the wild-type WCS358 and the siderophore-negative mutant with regard to the control of fusarium wilt was related to the production of pseudobactin 358. The production of pseudobactin 358 appeared to be responsible for the increased suppression by Fo47b10 combined with WCS358 relative to that with Fo47b10 alone. PMID:1444411

  14. Beltwide breeders' elite-Upland germplasm-pool assessment of Fusarium wilt (FOV) races 1 & 4 in California.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Host-plant resistance is currently the most economic and effective strategy for managing Fusarium wilt [Fusarium oxysporum f. sp. vasinfectum (FOV)] in the San Joaquin Valley (SJV) of California. Recently, a strain of Fusarium (race 4) was identified in the SJV that damages most cultivars of Pima co...

  15. Analyses of Fusarium wilt race 3 resistance in Upland cotton (Gossypium hirsutum L.).

    PubMed

    Abdullaev, Alisher A; Salakhutdinov, Ilkhom B; Egamberdiev, Sharof Sh; Kuryazov, Zarif; Glukhova, Ludmila A; Adilova, Azoda T; Rizaeva, Sofiya M; Ulloa, Mauricio; Abdurakhmonov, Ibrokhim Y

    2015-06-01

    Fusarium wilt [Fusarium oxysporum f.sp. vasinfectum (FOV) Atk. Sny & Hans] represents a serious threat to cotton (Gossypium spp.) production. For the last few decades, the FOV pathogen has become a significant problem in Uzbekistan causing severe wilt disease and yield losses of G. hirsutum L. cultivars. We present the first genetic analyses of FOV race 3 resistance on Uzbek Cotton Germplasm with a series of field and greenhouse artificial inoculation-evaluations and inheritance studies. The field experiments were conducted in two different sites: the experimental station in Zangiota region-Environment (Env) 1 and the Institute of Cotton Breeding (Env-2, Tashkent province). The Env-1 was known to be free of FOV while the Env-2 was known to be a heavily FOV infested soil. In both (Env-1 and Env-2) of these sites, field soil was inoculated with FOV race 3. F2 and an F3 Upland populations ("Mebane B1" × "11970") were observed with a large phenotypic variance for plant survival and FOV disease severity within populations and among control or check Upland accessions. Wilt symptoms among studied F2 individuals and F3 families significantly differed depending on test type and evaluation site. Distribution of Mendelian rations of susceptible (S) and resistant (R) phenotypes were 1S:1R field Env-1 and 3S:1R field Env-2 in the F2 population, and 1S:3R greenhouse site in the F3 population. The different segregation distribution of the Uzbek populations may be explained by differences in FOV inoculum level and environmental conditions during assays. However, genetic analysis indicated a recessive single gene action under high inoculum levels or disease pressure for FOV race 3 resistance. Uzbek germplasm may be more susceptible than expected to FOV race 3, and sources of resistance to FOV may be limited under the FOV inoculum levels present in highly-infested fields making the breeding process more complex. PMID:25896369

  16. Cost benefit analyses of using grafted watermelon transplants for Fusarium wilt disease control

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil-borne diseases such as Fusarium wilt continue to plague watermelon growers in intensive production areas where land resources are scarce and rotation of various crops is limited. Risk management alternatives, available to the farmer, have been reduced by the loss of soil fumigation chemicals s...

  17. Evaluations of Fusarium wilt resistance in Upland cotton from Uzbek cotton germplasm resources.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fusarium oxysporum f. sp. vasinfectum Atk. Sny & Hans (FOV), in combination with Verticillium dahliae Kleb, causes a wilt disease complex in cotton that significantly reduces yield. A highly virulent strain of FOV, No. 316, was isolated that caused up to 80% plant death in commercial cotton in Uzbe...

  18. Mapping QTL for Fusarium wilt Race 2 partial resistance in pea (Pisum sativum L.)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fusarium oxysporum f.sp. pisi (Fop) is present in pea production regions worldwide, and causes a vascular wilt resulting in significant crop losses. Four races of Fop have been identified and resistance to each reportedly conferred by an individual single dominant gene. Fnw confers resistance to Fop...

  19. Genetic and QTL mapping of Fusarium wilt race 1 resistance in cotton

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fusarium oxysporum f.sp. vasinfectum (FOV) Atk. Sny & Hans] causes a vascular wilt disease that significantly reduces yield in cotton (Gossypium spp.). Host-plant resistance can be highly effective in limiting FOV-induced yield loss. We conducted genetic and QTL analyses of FOV race 1 resistance by ...

  20. Routine mapping of Fusarium wilt resistance in BC1 populations of Arabidopsis thaliana

    PubMed Central

    2013-01-01

    Background Susceptibility to Fusarium wilt disease varies among wild accessions of Arabidopsis thaliana. Six RESISTANCE TO FUSARIUM OXYSPORUM (RFO) quantitative trait loci (QTLs) controlling the resistance of accession Columbia-0 (Col-0) and susceptibility of Taynuilt-0 to Fusarium oxysporum forma specialis matthioli (FOM) are detected in a recombinant population derived from a single backcross of the F1 hybrid (BC1). In particular, the RFO1 QTL appears to interact with three other loci, RFO2, RFO4 and RFO6, and is attributed to the gene At1g79670. Results When resistance to FOM was mapped in a new BC1 population, in which the loss-of-function mutant of At1g79670 replaced wild type as the Col-0 parent, RFO1s major effect and RFO1s interaction with RFO2, RFO4 and RFO6 were absent, showing that At1g79670 alone accounts for the RFO1 QTL. Resistance of two QTLs, RFO3 and RFO5, was independent of RFO1 and was reproduced in the new BC1 population. In analysis of a third BC1 population, resistance to a second pathogen, F. oxysporum forma specialis conglutinans race 1 (FOC1), was mapped and the major effect locus RFO7 was identified. Conclusions Natural quantitative resistance to F. oxysporum is largely specific to the infecting forma specialis because different RFO loci were responsible for resistance to FOM and FOC1. The mapping of quantitative disease resistance traits in BC1 populations, generated from crosses between sequenced Arabidopsis accessions, can be a routine procedure when genome-wide genotyping is efficient, economical and accessible. PMID:24172069

  1. Physiological and biochemical aspects of the resistance of banana plants to Fusarium wilt potentiated by silicon.

    PubMed

    Fortunato, Alessandro Antonio; Rodrigues, Fabrício Ávila; do Nascimento, Kelly Juliane Teles

    2012-10-01

    Silicon amendments to soil have resulted in a decrease of diseases caused by several soilborne pathogens affecting a wide number of crops. This study evaluated the physiological and biochemical mechanisms that may have increased resistance of banana to Fusarium wilt, caused by Fusarium oxysporum f. sp. cubense, after treatment with silicon (Si) amendment. Plants from the Grand Nain (resistant to F. oxysporum f. sp. cubense) and "Maçã" (susceptible to F. oxysporum f. sp. cubense) were grown in plastic pots amended with Si at 0 or 0.39 g/kg of soil (-Si or +Si, respectively) and inoculated with race 1 of F. oxysporum f. sp. cubense. Relative lesion length (RLL) and asymptomatic fungal colonization in tissue (AFCT) were evaluated at 40 days after inoculation. Root samples were collected at different times after inoculation with F. oxysporum f. sp. cubense to determine the level of lipid peroxidation, expressed as equivalents of malondialdehyde (MDA), hydrogen peroxide (H(2)O(2)), pigments (chlorophyll a, chlorophyll b, total chlorophyll, and carotenoids), total soluble phenolics (TSP), and lignin-thioglycolic acid (LTGA) derivatives; the activities of the enzymes phenylalanine ammonia-lyases glucanases (PALs), peroxidases (POXs), polyphenoloxidases (PPOs), β-1,3-glucanases (GLUs), and chitinases (CHIs); and Si concentration in roots. Root Si concentration was significantly increased by 35.3% for the +Si treatment compared with the -Si treatment. For Grand Nain, the root Si concentration was significantly increased by 12.8% compared with "Maçã." Plants from Grand Nain and "Maçã" in the +Si treatment showed significant reductions of 40.0 and 57.2%, respectively, for RLL compared with the -Si treatment. For the AFCT, there was a significant reduction of 18.5% in the +Si treatment compared with the -Si treatment. The concentration of MDA significantly decreased for plants from Grand Nain and "Maçã" supplied with Si compared with the -Si treatment while the concentrations of H(2)O(2) on roots and pigments on leaves significantly increased. The concentrations of TSP and LTGA derivatives as well as the PALs, PPOs, POXs, GLUs, and CHIs activities significantly increased on roots of plants from Grand Nain and "Maçã" from the +Si treatment compared with the -Si treatment. Results of this study suggest that the symptoms of Fusarium wilt on roots of banana plants supplied with Si decreased due to an increase in the concentrations of H(2)O(2), TSP, and LTGA derivatives and greater activities of PALs, PPOs, POXs, GLUs, and CHIs. PMID:22784251

  2. Challenges in Fusarium, a Trans-Kingdom Pathogen.

    PubMed

    van Diepeningen, Anne D; de Hoog, G Sybren

    2016-04-01

    Fusarium species are emerging human pathogens, next to being plant pathogens. Problems with Fusarium are in their diagnostics and in their difficult treatment, but also in what are actual Fusarium species or rather Fusarium-like species. In this issue Guevara-Suarez et al. (Mycopathologia. doi: 10.1007/s11046-016-9983-9 , 2016) characterized 89 isolates of Fusarium from Colombia showing especially lineages within the Fusarium solani and oxysporum species complexes to be responsible for onychomycosis. PMID:26966007

  3. Verticillium Wilt in Potato: Host-Pathogen Interactions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Verticillium wilt (VW) is a widespread disease that causes consistent yield losses in many potato growing regions worldwide. In the U.S., it is mainly caused by the soil-borne fungal pathogen Verticillium dahliae. Microsclerotia can survive in the soil for many years. When they germinate and infec...

  4. Thyme essential oil as a defense inducer of tomato against gray mold and Fusarium wilt.

    PubMed

    Ben-Jabeur, Maissa; Ghabri, Emna; Myriam, Machraoui; Hamada, Walid

    2015-09-01

    The potential of thyme essential oil in controlling gray mold and Fusarium wilt and inducing systemic acquired resistance in tomato seedlings and tomato grown in hydroponic system was evaluated. Thyme oil highly reduced 64% of Botrytis cinerea colonization on pretreated detached leaves compared to untreated control. Also, it played a significant decrease in Fusarium wilt severity especially at7 days post treatment when it was reduced to 30.76%. To explore the plant pathways triggered in response to thyme oil, phenolic compounds accumulation and peroxidase activity was investigated. Plant response was observed either after foliar spray or root feeding in hydroponics which was mostly attributed to peroxidases accumulation rather than phenolic compounds accumulation, and thyme oil seems to be more effective when applied to the roots. PMID:26002413

  5. Biocontrol of Fusarium wilt disease in tomato by Paenibacillus ehimensis KWN38.

    PubMed

    Naing, Kyaw Wai; Nguyen, Xuan Hoa; Anees, Muhammad; Lee, Yong Seong; Kim, Yong Cheol; Kim, Sang Jun; Kim, Myung Hee; Kim, Yong Hwan; Kim, Kil Yong

    2015-01-01

    This study was conducted to investigate biocontrol potential of Paenibacillus ehimensis KWN38 against Fusarium oxysporum f.sp. lycopersici causing Fusarium wilt disease in tomato. Our result showed that P. ehimensis KWN38 produced extracellular organic compounds and crude enzyme to inhibit F. oxysporum f.sp. lycopersici conidial germination in in vitro assays. Tomato seedlings were treated with water (W), grass medium (G), G with P. ehimensis KWN38 inoculation (GP) and G along with synthetic fungicide (GSf). Disease symptoms were was first observed in G and W at 12 days after infection (DAI) while symptoms were noticeable in the GP and GSf treatments at 20 and 24 DAI, respectively. Tomato plants treated with P. ehimensis KWN38 or fungicide significantly reduced Fusarium wilt disease incidence and severity as compared to control tomato plants treated with water and grass medium. The similar results were also found in the root mortality of tomato plants. At 25 DAI, most plants in control treatments (W and G) wilted and the brown vascular systems of infected plants was clearly differentiable from normal green vascular system of healthy plants from GP and GSf. Plants in the GP showed higher fresh and dry weights of both root and shoots than those in W and G treatments. Leaf peroxidase and polyphenol oxidase activities of tomato plants in G and W were higher than those in GP and GSf. Root enzyme activities showed a similar pattern but the values were higher than leaf enzyme. The results clearly demonstrated that P. ehimensis KWN38 may be considered as biocontrol agent of Fusarium wilt disease in tomato. PMID:25384610

  6. The Effects of Fungicide, Soil Fumigant, Bio-Organic Fertilizer and Their Combined Application on Chrysanthemum Fusarium Wilt Controlling, Soil Enzyme Activities and Microbial Properties.

    PubMed

    Zhao, Shuang; Chen, Xi; Deng, Shiping; Dong, Xuena; Song, Aiping; Yao, Jianjun; Fang, Weimin; Chen, Fadi

    2016-01-01

    Sustained monoculture often leads to a decline in soil quality, in particular to the build-up of pathogen populations, a problem that is conventionally addressed by the use of either fungicide and/or soil fumigation. This practice is no longer considered to be either environmentally sustainable or safe. While the application of organic fertilizer is seen as a means of combating declining soil fertility, it has also been suggested as providing some control over certain soil-borne plant pathogens. Here, a greenhouse comparison was made of the Fusarium wilt control efficacy of various treatments given to a soil in which chrysanthemum had been produced continuously for many years. The treatments comprised the fungicide carbendazim (MBC), the soil fumigant dazomet (DAZ), the incorporation of a Paenibacillus polymyxa SQR21 (P. polymyxa SQR21, fungal antagonist) enhanced bio-organic fertilizer (BOF), and applications of BOF combined with either MBC or DAZ. Data suggest that all the treatments evaluated show good control over Fusarium wilt. The MBC and DAZ treatments were effective in suppressing the disease, but led to significant decrease in urease activity and no enhancement of catalase activity in the rhizosphere soils. BOF including treatments showed significant enhancement in soil enzyme activities and microbial communities compared to the MBC and DAZ, evidenced by differences in bacterial/fungi (B/F) ratios, Shannon-Wiener indexes and urease, catalase and sucrase activities in the rhizosphere soil of chrysanthemum. Of all the treatments evaluated, DAZ/BOF application not only greatly suppressed Fusarium wilt and enhanced soil enzyme activities and microbial communities but also promoted the quality of chrysanthemum obviously. Our findings suggest that combined BOF with DAZ could more effectively control Fusarium wilt disease of chrysanthemum. PMID:27110753

  7. Assessment of Acala/Upland and Pima cottons response to Fusarium wilt disease in the San Joaquin Valley of California.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fusarium wilt of cotton in California has been considered a potentially serious fungal disease caused by the organism Fusarium oxysporum vas infectum (also called “FOV”) for many decades in areas of the San Joaquin Valley (SJV). This fungus is a soil-inhabiting organism. Certain forms of this pathog...

  8. Phylogeny and pathogenicity of Fusarium oxysporum isolates from cottonseed imported from Australia into California for dairy cattle feed

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A unique biotype of the Fusarium wilt pathogen found in Australia in 1993 is favored by neutral or alkaline heavy soils and does not require nematodes to cause disease, making it a new threat to 4-6 million acres of USA Upland cotton (Gossypium hirsutum L.). In 2001-2002, several shiploads of live ...

  9. Jasmonate Signalling and Defence Responses in the Model Legume Medicago truncatula—A Focus on Responses to Fusarium Wilt Disease

    PubMed Central

    Thatcher, Louise F.; Gao, Ling-Ling; Singh, Karam B.

    2016-01-01

    Jasmonate (JA)-mediated defences play important roles in host responses to pathogen attack, in particular to necrotrophic fungal pathogens that kill host cells in order to extract nutrients and live off the dead plant tissue. The root-infecting fungal pathogen Fusarium oxysporum initiates a necrotrophic growth phase towards the later stages of its lifecycle and is responsible for devastating Fusarium wilt disease on numerous legume crops worldwide. Here we describe the use of the model legume Medicago truncatula to study legume–F. oxysporum interactions and compare and contrast this against knowledge from other model pathosystems, in particular Arabidopsis thaliana–F. oxysporum interactions. We describe publically-available genomic, transcriptomic and genetic (mutant) resources developed in M. truncatula that enable dissection of host jasmonate responses and apply aspects of these herein during the M. truncatula-–F. oxysporum interaction. Our initial results suggest not all components of JA-responses observed in M. truncatula are shared with Arabidopsis in response to F. oxysporum infection. PMID:27135231

  10. Jasmonate Signalling and Defence Responses in the Model Legume Medicago truncatula-A Focus on Responses to Fusarium Wilt Disease.

    PubMed

    Thatcher, Louise F; Gao, Ling-Ling; Singh, Karam B

    2016-01-01

    Jasmonate (JA)-mediated defences play important roles in host responses to pathogen attack, in particular to necrotrophic fungal pathogens that kill host cells in order to extract nutrients and live off the dead plant tissue. The root-infecting fungal pathogen Fusarium oxysporum initiates a necrotrophic growth phase towards the later stages of its lifecycle and is responsible for devastating Fusarium wilt disease on numerous legume crops worldwide. Here we describe the use of the model legume Medicago truncatula to study legume-F. oxysporum interactions and compare and contrast this against knowledge from other model pathosystems, in particular Arabidopsis thaliana-F. oxysporum interactions. We describe publically-available genomic, transcriptomic and genetic (mutant) resources developed in M. truncatula that enable dissection of host jasmonate responses and apply aspects of these herein during the M. truncatula--F. oxysporum interaction. Our initial results suggest not all components of JA-responses observed in M. truncatula are shared with Arabidopsis in response to F. oxysporum infection. PMID:27135231

  11. Effect of vinegar residue compost amendments on cucumber growth and Fusarium wilt.

    PubMed

    Du, Nanshan; Shi, Lu; Du, Lantian; Yuan, Yinghui; Li, Bin; Sang, Ting; Sun, Jin; Shu, Sheng; Guo, Shirong

    2015-12-01

    Fusarium wilt of cucumber caused by Fusarium oxysporum f. sp. cucumerinum J. H. Owen is one of the major destructive soilborne diseases and results in considerable yield losses. Methyl bromide was once the most effective disease control method but has been confirmed as harmful to the environment. Using suppressive media as biological controls to assist crop growth is becoming popular. In this study, Fusarium wilt of cucumber was successfully controlled by a newly identified suppressive media: vinegar residue compost-amended media (vinegar residue compost mixed with peat and vermiculite in a 6:3:1 ratio (v/v) vinegar residue substrate (VRS). Greenhouse experiments were carried out to evaluate the effect of VRS on the growth of cucumber seedlings and disease suppression. The control was peat/vermiculite (2:1, v/v). To identify the mixed media most suitable for the growth of plants and their suppressiveness indicators, we evaluated the biological characteristics of cucumber, the physicochemical and biochemical properties of the growth media, and the enzyme activities. Total organic C (C(org)), microbial biomass C (C(mic)), basal respiration (R(mic)), and enzyme (catalase, invertase, urease, proteinase, phosphatase, β-glucosidase, and hydrolysis of fluorescein diacetate) activities increased significantly after vinegar waste compost amendment. The compost media also showed a significantly positive effect on the growth of cucumber seedlings and the suppression of the disease severity index (DSI, 38% reduction). The cucumber rhizosphere population of F. oxysporum f. sp. cucumerinum (FOC) was significantly lower in VRS than in the control. These results demonstrate convincingly that vinegar residue compost-amended media has a beneficial effect on cucumber growth and could be applied as a method for biological control of cucumber Fusarium wilt. PMID:26250808

  12. [Faba bean fusarium wilt (Fusarium oxysporum )control and its mechanism in different wheat varieties and faba bean intercropping system].

    PubMed

    Dong, Yan; Dong, Kun; Zheng, Yi; Tang, Li; Yang, Zhi-Xian

    2014-07-01

    Field experiment and hydroponic culture were conducted to investigate effects of three wheat varieties (Yunmai 42, Yunmai 47 and Mianyang 29) and faba bean intercropping on the shoot biomass, disease index of fusarium wilt, functional diversity of microbial community and the amount of Fusarium oxysporum in rhizosphere of faba bean. Contents and components of the soluble sugars, free amino acids and organic acids in the root exudates were also examined. Results showed that, compared with monocropped faba bean, shoot biomass of faba bean significantly increased by 16.6% and 13.4%, disease index of faba bean fusarium wilt significantly decreased by 47.6% and 23.3% as intercropped with Yunmai 42 and Yunmai 47, but no significant differences of both shoot biomass and disease index were found as intercropped with Mianyang 29. Compared with monocropped faba bean, the average well color development (AWCD value) and total utilization ability of carbon sources of faba bean significantly increased, the amount of Fusarium oxysporum of faba bean rhizosphere significantly decreased, and the microbial community structures of faba bean rhizosphere changed as intercropped with YM42 and YM47, while no significant effects as intercropped with MY29. Total contents of soluble sugar, free amino acids and organic acids in root exudates were in the trend of MY29>YM47>YM42. Contents of serine, glutamic, glycine, valine, methionine, phenylalanine, lysine in root exudates of MY29 were significantly higher than that in YM42 and YM47. The arginine was detected only in the root exudates of YM42 and YM47, and leucine was detected only in the root exudates of MY29. Six organic acids of tartaric acid, malic acid, citric acid, succinic acid, fumaric acid, t-aconitic acid were detected in root exudates of MY29 and YM47, and four organic acids of tartaric acid, malic acid, citric acid, fumaric acid were detected in root exudates of YM42. Malic acid content in root exudates of YM47 and MY29 was significantly higher than that of YM42. In conclusion, intercropping influenced the microbial activity and substrate utilization of soil microorganisms, altered the microbial community diversity in rhizosphere of faba bean, reduced the amount of F. oxysporum and disease index of faba bean fusarium wilt, and promoted faba bean growth. Effects of intercropping on disease control were influenced by the intercropped wheat variety, suggesting that the differences of root exudates of wheat were important factors that affected soil-borne diseases control in intercropping. PMID:25345048

  13. Expression of Rice Chitinase Gene in Genetically Engineered Tomato Confers Enhanced Resistance to Fusarium Wilt and Early Blight.

    PubMed

    Jabeen, Nyla; Chaudhary, Zubeda; Gulfraz, Muhammad; Rashid, Hamid; Mirza, Bushra

    2015-09-01

    This is the first study reporting the evaluation of transgenic lines of tomato harboring rice chitinase (RCG3) gene for resistance to two important fungal pathogens Fusarium oxysporum f. sp. lycopersici (Fol) causing fusarium wilt and Alternaria solani causing early blight (EB). In this study, three transgenic lines TL1, TL2 and TL3 of tomato Solanum lycopersicum Mill. cv. Riogrande genetically engineered with rice chitinase (RCG 3) gene and their R1 progeny was tested for resistance to Fol by root dip method and A. solani by detached leaf assay. All the R0 transgenic lines were highly resistant to these fungal pathogens compared to non-transgenic control plants. The pattern of segregation of three independent transformant for Fol and A. solani was also studied. Mendelian segregation was observed in transgenic lines 2 and 3 while it was not observed in transgenic line 1. It was concluded that introduction of chitinase gene in susceptible cultivar of tomato not only enhanced the resistance but was stably inherited in transgenic lines 2 and 3. PMID:26361473

  14. Expression of Rice Chitinase Gene in Genetically Engineered Tomato Confers Enhanced Resistance to Fusarium Wilt and Early Blight

    PubMed Central

    Jabeen, Nyla; Chaudhary, Zubeda; Gulfraz, Muhammad; Rashid, Hamid; Mirza, Bushra

    2015-01-01

    This is the first study reporting the evaluation of transgenic lines of tomato harboring rice chitinase (RCG3) gene for resistance to two important fungal pathogens Fusarium oxysporum f. sp. lycopersici (Fol) causing fusarium wilt and Alternaria solani causing early blight (EB). In this study, three transgenic lines TL1, TL2 and TL3 of tomato Solanum lycopersicum Mill. cv. Riogrande genetically engineered with rice chitinase (RCG 3) gene and their R1 progeny was tested for resistance to Fol by root dip method and A. solani by detached leaf assay. All the R0 transgenic lines were highly resistant to these fungal pathogens compared to non-transgenic control plants. The pattern of segregation of three independent transformant for Fol and A. solani was also studied. Mendelian segregation was observed in transgenic lines 2 and 3 while it was not observed in transgenic line 1. It was concluded that introduction of chitinase gene in susceptible cultivar of tomato not only enhanced the resistance but was stably inherited in transgenic lines 2 and 3. PMID:26361473

  15. Bacillus thuringiensis strain 199 can induce systemic resistance in tomato against Fusarium wilt

    PubMed Central

    Mahboob, Asrar; Javed, Asmat Ali

    2013-01-01

    The research work was performed to investigate the potential of Bacillus thuringiensis strain 199 to induce systemic resistance in tomato against Fusarium wilt. Roots of two-week-old seedlings of tomato plants were primed with bacterial strain. After 10 days of transplantation, some pots of tomato seedlings were provided with inoculum of Fusarium oxysporum lycopersici according to experimental design to induce disease. After 15 days of incubation period, plants challenged with F. oxysporum lycopersici alone were having obvious symptoms of Fusarium wilt. Plants that were treated with B. thuringiensis 199 + F. oxysporum lycopersici were having significant reduction of disease severity. Quantity of total phenolics increased 1.7-fold in bacterial-treated plants as compared to nontreated. Likewise, in case of defense-related enzymes, a significant increase of 1.3-, 1.8-, and 1.4-fold in polyphenol oxidase (PPO), phenyl ammonia lyase (PAL), and peroxidase (PO) was observed in comparison with untreated control. These results, hence, prove the potential of this bacterial strain for use as plant protection agent. PMID:24294498

  16. Characterization of the formae speciales of Fusarium oxysporum causing wilts of cucurbits by DNA fingerprinting with nuclear repetitive DNA sequences.

    PubMed Central

    Namiki, F; Shiomi, T; Kayamura, T; Tsuge, T

    1994-01-01

    The genetic relatedness of five formae speciales of Fusarium oxysporum causing wilts of cucurbit plants was determined by DNA fingerprinting with the moderately repetitive DNA sequences FOLR1 to FOLR4. The four FOLR clones were chosen from a genomic library made from F. oxysporum f. sp. lagenariae 03-05118. Total DNAs from 50 strains representing five cucurbit-infecting formae speciales, cucumerinum, melonis, lagenariae, niveum, and momordicae, and 6 strains of formae speciales pathogenic to other plants were digested with EcoRV and hybridized with 32P-labeled FOLR probes. The strains were clearly distinguishable at the formae specialis level on the basis of FOLR DNA fingerprints. Fifty-two fingerprint types were detected among the 56 strains by using all FOLR probes. These probes were used to infer phylogenetic relationships among the DNA fingerprint types by the unweighted pair group method using averages and parsimony analysis. The fingerprint types detected in each of the formae speciales cucumerinum, lagenariae, niveum, and momordicae were grouped into a single cluster. However, two different genetic groups occurred in the formae specialis melonis. The two groups also differed in pathogenicity: one group caused wilts of muskmelon and oriental melon, while the second was pathogenic only to muskmelon. The fingerprint types of different formae speciales pathogenic to plants other than cucurbits were distinguishable from one another and from the fingerprints of the cucurbit-infecting strains. These results suggest that the cucurbit-infecting formae speciales are intraspecific variants distinguishable at the DNA level and in their host range. Images PMID:8085813

  17. Comparative Proteomics Analyses of Two Races of Fusarium oxysporum f. sp. conglutinans that Differ in Pathogenicity

    PubMed Central

    Li, Erfeng; Ling, Jian; Wang, Gang; Xiao, Jiling; Yang, Yuhong; Mao, Zhenchuan; Wang, Xuchu; Xie, Bingyan

    2015-01-01

    Fusarium oxysporum is a soil-inhabiting fungus that induces vascular wilt and root rot in a variety of plants. F. oxysporum f. sp. conglutinans (Foc), which comprises two races, can cause wilt disease in cabbage. Compared with race 1 (52557−TM, R1), race 2 (58385−TM, R2) exhibits much stronger pathogenicity. Here, we provide the first proteome reference maps for Foc mycelium and conidia and identify 145 proteins with different abundances among the two races. Of these proteins, most of the high-abundance proteins in the R2 mycelium and conidia are involved in carbohydrate, amino acid and ion metabolism, which indicates that these proteins may play important roles in isolate R2’s stronger pathogenicity. The expression levels of 20 typical genes demonstrate similarly altered patterns compared to the proteomic analysis. The protein glucanosyltransferase, which is involved in carbohydrate metabolism, was selected for research. We knocked out the corresponding gene (gas1) and found that Foc-∆gas1 significantly reduced growth rate and virulence compared with wild type isolates. These results deepened our understanding of the proteins related to F. oxysporum pathogenicity in cabbage Fusarium wilt and provided new opportunities to control this disease. PMID:26333982

  18. Comparative Proteomics Analyses of Two Races of Fusarium oxysporum f. sp. conglutinans that Differ in Pathogenicity.

    PubMed

    Li, Erfeng; Ling, Jian; Wang, Gang; Xiao, Jiling; Yang, Yuhong; Mao, Zhenchuan; Wang, Xuchu; Xie, Bingyan

    2015-01-01

    Fusarium oxysporum is a soil-inhabiting fungus that induces vascular wilt and root rot in a variety of plants. F. oxysporum f. sp. conglutinans (Foc), which comprises two races, can cause wilt disease in cabbage. Compared with race 1 (52557(-TM), R1), race 2 (58385(-TM), R2) exhibits much stronger pathogenicity. Here, we provide the first proteome reference maps for Foc mycelium and conidia and identify 145 proteins with different abundances among the two races. Of these proteins, most of the high-abundance proteins in the R2 mycelium and conidia are involved in carbohydrate, amino acid and ion metabolism, which indicates that these proteins may play important roles in isolate R2's stronger pathogenicity. The expression levels of 20 typical genes demonstrate similarly altered patterns compared to the proteomic analysis. The protein glucanosyltransferase, which is involved in carbohydrate metabolism, was selected for research. We knocked out the corresponding gene (gas1) and found that Foc-∆gas1 significantly reduced growth rate and virulence compared with wild type isolates. These results deepened our understanding of the proteins related to F. oxysporum pathogenicity in cabbage Fusarium wilt and provided new opportunities to control this disease. PMID:26333982

  19. Corn seedling disease, fusaric acid as the wilt toxin and the need for biocontrol of Fusarium verticillioides and other Fusarium species

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fusaric acid (5-butylpicolinic acid) was first discovered during the laboratory culture of Fusarium heterosporum, and was one of the first fungal metabolites implicated in the pathogenesis of wilt symptoms of plants especially under adverse conditions. In addition to a primary role in plant pathoge...

  20. Soil microbial community structure in cucumber rhizosphere of different resistance cultivars to fusarium wilt.

    PubMed

    Yao, Huaiying; Wu, Fengzhi

    2010-06-01

    Cucumber fusarium wilt is a common soil-borne disease. We hypothesize that there is a relationship between the severity of disease and soil microbial ecology. In this work, culturable microbial populations, lipid fatty acid and community-level physiological profiles (CLPP) from rhizosphere soils of four different cucumber cultivars were investigated. Comparatively higher actinomycetes, mycorrhizal colonization and higher ratios of bacteria to fungi were found in the two resistant cultivars compared with the two susceptible cultivars. CLPP analysis showed that catabolic diversity indices were higher in the presence of two resistant cultivars. Phospholipid fatty acid (PLFA) profiles suggested that fungal (18:2omega6,9c) PLFA was enriched in the rhizosphere soils of the two susceptible cultivars, but some bacterial (16:0 and 15:0a) PLFAs were found in a lower relative abundance in these soils. The neutral lipid fatty acid 16:1omega5, which is an indicator of arbuscular mycorrhizal fungi, was enriched in the rhizosphere soils of the two resistant cultivars. All the three methods suggested that plant genotype had a significant impact on the soil microbial community composition and activity, and the differences in the rhizosphere microbial community may result in the differences in the resistance to fusarium wilt. PMID:20370829

  1. Marker-assisted selection of Fusarium wilt-resistant and gynoecious melon (Cucumis melo L.).

    PubMed

    Gao, P; Liu, S; Zhu, Q L; Luan, F S

    2015-01-01

    In this study, molecular markers were designed based on the sex determination genes ACS7 (A) and WIP1 (G) and the domain in the Fusarium oxysporum-resistant gene Fom-2 (F) in order to achieve selection of F. oxysporum-resistant gynoecious melon plants. Markers of A and F are cleaved amplified polymorphic sequences that distinguish alleles according to restriction analysis. Twenty F1 and 1863 F2 plants derived from the crosses between the gynoecious line WI998 and the Fusarium wilt-resistant line MR-1 were genotyped based on the markers. The results showed that the polymerase chain reaction and enzyme digestion results could be effectively used to identify plants with the AAggFF genotype in F2 populations. In the F2 population, 35 gynoecious wilt-resistant plants were selected by marker-assisted selection and were confirmed by disease infection assays, demonstrating that these markers can be used in breeding to select F. oxysporum-resistant gynoecious melon plants. PMID:26662419

  2. Progress in breeding for tolerance to Fusarium wilt (FOV) races 1 and 4 in the San Joaquin Valley (SJV) of California.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The vulnerability of cotton production in California to Fusarium wilt [Fusarium oxysporum f. sp. vasinfectum (FOV)] highlights the need for comprehensive research to protect the future of the cotton industry in the San Joaquin Valley (SJV). A recently identified problematic strain of Fusarium (race ...

  3. Phenylacetic Acid Is ISR Determinant Produced by Bacillus fortis IAGS162, Which Involves Extensive Re-modulation in Metabolomics of Tomato to Protect against Fusarium Wilt.

    PubMed

    Akram, Waheed; Anjum, Tehmina; Ali, Basharat

    2016-01-01

    Bacillus fortis IAGS162 has been previously shown to induce systemic resistance in tomato plants against Fusarium wilt disease. In the first phase of current study, the ISR determinant was isolated from extracellular metabolites of this bacterium. ISR bioassays combined with solvent extraction, column chromatography and GC/MS analysis proved that phenylacetic acid (PAA) was the potential ISR determinant that significantly ameliorated Fusarium wilt disease of tomato at concentrations of 0.1 and 1 mM. In the second phase, the biochemical basis of the induced systemic resistance (ISR) under influence of PAA was elucidated by performing non-targeted whole metabolomics through GC/MS analysis. Tomato plants were treated with PAA and fungal pathogen in various combinations. Exposure to PAA and subsequent pathogen challenge extensively re-modulated tomato metabolic networks along with defense related pathways. In addition, various phenylpropanoid precursors were significantly up-regulated in treatments receiving PAA. This work suggests that ISR elicitor released from B. fortis IAGS162 contributes to resistance against fungal pathogens through dynamic reprogramming of plant pathways that are functionally correlated with defense responses. PMID:27148321

  4. Phenylacetic Acid Is ISR Determinant Produced by Bacillus fortis IAGS162, Which Involves Extensive Re-modulation in Metabolomics of Tomato to Protect against Fusarium Wilt

    PubMed Central

    Akram, Waheed; Anjum, Tehmina; Ali, Basharat

    2016-01-01

    Bacillus fortis IAGS162 has been previously shown to induce systemic resistance in tomato plants against Fusarium wilt disease. In the first phase of current study, the ISR determinant was isolated from extracellular metabolites of this bacterium. ISR bioassays combined with solvent extraction, column chromatography and GC/MS analysis proved that phenylacetic acid (PAA) was the potential ISR determinant that significantly ameliorated Fusarium wilt disease of tomato at concentrations of 0.1 and 1 mM. In the second phase, the biochemical basis of the induced systemic resistance (ISR) under influence of PAA was elucidated by performing non-targeted whole metabolomics through GC/MS analysis. Tomato plants were treated with PAA and fungal pathogen in various combinations. Exposure to PAA and subsequent pathogen challenge extensively re-modulated tomato metabolic networks along with defense related pathways. In addition, various phenylpropanoid precursors were significantly up-regulated in treatments receiving PAA. This work suggests that ISR elicitor released from B. fortis IAGS162 contributes to resistance against fungal pathogens through dynamic reprogramming of plant pathways that are functionally correlated with defense responses. PMID:27148321

  5. The rhizosphere microbial community in a multiple parallel mineralization system suppresses the pathogenic fungus Fusarium oxysporum

    PubMed Central

    Fujiwara, Kazuki; Iida, Yuichiro; Iwai, Takashi; Aoyama, Chihiro; Inukai, Ryuya; Ando, Akinori; Ogawa, Jun; Ohnishi, Jun; Terami, Fumihiro; Takano, Masao; Shinohara, Makoto

    2013-01-01

    The rhizosphere microbial community in a hydroponics system with multiple parallel mineralization (MPM) can potentially suppress root-borne diseases. This study focused on revealing the biological nature of the suppression against Fusarium wilt disease, which is caused by the fungus Fusarium oxysporum, and describing the factors that may influence the fungal pathogen in the MPM system. We demonstrated that the rhizosphere microbiota that developed in the MPM system could suppress Fusarium wilt disease under in vitro and greenhouse conditions. The microbiological characteristics of the MPM system were able to control the population dynamics of F. oxysporum, but did not eradicate the fungal pathogen. The roles of the microbiological agents underlying the disease suppression and the magnitude of the disease suppression in the MPM system appear to depend on the microbial density. F. oxysporum that survived in the MPM system formed chlamydospores when exposed to the rhizosphere microbiota. These results suggest that the microbiota suppresses proliferation of F. oxysporum by controlling the pathogen's morphogenesis and by developing an ecosystem that permits coexistence with F. oxysporum. PMID:24311557

  6. Identification and confirmation of root-knot nematode and Fusarium wilt disease resistance traits in cotton substitution lines

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A recombinant inbred line population between Upland Gossypium hirsutum TM-1 and Pima G. barbadense 3-79 was previously used to identify QTL determining response to both root-not nematode and Fusarium wilt races 1 (FOV1) and 4 (FOV4), an economically important diseases in cotton. To confirm QTLs and...

  7. Rhizosphere Inhibition of Cucumber Fusarium Wilt by Different Surfactin- excreting Strains of Bacillus subtilis

    PubMed Central

    Jia, Ke; Gao, Yu-Han; Huang, Xiao-Qin; Guo, Rong-Jun; Li, Shi-Dong

    2015-01-01

    Bacillus subtilis B006 strain effectively suppresses the cucumber fusarium wilt caused by Fusarium oxysporum f. sp. cucumerinum (Foc). The population dynamics of Foc, strain B006 and its surfactin over-producing mutant B841 and surfactin-deficient mutant B1020, in the rhizosphere were determined under greenhouse conditions to elucidate the importance of the lipopeptides excreted by these strains in suppressing Foc. Results showed that B. subtilis strain B006 effectively suppressed the disease in natural soil by 42.9%, five weeks after transplanting, whereas B841 and B1020 suppressed the disease by only 22.6% and 7.1%, respectively. Quantitative PCR assays showed that effective colonization of strain B006 in the rhizosphere suppressed Foc propagation by more than 10 times both in nursery substrate and in field-infected soil. Reduction of Foc population at the cucumber stems in a range of 0.96 log10 ng/g to 2.39 log10 ng/g was attained at the third and the fifth weeks of B006 treatment in nursery substrate. In field-infected soil, all three treatments with B. subtilis suppressed Foc infection, indicated by the reduction of Foc population at a range of 2.91 log10 ng/g to 3.36 log10 ng/g at the stem base, one week after transplanting. This study reveals that the suppression of fusarium wilt disease is affected by the effective colonization of the surfactin-producing B. subtilis strain in the rhizosphere. These results improved our understanding of the biocontrol mechanism of the B. subtilis strain B006 in the natural soil and facilitate its application as biocontrol agent in the field. PMID:26060433

  8. Rhizosphere Inhibition of Cucumber Fusarium Wilt by Different Surfactin- excreting Strains of Bacillus subtilis.

    PubMed

    Jia, Ke; Gao, Yu-Han; Huang, Xiao-Qin; Guo, Rong-Jun; Li, Shi-Dong

    2015-06-01

    Bacillus subtilis B006 strain effectively suppresses the cucumber fusarium wilt caused by Fusarium oxysporum f. sp. cucumerinum (Foc). The population dynamics of Foc, strain B006 and its surfactin over-producing mutant B841 and surfactin-deficient mutant B1020, in the rhizosphere were determined under greenhouse conditions to elucidate the importance of the lipopeptides excreted by these strains in suppressing Foc. Results showed that B. subtilis strain B006 effectively suppressed the disease in natural soil by 42.9%, five weeks after transplanting, whereas B841 and B1020 suppressed the disease by only 22.6% and 7.1%, respectively. Quantitative PCR assays showed that effective colonization of strain B006 in the rhizosphere suppressed Foc propagation by more than 10 times both in nursery substrate and in field-infected soil. Reduction of Foc population at the cucumber stems in a range of 0.96 log10 ng/g to 2.39 log10 ng/g was attained at the third and the fifth weeks of B006 treatment in nursery substrate. In field-infected soil, all three treatments with B. subtilis suppressed Foc infection, indicated by the reduction of Foc population at a range of 2.91 log10 ng/g to 3.36 log10 ng/g at the stem base, one week after transplanting. This study reveals that the suppression of fusarium wilt disease is affected by the effective colonization of the surfactin-producing B. subtilis strain in the rhizosphere. These results improved our understanding of the biocontrol mechanism of the B. subtilis strain B006 in the natural soil and facilitate its application as biocontrol agent in the field. PMID:26060433

  9. Characterization of Fusarium wilt resistant somaclonal variants of banana cv. Rasthali by cDNA-RAPD.

    PubMed

    Ghag, Siddhesh B; Shekhawat, Upendra K S; Ganapathi, Thumballi R

    2014-12-01

    Fusarium wilt of banana, caused by Fusarium oxysporum f. sp. cubense (Foc), is counted among the most destructive diseases of crop plants in India. In the absence of any credible control measure to manage this disease, development of resistant cultivars is the best option. Somaclonal variations arising out of long term in vitro culture of plant tissues is an important source of genetic variability and the selection of somaclones having desired characteristics is a promising strategy to develop plants with improved characters. In the present study, we isolated a group of somaclonal variants of banana cv. Rasthali which showed efficient resistance towards Foc race 1 infection in repeated bioassays. cDNA-RAPD methodology using 96 decamer primers was used to characterize these somaclonal variants. Among the four differentially amplified bands obtained, one mapping to the coding region of a lipoxygenase gene was confirmed to be down regulated in the somaclones as compared to controls by real-time quantitative RT-PCR. Our results correlated well with earlier studies with lipoxygenase mutants in maize wherein reduced expression of lipoxygenase led to enhanced resistance towards Fusarium infection. PMID:25160909

  10. Identification of an Endophytic Antifungal Bacterial Strain Isolated from the Rubber Tree and Its Application in the Biological Control of Banana Fusarium Wilt

    PubMed Central

    Sun, Xuepiao; Zheng, Peng; Zhang, Jiaming

    2015-01-01

    Banana Fusarium wilt (also known as Panama disease) is one of the most disastrous plant diseases. Effective control methods are still under exploring. The endophytic bacterial strain ITBB B5-1 was isolated from the rubber tree, and identified as Serratia marcescens by morphological, biochemical, and phylogenetic analyses. This strain exhibited a high potential for biological control against the banana Fusarium disease. Visual agar plate assay showed that ITBB B5-1 restricted the mycelial growth of the pathogenic fungus Fusarium oxysporum f. sp. cubense race 4 (FOC4). Microscopic observation revealed that the cell wall of the FOC4 mycelium close to the co-cultured bacterium was partially decomposed, and the conidial formation was prohibited. The inhibition ratio of the culture fluid of ITBB B5-1 against the pathogenic fungus was 95.4% as estimated by tip culture assay. Chitinase and glucanase activity was detected in the culture fluid, and the highest activity was obtained at Day 2 and Day 3 of incubation for chitinase and glucanase, respectively. The filtrated cell-free culture fluid degraded the cell wall of FOC4 mycelium. These results indicated that chitinase and glucanase were involved in the antifungal mechanism of ITBB B5-1. The potted banana plants that were inoculated with ITBB B5-1 before infection with FOC4 showed 78.7% reduction in the disease severity index in the green house experiments. In the field trials, ITBB B5-1 showed a control effect of approximately 70.0% against the disease. Therefore, the endophytic bacterial strain ITBB B5-1 could be applied in the biological control of banana Fusarium wilt. PMID:26133557

  11. Identification of an Endophytic Antifungal Bacterial Strain Isolated from the Rubber Tree and Its Application in the Biological Control of Banana Fusarium Wilt.

    PubMed

    Tan, Deguan; Fu, Lili; Han, Bingyin; Sun, Xuepiao; Zheng, Peng; Zhang, Jiaming

    2015-01-01

    Banana Fusarium wilt (also known as Panama disease) is one of the most disastrous plant diseases. Effective control methods are still under exploring. The endophytic bacterial strain ITBB B5-1 was isolated from the rubber tree, and identified as Serratia marcescens by morphological, biochemical, and phylogenetic analyses. This strain exhibited a high potential for biological control against the banana Fusarium disease. Visual agar plate assay showed that ITBB B5-1 restricted the mycelial growth of the pathogenic fungus Fusarium oxysporum f. sp. cubense race 4 (FOC4). Microscopic observation revealed that the cell wall of the FOC4 mycelium close to the co-cultured bacterium was partially decomposed, and the conidial formation was prohibited. The inhibition ratio of the culture fluid of ITBB B5-1 against the pathogenic fungus was 95.4% as estimated by tip culture assay. Chitinase and glucanase activity was detected in the culture fluid, and the highest activity was obtained at Day 2 and Day 3 of incubation for chitinase and glucanase, respectively. The filtrated cell-free culture fluid degraded the cell wall of FOC4 mycelium. These results indicated that chitinase and glucanase were involved in the antifungal mechanism of ITBB B5-1. The potted banana plants that were inoculated with ITBB B5-1 before infection with FOC4 showed 78.7% reduction in the disease severity index in the green house experiments. In the field trials, ITBB B5-1 showed a control effect of approximately 70.0% against the disease. Therefore, the endophytic bacterial strain ITBB B5-1 could be applied in the biological control of banana Fusarium wilt. PMID:26133557

  12. Discovery of a new source of resistance to Fusarium oxysporum, cause of Fusarium wilt in Allium fistulosum, located on chromosome 2 of Allium cepa Aggregatum group.

    PubMed

    Vu, Hoa Q; El-Sayed, Magdi A; Ito, Shin-Ichi; Yamauchi, Naoki; Shigyo, Masayoshi

    2012-11-01

    This study was carried out to evaluate the antifungal effect of Allium cepa Aggregatum group (shallot) metabolites on Fusarium oxysporum and to determine the shallot chromosome(s) related to Fusarium wilt resistance using a complete set of eight Allium fistulosum - shallot monosomic addition lines. The antifungal effects of hexane, butanol, and water extraction fractions from bulbs of shallot on 35 isolates of F. oxysporum were examined using the disc diffusion method. Only hexane and butanol fractions showed high antifungal activity. Shallot showed no symptom of disease after inoculation with F. oxysporum f. sp. cepae. The phenolic content of the roots and the saponin content of root exudates of inoculated shallot increased to much higher levels than those of the control at 3 days after inoculation. Application of freeze-dried shallot root exudates to seeds of A. fistulosum soaked in a spore suspension of F. oxysporum resulted in protection of seedlings against infection. Among eight monosomic addition lines and A. fistulosum, FF+2A showed the highest resistance to Fusarium wilt. This monosomic addition line also showed a specific saponin band derived from shallot on the thin layer chromatography profile of saponins in the eight monosomic addition lines. The chromosome 2A of shallot might possess some of the genes related to Fusarium wilt resistance. PMID:23199574

  13. Proteomics of Fusarium oxysporum Race 1 and Race 4 Reveals Enzymes Involved in Carbohydrate Metabolism and Ion Transport That Might Play Important Roles in Banana Fusarium Wilt

    PubMed Central

    Peng, Ming; Zeng, Huicai; Wang, Dan; Li, Bo; Tong, Zheng; Chang, Lili; Jin, Xiang; Wang, Xuchu

    2014-01-01

    Banana Fusarium wilt is a soil–spread fungal disease caused by Fusarium oxysporum. In China, the main virulence fungi in banana are F. oxysporum race 1 (F1, weak virulence) and race 4 (F4, strong virulence). To date, no proteomic analyses have compared the two races, but the difference in virulence between F1 and F4 might result from their differentially expressed proteins. Here we report the first comparative proteomics of F1 and F4 cultured under various conditions, and finally identify 99 protein species, which represent 59 unique proteins. These proteins are mainly involved in carbohydrate metabolism, post-translational modification, energy production, and inorganic ion transport. Bioinformatics analysis indicated that among the 46 proteins identified from F4 were several enzymes that might be important for virulence. Reverse transcription PCR analysis of the genes for 15 of the 56 proteins revealed that their transcriptional patterns were similar to their protein expression patterns. Taken together, these data suggest that proteins involved in carbohydrate metabolism and ion transport may be important in the pathogenesis of banana Fusarium wilt. Some enzymes such as catalase-peroxidase, galactosidase and chitinase might contribute to the strong virulence of F4. Overexpression or knockout of the genes for the F4-specific proteins will help us to further understand the molecular mechanism of Fusarium-induced banana wilt. PMID:25460190

  14. Comparative genomics reveals mobile pathogenicity chromosomes in Fusarium

    PubMed Central

    Ma, Li-Jun; van der Does, H. Charlotte; Borkovich, Katherine A.; Coleman, Jeffrey J.; Daboussi, Marie-Josée; Di Pietro, Antonio; Dufresne, Marie; Freitag, Michael; Grabherr, Manfred; Henrissat, Bernard; Houterman, Petra M.; Kang, Seogchan; Shim, Won-Bo; Woloshuk, Charles; Xie, Xiaohui; Xu, Jin-Rong; Antoniw, John; Baker, Scott E.; Bluhm, Burton H.; Breakspear, Andrew; Brown, Daren W.; Butchko, Robert A. E.; Chapman, Sinead; Coulson, Richard; Coutinho, Pedro M.; Danchin, Etienne G. J.; Diener, Andrew; Gale, Liane R.; Gardiner, Donald M.; Goff, Stephen; Hammond-Kosack, Kim E.; Hilburn, Karen; Hua-Van, Aurélie; Jonkers, Wilfried; Kazan, Kemal; Kodira, Chinnappa D.; Koehrsen, Michael; Kumar, Lokesh; Lee, Yong-Hwan; Li, Liande; Manners, John M.; Miranda-Saavedra, Diego; Mukherjee, Mala; Park, Gyungsoon; Park, Jongsun; Park, Sook-Young; Proctor, Robert H.; Regev, Aviv; Ruiz-Roldan, M. Carmen; Sain, Divya; Sakthikumar, Sharadha; Sykes, Sean; Schwartz, David C.; Turgeon, B. Gillian; Wapinski, Ilan; Yoder, Olen; Young, Sarah; Zeng, Qiandong; Zhou, Shiguo; Galagan, James; Cuomo, Christina A.; Kistler, H. Corby; Rep, Martijn

    2011-01-01

    Fusarium species are among the most important phytopathogenic and toxigenic fungi. To understand the molecular underpinnings of pathogenicity in the genus Fusarium, we compared the genomes of three phenotypically diverse species: Fusarium graminearum, Fusarium verticillioides and Fusarium oxysporum f. sp. lycopersici. Our analysis revealed lineage-specific (LS) genomic regions in F. oxysporum that include four entire chromosomes and account for more than one-quarter of the genome. LS regions are rich in transposons and genes with distinct evolutionary profiles but related to pathogenicity, indicative of horizontal acquisition. Experimentally, we demonstrate the transfer of two LS chromosomes between strains of F. oxysporum, converting a non-pathogenic strain into a pathogen. Transfer of LS chromosomes between otherwise genetically isolated strains explains the polyphyletic origin of host specificity and the emergence of new pathogenic lineages in F. oxysporum. These findings put the evolution of fungal pathogenicity into a new perspective. PMID:20237561

  15. Biochemical Defenses Induced by Mycorrhizae Fungi Glomus Mosseae in Controlling Strawberry Fusarium Wilt.

    PubMed

    Yanan, Wang; Xusheng, Zhao; Baozhong, Yin; Wenchao, Zhen; Jintang, Guo

    2015-01-01

    The effect of VAM on reducing wilt caused by Fusarium oxysporum Schlecht. f.sp. fragariae Winks et Williams (FO) infection in strawberry and the possible mechanisms involved were investigated. Two key substance involved in disease defenses, lignin and hydroxyproline-rich glycoprotein were induced and formed in the cell wall of strawberry root, and the peak content of lignin and hydroxyproline-rich glycoprotein occurred on the 25(th) day (149.52mg/g) and on the 15(th) day (10.08 mg/g). The activity of protective enzymes SOD, POD and CAT inoculation with VAM significantly increased when compared with the control under both CK (natural growth) and inoculated with FO. The conductivity of VAM plus FO treatment was higher than the CK treatment, but significantly was lower than the FO treatment. PMID:26998177

  16. Biochemical Defenses Induced by Mycorrhizae Fungi Glomus Mosseae in Controlling Strawberry Fusarium Wilt

    PubMed Central

    Yanan, Wang; Xusheng, Zhao; Baozhong, Yin; Wenchao, Zhen; Jintang, Guo

    2015-01-01

    The effect of VAM on reducing wilt caused by Fusarium oxysporum Schlecht. f.sp. fragariae Winks et Williams (FO) infection in strawberry and the possible mechanisms involved were investigated. Two key substance involved in disease defenses, lignin and hydroxyproline-rich glycoprotein were induced and formed in the cell wall of strawberry root, and the peak content of lignin and hydroxyproline-rich glycoprotein occurred on the 25th day (149.52mg/g) and on the 15th day (10.08 mg/g). The activity of protective enzymes SOD, POD and CAT inoculation with VAM significantly increased when compared with the control under both CK (natural growth) and inoculated with FO. The conductivity of VAM plus FO treatment was higher than the CK treatment, but significantly was lower than the FO treatment. PMID:26998177

  17. Biochemical markers assisted screening of Fusarium wilt resistant Musa paradisiaca (L.) cv. puttabale micropropagated clones.

    PubMed

    Venkatesh; Krishna, V; Kumar, K Girish; Pradeepa, K; Kumar, S R Santosh; Kumar, R Shashi

    2013-07-01

    An efficient protocol was standardized for screening of panama wilt resistant Musa paradisiaca cv. Puttabale clones, an endemic cultivar of Karnataka, India. The synergistic effect of 6-benzyleaminopurine (2 to 6 mg/L) and thidiazuron (0.1 to 0.5 mg/L) on MS medium provoked multiple shoot induction from the excised meristem. An average of 30.10 +/- 5.95 shoots was produced per propagule at 4 mg/L 6-benzyleaminopurine and 0.3 mg/L thidiazuron concentrations. Elongation of shoots observed on 5 mg/L BAP augmented medium with a mean length of 8.38 +/- 0.30 shoots per propagule. For screening of disease resistant clones, multiple shoot buds were mutated with 0.4% ethyl-methane-sulfonate and cultured on MS medium supplemented with Fusarium oxysporum f. sp. cubense (FOC) culture filtrate (5-15%). Two month old co-cultivated secondary hardened plants were used for screening of disease resistance against FOC by the determination of biochemical markers such as total phenol, phenylalanine ammonia lyase, oxidative enzymes like peroxidase, polyphenol oxidase, catalase and PR-proteins like chitinase, beta-1-3 glucanase activities. The mutated clones of M. paradisiaca cv. Puttabale cultured on FOC culture filtrate showed significant increase in the levels of biochemical markers as an indicative of acquiring disease resistant characteristics to FOC wilt. PMID:23898552

  18. Characterization of Novel Trichoderma asperellum Isolates to Select Effective Biocontrol Agents Against Tomato Fusarium Wilt.

    PubMed

    El Komy, Mahmoud H; Saleh, Amgad A; Eranthodi, Anas; Molan, Younes Y

    2015-03-01

    The use of novel isolates of Trichoderma with efficient antagonistic capacity against Fusarium oxysporum f. sp. lycopersici (FOL) is a promising alternative strategy to pesticides for tomato wilt management. We evaluated the antagonistic activity of 30 isolates of T. asperellum against 4 different isolates of FOL. The production of extracellular cell wall degrading enzymes of the antagonistic isolates was also measured. The random amplified polymorphic DNA (RAPD) method was applied to assess the genetic variability among the T. asperellum isolates. All of the T. asperellum isolates significantly reduced the mycelial growth of FOL isolates but the amount of growth reduction varied significantly as well. There was a correlation between the antagonistic capacity of T. asperellum isolates towards FOL and their lytic enzyme production. Isolates showing high levels of chitinase and β-1,3-glucanase activities strongly inhibited the growth of FOL isolates. RAPD analysis showed a high level of genetic variation among T. asperellum isolates. The UPGMA dendrogram revealed that T. asperellum isolates could not be grouped by their anta- gonistic behavior or lytic enzymes production. Six isolates of T. asperellum were highly antagonistic towards FOL and potentially could be used in commercial agriculture to control tomato wilt. Our results are consistent with the conclusion that understanding the genetic variation within Trichoderma isolates and their biochemical capabilities are required for the selection of effective indigenous fungal strains for the use as biocontrol agents. PMID:25774110

  19. Characterization of Novel Trichoderma asperellum Isolates to Select Effective Biocontrol Agents Against Tomato Fusarium Wilt

    PubMed Central

    El_Komy, Mahmoud H.; Saleh, Amgad A.; Eranthodi, Anas; Molan, Younes Y.

    2015-01-01

    The use of novel isolates of Trichoderma with efficient antagonistic capacity against Fusarium oxysporum f. sp. lycopersici (FOL) is a promising alternative strategy to pesticides for tomato wilt management. We evaluated the antagonistic activity of 30 isolates of T. asperellum against 4 different isolates of FOL. The production of extracellular cell wall degrading enzymes of the antagonistic isolates was also measured. The random amplified polymorphic DNA (RAPD) method was applied to assess the genetic variability among the T. asperellum isolates. All of the T. asperellum isolates significantly reduced the mycelial growth of FOL isolates but the amount of growth reduction varied significantly as well. There was a correlation between the antagonistic capacity of T. asperellum isolates towards FOL and their lytic enzyme production. Isolates showing high levels of chitinase and β-1,3-glucanase activities strongly inhibited the growth of FOL isolates. RAPD analysis showed a high level of genetic variation among T. asperellum isolates. The UPGMA dendrogram revealed that T. asperellum isolates could not be grouped by their anta- gonistic behavior or lytic enzymes production. Six isolates of T. asperellum were highly antagonistic towards FOL and potentially could be used in commercial agriculture to control tomato wilt. Our results are consistent with the conclusion that understanding the genetic variation within Trichoderma isolates and their biochemical capabilities are required for the selection of effective indigenous fungal strains for the use as biocontrol agents. PMID:25774110

  20. Verticillium comparative genomics yields insights into niche adaptation by plant vascular wilt pathogens.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The vascular wilt fungi Verticillium dahliae and V. albo-atrum infect over 200 plant species, causing billions of dollars in annual losses. The characteristic vascular wilt symptoms are a result of colonization and proliferation of the pathogens in the xylem vessels. To gain insights into the mechan...

  1. Comparative genomics yields insights into niche adaptation of plant vascular wilt pathogens.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The vascular wilt fungi Verticillium dahliae and V. albo-atrum infect over 200 plant species, causing billions of dollars in annual crop losses. The characteristic wilt symptoms are a result of colonization and proliferation of the pathogens in the xylem vessels, which undergo fluctuations in osmola...

  2. Changes induced by Trichoderma harzianum in suppressive compost controlling Fusarium wilt.

    PubMed

    Blaya, Josefa; López-Mondéjar, Rubén; Lloret, Eva; Pascual, Jose Antonio; Ros, Margarita

    2013-09-01

    The addition of species of Trichoderma to compost is a widespread technique used to control different plant diseases. The biological control activity of these species is mainly attributable to a combination of several mechanisms of action, which may affect the microbiota involved in the suppressiveness of compost. This study was therefore performed to determine the effect of inoculation of Trichoderma harzianum (T. harzianum) on compost, focusing on bacterial community structure (16S rRNA) and chitinase gene diversity. In addition, the ability of vineyard pruning waste compost, amended (GCTh) or not (GC) with T. harzianum, to suppress Fusarium wilt was evaluated. The addition of T. harzianum resulted in a high relative abundance of certain chitinolytic bacteria as well as in remarkable protection against Fusarium oxysporum comparable to that induced by compost GC. Moreover, variations in the abiotic characteristics of the media, such as pH, C, N and iron levels, were observed. Despite the lower diversity of chitinolytic bacteria found in GCTh, the high relative abundance of Streptomyces spp. may be involved in the suppressiveness of this growing media. The higher degree of compost suppressiveness achieved after the addition of T. harzianum may be due not only to its biocontrol ability, but also to changes promoted in both abiotic and biotic characteristics of the growing media. PMID:25149244

  3. Genetics of Fusarium Wilt Resistance in Pigeonpea (Cajanus cajan) and Efficacy of Associated SSR Markers.

    PubMed

    Singh, Deepu; Sinha, B; Rai, V P; Singh, M N; Singh, D K; Kumar, R; Singh, A K

    2016-04-01

    Inheritance of resistance to Fusarium wilt (FW) disease caused by Fusarium udum was investigated in pigeonpea using four different long duration FW resistant genotypes viz., BDN-2004-1, BDN-2001-9, BWR-133 and IPA-234. Based on the F2 segregation pattern, FW resistance has been reported to be governed by one dominant gene in BDN-2004-1 and BDN-2001-9, two duplicate dominant genes in BWR-133 and two dominant complimentary genes in resistance source IPA-234. Further, the efficacy of six simple sequence repeat (SSR) markers namely, ASSR-1, ASSR-23, ASSR-148, ASSR-229, ASSR-363 and ASSR-366 reported to be associated with FW resistance were also tested and concluded that markers ASSR-1, ASSR-23, ASSR-148 will be used for screening of parental genotypes in pigeonpea FW resistance breeding programs. The information on genetics of FW resistance generated from this study would be used, to introgress FW resistance into susceptible but highly adopted cultivars through marker-assisted backcross breeding and in conventional breeding programs. PMID:27147929

  4. Genetics of Fusarium Wilt Resistance in Pigeonpea (Cajanus cajan) and Efficacy of Associated SSR Markers

    PubMed Central

    Singh, Deepu; Sinha, B.; Rai, V. P.; Singh, M. N.; Singh, D. K.; Kumar, R.; Singh, A. K.

    2016-01-01

    Inheritance of resistance to Fusarium wilt (FW) disease caused by Fusarium udum was investigated in pigeonpea using four different long duration FW resistant genotypes viz., BDN-2004-1, BDN-2001-9, BWR-133 and IPA-234. Based on the F2 segregation pattern, FW resistance has been reported to be governed by one dominant gene in BDN-2004-1 and BDN-2001-9, two duplicate dominant genes in BWR-133 and two dominant complimentary genes in resistance source IPA-234. Further, the efficacy of six simple sequence repeat (SSR) markers namely, ASSR-1, ASSR-23, ASSR-148, ASSR-229, ASSR-363 and ASSR-366 reported to be associated with FW resistance were also tested and concluded that markers ASSR-1, ASSR-23, ASSR-148 will be used for screening of parental genotypes in pigeonpea FW resistance breeding programs. The information on genetics of FW resistance generated from this study would be used, to introgress FW resistance into susceptible but highly adopted cultivars through marker-assisted backcross breeding and in conventional breeding programs. PMID:27147929

  5. Thermographic visualization of leaf response in cucumber plants infected with the soil-borne pathogen Fusarium oxysporum f. sp. cucumerinum.

    PubMed

    Wang, Min; Ling, Ning; Dong, Xian; Zhu, Yiyong; Shen, Qirong; Guo, Shiwei

    2012-12-01

    Infection with the soil-borne pathogen Fusarium oxysporum f. sp. cucumerinum (FOC), which causes Fusarium wilt of cucumber plants, might result in changes in plant transpiration and water status within leaves. To monitor leaf response in cucumber infected with FOC, digital infrared thermography (DIT) was employed to detect changes in leaf temperature. During the early stages of FOC infection, stomata closure was induced by ABA in leaves, resulting in a decreased transpiration rate and increased leaf temperature. Subsequently, cell death occurred, accompanied by water loss, resulting in a little decrease in leaf temperature. A negative correlation between transpiration rate and leaf temperature was existed. But leaf temperature exhibited a special pattern with different disease severity on light-dark cycle. Lightly wilted leaves had a higher temperature in light and a lower temperature in dark than did in healthy leaves. We identified that the water loss from wilted leaves was regulated not by stomata but rather by cells damage caused by pathogen infection. Finally, water balance in infected plants became disordered and dead tissue was dehydrated, so leaf temperature increased again. These data suggest that membrane injury caused by FOC infection induces uncontrolled water loss from damaged cells and an imbalance in leaf water status, and ultimately accelerate plant wilting. Combining detection of the temperature response of leaves to light-dark conditions, DIT not only permits noninvasive detection and indirect visualization of the development of the soil-borne disease Fusarium wilt, but also demonstrates certain internal metabolic processes correlative with water status. PMID:23103050

  6. Morphological and comparative genomic analyses of pathogenic and non-pathogenic Fusarium solani isolated from Dalbergia sissoo.

    PubMed

    Arif, M; Zaidi, N W; Haq, Q M R; Singh, Y P; Taj, G; Kar, C S; Singh, U S

    2015-06-01

    Sissoo or shisham (Dalbergia sissoo Roxb.) is one of the finest wood of South Asia. Fusarium solani is a causal organism of sissoo wilt, decline, or dieback. It is also a potential causal organism associated with other valuable tree species. Thirty-eight Fusarium isolates including 24 F. solani and 14 Fusarium sp., were obtained in 2005 from different geographical locations in India. All 38 (18 pathogenic and 20 non-pathogenic) isolates were characterized for genomic analysis, growth behaviour, pigmentation and sensitivity to carbendazim. Based on growth pattern, growth rate, pigmentation and sensitivity to carbendazim, all 38 isolates showed a wide range of variability, but no correlation with pathogenicity or geographical distribution. Three techniques were used for comparative genomic analysis: random amplified polymorphic DNA (RAPD); inter simple sequence repeats (ISSR); and simple sequence repeats (SSR). A total of 90 primers targeting different genome regions resulted a total of 1159 loci with an average of 12.88 loci per primer. These primers showed high genomic variability among the isolates. The maximum loci (14.64) per primer were obtained with RAPD. The total variation of the first five principal components for RAPD, ISSR, SSR and combined analysis were estimated as 47.42, 48.21, 46.30 and 46.78 %, respectively. Among the molecular markers, highest Pearson correlation value (r = 0.957) was recorded with combination of RAPD and SSR followed by RAPD and ISSR (r = 0.952), and SSR and ISSR (r = 0.942). The combination of these markers would be similarly effective as single marker system i.e. RAPD, ISSR and SSR. Based on polymorphic information content (PIC = 0.619) and highest coefficient (r = 0.995), RAPD was found to be the most efficient marker system compared to ISSR and SSR. This study will assist in understanding the population biology of wilt causing phytopathogen, F. solani, and in assisting with integrated disease management measures. PMID:25605046

  7. Comparative functional genomics of plant pathogenic Fusarium species

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fusarium species are among the most economically important group of plant pathogenic fungi. Comparison of the four currently available Fusarium genome sequences allows an unsurpassed and unprecedented ability to predict genes, determine synteny and define regulatory sequences for genes in phytopatho...

  8. Host-induced post-transcriptional hairpin RNA-mediated gene silencing of vital fungal genes confers efficient resistance against Fusarium wilt in banana.

    PubMed

    Ghag, Siddhesh B; Shekhawat, Upendra K S; Ganapathi, Thumballi R

    2014-06-01

    Fusarium wilt, caused by Fusarium oxysporum f. sp. cubense (Foc), is among the most destructive diseases of banana (Musa spp.). Because no credible control measures are available, development of resistant cultivars through genetic engineering is the only option. We investigated whether intron hairpin RNA (ihpRNA)-mediated expression of small interfering RNAs (siRNAs) targeted against vital fungal genes (velvet and Fusarium transcription factor 1) in transgenic banana could achieve effective resistance against Foc. Partial sequences of these two genes were assembled as ihpRNAs in suitable binary vectors (ihpRNA-VEL and ihpRNA-FTF1) and transformed into embryogenic cell suspensions of banana cv. Rasthali by Agrobacterium-mediated genetic transformation. Eleven transformed lines derived from ihpRNA-VEL and twelve lines derived from ihpRNA-FTF1 were found to be free of external and internal symptoms of Foc after 6-week-long greenhouse bioassays. The five selected transgenic lines for each construct continued to resist Foc at 8 months postinoculation. Presence of specific siRNAs derived from the two ihpRNAs in transgenic banana plants was confirmed by Northern blotting and Illumina sequencing of small RNAs derived from the transgenic banana plants. The present study represents an important effort in proving that host-induced post-transcriptional ihpRNA-mediated gene silencing of vital fungal genes can confer efficient resistance against debilitating pathogens in crop plants. PMID:24476152

  9. The xylem as battleground for plant hosts and vascular wilt pathogens

    PubMed Central

    Yadeta, Koste A.; J. Thomma, Bart P. H.

    2013-01-01

    Vascular wilts are among the most destructive plant diseases that occur in annual crops as well as in woody perennials. These diseases are generally caused by soil-borne bacteria, fungi, and oomycetes that infect through the roots and enter the water-conducting xylem vessels where they proliferate and obstruct the transportation of water and minerals. As a consequence, leaves wilt and die, which may lead to impairment of the whole plant and eventually to death of the plant. Cultural, chemical, and biological measures to control this group of plant pathogens are generally ineffective, and the most effective control strategy is the use of genetic resistance. Owing to the fact that vascular wilt pathogens live deep in the interior of their host plants, studies into the biology of vascular pathogens are complicated. However, to design novel strategies to combat vascular wilt diseases, understanding the (molecular) biology of vascular pathogens and the molecular mechanisms underlying plant defense against these pathogens is crucial. In this review, we discuss the current knowledge on interactions of vascular wilt pathogens with their host plants, with emphasis on host defense responses against this group of pathogens. PMID:23630534

  10. Rapid and Efficient Estimation of Pea Resistance to the Soil-Borne Pathogen Fusarium oxysporum by Infrared Imaging

    PubMed Central

    Rispail, Nicolas; Rubiales, Diego

    2015-01-01

    Fusarium wilts are widespread diseases affecting most agricultural crops. In absence of efficient alternatives, sowing resistant cultivars is the preferred approach to control this disease. However, actual resistance sources are often overcome by new pathogenic races, forcing breeders to continuously search for novel resistance sources. Selection of resistant accessions, mainly based on the evaluation of symptoms at timely intervals, is highly time-consuming. Thus, we tested the potential of an infra-red imaging system in plant breeding to speed up this process. For this, we monitored the changes in surface leaf temperature upon infection by F. oxysporum f. sp. pisi in several pea accessions with contrasting response to Fusarium wilt under a controlled environment. Using a portable infra-red imaging system we detected a significant temperature increase of at least 0.5 °C after 10 days post-inoculation in the susceptible accessions, while the resistant accession temperature remained at control level. The increase in leaf temperature at 10 days post-inoculation was positively correlated with the AUDPC calculated over a 30 days period. Thus, this approach allowed the early discrimination between resistant and susceptible accessions. As such, applying infra-red imaging system in breeding for Fusarium wilt resistance would contribute to considerably shorten the process of selection of novel resistant sources. PMID:25671514

  11. Rapid and efficient estimation of pea resistance to the soil-borne pathogen Fusarium oxysporum by infrared imaging.

    PubMed

    Rispail, Nicolas; Rubiales, Diego

    2015-01-01

    Fusarium wilts are widespread diseases affecting most agricultural crops. In absence of efficient alternatives, sowing resistant cultivars is the preferred approach to control this disease. However, actual resistance sources are often overcome by new pathogenic races, forcing breeders to continuously search for novel resistance sources. Selection of resistant accessions, mainly based on the evaluation of symptoms at timely intervals, is highly time-consuming. Thus, we tested the potential of an infra-red imaging system in plant breeding to speed up this process. For this, we monitored the changes in surface leaf temperature upon infection by F. oxysporum f. sp. pisi in several pea accessions with contrasting response to Fusarium wilt under a controlled environment. Using a portable infra-red imaging system we detected a significant temperature increase of at least 0.5 °C after 10 days post-inoculation in the susceptible accessions, while the resistant accession temperature remained at control level. The increase in leaf temperature at 10 days post-inoculation was positively correlated with the AUDPC calculated over a 30 days period. Thus, this approach allowed the early discrimination between resistant and susceptible accessions. As such, applying infra-red imaging system in breeding for Fusarium wilt resistance would contribute to considerably shorten the process of selection of novel resistant sources. PMID:25671514

  12. Identification of a Novel Small Cysteine-Rich Protein in the Fraction from the Biocontrol Fusarium oxysporum Strain CS-20 that Mitigates Fusarium Wilt Symptoms and Triggers Defense Responses in Tomato.

    PubMed

    Shcherbakova, Larisa A; Odintsova, Tatyana I; Stakheev, Alexander A; Fravel, Deborah R; Zavriev, Sergey K

    2015-01-01

    The biocontrol effect of the non-pathogenic Fusarium oxysporum strain CS-20 against the tomato wilt pathogen F. oxysporum f. sp. lycopersici (FOL) has been previously reported to be primarily plant-mediated. This study shows that CS-20 produces proteins, which elicit defense responses in tomato plants. Three protein-containing fractions were isolated from CS-20 biomass using size exclusion chromatography. Exposure of seedling roots to one of these fractions prior to inoculation with pathogenic FOL strains significantly reduced wilt severity. This fraction initiated an ion exchange response in cultured tomato cells resulting in a reversible alteration of extracellular pH; increased tomato chitinase activity, and induced systemic resistance by enhancing PR-1 expression in tomato leaves. Two other protein fractions were inactive in seedling protection. The main polypeptide (designated CS20EP), which was specifically present in the defense-inducing fraction and was not detected in inactive protein fractions, was identified. The nucleotide sequence encoding this protein was determined, and its complete amino acid sequence was deduced from direct Edman degradation (25 N-terminal amino acid residues) and DNA sequencing. The CS20EP was found to be a small basic cysteine-rich protein with a pI of 9.87 and 23.43% of hydrophobic amino acid residues. BLAST search in the NCBI database showed that the protein is new; however, it displays 48% sequence similarity with a hypothetical protein FGSG_10784 from F. graminearum strain PH-1. The contribution of CS20EP to elicitation of tomato defense responses resulting in wilt mitigating is discussed. PMID:26779237

  13. Identification of a Novel Small Cysteine-Rich Protein in the Fraction from the Biocontrol Fusarium oxysporum Strain CS-20 that Mitigates Fusarium Wilt Symptoms and Triggers Defense Responses in Tomato

    PubMed Central

    Shcherbakova, Larisa A.; Odintsova, Tatyana I.; Stakheev, Alexander A.; Fravel, Deborah R.; Zavriev, Sergey K.

    2016-01-01

    The biocontrol effect of the non-pathogenic Fusarium oxysporum strain CS-20 against the tomato wilt pathogen F. oxysporum f. sp. lycopersici (FOL) has been previously reported to be primarily plant-mediated. This study shows that CS-20 produces proteins, which elicit defense responses in tomato plants. Three protein-containing fractions were isolated from CS-20 biomass using size exclusion chromatography. Exposure of seedling roots to one of these fractions prior to inoculation with pathogenic FOL strains significantly reduced wilt severity. This fraction initiated an ion exchange response in cultured tomato cells resulting in a reversible alteration of extracellular pH; increased tomato chitinase activity, and induced systemic resistance by enhancing PR-1 expression in tomato leaves. Two other protein fractions were inactive in seedling protection. The main polypeptide (designated CS20EP), which was specifically present in the defense-inducing fraction and was not detected in inactive protein fractions, was identified. The nucleotide sequence encoding this protein was determined, and its complete amino acid sequence was deduced from direct Edman degradation (25 N-terminal amino acid residues) and DNA sequencing. The CS20EP was found to be a small basic cysteine-rich protein with a pI of 9.87 and 23.43% of hydrophobic amino acid residues. BLAST search in the NCBI database showed that the protein is new; however, it displays 48% sequence similarity with a hypothetical protein FGSG_10784 from F. graminearum strain PH-1. The contribution of CS20EP to elicitation of tomato defense responses resulting in wilt mitigating is discussed. PMID:26779237

  14. The lateral organ boundaries domain transcription factor LBD20 functions in Fusarium wilt Susceptibility and jasmonate signaling in Arabidopsis.

    PubMed

    Thatcher, Louise F; Powell, Jonathan J; Aitken, Elizabeth A B; Kazan, Kemal; Manners, John M

    2012-09-01

    The LATERAL ORGAN BOUNDARIES (LOB) DOMAIN (LBD) gene family encodes plant-specific transcriptional regulators functioning in organ development. In a screen of Arabidopsis (Arabidopsis thaliana) sequence-indexed transferred DNA insertion mutants, we found disruption of the LOB DOMAIN-CONTAINING PROTEIN20 (LBD20) gene led to increased resistance to the root-infecting vascular wilt pathogen Fusarium oxysporum. In wild-type plants, LBD20 transcripts were barely detectable in leaves but abundant in roots, where they were further induced after F. oxysporum inoculation or methyl jasmonate treatment. Induction of LBD20 expression in roots was abolished in coronatine insensitive1 (coi1) and myc2 (allelic to jasmonate insensitive1) mutants, suggesting LBD20 may function in jasmonate (JA) signaling. Consistent with this, expression of the JA-regulated THIONIN2.1 (Thi2.1) and VEGETATIVE STORAGE PROTEIN2 (VSP2) genes were up-regulated in shoots of lbd20 following treatment of roots with F. oxysporum or methyl jasmonate. However, PLANT DEFENSIN1.2 expression was unaltered, indicating a repressor role for LBD20 in a branch of the JA-signaling pathway. Plants overexpressing LBD20 (LBD20-OX) had reduced Thi2.1 and VSP2 expression. There was a significant correlation between increased LBD20 expression in the LBD20-OX lines with both Thi2.1 and VSP2 repression, and reduced survival following F. oxysporum infection. Chlorosis resulting from application of F. oxysporum culture filtrate was also reduced in lbd20 leaves relative to the wild type. Taken together, LBD20 is a F. oxysporum susceptibility gene that appears to regulate components of JA signaling downstream of COI1 and MYC2 that are required for full elicitation of F. oxysporum- and JA-dependent responses. To our knowledge, this is the first demonstration of a role for a LBD gene family member in either biotic stress or JA signaling. PMID:22786889

  15. Comparison of Fungal Community in Black Pepper-Vanilla and Vanilla Monoculture Systems Associated with Vanilla Fusarium Wilt Disease.

    PubMed

    Xiong, Wu; Zhao, Qingyun; Xue, Chao; Xun, Weibing; Zhao, Jun; Wu, Huasong; Li, Rong; Shen, Qirong

    2016-01-01

    Long-term vanilla monocropping often results in the occurrence of vanilla Fusarium wilt disease, seriously affecting its production all over the world. In the present study, vanilla exhibited significantly less Fusarium wilt disease in the soil of a long-term continuously cropped black pepper orchard. The entire fungal communities of bulk and rhizosphere soils between the black pepper-vanilla system (i.e., vanilla cropped in the soil of a continuously cropped black pepper orchard) and vanilla monoculture system were compared through the deep pyrosequencing. The results showed that the black pepper-vanilla system revealed a significantly higher fungal diversity than the vanilla monoculture system in both bulk and rhizosphere soils. The UniFrac-weighted PCoA analysis revealed significant differences in bulk soil fungal community structures between the two cropping systems, and fungal community structures were seriously affected by the vanilla root system. In summary, the black pepper-vanilla system harbored a lower abundance of Fusarium oxysporum in the vanilla rhizosphere soil and increased the putatively plant-beneficial fungal groups such as Trichoderma and Penicillium genus, which could explain the healthy growth of vanilla in the soil of the long-term continuously cropped black pepper field. Thus, cropping vanilla in the soil of continuously cropped black pepper fields for maintaining the vanilla industry is executable and meaningful as an agro-ecological system. PMID:26903995

  16. Effect of Iron Availability on Induction of Systemic Resistance to Fusarium Wilt of Chickpea by Pseudomonas spp.

    PubMed Central

    Saikia, Ratul; Srivastava, Alok K.; Singh, Kiran; Lee, Min-Woong

    2005-01-01

    Selected isolates of Pseudomonas fluorescens (Pf4-92 and PfRsC5) and P. aeruginosa (PaRsG18 and PaRsG27) were examined for growth promotion and induced systemic resistance against Fusarium wilt of chickpea. Significant increase in plant height was observed in Pseudomonas treated plants. However, plant growth was inhibited when isolates of Pseudomonas were used in combination with Fusarium oxysporum f. sp. ciceri (FocRs1). It was also observed that the Pseudomonas spp. was colonized in root of chickpea and significantly suppressed the disease in greenhouse condition. Rock wool bioassay technique was used to study the effect of iron availability on the induction of systemic resistance to Fusarium wilt of chickpea mediated by the Pseudomonas spp. All the isolates of Pseudomonas spp. showed greater disease control in the induced systemic resistance (ISR) bioassay when iron availability in the nutrient solution was low. High performance liquid chromatography (HPLC) analysis indicated that all the bacterial isolates produced more salicylic acid (SA) at low iron (10µM EDDHA) than high iron availability (10µFe3+ EDDHA). Except PaRsG27, all the three isolates produced more pseudobactin at low iron than high iron availability. PMID:24049472

  17. Comparison of Fungal Community in Black Pepper-Vanilla and Vanilla Monoculture Systems Associated with Vanilla Fusarium Wilt Disease

    PubMed Central

    Xiong, Wu; Zhao, Qingyun; Xue, Chao; Xun, Weibing; Zhao, Jun; Wu, Huasong; Li, Rong; Shen, Qirong

    2016-01-01

    Long-term vanilla monocropping often results in the occurrence of vanilla Fusarium wilt disease, seriously affecting its production all over the world. In the present study, vanilla exhibited significantly less Fusarium wilt disease in the soil of a long-term continuously cropped black pepper orchard. The entire fungal communities of bulk and rhizosphere soils between the black pepper-vanilla system (i.e., vanilla cropped in the soil of a continuously cropped black pepper orchard) and vanilla monoculture system were compared through the deep pyrosequencing. The results showed that the black pepper-vanilla system revealed a significantly higher fungal diversity than the vanilla monoculture system in both bulk and rhizosphere soils. The UniFrac-weighted PCoA analysis revealed significant differences in bulk soil fungal community structures between the two cropping systems, and fungal community structures were seriously affected by the vanilla root system. In summary, the black pepper-vanilla system harbored a lower abundance of Fusarium oxysporum in the vanilla rhizosphere soil and increased the putatively plant-beneficial fungal groups such as Trichoderma and Penicillium genus, which could explain the healthy growth of vanilla in the soil of the long-term continuously cropped black pepper field. Thus, cropping vanilla in the soil of continuously cropped black pepper fields for maintaining the vanilla industry is executable and meaningful as an agro-ecological system. PMID:26903995

  18. Evaluation of methods to detect the cotton pathogen Fusarium oxysporum f. sp. vasinfectum race 4

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fusarium wilt caused by Fusarium oxysporum f. sp. vasinfectum (Fov) is an important disease of cotton. Fov race 4, identified in the San Joaquin Valley of California, has caused serious losses and is a potential threat to US cotton production. Tests have been developed to rapidly identify race 4 i...

  19. Fusaric acid production and pathogenicity of Fusarium oxysporum f. sp. vasinfectum

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In recent years, Fusarium wilt of cotton has gained increased importance with the emergence of extremely virulent strains of Fusarium oxysporum f. sp. vasinfectum. The recent discovery of new pathotypes not previously found in the U.S. is of particular concern to the cotton industry. In addition, a ...

  20. Inheritance and QTL mapping of Fusarium wilt race 4 resistance in cotton.

    PubMed

    Ulloa, Mauricio; Hutmacher, Robert B; Roberts, Philip A; Wright, Steven D; Nichols, Robert L; Michael Davis, R

    2013-05-01

    Diseases such as Fusarium wilt [Fusarium oxysporum f.sp. vasinfectum (FOV) Atk. Sny & Hans] represent expanding threats to cotton production. Integrating disease resistance into high-yielding, high-fiber quality cotton (Gossypium spp.) cultivars is one of the most important objectives in cotton breeding programs worldwide. In this study, we conducted a comprehensive analysis of gene action in cotton governing FOV race 4 resistance by combining conventional inheritance and quantitative trait loci (QTL) mapping with molecular markers. A set of diverse cotton populations was generated from crosses encompassing multiple genetic backgrounds. FOV race 4 resistance was investigated using seven parents and their derived populations: three intraspecific (G. hirsutum × G. hirsutum L. and G. barbadense × G. barbadense L.) F1 and F2; five interspecific (G. hirsutum × G. barbadense) F1 and F2; and one RIL. Parents and populations were evaluated for disease severity index (DSI) of leaves, and vascular stem and root staining (VRS) in four greenhouse and two field experiments. Initially, a single resistance gene (Fov4) model was observed in F2 populations based on inheritance of phenotypes. This single Fov4 gene had a major dominant gene action and conferred resistance to FOV race 4 in Pima-S6. The Fov4 gene appears to be located near a genome region on chromosome 14 marked with a QTL Fov4-C14 1 , which made the biggest contribution to the FOV race 4 resistance of the generated F2 progeny. Additional genetic and QTL analyses also identified a set of 11 SSR markers that indicated the involvement of more than one gene and gene interactions across six linkage groups/chromosomes (3, 6, 8, 14, 17, and 25) in the inheritance of FOV race 4 resistance. QTLs detected with minor effects in these populations explained 5-19 % of the DSI or VRS variation. Identified SSR markers for the resistance QTLs with major and minor effects will facilitate for the first time marker-assisted selection for the introgression of FOV race 4 resistance into elite cultivars during the breeding process. PMID:23471458

  1. Phylogeny and pathogenicity of Fusarium oxysporum isolates from cottonseed imported from Australia into California for dairy cattle feed.

    PubMed

    Liu, Jinggao; Bell, Alois A; Wheeler, Michael H; Stipanovic, Robert D; Puckhaber, Lorraine S

    2011-11-01

    A unique biotype of the Fusarium wilt pathogen, Fusarium oxysporum Schlecht. f.sp. vasinfectum (Atk) Sny. & Hans., found in Australia in 1993 is favored by neutral or alkaline heavy soils and does not require plant parasitic nematodes to cause disease. This makes it a threat to 4-6 million acres of USA Upland cotton ( Gossypium hirsutum L.) that is grown on heavy alkaline soil and currently is not affected by Fusarium wilt. In 2001-2002, several shiploads of live cottonseed were imported into California for dairy cattle feed. Thirteen F. oxysporum f.sp. vasinfectum isolates and four isolates of a Fusarium spp. that resembled F. oxysporum were isolated from the imported cottonseed. The isolates, designated by an AuSeed prefix, formed four vegetative compatibility groups (VCG) all of which were incompatible with tester isolates for 18 VCGs found in the USA. Isolate AuSeed14 was vegetatively compatible with the four reference isolates of Australian biotype VCG01111. Phylogenetic analyses based on EF-1α, PHO, BT, Mat1-1, and Mat1-2 gene sequences separated the 17 seed isolates into three lineages (race A, race 3, and Fusarium spp.) with AuSeed14 clustering into race 3 lineage or race A lineage depending on the genes analyzed. Indel analysis of the EF-1α gene sequences revealed a close evolutionary relationship among AuSeed14, Australian biotype reference isolates, and the four Fusarium spp. isolates. The Australian seed isolates and the four Australian biotype reference isolates caused disease with root-dip inoculation, but not with stem-puncture inoculation. Thus, they were a vascular incompetent pathotype. In contrast, USA race A lineage isolates readily colonized vascular tissue and formed a vascular competent pathotype when introduced directly into xylem vessels. The AuSeed14 isolate was as pathogenic as the Australian biotype, and it or related isolates could cause a severe Fusarium wilt problem in USA cotton fields if they become established. PMID:22004096

  2. Fusarium foetens, a new species pathogenic to begonia elatior hybrids (Begonia x hiemalis) and the sister taxon of the Fusarium oxysporum species complex.

    PubMed

    Schroers, H-J; Baayen, R P; Meffert, J P; de Gruyter, J; Hooftman, M; O'Donnell, K

    2004-01-01

    A new disease recently was discovered in begonia elatior hybrid (Begonia × hiemalis) nurseries in The Netherlands. Diseased plants showed a combination of basal rot, vein yellowing and wilting and the base of collapsing plants was covered by unusually large masses of Fusarium macroconidia. A species of Fusarium was isolated consistently from the discolored veins of leaves and stems. It differed morphologically from F. begoniae, a known agent of begonia flower, leaf and stem blight. The Fusarium species resembled members of the F. oxysporum species complex in producing short monophialides on the aerial mycelium and abundant chlamydospores. Other phenotypic characters such as polyphialides formed occasionally in at least some strains, relatively long monophialides intermingled with the short monophialides formed on the aerial mycelium, distinct sporodochial conidiomata, and distinct pungent colony odor distinguished it from the F. oxysporum species complex. Phylogenetic analyses of partial sequences of the mitochondrial small subunit of the ribosomal DNA (mtSSU rDNA), nuclear translation elongation factor 1α (EF-1α) and β-tubulin gene exons and introns indicate that the Fusarium species represents a sister group of the F. oxysporum species complex. Begonia × hiemalis cultivars Bazan, Bellona and Netja Dark proved to be highly susceptible to the new species. Inoculated plants developed tracheomycosis within 4 wk, and most died within 8 wk. The new taxon was not pathogenic to Euphorbia pulcherrima, Impatiens walleriana and Saintpaulia ionantha that commonly are grown in nurseries along with B. × hiemalis. Inoculated plants of Cyclamen persicum did not develop the disease but had discolored vessels from which the inoculated fungus was isolated. Given that the newly discovered begonia pathogen is distinct in pathogenicity, morphology and phylogeny from other fusaria, it is described here as a new species, Fusarium foetens. PMID:21148861

  3. Proteomic analysis of conidia germination in Fusarium oxysporum f. sp. cubense tropical race 4 reveals new targets in ergosterol biosynthesis pathway for controlling Fusarium wilt of banana.

    PubMed

    Deng, Gui-Ming; Yang, Qiao-Song; He, Wei-Di; Li, Chun-Yu; Yang, Jing; Zuo, Cun-Wu; Gao, Jie; Sheng, Ou; Lu, Shao-Yun; Zhang, Sheng; Yi, Gan-Jun

    2015-09-01

    Conidial germination is a crucial step of the soilborne fungus Fusarium oxysporum f. sp. cubense tropical race 4 (Foc TR4), a most important lethal disease of banana. In this study, a total of 3659 proteins were identified by isobaric tags for relative and absolute quantitation (iTRAQ)-based comparative proteomic approach, of which 1009 were differentially expressed during conidial germination of the fungus at 0, 3, 7, and 11 h. Functional classification and bioinformatics analysis revealed that the majority of the differentially expressed proteins are involved in six metabolic pathways. Particularly, all differential proteins involved in the ergosterol biosynthesis pathway were significantly upregulated, indicating the importance of the ergosterol biosynthesis pathway to the conidial germination of Foc TR4. Quantitative RT-PCR, western blotting, and in vitro growth inhibition assay by several categories of fungicides on the Foc TR4 were used to validate the proteomics results. Four enzymes, C-24 sterol methyltransferase (ERG6), cytochrome P450 lanosterol C-14α-demethylase (EGR11), hydroxymethylglutaryl-CoA synthase (ERG13), and C-4 sterol methyl oxidase (ERG25), in the ergosterol biosynthesis pathway were identified and verified, and they hold great promise as new targets for effective inhibition of Foc TR4 early growth in controlling Fusarium wilt of banana. To the best of our knowledge, this report represents the first comprehensive study on proteomics profiling of conidia germination in Foc TR4. It provides new insights into a better understanding of the developmental processes of Foc TR4 spores. More importantly, by host plant-induced gene silencing (HIGS) technology, the new targets reported in this work allow us to develop novel transgenic banana leading to high protection from Fusarium wilt and to explore more effective antifungal drugs against either individual or multiple target proteins of Foc TR4. PMID:26129952

  4. Verticillium comparative genomics yields insights into niche adaptation by plant vascular wilt pathogens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The vascular wilt fungi Verticillium dahliae and V. albo-atrum infect over 200 plant species worldwide, causing recurring crop losses estimated in the billions of dollars annually. Plant pathogenic Verticillium species are soilborne, and produce dormant structures that enable survival for years in ...

  5. Verticillium Wilt in Potato: Host-Pathogen Interactions and Breeding for Resistance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Verticillium wilt (VW) is a widespread disease that causes consistent yield losses in many potato growing regions worldwide. In the U.S., it is mainly caused by the soil-borne fungal pathogen Verticillium dahliae. Microsclerotia can survive in the soil for many years. When they germinate and infe...

  6. Genome sequence of the tobacco bacterial wilt pathogen Ralstonia solanacearum.

    PubMed

    Li, Zefeng; Wu, Sanling; Bai, Xuefei; Liu, Yun; Lu, Jianfei; Liu, Yong; Xiao, Bingguang; Lu, Xiuping; Fan, Longjiang

    2011-11-01

    Ralstonia solanacearum is a causal agent of plant bacterial wilt with thousands of distinct strains in a heterogeneous species complex. Here we report the genome sequence of a phylotype IB strain, Y45, isolated from tobacco (Nicotiana tabacum) in China. Compared with the published genomes of eight strains which were isolated from other hosts and habitats, 794 specific genes and many rearrangements/inversion events were identified in the tobacco strain, demonstrating that this strain represents an important node within the R. solanacearum complex. PMID:21994922

  7. Arabidopsis is susceptible to the cereal ear blight fungal pathogens Fusarium graminearum and Fusarium culmorum.

    PubMed

    Urban, Martin; Daniels, Steve; Mott, Ellie; Hammond-Kosack, Kim

    2002-12-01

    The fungal pathogens Fusarium graminearum and F. culmorum cause ear blight disease on cereal crops worldwide. The disease lowers both grain quality and grain safety. Disease prevalence is increasing due to changes in cropping practices and the difficulties encountered by plant breeders when trying to introgress the polygene-based resistance. The molecular basis of resistance to Fusarium ear blight in cereal species is poorly understood. This is primarily due to the large size of cereal genomes and the expensive resources required to undertake gene function studies in cereals. We therefore explored the possibility of developing various model floral infection systems that would be more amenable to experimental manipulation and high-throughput gene function studies. The floral tissues of tobacco, tomato, soybean and Arabidopsis were inoculated with Fusarium conidia and this resulted in disease symptoms on anthers, anther filaments and petals in each plant species. However, only in Arabidopsis did this initial infection then spread into the developing siliques and seeds. A survey of 236 Arabidopsis ecotypes failed to identify a single genotype that was extremely resistant or susceptible to Fusarium floral infections. Three Arabidopsis floral mutants that failed to develop anthers and/or functional pollen (i.e. agamous-1, apetala1-3 and dad1) were significantly less susceptible to Fusarium floral infection than wild type. Deoxynivalenol (DON) mycotoxin production was also detected in Fusarium-infected flowers at >1 ppm. This novel floral pathosystem for Arabidopsis appears to be highly representative of a serious cereal crop disease. PMID:12492838

  8. Comparative Genomics Reveals Mobile Pathogenicity Chromosomes in Fusarium

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fusarium species are among the most important phytopathogenic and toxigenic fungi, having significant impact on crop production and animal health. Distinctively, strains of F. oxysporum exhibit wide host range and are pathogenic to both plant and animal species, reflecting remarkable genetic adapta...

  9. Rhizobacterium-mediated growth promotion and expression of stress enzymes in Glycine max L. Merrill against Fusarium wilt upon challenge inoculation.

    PubMed

    Jain, Shekhar; Vaishnav, Anukool; Kasotia, Amrita; Kumari, Sarita; Gaur, Rajarshi Kumar; Choudhary, Devendra Kumar

    2014-02-01

    Wilt disease of soybean caused by a very common soil-borne fungus, Fusarium oxysporum is one of the most destructive diseases of the crop. The aim of the present study was to characterize plant growth-promotion activities and induced resistance of a rhizobacterial strain for the soybean plant against F. oxysporum. Rhizobacterium strain SJ-5 exhibited plant growth-promotion characteristics and antagonistic activity against the test pathogen on dual plate assay. It was identified as a Carnobacterium sp. A 950 bp PCR product was amplified from Carnobacterium sp. strain SJ-5, using zwittermicin A self-resistance gene-specific primers (zmaR). The strain produced indole 3-acetic acid (19 μg/ml) in the presence of salt stress and exhibited growth in Dworkin and Foster salt medium amended with 1-aminocyclopropane-1-carboxylate (ACC) through ACC deaminase activity (277 nmol/mg/h) as compared to the control. Strain seeds treated with the strain significantly enhanced the quorum of healthy plants after challenge inoculation at 14 days after seeding. An increase in the activity of stress enzymes after challenge inoculation with the test pathogen is reported. Treatment with the bacterium resulted in an increase in the chlorophyll content in the leaves in comparison with challenge-inoculated plants. PMID:23933805

  10. A POLYKETIDE SYNTHASE GENE AND AN ASPARTATE KINASE LIKE GENE ARE REQUIRED FOR THE BIOSYNTHESIS OF FUSARIC ACID IN FUSARIUM OXYSPORUM F. SP. VASINFECTUM

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A genetically unique strain of the Fusarium wilt pathogen was first recognized in wilted and dead Upland cotton seedlings in Australia in 1993. Since that time the disease spread rapidly despite stringent containment practices. The Australian biotype isolates of Fusarium oxysporum f. sp. vasinfec...

  11. A polyketide synthase gene and an aspartate kinase like gene are required for the biosynthesis of fusaric acid in Fusarium Oxysporum f. sp. Vasinfectum

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A genetically unique strain of the Fusarium wilt pathogen was first recognized in wilted and dead Upland cotton seedlings in Australia in 1993. Since that time the disease spread rapidly despite stringent containment practices. The Australian biotype isolates of Fusarium oxysporum f. sp. vasinfec...

  12. Biosynthesis of fusaric acid by Fusarium oxysporum f. sp. vasinfectum

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A genetically unique biotype of the Fusarium wilt pathogen was first recognized in wilted and dead Upland cotton (Gossypium hirsutum) seedlings in Australia in 1993. Since that time, the disease has spread rapidly with losses greater than 90 percent in some Australian fields where it was first disc...

  13. The tomato I-3 gene: a novel gene for resistance to Fusarium wilt disease.

    PubMed

    Catanzariti, Ann-Maree; Lim, Ginny T T; Jones, David A

    2015-07-01

    Plant resistance proteins provide race-specific immunity through the recognition of pathogen effectors. The resistance genes I, I-2 and I-3 have been incorporated into cultivated tomato (Solanum lycopersicum) from wild tomato species to confer resistance against Fusarium oxysporum f. sp. lycopersici (Fol) races 1, 2 and 3, respectively. Although the Fol effectors corresponding to these resistance genes have all been identified, only the I-2 resistance gene has been isolated from tomato. To isolate the I-3 resistance gene, we employed a map-based cloning approach and used transgenic complementation to test candidate genes for resistance to Fol race 3. Here, we describe the fine mapping and sequencing of genes at the I-3 locus, which revealed a family of S-receptor-like kinase (SRLK) genes. Transgenic tomato lines were generated with three of these SRLK genes and one was found to confer Avr3-dependent resistance to Fol race 3, confirming it to be I-3. The finding that I-3 encodes an SRLK reveals a new pathway for Fol resistance and a new class of resistance genes, of which Pi-d2 from rice is also a member. The identification of I-3 also allows the investigation of the complex effector-resistance protein interaction involving Avr1-mediated suppression of I-2- and I-3-dependent resistance in tomato. PMID:25740416

  14. Polyamine metabolism in flax in response to treatment with pathogenic and non–pathogenic Fusarium strains

    PubMed Central

    Wojtasik, Wioleta; Kulma, Anna; Namysł, Katarzyna; Preisner, Marta; Szopa, Jan

    2015-01-01

    Flax crop yield is limited by various environmental stress factors, but the largest crop losses worldwide are caused by Fusarium infection. Polyamines are one of the many plant metabolites possibly involved in the plant response to infection. However, in flax plants the polyamine composition, genes involved in polyamine synthesis, and in particular their regulation, were previously unknown. The aim of this study was to investigate the polyamine synthesis pathway in flax and its involvement in response to pathogen infection. It is well established that polyamines are essential for the growth and development of both plants and fungi, but their role in pathogen infection still remains unknown. In our study we correlated the expression of genes involved in polyamine metabolism with the polyamine levels in plant tissues and compared the results for flax seedlings treated with two pathogenic and one non-pathogenic strains of Fusarium. We observed an increase in the expression of genes participating in polyamine synthesis after fungal infection, and it was reflected in an increase of polyamine content in the plant tissues. The highest level of mRNA was characteristic for ornithine decarboxylase during infection with all tested, pathogenic and non-pathogenic, Fusarium strains and the arginine decarboxylase gene during infection with the pathogenic strain of Fusarium culmorum. The main polyamine identified in the flax seedlings was putrescine, and its level changed the most during infection. Moreover, the considerable increase in the contents of cell wall-bound polyamines compared to the levels of free and conjugated polyamines may indicate that their main role during pathogen infection lies in strengthening of the cell wall. In vitro experiments showed that the polyamines inhibit Fusarium growth, which suggests that they play an important role in plant defense mechanisms. Furthermore, changes in metabolism and content of polyamines indicate different defense mechanisms activated in flax in response to infection by pathogenic and non-pathogenic Fusarium strains. PMID:25972886

  15. Fungal cell wall polymer based nanoparticles in protection of tomato plants from wilt disease caused by Fusarium oxysporum f.sp. lycopersici.

    PubMed

    Sathiyabama, M; Charles, R Einstein

    2015-11-20

    Cell wall polymer (chitosan) was isolated from Fusarium oxysporum f.sp. lycopersici. They were cross linked with sodium tripolyphosphate (TPP) to synthesize nanoparticles (CWP-NP). The nanoparticles were characterized by FTIR, DLS, SEM, XRD and NMR analyses. The isolated CWP-NP exhibit antifungal activity under in vitro condition. The foliar application of the CWP-NP to tomato plants challenged with F. oxysporum f. sp. lycopersici showed delay in wilt disease symptom expression and reduce the wilt disease severity. Treated plants also showed enhanced yield. These results suggested the role of the CWP-NP in protecting tomato plants from F. oxysporum f.sp. lycopersici infection. PMID:26344296

  16. Genetic and Pathogenic Variability of Fusarium oxysporum f. sp. cepae Isolated from Onion and Welsh Onion in Japan.

    PubMed

    Sasaki, Kazunori; Nakahara, Katsuya; Tanaka, Shuhei; Shigyo, Masayoshi; Ito, Shin-ichi

    2015-04-01

    Fusarium oxysporum f. sp. cepae causes Fusarium basal rot in onion (common onion) and Fusarium wilt in Welsh onion. Although these diseases have been detected in various areas in Japan, knowledge about the genetic and pathogenic variability of F. oxysporum f. sp. cepae is very limited. In this study, F. oxysporum f. sp. cepae was isolated from onion and Welsh onion grown in 12 locations in Japan, and a total of 55 F. oxysporum f. sp. cepae isolates (27 from onion and 28 from Welsh onion) were characterized based on their rDNA intergenic spacer (IGS) and translation elongation factor-1α (EF-1α) nucleotide sequences, vegetative compatibility groups (VCGs), and the presence of the SIX (secreted in xylem) homologs. Phylogenetic analysis of IGS sequences showed that these isolates were grouped into eight clades (A to H), and 20 onion isolates belonging to clade H were monophyletic and assigned to the same VCG. All the IGS-clade H isolates possessed homologs of SIX3, SIX5, and SIX7. The SIX3 homolog was located on a 4 Mb-sized chromosome in the IGS-clade H isolates. Pathogenicity tests using onion seedlings showed that all the isolates with high virulence were in the IGS-clade H. These results suggest that F. oxysporum f. sp. cepae isolates belonging to the IGS-clade H are genetically and pathogenically different from those belonging to the other IGS clades. PMID:25412011

  17. An Integrated Approach to Biological Control of Fusarium in Containerized Crops

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Although considerable progress has been made in controlling soilborne plant pathogens utilizing traditional approaches, Fusarium wilts have presented an ongoing challenge. The lack of availability of effective fungicides, the limited effectiveness of biocontrol agents, and the general inconsistency...

  18. Identification and evaluation of two diagnostic markers linked to Fusarium wilt resistance (race 4) in banana (Musa spp.).

    PubMed

    Wang, Wei; Hu, Yulin; Sun, Dequan; Staehelin, Christian; Xin, Dawei; Xie, Jianghui

    2012-01-01

    Fusarium wilt caused by the fungus Fusarium oxysporum f. sp. cubense race 4 (FOC4) results in vascular tissue damage and ultimately death of banana (Musa spp.) plants. Somaclonal variants of in vitro micropropagated banana can hamper success in propagation of genotypes resistant to FOC4. Early identification of FOC4 resistance in micropropagated banana plantlets is difficult, however. In this study, we identified sequence-characterized amplified region (SCAR) markers of banana associated with resistance to FOC4. Using pooled DNA from resistant or susceptible genotypes and 500 arbitrary 10-mer oligonucleotide primers, 24 random amplified polymorphic DNA (RAPD) products were identified. Two of these RAPD markers were successfully converted to SCAR markers, called ScaU1001 (GenBank accession number HQ613949) and ScaS0901 (GenBank accession number HQ613950). ScaS0901 and ScaU1001 could be amplified in FOC4-resistant banana genotypes ("Williams 8818-1" and Goldfinger), but not in five tested banana cultivars susceptible to FOC4. The two SCAR markers were then used to identify a somaclonal variant of the genotype "Williams 8818-1", which lost resistance to FOC4. Hence, the identified SCAR markers can be applied for a rapid quality control of FOC4-resistant banana plantlets immediately after the in vitro micropropagation stage. Furthermore, ScaU1001 and ScaS0901 will facilitate marker-assisted selection of new banana cultivars resistant to FOC4. PMID:21547366

  19. Fusarium graminearum: an pathogen of maize in Nepal, pathogenic variability and mycotoxins

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fusarium graminearum is an important pathogen of maize in hills of Nepal. It predominantly occurs on maize grown in cool and humid environment of high hills. The pathogen is also known to infect other cereal crops including wheat and rice causing important diseases. The incidence of ear rot is hi...

  20. Comparative genomics reveals mobile pathogenicity chromosomes in Fusarium

    SciTech Connect

    Ma, Li Jun; van der Does, H. C.; Borkovich, Katherine A.; Coleman, Jeffrey J.; Daboussi, Marie-Jose; Di Pietro, Antonio; Dufresne, Marie; Freitag, Michael; Grabherr, Manfred; Henrissat, Bernard; Houterman, Petra M.; Kang, Seogchan; Shim, Won-Bo; Wolochuk, Charles; Xie, Xiaohui; Xu, Jin Rong; Antoniw, John; Baker, Scott E.; Bluhm, Burton H.; Breakspear, Andrew; Brown, Daren W.; Butchko, Robert A.; Chapman, Sinead; Coulson, Richard; Coutinho, Pedro M.; Danchin, Etienne G.; Diener, Andrew; Gale, Liane R.; Gardiner, Donald; Goff, Steven; Hammond-Kossack, Kim; Hilburn, Karen; Hua-Van, Aurelie; Jonkers, Wilfried; Kazan, Kemal; Kodira, Chinnappa D.; Koehrsen, Michael; Kumar, Lokesh; Lee, Yong Hwan; Li, Liande; Manners, John M.; Miranda-Saavedra, Diego; Mukherjee, Mala; Park, Gyungsoon; Park, Jongsun; Park, Sook Young; Proctor, Robert H.; Regev, Aviv; Ruiz-Roldan, M. C.; Sain, Divya; Sakthikumar, Sharadha; Sykes, Sean; Schwartz, David C.; Turgeon, Barbara G.; Wapinski, Ilan; Yoder, Olen; Young, Sarah; Zeng, Qiandong; Zhou, Shiguo; Galagan, James; Cuomo, Christina A.; Kistler, H. Corby; Rep, Martijn

    2010-03-18

    Fusarium species are among the most important phytopathogenic and toxigenic fungi, having significant impact on crop production and animal health. Distinctively, members of the F. oxysporum species complex exhibit wide host range but discontinuously distributed host specificity, reflecting remarkable genetic adaptability. To understand the molecular underpinnings of diverse phenotypic traits and their evolution in Fusarium, we compared the genomes of three economically important and phylogenetically related, yet phenotypically diverse plant-pathogenic species, F. graminearum, F. verticillioides and F. oxysporum f. sp. lycopersici. Our analysis revealed greatly expanded lineage-specific (LS) genomic regions in F. oxysporum that include four entire chromosomes, accounting for more than one-quarter of the genome. LS regions are rich in transposons and genes with distinct evolutionary profiles but related to pathogenicity. Experimentally, we demonstrate for the first time the transfer of two LS chromosomes between strains of F. oxysporum, resulting in the conversion of a non-pathogenic strain into a pathogen. Transfer of LS chromosomes between otherwise genetically isolated strains explains the polyphyletic origin of host specificity and the emergence of new pathogenic lineages in the F. oxysporum species complex, putting the evolution of fungal pathogenicity into a new perspective.

  1. Pathogenicity of two species of Fusarium on some cultivars of bean in greenhouse.

    PubMed

    Faraji, M; Okhovvat, S M

    2005-01-01

    Twenty isolates of Fusarium oxysporum and F. solani were isolated from the infected roots of bean in different farms of east Azarbaijan and Tehran Provinces and their pathogenicity determined. Most isolates of the fungi were identified as F. oxysporun. They caused root rot, yellowing and wilting of bean in the field. In this test, the roots of 6 cultivars of bean seedlings soaked in suspension of the 7 isolates of the fungi (a1, Gogan, a2, Bilverdi, a3, Savojbolagh-Hashtgerd, a4, field of Agr. Coll. a5, Khomein, a6, Ramjin of F. oxysporum and a7 of F. solani of Varamin, Iran) for 5 minute (106 spores/ml.) then transplanted into the sterilized soil in 4 pots (as replication). For control (a8) the roots soaked in distilled water. The results showed that percentage average of necrotic roots and crowns of isolates al, a2, a3, a5, a6, a7 was %20.31 in group a, a4 was %43.52 in group b and a8 was %2.77 in group c after 3 weeks. The isolate a4 (from the field of Agricultural College, Karaj) was more infectious than the other because it caused wilting, yellowing the leaves and decreased the growth very soon, followed by a5 with %25.32 rate was more pathogenic. Bean cultivar Goli-Red was more tolerant with %10.02 than the others of 16.29 (Naz Red) to 25.15 percent of necrotic the roots & stems. PMID:16637191

  2. CHARACTERIZATION OF FUSARIUM OXYSPORUM ISOLATES FROM COMMON BEAN AND SUGAR BEET USIG PATHOGENICITY ASSAYS AND RANDOM AMPLIFIED POLYMORPHIC DNA MARKERS.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Technical Abstract. Fusarium wilt is an economically important fungal disease of common bean and Fusarium yellows of sugar beet in the Central High Plains (CHP) region of the United States with yield losses approaching 30% under appropriate environmental conditions. The objective of this study was ...

  3. Progress report on a contemporary survey of the Fusarium wilt fungus in the United States

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The last survey of Fusarium oxysporum f. sp. vasinfectum in the U.S. was conducted in 1985. Since that time, race 4, previously thought to occur only in Asia, appeared in California in 2001, causing significant problems for the San Joaquin Valley cotton industry. Also, the presence of race 8 has bee...

  4. A Network Approach to Predict Pathogenic Genes for Fusarium graminearum

    PubMed Central

    Liu, Xiaoping; Tang, Wei-Hua; Zhao, Xing-Ming; Chen, Luonan

    2010-01-01

    Fusarium graminearum is the pathogenic agent of Fusarium head blight (FHB), which is a destructive disease on wheat and barley, thereby causing huge economic loss and health problems to human by contaminating foods. Identifying pathogenic genes can shed light on pathogenesis underlying the interaction between F. graminearum and its plant host. However, it is difficult to detect pathogenic genes for this destructive pathogen by time-consuming and expensive molecular biological experiments in lab. On the other hand, computational methods provide an alternative way to solve this problem. Since pathogenesis is a complicated procedure that involves complex regulations and interactions, the molecular interaction network of F. graminearum can give clues to potential pathogenic genes. Furthermore, the gene expression data of F. graminearum before and after its invasion into plant host can also provide useful information. In this paper, a novel systems biology approach is presented to predict pathogenic genes of F. graminearum based on molecular interaction network and gene expression data. With a small number of known pathogenic genes as seed genes, a subnetwork that consists of potential pathogenic genes is identified from the protein-protein interaction network (PPIN) of F. graminearum, where the genes in the subnetwork are further required to be differentially expressed before and after the invasion of the pathogenic fungus. Therefore, the candidate genes in the subnetwork are expected to be involved in the same biological processes as seed genes, which imply that they are potential pathogenic genes. The prediction results show that most of the pathogenic genes of F. graminearum are enriched in two important signal transduction pathways, including G protein coupled receptor pathway and MAPK signaling pathway, which are known related to pathogenesis in other fungi. In addition, several pathogenic genes predicted by our method are verified in other pathogenic fungi, which demonstrate the effectiveness of the proposed method. The results presented in this paper not only can provide guidelines for future experimental verification, but also shed light on the pathogenesis of the destructive fungus F. graminearum. PMID:20957229

  5. Insight into the molecular requirements for pathogenicity of Fusarium oxysporum f. sp. lycopersici through large-scale insertional mutagenesis

    PubMed Central

    Michielse, Caroline B; van Wijk, Ringo; Reijnen, Linda; Cornelissen, Ben JC; Rep, Martijn

    2009-01-01

    Background Fusarium oxysporum f. sp. lycopersici is the causal agent of vascular wilt disease in tomato. In order to gain more insight into the molecular processes in F. oxysporum necessary for pathogenesis and to uncover the genes involved, we used Agrobacterium-mediated insertional mutagenesis to generate 10,290 transformants and screened the transformants for loss or reduction of pathogenicity. Results This led to the identification of 106 pathogenicity mutants. Southern analysis revealed that the average T-DNA insertion is 1.4 and that 66% of the mutants carry a single T-DNA. Using TAIL-PCR, chromosomal T-DNA flanking regions were isolated and 111 potential pathogenicity genes were identified. Conclusions Functional categorization of the potential pathogenicity genes indicates that certain cellular processes, such as amino acid and lipid metabolism, cell wall remodeling, protein translocation and protein degradation, seem to be important for full pathogenicity of F. oxysporum. Several known pathogenicity genes were identified, such as those encoding chitin synthase V, developmental regulator FlbA and phosphomannose isomerase. In addition, complementation and gene knock-out experiments confirmed that a glycosylphosphatidylinositol-anchored protein, thought to be involved in cell wall integrity, a transcriptional regulator, a protein with unknown function and peroxisome biogenesis are required for full pathogenicity of F. oxysporum. PMID:19134172

  6. Next-generation sequencing for identification of candidate genes for Fusarium wilt and sterility mosaic disease in pigeonpea (Cajanus cajan).

    PubMed

    Singh, Vikas K; Khan, Aamir W; Saxena, Rachit K; Kumar, Vinay; Kale, Sandip M; Sinha, Pallavi; Chitikineni, Annapurna; Pazhamala, Lekha T; Garg, Vanika; Sharma, Mamta; Sameer Kumar, Chanda Venkata; Parupalli, Swathi; Vechalapu, Suryanarayana; Patil, Suyash; Muniswamy, Sonnappa; Ghanta, Anuradha; Yamini, Kalinati Narasimhan; Dharmaraj, Pallavi Subbanna; Varshney, Rajeev K

    2016-05-01

    To map resistance genes for Fusarium wilt (FW) and sterility mosaic disease (SMD) in pigeonpea, sequencing-based bulked segregant analysis (Seq-BSA) was used. Resistant (R) and susceptible (S) bulks from the extreme recombinant inbred lines of ICPL 20096 × ICPL 332 were sequenced. Subsequently, SNP index was calculated between R- and S-bulks with the help of draft genome sequence and reference-guided assembly of ICPL 20096 (resistant parent). Seq-BSA has provided seven candidate SNPs for FW and SMD resistance in pigeonpea. In parallel, four additional genotypes were re-sequenced and their combined analysis with R- and S-bulks has provided a total of 8362 nonsynonymous (ns) SNPs. Of 8362 nsSNPs, 60 were found within the 2-Mb flanking regions of seven candidate SNPs identified through Seq-BSA. Haplotype analysis narrowed down to eight nsSNPs in seven genes. These eight nsSNPs were further validated by re-sequencing 11 genotypes that are resistant and susceptible to FW and SMD. This analysis revealed association of four candidate nsSNPs in four genes with FW resistance and four candidate nsSNPs in three genes with SMD resistance. Further, In silico protein analysis and expression profiling identified two most promising candidate genes namely C.cajan_01839 for SMD resistance and C.cajan_03203 for FW resistance. Identified candidate genomic regions/SNPs will be useful for genomics-assisted breeding in pigeonpea. PMID:26397045

  7. Deep 16S rRNA pyrosequencing reveals a bacterial community associated with Banana Fusarium Wilt disease suppression induced by bio-organic fertilizer application.

    PubMed

    Shen, Zongzhuan; Wang, Dongsheng; Ruan, Yunze; Xue, Chao; Zhang, Jian; Li, Rong; Shen, Qirong

    2014-01-01

    Our previous work demonstrated that application of a bio-organic fertilizer (BIO) to a banana mono-culture orchard with serious Fusarium wilt disease effectively decreased the number of soil Fusarium sp. and controlled the soil-borne disease. Because bacteria are an abundant and diverse group of soil organisms that responds to soil health, deep 16 S rRNA pyrosequencing was employed to characterize the composition of the bacterial community to investigate how it responded to BIO or the application of other common composts and to explore the potential correlation between bacterial community, BIO application and Fusarium wilt disease suppression. After basal quality control, 137,646 sequences and 9,388 operational taxonomic units (OTUs) were obtained from the 15 soil samples. Proteobacteria, Acidobacteria, Bacteroidetes, Gemmatimonadetes and Actinobacteria were the most frequent phyla and comprised up to 75.3% of the total sequences. Compared to the other soil samples, BIO-treated soil revealed higher abundances of Gemmatimonadetes and Acidobacteria, while Bacteroidetes were found in lower abundance. Meanwhile, on genus level, higher abundances compared to other treatments were observed for Gemmatimonas and Gp4. Correlation and redundancy analysis showed that the abundance of Gemmatimonas and Sphingomonas and the soil total nitrogen and ammonium nitrogen content were higher after BIO application, and they were all positively correlated with disease suppression. Cumulatively, the reduced Fusarium wilt disease incidence that was seen after BIO was applied for 1-year might be attributed to the general suppression based on a shift within the bacteria soil community, including specific enrichment of Gemmatimonas and Sphingomonas. PMID:24871319

  8. Deep 16S rRNA Pyrosequencing Reveals a Bacterial Community Associated with Banana Fusarium Wilt Disease Suppression Induced by Bio-Organic Fertilizer Application

    PubMed Central

    Ruan, Yunze; Xue, Chao; Zhang, Jian; Li, Rong; Shen, Qirong

    2014-01-01

    Our previous work demonstrated that application of a bio-organic fertilizer (BIO) to a banana mono-culture orchard with serious Fusarium wilt disease effectively decreased the number of soil Fusarium sp. and controlled the soil-borne disease. Because bacteria are an abundant and diverse group of soil organisms that responds to soil health, deep 16 S rRNA pyrosequencing was employed to characterize the composition of the bacterial community to investigate how it responded to BIO or the application of other common composts and to explore the potential correlation between bacterial community, BIO application and Fusarium wilt disease suppression. After basal quality control, 137,646 sequences and 9,388 operational taxonomic units (OTUs) were obtained from the 15 soil samples. Proteobacteria, Acidobacteria, Bacteroidetes, Gemmatimonadetes and Actinobacteria were the most frequent phyla and comprised up to 75.3% of the total sequences. Compared to the other soil samples, BIO-treated soil revealed higher abundances of Gemmatimonadetes and Acidobacteria, while Bacteroidetes were found in lower abundance. Meanwhile, on genus level, higher abundances compared to other treatments were observed for Gemmatimonas and Gp4. Correlation and redundancy analysis showed that the abundance of Gemmatimonas and Sphingomonas and the soil total nitrogen and ammonium nitrogen content were higher after BIO application, and they were all positively correlated with disease suppression. Cumulatively, the reduced Fusarium wilt disease incidence that was seen after BIO was applied for 1-year might be attributed to the general suppression based on a shift within the bacteria soil community, including specific enrichment of Gemmatimonas and Sphingomonas. PMID:24871319

  9. Morphological and molecular characterization of Fusarium spp pathogenic to pecan tree in Brazil.

    PubMed

    Lazarotto, M; Milanesi, P M; Muniz, M F B; Reiniger, L R S; Beltrame, R; Harakava, R; Blume, E

    2014-01-01

    The occurrence of Fusarium spp associated with pecan tree (Carya illinoinensis) diseases in Brazil has been observed in recent laboratory analyses in Rio Grande do Sul State. Thus, in this study, we i) obtained Fusarium isolates from plants with disease symptoms; ii) tested the pathogenicity of these Fusarium isolates to pecan; iii) characterized and grouped Fusarium isolates that were pathogenic to the pecan tree based on morphological characteristics; iv) identified Fusarium spp to the species complex level through TEF-1α sequencing; and v) compared the identification methods used in the study. Fifteen isolates collected from the inflorescences, roots, and seeds of symptomatic plants (leaf necrosis or root rot) were used for pathogenicity tests. Morphological characterization was conducted using only pathogenic isolates, for a total of 11 isolates, based on the mycelial growth rate, sporulation, colony pigmentation, and conidial length and width variables. Pathogenic isolates were grouped based on morphological characteristics, and molecular characterization was performed by sequencing TEF-1α genes. Pathogenic isolates belonging to the Fusarium chlamydosporum species complex, Fusarium graminearum species complex, Fusarium proliferatum, and Fusarium oxysporum were identified based on the TEF-1α region. Morphological characteristics were used to effectively differentiate isolates and group the isolates according to genetic similarity, particularly conidial width, which emerged as a key morphological descriptor in this study. PMID:25501150

  10. Development and evaluation of a TaqMan Real-Time PCR assay for Fusarium oxysporum f. sp. spinaciae

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fusarium oxysporum f. sp. spinaciae, causal agent of spinach Fusarium wilt, is an important soilborne pathogen in many areas of the world where spinach is grown. The pathogen is persistent in acid soils of maritime western Oregon and Washington, the only region of the USA suitable for commercial spi...

  11. The Lateral Organ Boundaries Domain Transcription Factor LBD20 Functions in Fusarium Wilt Susceptibility and Jasmonate Signaling in Arabidopsis1[W

    PubMed Central

    Thatcher, Louise F.; Powell, Jonathan J.; Aitken, Elizabeth A.B.; Kazan, Kemal; Manners, John M.

    2012-01-01

    The LATERAL ORGAN BOUNDARIES (LOB) DOMAIN (LBD) gene family encodes plant-specific transcriptional regulators functioning in organ development. In a screen of Arabidopsis (Arabidopsis thaliana) sequence-indexed transferred DNA insertion mutants, we found disruption of the LOB DOMAIN-CONTAINING PROTEIN20 (LBD20) gene led to increased resistance to the root-infecting vascular wilt pathogen Fusarium oxysporum. In wild-type plants, LBD20 transcripts were barely detectable in leaves but abundant in roots, where they were further induced after F. oxysporum inoculation or methyl jasmonate treatment. Induction of LBD20 expression in roots was abolished in coronatine insensitive1 (coi1) and myc2 (allelic to jasmonate insensitive1) mutants, suggesting LBD20 may function in jasmonate (JA) signaling. Consistent with this, expression of the JA-regulated THIONIN2.1 (Thi2.1) and VEGETATIVE STORAGE PROTEIN2 (VSP2) genes were up-regulated in shoots of lbd20 following treatment of roots with F. oxysporum or methyl jasmonate. However, PLANT DEFENSIN1.2 expression was unaltered, indicating a repressor role for LBD20 in a branch of the JA-signaling pathway. Plants overexpressing LBD20 (LBD20-OX) had reduced Thi2.1 and VSP2 expression. There was a significant correlation between increased LBD20 expression in the LBD20-OX lines with both Thi2.1 and VSP2 repression, and reduced survival following F. oxysporum infection. Chlorosis resulting from application of F. oxysporum culture filtrate was also reduced in lbd20 leaves relative to the wild type. Taken together, LBD20 is a F. oxysporum susceptibility gene that appears to regulate components of JA signaling downstream of COI1 and MYC2 that are required for full elicitation of F. oxysporum- and JA-dependent responses. To our knowledge, this is the first demonstration of a role for a LBD gene family member in either biotic stress or JA signaling. PMID:22786889

  12. FUSARIUM FOETENS, A NEW SPECIES PATHOGENIC TO ELATIOR BEGONIA (BEGONIA X HIEMALIS) HYBRIDS AND THE SISTER TAXON OF THE FUSARIUM OXYSPORUM SPECIES COMPLEX

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A new disease was recently discovered in Elatior hybrid begonia (Begonia x hiemalis) nurseries in The Netherlands. Diseased plants showed a combination of basal rot, vein yellowing and wilting. A species of Fusarium was consistently isolated from the discolored veins of leaves and stems. This spe...

  13. Construction of cDNA expression library of watermelon for isolation of ClWRKY1 transcription factors gene involved in resistance to Fusarium wilt.

    PubMed

    Yang, Bing-Yan; Huo, Xiu-Ai; Li, Peng-Fei; Wang, Cui-Xia; Duan, Hui-Jun

    2014-08-01

    Full-length cDNAs are very important for genome annotation and functional analysis of genes. The number of full-length cDNAs from watermelon remains limited. Here we report first the construction of a full-length enriched cDNA library from Fusarium wilt stressed watermelon (Citrullus lanatus Thunb.) cultivar PI296341 root tissues using the SMART method. The titer of primary cDNA library and amplified library was 2.21 x 10(6) and 2.0 x 10(10) pfu/ml, respectively and the rate of recombinant was above 85%. The size of insert fragment ranged from 0.3 to 2.0 kb. In this study, we first cloned a gene named ClWRKY1, which was 1981 bp long and encoded a protein consisting of 394 amino acids. It contained two characteristic WRKY domains and two zinc finger motifs. Quantitative real-time PCR showed that ClWRKY1 expression levels reached maximum level at 12 h after inoculation with Fusarium oxysporum f. sp. niveum. The full-length cDNA library of watermelon root tissues is not only essential for the cloning of genes which are known, but also an initial key for the screening and cloning of new genes that might be involved in resistance to Fusarium wilt. PMID:25296501

  14. Adaptive Potential of Maritime Pine (Pinus pinaster) Populations to the Emerging Pitch Canker Pathogen, Fusarium circinatum

    PubMed Central

    Elvira-Recuenco, Margarita; Iturritxa, Eugenia; Majada, Juan; Alia, Ricardo; Raposo, Rosa

    2014-01-01

    There is a concern on how emerging pests and diseases will affect the distribution range and adaptability of their host species, especially due to different conditions derived from climate change and growing globalization. Fusarium circinatum, which causes pitch canker disease in Pinus species, is an exotic pathogen of recent introduction in Spain that threatens its maritime pine (P. pinaster) stands. To predict the impact this disease will have on the species, we examine host resistance traits and their genetic architecture. Resistance phenotyping was done in a clonal provenance/progeny trial, using three-year-old cuttings artificially inoculated with the pathogen and maintained under controlled environmental conditions. A total number of 670 ramets were assessed, distributed in 10 populations, with a total of 47 families, 2 to 5 half-sibs per family, and 3–7 ramets per clone. High genetic variation was found at the three hierarchical levels studied: population, family and clone, being both additive and non-additive effects important. Narrow-sense and broad-sense heritability estimates were relatively high, with respective values of 0.43–0.58 and 0.51–0.8, depending on the resistance traits measured (lesion length, lesion length rate, time to wilting, and survival). These values suggest the species' high capacity of evolutionary response to the F. circinatum pathogen. A population originated in Northern Spain was the most resistant, while another from Morocco was the most susceptible. The total number of plants that did not show lesion development or presented a small lesion (length<30 mm) was 224 out of 670, indicating a high proportion of resistant trees in the offspring within the analyzed populations. We found large differences among populations and considerable genetic variation within populations, which should allow, through natural or artificial selection, the successful adaptation of maritime pine to pitch canker disease. PMID:25500822

  15. Adaptive potential of maritime pine (Pinus pinaster) populations to the emerging pitch canker pathogen, Fusarium circinatum.

    PubMed

    Elvira-Recuenco, Margarita; Iturritxa, Eugenia; Majada, Juan; Alia, Ricardo; Raposo, Rosa

    2014-01-01

    There is a concern on how emerging pests and diseases will affect the distribution range and adaptability of their host species, especially due to different conditions derived from climate change and growing globalization. Fusarium circinatum, which causes pitch canker disease in Pinus species, is an exotic pathogen of recent introduction in Spain that threatens its maritime pine (P. pinaster) stands. To predict the impact this disease will have on the species, we examine host resistance traits and their genetic architecture. Resistance phenotyping was done in a clonal provenance/progeny trial, using three-year-old cuttings artificially inoculated with the pathogen and maintained under controlled environmental conditions. A total number of 670 ramets were assessed, distributed in 10 populations, with a total of 47 families, 2 to 5 half-sibs per family, and 3-7 ramets per clone. High genetic variation was found at the three hierarchical levels studied: population, family and clone, being both additive and non-additive effects important. Narrow-sense and broad-sense heritability estimates were relatively high, with respective values of 0.43-0.58 and 0.51-0.8, depending on the resistance traits measured (lesion length, lesion length rate, time to wilting, and survival). These values suggest the species' high capacity of evolutionary response to the F. circinatum pathogen. A population originated in Northern Spain was the most resistant, while another from Morocco was the most susceptible. The total number of plants that did not show lesion development or presented a small lesion (length<30 mm) was 224 out of 670, indicating a high proportion of resistant trees in the offspring within the analyzed populations. We found large differences among populations and considerable genetic variation within populations, which should allow, through natural or artificial selection, the successful adaptation of maritime pine to pitch canker disease. PMID:25500822

  16. Petunia floral defensins with unique prodomains as novel candidates for development of fusarium wilt resistance in transgenic banana plants.

    PubMed

    Ghag, Siddhesh B; Shekhawat, Upendra K Singh; Ganapathi, Thumballi R

    2012-01-01

    Antimicrobial peptides are a potent group of defense active molecules that have been utilized in developing resistance against a multitude of plant pathogens. Floral defensins constitute a group of cysteine-rich peptides showing potent growth inhibition of pathogenic filamentous fungi especially Fusarium oxysporum in vitro. Full length genes coding for two Petunia floral defensins, PhDef1 and PhDef2 having unique C-terminal 31 and 27 amino acid long predicted prodomains, were overexpressed in transgenic banana plants using embryogenic cells as explants for Agrobacterium-mediated genetic transformation. High level constitutive expression of these defensins in elite banana cv. Rasthali led to significant resistance against infection of Fusarium oxysporum f. sp. cubense as shown by in vitro and ex vivo bioassay studies. Transgenic banana lines expressing either of the two defensins were clearly less chlorotic and had significantly less infestation and discoloration in the vital corm region of the plant as compared to untransformed controls. Transgenic banana plants expressing high level of full-length PhDef1 and PhDef2 were phenotypically normal and no stunting was observed. In conclusion, our results suggest that high-level constitutive expression of floral defensins having distinctive prodomains is an efficient strategy for development of fungal resistance in economically important fruit crops like banana. PMID:22745785

  17. Petunia Floral Defensins with Unique Prodomains as Novel Candidates for Development of Fusarium Wilt Resistance in Transgenic Banana Plants

    PubMed Central

    Ghag, Siddhesh B.; Shekhawat, Upendra K. Singh; Ganapathi, Thumballi R.

    2012-01-01

    Antimicrobial peptides are a potent group of defense active molecules that have been utilized in developing resistance against a multitude of plant pathogens. Floral defensins constitute a group of cysteine-rich peptides showing potent growth inhibition of pathogenic filamentous fungi especially Fusarium oxysporum in vitro. Full length genes coding for two Petunia floral defensins, PhDef1 and PhDef2 having unique C- terminal 31 and 27 amino acid long predicted prodomains, were overexpressed in transgenic banana plants using embryogenic cells as explants for Agrobacterium–mediated genetic transformation. High level constitutive expression of these defensins in elite banana cv. Rasthali led to significant resistance against infection of Fusarium oxysporum f. sp. cubense as shown by in vitro and ex vivo bioassay studies. Transgenic banana lines expressing either of the two defensins were clearly less chlorotic and had significantly less infestation and discoloration in the vital corm region of the plant as compared to untransformed controls. Transgenic banana plants expressing high level of full-length PhDef1 and PhDef2 were phenotypically normal and no stunting was observed. In conclusion, our results suggest that high-level constitutive expression of floral defensins having distinctive prodomains is an efficient strategy for development of fungal resistance in economically important fruit crops like banana. PMID:22745785

  18. Detoxification of the Fusarium toxin fusaric acid by the soil fungus Aspergillus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The fungal pathogen Fusarium oxysporum f. sp. vasinfectum (Fov) causes Fusarium wilt in cotton (Gossypium hirsutum L.) and produces the toxin fusaric acid (FA). Previous research indicates that in the high producing strains of Fov, FA plays an important role in virulence. To address the problems o...

  19. Detection of Goss's Wilt Pathogen Clavibacter michiganensis subsp. nebraskensis in Maize by Loop-Mediated Amplification.

    PubMed

    Yasuhara-Bell, Jarred; de Silva, Asoka; Heuchelin, Scott A; Chaky, Jennifer L; Alvarez, Anne M

    2016-03-01

    The Goss's wilt pathogen, Clavibacter michiganensis subsp. nebraskensis, can cause considerable losses in maize (Zea mays) production. Diagnosis of Goss's wilt currently is based on symptomology and identification of C. michiganensis subsp. nebraskensis, following isolation on a semiselective medium and/or serological testing. In an effort to provide a more efficient identification method, a loop-mediated amplification (LAMP) assay was developed to detect the tripartite ATP-independent periplasmic (TRAP)-type C4-dicarboxylate transport system large permease component and tested using strains of C. michiganensis subsp. nebraskensis, all other C. michiganensis subspecies and several genera of nontarget bacteria. Only strains of C. michiganensis subsp. nebraskensis reacted positively with the LAMP assay. The LAMP assay was then used to identify bacterial isolates from diseased maize. 16S rDNA and dnaA sequence analyses were used to confirm the identity of the maize isolates and validate assay specificity. The Cmm ImmunoStrip assay was included as a presumptive identification test of C. michiganensis subsp. nebraskensis at the species level. The Cmn-LAMP assay was further tested using symptomatic leaf tissue. The Cmn-LAMP assay was run in a hand-held real-time monitoring device (SMART-DART) and performed equally to in-lab quantitative polymerase chain reaction equipment. The Cmn-LAMP assay accurately identified C. michiganensis subsp. nebraskensis and has potential as a field test. The targeted sequence also has potential application in other molecular detection platforms. PMID:26595113

  20. Diversity and chemotaxis of soil bacteria with antifungal activity against Fusarium wilt of banana.

    PubMed

    Li, Ping; Ma, Li; Feng, Yun Li; Mo, Ming He; Yang, Fa Xiang; Dai, Hao Fu; Zhao, You Xing

    2012-10-01

    The chemotactic response of bacteria to root exudates plays an important role in the colonization of bacteria in the rhizosphere. In this study, 420 strains of antifungal bacteria against Fusarium oxysporum f. sp. cubense (Foc) were screened for chemotaxis based on a cheA molecular diagnostic method. A total of 124 strains with antifungal efficiencies of 27.26-67.14% generated a characteristic band of cheA. The chemotaxis of 97 bacterial strains producing a cheA band was confirmed using the drop assay and swarm plate assay using catechol, p-hydroxybenzoic acid, salicylic acid, and asparagine as the attractants. A phylogenetic analysis based on restriction fragment length polymorphisms (RFLPs) and 16S rDNA sequences indicated that the 124 chemotactic antagonists of Foc were affiliated with 18 species of Paenibacillaceae, Bacillaceae, Streptomycineae, Enterobacteriaceae, and Pseudomonadaceae. The chemical composition of banana root exudates were analyzed by GC-MS, and 62 compounds, including alkanes, alkenes, naphthalenes, benzenes, and alcohols, were evaluated. Five representative antagonists of Foc showed 1.76- to 7.75-fold higher chemotactic responses than the control to seven compounds in banana root exudates, as determination by capillary assays. PMID:22763749

  1. In vitro study of the growth, development and pathogenicity responses of Fusarium oxysporum to phthalic acid, an autotoxin from Lanzhou lily.

    PubMed

    Wu, Zhijiang; Yang, Liu; Wang, Ruoyu; Zhang, Yubao; Shang, Qianhan; Wang, Le; Ren, Qin; Xie, Zhongkui

    2015-08-01

    Continuous monoculture of Lanzhou lily (Lilium davidii var. unicolor Cotton) results in frequent incidence of fusarium wilt caused by Fusarium oxysporum. Phthalic acid (PA), a principal autotoxin from root exudates of Lanzhou lily, is involved in soil sickness by inducing autotoxicity. The aim of this study was to evaluate the direct allelopathic effects of PA on the growth, development and pathogenicity of F. oxysporum in vitro based on an ecologically relevant soil concentration. The results showed that PA slightly but not significantly inhibited the colony growth (mycelial growth) and fungal biomass of F. oxysporum at low concentrations ranging from 0.05 to 0.5 mM, and significantly inhibited the colony growth at the highest concentration (1 mM). None of the PA concentrations tested significantly inhibited the conidial germination and sporulation of F. oxysporum in liquid medium. However, mycotoxin (fusaric acid) yield and pathogenesis-related hydrolytic enzyme (protease, pectinase, cellulase, and amylase) activities were significantly stimulated in liquid cultures of F. oxysporum containing PA at ≥ 0.25 mM. We conclude that PA at a soil level (i.e. 0.25 mM) is involved in plant-pathogen allelopathy as a stimulator of mycotoxin production and hydrolytic enzyme activities in F. oxysporum, which is possibly one of the mechanisms responsible for promoting the wilt disease of lily. PMID:25994089

  2. Molecular genetic classification of Fusarium oxysporum f. sp. vasinfectum races

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An understanding of the pathogenic diversity present in a population of a given disease organism is necessary for the effective development and deployment of host-plant resistance. The need for rapid and accurate diagnostic tools for identifying races or genotypes of the Fusarium wilt pathogen, Fusa...

  3. Cross pathogenicity and vegetative compatibility of Fusarium oxysporum isolated from sugar beet

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fusarium oxysporum f. sp. betae, which causes Fusarium yellows in sugar beet, can be highly variable in virulence and morphology, with further diversity derived due to the wide geographic distribution of sugar beet production. Little is known about factors that determine pathogenicity to sugar beet...

  4. Widespread occurrence of diverse human pathogenic types of the fungus Fusarium detected in plumbing drains

    Technology Transfer Automated Retrieval System (TEKTRAN)

    It has been proposed that plumbing systems might serve as a significant environmental reservoir of human pathogenic isolates of Fusarium. We tested this hypothesis by performing the first extensive multilocus sequence typing (MLST) survey of plumbing drain-associated Fusarium isolates, and comparing...

  5. Tomato Genome-Wide Transcriptional Responses to Fusarium Wilt and Tomato Mosaic Virus

    PubMed Central

    Andolfo, Giuseppe; Ferriello, Francesca; Tardella, Luca; Ferrarini, Alberto; Sigillo, Loredana; Frusciante, Luigi; Ercolano, Maria Raffaella

    2014-01-01

    Since gene expression approaches constitute a starting point for investigating plant–pathogen systems, we performed a transcriptional analysis to identify a set of genes of interest in tomato plants infected with F. oxysporum f. sp. lycopersici (Fol) and Tomato Mosaic Virus (ToMV). Differentially expressed tomato genes upon inoculation with Fol and ToMV were identified at two days post-inoculation. A large overlap was found in differentially expressed genes throughout the two incompatible interactions. However, Gene Ontology enrichment analysis evidenced specific categories in both interactions. Response to ToMV seems more multifaceted, since more than 70 specific categories were enriched versus the 30 detected in Fol interaction. In particular, the virus stimulated the production of an invertase enzyme that is able to redirect the flux of carbohydrates, whereas Fol induced a homeostatic response to prevent the fungus from killing cells. Genomic mapping of transcripts suggested that specific genomic regions are involved in resistance response to pathogen. Coordinated machinery could play an important role in prompting the response, since 60% of pathogen receptor genes (NB-ARC-LRR, RLP, RLK) were differentially regulated during both interactions. Assessment of genomic gene expression patterns could help in building up models of mediated resistance responses. PMID:24804963

  6. Action and reaction of host and pathogen during Fusarium head blight disease.

    PubMed

    Walter, Stephanie; Nicholson, Paul; Doohan, Fiona M

    2010-01-01

    The Fusarium species Fusarium graminearum and Fusarium culmorum, which are responsible for Fusarium head blight (FHB) disease, reduce world-wide cereal crop yield and, as a consequence of their mycotoxin production in cereal grain, impact on both human and animal health. Their study is greatly promoted by the availability of the genomic sequence of F. graminearum and transcriptomic resources for both F. graminearum and its cereal hosts. Functional genomic, proteomic and metabolomic studies, in combination with targeted mutagenesis or transgenic studies, are unravelling the complex mechanisms involved in Fusarium infection, penetration and colonization of host tissues, and host avoidance thereof. This review illuminates and integrates emerging knowledge regarding the molecular crosstalk between Fusarium and its small-grain cereal hosts. An understanding of the complexity of the host-pathogen interactions will be instrumental in designing new efficient strategies for the control of FHB disease. PMID:19807873

  7. Extracellular peptidases of the cereal pathogen Fusarium graminearum

    PubMed Central

    Lowe, Rohan G. T.; McCorkelle, Owen; Bleackley, Mark; Collins, Christine; Faou, Pierre; Mathivanan, Suresh; Anderson, Marilyn

    2015-01-01

    The plant pathogenic fungus Fusarium graminearum (Fgr) creates economic and health risks in cereals agriculture. Fgr causes head blight (or scab) of wheat and stalk rot of corn, reducing yield, degrading grain quality, and polluting downstream food products with mycotoxins. Fungal plant pathogens must secrete proteases to access nutrition and to breakdown the structural protein component of the plant cell wall. Research into the proteolytic activity of Fgr is hindered by the complex nature of the suite of proteases secreted. We used a systems biology approach comprising genome analysis, transcriptomics and label-free quantitative proteomics to characterize the peptidases deployed by Fgr during growth. A combined analysis of published microarray transcriptome datasets revealed seven transcriptional groupings of peptidases based on in vitro growth, in planta growth, and sporulation behaviors. A high resolution mass spectrometry-based proteomics analysis defined the extracellular proteases secreted by F. graminearum. A meta-classification based on sequence characters and transcriptional/translational activity in planta and in vitro provides a platform to develop control strategies that target Fgr peptidases. PMID:26635820

  8. Stable integration and expression of wasabi defensin gene in "Egusi" melon (Colocynthis citrullus L.) confers resistance to Fusarium wilt and Alternaria leaf spot.

    PubMed

    Ntui, Valentine Otang; Thirukkumaran, Gunaratnam; Azadi, Pejman; Khan, Raham Sher; Nakamura, Ikuo; Mii, Masahiro

    2010-09-01

    Production of "Egusi" melon (Colocynthis citrullus L.) in West Africa is limited by fungal diseases, such as Alternaria leaf spot and Fusarium wilt. In order to engineer "Egusi" resistant to these diseases, cotyledonary explants of two "Egusi" genotypes, 'Ejagham' and NHC1-130, were transformed with Agrobacterium tumefaciens strain EHA101 harbouring wasabi defensin gene (isolated from Wasabia japonica L.) in a binary vector pEKH1. After co-cultivation for 3 days, infected explants were transferred to MS medium containing 100 mg l(-l) kanamycin to select transformed tissues. After 3 weeks of culture, adventitious shoots appeared directly along the edges of the explants. As much as 19 out of 52 (36.5%) and 25 out of 71 (35.2%) of the explants in genotype NHC1-130 and 'Ejagham', respectively, formed shoots after 6 weeks of culture. As much as 74% (14 out of 19) of the shoots regenerated in genotype NHC1-130 and 72% (18 out of 25) of those produced in genotype 'Ejagham' were transgenic. A DNA fragment corresponding to the wasabi defensin gene or the selection marker nptII was amplified by PCR from the genomic DNA of all regenerated plant clones rooted on hormone-free MS medium under the same selection pressure, suggesting their transgenic nature. Southern blot analysis confirmed successful integration of 1-5 copies of the transgene. RT-PCR, northern and western blot analyses revealed that wasabi defensin gene was expressed in transgenic lines. Transgenic lines showed increased levels of resistance to Alternaria solani, which causes Alternaria leaf spot and Fusarium oxysporum, which causes Fusarium wilt, as compared to that of untransformed plants. PMID:20552202

  9. Analysis of root-knot nematode and fusarium wilt disease resistance in cotton (Gossypium spp.) using chromosome substitution lines from two alien species.

    PubMed

    Ulloa, M; Wang, C; Saha, S; Hutmacher, R B; Stelly, D M; Jenkins, J N; Burke, J; Roberts, P A

    2016-04-01

    Chromosome substitution (CS) lines in plants are a powerful genetic resource for analyzing the contribution of chromosome segments to phenotypic variance. In this study, a series of interspecific cotton (Gossypium spp.) CS lines were used to identify a new germplasm resource, and to validate chromosomal regions and favorable alleles associated with nematode or fungal disease resistance traits. The CS lines were developed in the G. hirsutum L. TM-1 background with chromosome or chromosome segment substitutions from G. barbadense L. Pima 3-79 or G. tomentosum. Root-knot nematode (Meloidogyne incognita) and fusarium wilt (Fusarium oxysporum f. sp. vasinfectum) (races 1 and 4) resistance alleles and quantitative trait loci (QTL) previously placed on cotton chromosomes using SSR markers in two interspecific recombinant inbred line populations were chosen for testing. Phenotypic responses of increased resistance or susceptibility in controlled inoculation and infested field assays confirmed the resistance QTLs, based on substitution with the positive or negative allele for resistance. Lines CS-B22Lo, CS-B04, and CS-B18 showed high resistance to nematode root-galling, confirming QTLs on chromosomes 4 and 22 (long arm) with resistance alleles from Pima 3-79. Line CS-B16 had less fusarium race 1-induced vascular root staining and higher percent survival than the TM-1 parent, confirming a major resistance QTL on chromosome 16. Lines CS-B(17-11) and CS-B17 had high fusarium race 4 vascular symptoms and low survival due to susceptible alleles introgressed from Pima 3-79, confirming the localization on chromosome 17 of an identified QTL with resistance alleles from TM1 and other resistant lines. Analyses validated regions on chromosomes 11, 16, and 17 harboring nematode and fusarium wilt resistance genes and demonstrated the value of CS lines as both a germplasm resource for breeding programs and as a powerful genetic analysis tool for determining QTL effects for disease resistance. CS lines carrying small alien chromosome segments with favorable QTL alleles could be used for effective introgression of biotic stress resistance or many other desirable traits by targeting gene interactions and reducing linkage drag effects. PMID:26882892

  10. Genome-Wide Analysis in Three Fusarium Pathogens Identifies Rapidly Evolving Chromosomes and Genes Associated with Pathogenicity

    PubMed Central

    Sperschneider, Jana; Gardiner, Donald M.; Thatcher, Louise F.; Lyons, Rebecca; Singh, Karam B.; Manners, John M.; Taylor, Jennifer M.

    2015-01-01

    Pathogens and hosts are in an ongoing arms race and genes involved in host–pathogen interactions are likely to undergo diversifying selection. Fusarium plant pathogens have evolved diverse infection strategies, but how they interact with their hosts in the biotrophic infection stage remains puzzling. To address this, we analyzed the genomes of three Fusarium plant pathogens for genes that are under diversifying selection. We found a two-speed genome structure both on the chromosome and gene group level. Diversifying selection acts strongly on the dispensable chromosomes in Fusarium oxysporum f. sp. lycopersici and on distinct core chromosome regions in Fusarium graminearum, all of which have associations with virulence. Members of two gene groups evolve rapidly, namely those that encode proteins with an N-terminal [SG]-P-C-[KR]-P sequence motif and proteins that are conserved predominantly in pathogens. Specifically, 29 F. graminearum genes are rapidly evolving, in planta induced and encode secreted proteins, strongly pointing toward effector function. In summary, diversifying selection in Fusarium is strongly reflected as genomic footprints and can be used to predict a small gene set likely to be involved in host–pathogen interactions for experimental verification. PMID:25994930

  11. Antagonistic activity of Bacillus subtilis SB1 and its biocontrol effect on tomato bacterial wilt

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A potential biocontrol agent of bacterial wilt, Bacillus subtilis SB1, isolated from tomato roots, showed a broad-spectrum of antimicrobial activity in in vitro experiments. It inhibited the growth of many plant pathogens, including Ralstonia solanacearum, Xanthomonas oryzae pv. oryzae, Fusarium ox...

  12. Cytochemical Labeling for Fungal and Host Components in Plant Tissues Inoculated with Fungal Wilt Pathogens

    NASA Astrophysics Data System (ADS)

    Ouellette, G. B.; Baayen, R. P.; Chamberland, H.; Simard, M.; Rioux, D.; Charest, P. M.

    2004-08-01

    Antibodies to detect pectin in present investigations attached to distinct fibrils in vessel lumina. In carnation infected with an isolate of Fusarium oxysporum f.sp., labeling of pathogen cells also occurred; in a resistant cultivar (cv.), it was coincident with proximate pectin fibrils and linked to altered fungal walls, which was the opposite in the susceptible cv., indicating that hindrance of pathogen ability to degrade pectin may be related to resistance. Labeling of the fungus in culture was nil, except in media containing pectin, showing that pectin is not native to the pathogen. Labeling of fungal walls for cellulose in elm (inoculated with Ophiostoma novo-ulmi) and carnation also occurred, linked to adsorbed host wall components. The chitin probe often attached to dispersed matter, in vessel lumina, traceable to irregularly labeled fungal cells and host wall degradation products. With an anti-horseradish peroxidase probe, host and fungal walls were equally labeled, and with a glucosidase, differences of labeling between these walls were observed, depending on pH of the test solution. Fungal extracellular matter and filamentous structures, present in fungal walls, predominantly in another elm isolate (Phaeotheca dimorphospora), did not label with any of the probes used. However, in cultures of this fungus, extracellular material labeled, even at a distance from the colony margin, with an anti-fimbriae probe.

  13. Occurrence of Root Rot and Vascular Wilt Diseases in Roselle (Hibiscus sabdariffa L.) in Upper Egypt

    PubMed Central

    Hassan, Naglaa; Shimizu, Masafumi

    2014-01-01

    Roselle (Hibiscus sabdariffa L.) family Malvaceae is an important crop used in food, cosmetics and pharmaceutics industries. Roselle is cultivated mainly in Upper Egypt (Qena and Aswan governorates) producing 94% of total production. Root rot disease of roselle is one of the most important diseases that attack both seedlings and adult plants causing serious losses in crop productivity and quality. The main objective of the present study is to identify and characterize pathogens associated with root rot and wilt symptoms of roselle in Qena, Upper Egypt and evaluate their pathogenicity under greenhouse and field condition. Fusarium oxysporum, Macrophomina phaseolina, Fusarium solani, Fusarium equiseti and Fusarium semitectum were isolated from the natural root rot diseases in roselle. All isolated fungi were morphologically characterized and varied in their pathogenic potentialities. They could attack roselle plants causing damping-off and root rot/wilt diseases in different pathogenicity tests. The highest pathogenicity was caused by F. oxysporum and M. phaseolina followed by F. solani. The least pathogenic fungi were F. equiseti followed by F. semitectum. It obviously noted that Baladi roselle cultivar was more susceptible to infection with all tested fungi than Sobhia 17 under greenhouse and field conditions. This is the first report of fungal pathogens causing root rot and vascular wilt in roselle in Upper Egypt. PMID:24808737

  14. Occurrence of Root Rot and Vascular Wilt Diseases in Roselle (Hibiscus sabdariffa L.) in Upper Egypt.

    PubMed

    Hassan, Naglaa; Shimizu, Masafumi; Hyakumachi, Mitsuro

    2014-03-01

    Roselle (Hibiscus sabdariffa L.) family Malvaceae is an important crop used in food, cosmetics and pharmaceutics industries. Roselle is cultivated mainly in Upper Egypt (Qena and Aswan governorates) producing 94% of total production. Root rot disease of roselle is one of the most important diseases that attack both seedlings and adult plants causing serious losses in crop productivity and quality. The main objective of the present study is to identify and characterize pathogens associated with root rot and wilt symptoms of roselle in Qena, Upper Egypt and evaluate their pathogenicity under greenhouse and field condition. Fusarium oxysporum, Macrophomina phaseolina, Fusarium solani, Fusarium equiseti and Fusarium semitectum were isolated from the natural root rot diseases in roselle. All isolated fungi were morphologically characterized and varied in their pathogenic potentialities. They could attack roselle plants causing damping-off and root rot/wilt diseases in different pathogenicity tests. The highest pathogenicity was caused by F. oxysporum and M. phaseolina followed by F. solani. The least pathogenic fungi were F. equiseti followed by F. semitectum. It obviously noted that Baladi roselle cultivar was more susceptible to infection with all tested fungi than Sobhia 17 under greenhouse and field conditions. This is the first report of fungal pathogens causing root rot and vascular wilt in roselle in Upper Egypt. PMID:24808737

  15. Fusarium azukicola sp. nov., an exotic azuki bean root-rot pathogen in Hokkaido, Japan

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We report on the phenotypic, molecular phylogenetic and pathogenic characterization of a novel azuki bean (Vigna angularis) root-rot (BRR) pathogen from Hokkaido, Japan, which is formally described herein as Fusarium azukicola. This species can be distinguished phenotypically from the other Phaseolu...

  16. Complete mitochondrial genome of the Verticillium-wilt causing plant pathogen Verticillium nonalfalfae.

    PubMed

    Jelen, Vid; de Jonge, Ronnie; Van de Peer, Yves; Javornik, Branka; Jakše, Jernej

    2016-01-01

    Verticillium nonalfalfae is a fungal plant pathogen that causes wilt disease by colonizing the vascular tissues of host plants. The disease induced by hop isolates of V. nonalfalfae manifests in two different forms, ranging from mild symptoms to complete plant dieback, caused by mild and lethal pathotypes, respectively. Pathogenicity variations between the causal strains have been attributed to differences in genomic sequences and perhaps also to differences in their mitochondrial genomes. We used data from our recent Illumina NGS-based project of genome sequencing V. nonalfalfae to study the mitochondrial genomes of its different strains. The aim of the research was to prepare a V. nonalfalfae reference mitochondrial genome and to determine its phylogenetic placement in the fungal kingdom. The resulting 26,139 bp circular DNA molecule contains a full complement of the 14 "standard" fungal mitochondrial protein-coding genes of the electron transport chain and ATP synthase subunits, together with a small rRNA subunit, a large rRNA subunit, which contains ribosomal protein S3 encoded within a type IA-intron and 26 tRNAs. Phylogenetic analysis of this mitochondrial genome placed it in the Verticillium spp. lineage in the Glomerellales group, which is also supported by previous phylogenetic studies based on nuclear markers. The clustering with the closely related Verticillium dahliae mitochondrial genome showed a very conserved synteny and a high sequence similarity. Two distinguishing mitochondrial genome features were also found-a potential long non-coding RNA (orf414) contained only in the Verticillium spp. of the fungal kingdom, and a specific fragment length polymorphism observed only in V. dahliae and V. nubilum of all the Verticillium spp., thus showing potential as a species specific biomarker. PMID:26839950

  17. Complete mitochondrial genome of the Verticillium-wilt causing plant pathogen Verticillium nonalfalfae

    PubMed Central

    Jelen, Vid; de Jonge, Ronnie; Van de Peer, Yves; Javornik, Branka; Jakše, Jernej

    2016-01-01

    Verticillium nonalfalfae is a fungal plant pathogen that causes wilt disease by colonizing the vascular tissues of host plants. The disease induced by hop isolates of V. nonalfalfae manifests in two different forms, ranging from mild symptoms to complete plant dieback, caused by mild and lethal pathotypes, respectively. Pathogenicity variations between the causal strains have been attributed to differences in genomic sequences and perhaps also to differences in their mitochondrial genomes. We used data from our recent Illumina NGS-based project of genome sequencing V. nonalfalfae to study the mitochondrial genomes of its different strains. The aim of the research was to prepare a V. nonalfalfae reference mitochondrial genome and to determine its phylogenetic placement in the fungal kingdom. The resulting 26,139 bp circular DNA molecule contains a full complement of the 14 "standard" fungal mitochondrial protein-coding genes of the electron transport chain and ATP synthase subunits, together with a small rRNA subunit, a large rRNA subunit, which contains ribosomal protein S3 encoded within a type IA-intron and 26 tRNAs. Phylogenetic analysis of this mitochondrial genome placed it in the Verticillium spp. lineage in the Glomerellales group, which is also supported by previous phylogenetic studies based on nuclear markers. The clustering with the closely related Verticillium dahliae mitochondrial genome showed a very conserved synteny and a high sequence similarity. Two distinguishing mitochondrial genome features were also found—a potential long non-coding RNA (orf414) contained only in the Verticillium spp. of the fungal kingdom, and a specific fragment length polymorphism observed only in V. dahliae and V. nubilum of all the Verticillium spp., thus showing potential as a species specific biomarker. PMID:26839950

  18. Potential impact of a new highly virulent race of Fusarium oxysporum f. sp. niveum in watermelon in the U.S.A.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fusarium wilt of watermelon was first reported in the United States in 1894. Although there exists variation in virulence within the pathogen population, Fusarium oxysporum f. sp. niveum, differentiation of isolates into races did not occur for 70 years. Currently, three races (0, 1, and 2) of F. ...

  19. Saprophytic and Potentially Pathogenic Fusarium Species from Peat Soil in Perak and Pahang.

    PubMed

    Karim, Nurul Farah Abdul; Mohd, Masratulhawa; Nor, Nik Mohd Izham Mohd; Zakaria, Latiffah

    2016-02-01

    Isolates of Fusarium were discovered in peat soil samples collected from peat swamp forest, waterlogged peat soil, and peat soil from oil palm plantations. Morphological characteristics were used to tentatively identify the isolates, and species confirmation was based on the sequence of translation elongation factor-1α (TEF-1α) and phylogenetic analysis. Based on the closest match of Basic Local Alignment Search Tool (BLAST) searches against the GenBank and Fusarium-ID databases, five Fusarium species were identified, namely F. oxysporum (60%), F. solani (23%), F. proliferatum (14%), F. semitectum (1%), and F. verticillioides (1%). From a neighbour-joining tree of combined TEF-1α and β-tubulin sequences, isolates from the same species were clustered in the same clade, though intraspecies variations were observed from the phylogenetic analysis. The Fusarium species isolated in the present study are soil inhabitants and are widely distributed worldwide. These species can act as saprophytes and decomposers as well as plant pathogens. The presence of Fusarium species in peat soils suggested that peat soils could be a reservoir of plant pathogens, as well-known plant pathogenic species such F. oxysporum, F. solani, F. proliferatum, and F. verticillioides were identified. The results of the present study provide knowledge on the survival and distribution of Fusarium species. PMID:27019679

  20. Saprophytic and Potentially Pathogenic Fusarium Species from Peat Soil in Perak and Pahang

    PubMed Central

    Karim, Nurul Farah Abdul; Mohd, Masratulhawa; Nor, Nik Mohd Izham Mohd; Zakaria, Latiffah

    2016-01-01

    Isolates of Fusarium were discovered in peat soil samples collected from peat swamp forest, waterlogged peat soil, and peat soil from oil palm plantations. Morphological characteristics were used to tentatively identify the isolates, and species confirmation was based on the sequence of translation elongation factor-1α (TEF-1α) and phylogenetic analysis. Based on the closest match of Basic Local Alignment Search Tool (BLAST) searches against the GenBank and Fusarium-ID databases, five Fusarium species were identified, namely F. oxysporum (60%), F. solani (23%), F. proliferatum (14%), F. semitectum (1%), and F. verticillioides (1%). From a neighbour-joining tree of combined TEF-1α and β-tubulin sequences, isolates from the same species were clustered in the same clade, though intraspecies variations were observed from the phylogenetic analysis. The Fusarium species isolated in the present study are soil inhabitants and are widely distributed worldwide. These species can act as saprophytes and decomposers as well as plant pathogens. The presence of Fusarium species in peat soils suggested that peat soils could be a reservoir of plant pathogens, as well-known plant pathogenic species such F. oxysporum, F. solani, F. proliferatum, and F. verticillioides were identified. The results of the present study provide knowledge on the survival and distribution of Fusarium species. PMID:27019679

  1. HapX-mediated iron homeostasis is essential for rhizosphere competence and virulence of the soilborne pathogen Fusarium oxysporum.

    PubMed

    Lpez-Berges, Manuel S; Capilla, Javier; Turr, David; Schafferer, Lukas; Matthijs, Sandra; Jchl, Christoph; Cornelis, Pierre; Guarro, Josep; Haas, Hubertus; Di Pietro, Antonio

    2012-09-01

    Soilborne fungal pathogens cause devastating yield losses and are highly persistent and difficult to control. During the infection process, these organisms must cope with limited availability of iron. Here we show that the bZIP protein HapX functions as a key regulator of iron homeostasis and virulence in the vascular wilt fungus Fusarium oxysporum. Deletion of hapX does not affect iron uptake but causes derepression of genes involved in iron-consuming pathways, leading to impaired growth under iron-depleted conditions. F. oxysporum strains lacking HapX are reduced in their capacity to invade and kill tomato (Solanum lycopersicum) plants and immunodepressed mice. The virulence defect of ?hapX on tomato plants is exacerbated by coinoculation of roots with a biocontrol strain of Pseudomonas putida, but not with a siderophore-deficient mutant, indicating that HapX contributes to iron competition of F. oxysporum in the tomato rhizosphere. These results establish a conserved role for HapX-mediated iron homeostasis in fungal infection of plants and mammals. PMID:22968717

  2. Functional genomic studies of pathogenicity in Fusarium graminearum

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Head blight or scab caused by Fusarium graminearum is a disease of wheat and barley that occurs worldwide and that has great impact on U.S. agriculture and society. Infested cereals are often contaminated with trichothecene and estrogenic mycotoxins. To better understand fungal pathogenesis and deve...

  3. Experimental pathogenicity of four opportunist Fusarium species in a murine model.

    PubMed

    Mayayo, E; Pujol, I; Guarro, J

    1999-04-01

    A murine model with immunocompetent animals was used in a comparative study of experimental pathogenicity of 13 isolates belonging to the four most frequent pathogenic species of Fusarium in man (F. solani, F. oxysporum, F. verticillioides and F. proliferatum). Inocula of 5 x 10(6) conidia/mouse of each isolate of Fusarium were injected into a lateral vein of the tail of the mice to produce a systemic infection. F. solani was the most virulent species; the five strains of this species assayed caused the death of all the animals tested in <19 days. The other species of Fusarium were not virulent in this model. The organs mainly affected by F. solani were the kidneys and the heart. These findings correlate with the clinical evidence and demonstrate that there is a high risk associated with infection by F. solani, especially for immunocompromised patients. PMID:10509478

  4. Phylogenetic analysis based on the PKS gene involved in fusaric acid biosynthesis production reveals close relationship between US race 1 lineage isolates & Australian biotype isolates of Fusarium Oxysporum f. sp. Vasinfectum

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Isolates of Fusarium oxysporum f. sp. vasinfectum, the causal agent of fusarium wilt of cotton, vary significantly in their virulence. Isolates have been further subcategorized into pathogenic races based on their differential interaction with host genotypes. Phylogenetic analysis based on three n...

  5. The Fusarium graminearum genome reveals a link between localized polymorphism and pathogen specialization

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The filamentous fungus Fusarium graminearum is a major destructive pathogen of cultivated cereals. We have sequenced and annotated the F. graminearum genome, and found it includes very few repetitive sequences. We experimentally demonstrate that repeats are mutated by the process of repeat-induced p...

  6. Fusarium verticillioides chitin synthases CHS5 and CHS7 are required for normal growth and pathogenicity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fusarium verticillioides is both an endophyte and a pathogen of maize and is a health threat in many areas of the world because it can contaminate maize with fumonisins, a toxic secondary metabolite. We identified eight putative chitin synthase (CHS) genes in F. verticillioides genomic sequence and...

  7. First Report of Sexual Reproduction by the Soybean Sudden Death Syndrome Pathogen Fusarium tucumaniae in Nature

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Of the four fusaria that have been shown to cause soybean sudden death syndrome (SDS), field surveys indicate that Fusarium tucumaniae is the most important and genetically diverse SDS pathogen in Argentina. Although none of the SDS fusaria have been shown to produce perithecia in nature, a heteroth...

  8. BIOLOGICAL, PATHOGENIC, AND MOLECULAR CHARACTERIZATION OF FUSARIUM SOLANI F. SP. GLYCINES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soybean sudden death syndrome (SDS) is caused by Fusarium solani f. sp. glycines (FSG). Over the last 5 years an internationsl collection of FSG isolates has been established and maintained at the National Soybean Pathogen Collection Center. FSG isolates grew slowly and appeared reddish light blue t...

  9. Sexual reproduction in the soybean sudden death syndrome pathogen Fusarium tucumaniae

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The symptoms of soybean sudden death syndrome (SDS) include leaf chlorosis and necrosis, root rot, defoliation and death. Four members of the Fusarium solani species complex are known to cause these symptoms on soybean. Thus far, three of these pathogens have only been found in South America (i.e....

  10. A fungal symbiont of plant-roots modulates mycotoxin gene expression in the pathogen Fusarium sambucinum

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fusarium trichothecenes are fungal toxins that cause disease on infected plants and, more importantly, health problems for humans and animals that consume infected fruits or vegetables. Unfortunately, there are few methods for controlling the growth of mycotoxin production pathogens. In this study, ...

  11. Nitric oxide detoxification by Fusarium verticillioides flavohemoglobin and role in pathogenicity of maize

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fusarium verticillioides is a non-obligate plant pathogen of maize causing a number of specific diseases, including root rot, kernel rot, seed rot, stalk rot, and seedling blight. The saprophytic nature of this fungus, its production of the mycotoxin fumonisin, and complex relationship maize puts t...

  12. The Fusarium graminearum species complex comprises at least 16 phylogenetically distinct head blight pathogens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fusarium head blight (FHB) or scab of cereals is one of the most economically devastating plant diseases in the world today. FHB outbreaks and epidemics of wheat and barley cause significant reduction in yields; these pathogens also frequently contaminate grain with deoxynivalenol or nivalenol trich...

  13. Activation of salicylic acid metabolism and signal transduction can enhance resistance to Fusarium wilt in banana (Musa acuminata L. AAA group, cv. Cavendish).

    PubMed

    Wang, Zhuo; Jia, Caihong; Li, Jingyang; Huang, Suzhen; Xu, Biyu; Jin, Zhiqiang

    2015-01-01

    Fusarium wilt caused by the fungus Fusarium oxysporum f. sp. cubens (Foc) is the most serious disease that attacks banana plants. Salicylic acid (SA) can play a key role in plant-microbe interactions. Our study is the first to examine the role of SA in conferring resistance to Foc TR4 in banana (Musa acuminata L. AAA group, cv. Cavendish), which is the greatest commercial importance cultivar in Musa. We used quantitative real-time reverse polymerase chain reaction (qRT-PCR) to analyze the expression profiles of 45 genes related to SA biosynthesis and downstream signaling pathways in a susceptible banana cultivar (cv. Cavendish) and a resistant banana cultivar (cv. Nongke No. 1) inoculated with Foc TR4. The expression of genes involved in SA biosynthesis and downstream signaling pathways was suppressed in a susceptible cultivar and activated in a resistant cultivar. The SA levels in each treatment arm were measured using high-performance liquid chromatography. SA levels were decreased in the susceptible cultivar and increased in the resistant cultivar. Finally, we examined the contribution of exogenous SA to Foc TR4 resistance in susceptible banana plants. The expression of genes involved in SA biosynthesis and signal transduction pathways as well as SA levels were significantly increased. The results suggest that one reason for banana susceptibility to Foc TR4 is that expression of genes involved in SA biosynthesis and SA levels are suppressed and that the induced resistance observed in banana against Foc TR4 might be a case of salicylic acid-dependent systemic acquired resistance. PMID:25277445

  14. Interaction of Fusarium oxysporum f. sp. ciceri and Meloidogyne javanica on Cicer arietinum

    PubMed Central

    Maheswari, T. Uma; Sharma, S. B.; Reddy, D. D. R.; Haware, M. P.

    1997-01-01

    Interaction of Meloidogyne javanica and Fusarium oxysporum f. sp. ciceri was studied on Fusarium wilt-susceptible (JG 62 and K 850) and resistant (JG 74 and Avrodhi) chickpea cultivars. In greenhouse experiments, inoculation of M. javanica juveniles prior to F. oxysporum f. sp. ciceri caused greater wilt incidence in susceptible cultivars and induced vascular discoloration in roots of resistant cultivars. Nematode reproduction was greatest (P = 0.05) at 25 °C. Number of galls and percentage of root area galled increased when the temperature was increased from 15 °C to 25 °C. Wilt incidence was greater at 20 °C than at 25 °C. Chlorosis of leaves and vascular discoloration of plants did not occur at 15 °C. The nematode enhanced the wilt incidence in wilt-susceptible cultivars only at 25 °C. Interaction between the two pathogens on shoot and root weights was significant only at 20 °C, and F. o. ciceri suppressed the nematode density at this temperature. Wilt incidence was greater in clayey (48% clay) than in loamy sand (85% sand) soils. The nematode caused greater plant damage on loamy sand than on clayey soil. Fusarium wilt resistance in Avrodhi and JG 74 was stable in the presence of M. javanica across temperatures and soil types. PMID:19274140

  15. Characterization of a population of Fusarium oxysporum, from sugar beet, using the population structure of putative pathogenicity genes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    WEBB, KIMBERLY M.*, PAUL COVEY, BRETT KUWITZKY, AND MIA HANSON, USDA-ARS, Sugar Beet Research Unit, 1701 Centre Ave., Fort Collins, CO 80526. Characterization of a population of Fusarium oxysporum, from sugar beet, using the population structure of putative pathogenicity genes. Fusarium oxysp...

  16. GENOMIC ANALYSIS OF HOST-PATHOGEN INTERACTION BETWEEN FUSARIUM GRAMINEARUM AND WHEAT DURING EARLY STAGES OF DISEASE DEVELOPMENT

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fusarium graminearum strains responsible for causing the plant disease Fusarium head blight vary greatly in their ability to cause disease and produce mycotoxins on wheat. With the goal of understanding fungal gene expression related to pathogenicity, three cDNA libraries were created by suppression...

  17. Fungal microbiota from rain water and pathogenicity of Fusarium species isolated from atmospheric dust and rainfall dust.

    PubMed

    Palmero, D; Rodríguez, J M; de Cara, M; Camacho, F; Iglesias, C; Tello, J C

    2011-01-01

    In order to determine the presence of Fusarium spp. in atmospheric dust and rainfall dust, samples were collected during September 2007, and July, August, and October 2008. The results reveal the prevalence of airborne Fusarium species coming from the atmosphere of the South East coast of Spain. Five different Fusarium species were isolated from the settling dust: Fusarium oxysporum, F. solani, F. equiseti, F. dimerum, and F. proliferatum. Moreover, rainwater samples were obtained during significant rainfall events in January and February 2009. Using the dilution-plate method, 12 fungal genera were identified from these rainwater samples. Specific analyses of the rainwater revealed the presence of three species of Fusarium: F. oxysporum, F. proliferatum and F. equiseti. A total of 57 isolates of Fusarium spp. obtained from both rainwater and atmospheric rainfall dust sampling were inoculated onto melon (Cucumis melo L.) cv. Piñonet and tomato (Lycopersicon esculentum Mill.) cv. San Pedro. These species were chosen because they are the main herbaceous crops in Almeria province. The results presented in this work indicate strongly that spores or propagules of Fusarium are able to cross the continental barrier carried by winds from the Sahara (Africa) to crop or coastal lands in Europe. Results show differences in the pathogenicity of the isolates tested. Both hosts showed root rot when inoculated with different species of Fusarium, although fresh weight measurements did not bring any information about the pathogenicity. The findings presented above are strong indications that long-distance transmission of Fusarium propagules may occur. Diseases caused by species of Fusarium are common in these areas. They were in the past, and are still today, a problem for greenhouses crops in Almería, and many species have been listed as pathogens on agricultural crops in this region. Saharan air masses dominate the Mediterranean regions. The evidence of long distance dispersal of Fusarium spp. by atmospheric dust and rainwater together with their proved pathogenicity must be taken into account in epidemiological studies. PMID:20820862

  18. Development of a Selective Medium for the Fungal Pathogen Fusarium graminearum Using Toxoflavin Produced by the Bacterial Pathogen Burkholderia glumae

    PubMed Central

    Jung, Boknam; Lee, Sehee; Ha, Jiran; Park, Jong-Chul; Han, Sung-Sook; Hwang, Ingyu; Lee, Yin-Won; Lee, Jungkwan

    2013-01-01

    The ascomycete fungus Fusarium graminearum is a major causal agent for Fusarium head blight in cereals and produces mycotoxins such as trichothecenes and zearalenone. Isolation of the fungal strains from air or cereals can be hampered by various other airborne fungal pathogens and saprophytic fungi. In this study, we developed a selective medium specific to F. graminearum using toxoflavin produced by the bacterial pathogen Burkholderia glumae. F. graminearum was resistant to toxoflavin, while other fungi were sensitive to this toxin. Supplementing toxoflavin into medium enhanced the isolation of F. graminearum from rice grains by suppressing the growth of saprophytic fungal species. In addition, a medium with or without toxoflavin exposed to wheat fields for 1 h had 84% or 25%, respectively, of colonies identified as F. graminearum. This selection medium provides an efficient tool for isolating F. graminearum, and can be adopted by research groups working on genetics and disease forecasting. PMID:25288974

  19. Development of a Selective Medium for the Fungal Pathogen Fusarium graminearum Using Toxoflavin Produced by the Bacterial Pathogen Burkholderia glumae.

    PubMed

    Jung, Boknam; Lee, Sehee; Ha, Jiran; Park, Jong-Chul; Han, Sung-Sook; Hwang, Ingyu; Lee, Yin-Won; Lee, Jungkwan

    2013-12-01

    The ascomycete fungus Fusarium graminearum is a major causal agent for Fusarium head blight in cereals and produces mycotoxins such as trichothecenes and zearalenone. Isolation of the fungal strains from air or cereals can be hampered by various other airborne fungal pathogens and saprophytic fungi. In this study, we developed a selective medium specific to F. graminearum using toxoflavin produced by the bacterial pathogen Burkholderia glumae. F. graminearum was resistant to toxoflavin, while other fungi were sensitive to this toxin. Supplementing toxoflavin into medium enhanced the isolation of F. graminearum from rice grains by suppressing the growth of saprophytic fungal species. In addition, a medium with or without toxoflavin exposed to wheat fields for 1 h had 84% or 25%, respectively, of colonies identified as F. graminearum. This selection medium provides an efficient tool for isolating F. graminearum, and can be adopted by research groups working on genetics and disease forecasting. PMID:25288974

  20. Evaluation of two novel barcodes for species recognition of opportunistic pathogens in Fusarium.

    PubMed

    Al-Hatmi, Abdullah M S; Van Den Ende, A H G Gerrits; Stielow, J Benjamin; Van Diepeningen, Anne D; Seifert, Keith A; McCormick, Wayne; Assabgui, Rafik; Gräfenhan, Tom; De Hoog, G Sybren; Levesque, C André

    2016-02-01

    The genus Fusarium includes more than 200 species of which 73 have been isolated from human infections. Fusarium species are opportunistic human pathogens with variable aetiology. Species determination is best made with the combined phylogeny of protein-coding genes such as elongation factor (TEF1), RNA polymerase (RPB2) and the partial β-tubulin (BT2) gene. The internal transcribed spacers 1, 2 and 5.8S rRNA gene (ITS) have also been used, however, ITS cannot discriminate several closely related species and has nonorthologous copies in Fusarium. Currently, morphological approaches and tree-building methods are in use to define species and to discover hitherto undescribed species. Aftter a species is defined, DNA barcoding approaches can be used to identify species by the presence or absence of discrete nucleotide characters. We demonstrate the potential of two recently discovered DNA barcode loci, topoisomerase I (TOP1) and phosphoglycerate kinase (PGK), in combination with other routinely used markers such as TEF1, in an analysis of 144 Fusarium strains belonging to 52 species. Our barcoding study using TOP1 and PKG provided concordance of molecular data with TEF1. The currently accepted Fusarium species sampled were well supported in phylogenetic trees of both new markers. PMID:26781379

  1. A proteomic study of in-root interactions between chickpea pathogens: the root-knot nematode Meloidogyne artiellia and the soil-borne fungus Fusarium oxysporum f. sp. ciceris race 5.

    PubMed

    Palomares-Rius, Juan E; Castillo, Pablo; Navas-Cortés, Juan A; Jiménez-Díaz, Rafael M; Tena, Manuel

    2011-09-01

    Fusarium wilt caused by the fungus Fusarium oxysporum f. sp. ciceris (Foc) is the main soil-borne disease limiting chickpea production. Management of this disease is achieved mainly by the use of resistant cultivars. However, co-infection of a Foc-resistant plant by the fungus and the root-knot nematode Meloidogyne artiellia (Ma) causes breakdown of the resistance and thus limits its efficacy in the control of Fusarium wilt. In this work we aimed to reveal key aspects of chickpea:Foc:Ma interactions, studying fungal- and nematode-induced changes in root proteins, using chickpea lines 'CA 336.14.3.0' and 'ICC 14216K' that show similar resistant (Foc race 5) and susceptible (Ma) responses to either pathogen alone but a differential response after co-infection with both pathogens. 'CA 336.14.3.0' and 'ICC 14216K' chickpea plants were challenged with Foc race 5 and Ma, either in single or in combined inoculations, and the root proteomes were analyzed by two-dimensional gel electrophoresis using three biological replicates. Pairwise comparisons of treatments indicated that 47 protein spots in 'CA 336.14.3.0' and 31 protein spots in 'ICC 14216K' underwent significant changes in intensity. The responsive protein spots tentatively identified by MALDI TOF-TOF MS (27 spots for 'CA 336.14.3.0' and 15 spots for 'ICC 14216K') indicated that same biological functions were involved in the responses of either chickpea line to Foc race 5 and Ma, although common as well as line-specific responsive proteins were found within the different biological functions. To the best of our knowledge, this is the first study at the root proteome level of chickpea response to a biotic stress imposed by single and joint infections by two major soil-borne pathogens. PMID:21640211

  2. Identification of pathogenicity-related genes in the vascular wilt fungus verticillium dahliae by agrobacterium tumefaciens-mediated t-DNA insertional mutagenesis.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Verticillium dahliae is the causal agent of vascular wilt in many economically important crops worldwide. Identification of genes that underpin pathogenicity or virulence may suggest targets for alternative control methods for this fungus. In this study, Agrobacterium tumefaciens-mediated transform...

  3. Interaction between Meloidogyne incognita and Fusarium oxysporum f. sp. phaseoli on Selected Bean Genotypes

    PubMed Central

    France, R. A.; S.Abawi, G.

    1994-01-01

    Four bean genotypes (IPA-1, A-107, A-211, and Calima), representing all possible combinations of resistance and susceptibility to Fusarium oxysporum f. sp. phaseoli (Fop) and Meloidogyne incognita, were each inoculated with three population densities of these pathogens. Calima and A-107 were resistant to Fop; A-107 and A-211 were resistant to M. incognita; and IPA-1 was susceptible to both pathogens. In Fop-susceptible lines (IPA-1 and A-211), the presence of M. incognita contributed to an earlier onset and increased severity of Fusarium wilt symptoms and plant stunting. However, the Fop-resistant Calima developed symptoms of Fusarium wilt only in the presence of M. incognita. Genotype A-107 (resistant to both M. incognita and Fop) exhibited Fusarium wilt symptoms and a moderately susceptible reaction to Fop only after the breakdown of its M. incognita resistance by elevated incubation temperatures (27 C). Root galling and reproduction of M. incognita was generally increased as inoculum density of M. incognita was increased on the M. incognita susceptible cultivars. However, these factors were decreased as the inoculum density of Fop was increased. It was concluded that severe infections of bean roots by M. incognita increase the severity of Fusarium wilt on Fop-susceptible genotypes and may modify the resistant reaction to Fop. PMID:19279917

  4. The Wor1-like protein Fgp1 regulates pathogenicity, toxin synthesis and reproduction in the phytopathogenic fungus Fusarium graminearum

    Technology Transfer Automated Retrieval System (TEKTRAN)

    WOR1 is a gene for a conserved fungal regulatory protein controlling the dimorphic switch and pathogenicity in Candida albicans and its ortholog in the plant pathogen Fusarium oxysporum, called SGE1, is also required for pathogenicity and expression of plant effector proteins. F. graminearum, an imp...

  5. PAM: Particle automata model in simulation of Fusarium graminearum pathogen expansion.

    PubMed

    Wcisło, Rafał; Miller, S Shea; Dzwinel, Witold

    2016-01-21

    The multi-scale nature and inherent complexity of biological systems are a great challenge for computer modeling and classical modeling paradigms. We present a novel particle automata modeling metaphor in the context of developing a 3D model of Fusarium graminearum infection in wheat. The system consisting of the host plant and Fusarium pathogen cells can be represented by an ensemble of discrete particles defined by a set of attributes. The cells-particles can interact with each other mimicking mechanical resistance of the cell walls and cell coalescence. The particles can move, while some of their attributes can be changed according to prescribed rules. The rules can represent cellular scales of a complex system, while the integrated particle automata model (PAM) simulates its overall multi-scale behavior. We show that due to the ability of mimicking mechanical interactions of Fusarium tip cells with the host tissue, the model is able to simulate realistic penetration properties of the colonization process reproducing both vertical and lateral Fusarium invasion scenarios. The comparison of simulation results with micrographs from laboratory experiments shows encouraging qualitative agreement between the two. PMID:26549468

  6. The Genome Sequence of the Fungal Pathogen Fusarium virguliforme That Causes Sudden Death Syndrome in Soybean

    PubMed Central

    Srivastava, Subodh K.; Huang, Xiaoqiu; Brar, Hargeet K.; Fakhoury, Ahmad M.; Bluhm, Burton H.; Bhattacharyya, Madan K.

    2014-01-01

    Fusarium virguliforme causes sudden death syndrome (SDS) of soybean, a disease of serious concern throughout most of the soybean producing regions of the world. Despite the global importance, little is known about the pathogenesis mechanisms of F. virguliforme. Thus, we applied Next-Generation DNA Sequencing to reveal the draft F. virguliforme genome sequence and identified putative pathogenicity genes to facilitate discovering the mechanisms used by the pathogen to cause this disease. Methodology/Principal Findings We have generated the draft genome sequence of F. virguliforme by conducting whole-genome shotgun sequencing on a 454 GS-FLX Titanium sequencer. Initially, single-end reads of a 400-bp shotgun library were assembled using the PCAP program. Paired end sequences from 3 and 20 Kb DNA fragments and approximately 100 Kb inserts of 1,400 BAC clones were used to generate the assembled genome. The assembled genome sequence was 51 Mb. The N50 scaffold number was 11 with an N50 Scaffold length of 1,263 Kb. The AUGUSTUS gene prediction program predicted 14,845 putative genes, which were annotated with Pfam and GO databases. Gene distributions were uniform in all but one of the major scaffolds. Phylogenic analyses revealed that F. virguliforme was closely related to the pea pathogen, Nectria haematococca. Of the 14,845 F. virguliforme genes, 11,043 were conserved among five Fusarium species: F. virguliforme, F. graminearum, F. verticillioides, F. oxysporum and N. haematococca; and 1,332 F. virguliforme-specific genes, which may include pathogenicity genes. Additionally, searches for candidate F. virguliforme pathogenicity genes using gene sequences of the pathogen-host interaction database identified 358 genes. Conclusions The F. virguliforme genome sequence and putative pathogenicity genes presented here will facilitate identification of pathogenicity mechanisms involved in SDS development. Together, these resources will expedite our efforts towards discovering pathogenicity mechanisms in F. virguliforme. This will ultimately lead to improvement of SDS resistance in soybean. PMID:24454689

  7. Analysis of Pineapple Mealybug Wilt Associated Virus -1 and -2 for Potential RNA Silencing Suppressors and Pathogenicity Factors

    PubMed Central

    Dey, Kishore K.; Borth, Wayne B.; Melzer, Michael J.; Wang, Ming-Li; Hu, John S.

    2015-01-01

    Higher plants use RNA silencing to defend against viral infections. As a counter defense, plant viruses have evolved proteins that suppress RNA silencing. Mealybug wilt of pineapple (MWP), an important disease of pineapple, has been associated with at least three distinct viruses, Pineapple mealybug wilt associated virus -1, -2, and -3 (PMWaV-1, -2, and -3). Selected open reading frames (ORFs) of PMWaV-1 and PMWaV-2 were screened for their local and systemic suppressor activities in Agrobacterium-mediated transient assays using green fluorescent protein (GFP) in Nicotiana benthamiana. Results indicate that PMWaV-2 utilizes a multiple-component RNA silencing suppression mechanism. Two proteins, p20 and CP, target both local and systemic silencing in N. benthamiana, while the p22 and CPd proteins target only systemic silencing. In the related virus PMWaV-1, we found that only one of the encoded proteins, p61, had only systemic suppressor activity. Of all the proteins tested from both viruses, only the PMWaV-2 p20 protein suppressed local silencing induced by double-stranded RNA (dsRNA), but only when low levels of inducing dsRNA were used. None of the proteins analyzed could interfere with the short distance spread of silencing. We examined the mechanism of systemic suppression activity by investigating the effect of PMWaV-2-encoded p20 and CP proteins on secondary siRNAs. Our results suggest that the PMWaV-2 p20 and CP proteins block the systemic silencing signal by repressing production of secondary siRNAs. We also demonstrate that the PMWaV-2 p20 and p22 proteins enhanced the pathogenicity of Potato virus X in N. benthamiana. PMID:25751306

  8. Analysis of pineapple mealybug wilt associated virus -1 and -2 for potential RNA silencing suppressors and pathogenicity factors.

    PubMed

    Dey, Kishore K; Borth, Wayne B; Melzer, Michael J; Wang, Ming-Li; Hu, John S

    2015-03-01

    Higher plants use RNA silencing to defend against viral infections. As a counter defense, plant viruses have evolved proteins that suppress RNA silencing. Mealybug wilt of pineapple (MWP), an important disease of pineapple, has been associated with at least three distinct viruses, Pineapple mealybug wilt associated virus -1, -2, and -3 (PMWaV-1, -2, and -3). Selected open reading frames (ORFs) of PMWaV-1 and PMWaV-2 were screened for their local and systemic suppressor activities in Agrobacterium-mediated transient assays using green fluorescent protein (GFP) in Nicotiana benthamiana. Results indicate that PMWaV-2 utilizes a multiple-component RNA silencing suppression mechanism. Two proteins, p20 and CP, target both local and systemic silencing in N. benthamiana, while the p22 and CPd proteins target only systemic silencing. In the related virus PMWaV-1, we found that only one of the encoded proteins, p61, had only systemic suppressor activity. Of all the proteins tested from both viruses, only the PMWaV-2 p20 protein suppressed local silencing induced by double-stranded RNA (dsRNA), but only when low levels of inducing dsRNA were used. None of the proteins analyzed could interfere with the short distance spread of silencing. We examined the mechanism of systemic suppression activity by investigating the effect of PMWaV-2-encoded p20 and CP proteins on secondary siRNAs. Our results suggest that the PMWaV-2 p20 and CP proteins block the systemic silencing signal by repressing production of secondary siRNAs. We also demonstrate that the PMWaV-2 p20 and p22 proteins enhanced the pathogenicity of Potato virus X in N. benthamiana. PMID:25751306

  9. Structure-Activity Relationships of Antimicrobial Gallic Acid Derivatives from Pomegranate and Acacia Fruit Extracts against Potato Bacterial Wilt Pathogen.

    PubMed

    Farag, Mohamed A; Al-Mahdy, Dalia A; Salah El Dine, Riham; Fahmy, Sherifa; Yassin, Aymen; Porzel, Andrea; Brandt, Wolfgang

    2015-06-01

    Bacterial wilts of potato, tomato, pepper, and or eggplant caused by Ralstonia solanacearum are among the most serious plant diseases worldwide. In this study, the issue of developing bactericidal agents from natural sources against R. solanacearum derived from plant extracts was addressed. Extracts prepared from 25 plant species with antiseptic relevance in Egyptian folk medicine were screened for their antimicrobial properties against the potato pathogen R. solancearum by using the disc-zone inhibition assay and microtitre plate dilution method. Plants exhibiting notable antimicrobial activities against the tested pathogen include extracts from Acacia arabica and Punica granatum. Bioactivity-guided fractionation of A. arabica and P. granatum resulted in the isolation of bioactive compounds 3,5-dihydroxy-4-methoxybenzoic acid and gallic acid, in addition to epicatechin. All isolates displayed significant antimicrobial activities against R. solanacearum (MIC values 0.5-9 mg/ml), with 3,5-dihydroxy-4-methoxybenzoic acid being the most effective one with a MIC value of 0.47 mg/ml. We further performed a structure-activity relationship (SAR) study for the inhibition of R. solanacearum growth by ten natural, structurally related benzoic acids. PMID:26080741

  10. Plant defense response against Fusarium oxysporum and strategies to develop tolerant genotypes in banana.

    PubMed

    Swarupa, V; Ravishankar, K V; Rekha, A

    2014-04-01

    Soil-borne fungal pathogen, Fusarium oxysporum causes major economic losses by inducing necrosis and wilting symptoms in many crop plants. Management of fusarium wilt is achieved mainly by the use of chemical fungicides which affect the soil health and their efficiency is often limited by pathogenic variability. Hence understanding the nature of interaction between pathogen and host may help to select and improve better cultivars. Current research evidences highlight the role of oxidative burst and antioxidant enzymes indicating that ROS act as an important signaling molecule in banana defense response against Fusarium oxysporum f.sp. cubense. The role of jasmonic acid signaling in plant defense against necrotrophic pathogens is well recognized. But recent studies show that the role of salicylic acid is complex and ambiguous against necrotrophic pathogens like Fusarium oxysporum, leading to many intriguing questions about its relationship between other signaling compounds. In case of banana, a major challenge is to identify specific receptors for effector proteins like SIX proteins and also the components of various signal transduction pathways. Significant progress has been made to uncover the role of defense genes but is limited to only model plants such as Arabidopsis and tomato. Keeping this in view, we review the host response, pathogen diversity, current understanding of biochemical and molecular changes that occur during host and pathogen interaction. Developing resistant cultivars through mutation, breeding, transgenic and cisgenic approaches have been discussed. This would help us to understand host defenses against Fusarium oxysporum and to formulate strategies to develop tolerant cultivars. PMID:24420701

  11. The transcription factor FgStuAp influences spore development, pathogenicity, and secondary metabolism in Fusarium graminearum

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fusarium graminearum is an important plant-pathogenic fungus and the major cause of cereal head blight. Here, we report the functional analysis of FgStuA, the gene for a transcription factor with homology to key developmental regulators in fungi. The deletion mutant was greatly reduced in pathogenic...

  12. Genetic diversity of the bacterial wilt pathogen Ralstonia solanacearum using a RAPD marker.

    PubMed

    Nishat, Sayeda; Hamim, Islam; Khalil, M Ibrahim; Ali, Md Ayub; Hossain, Muhammed Ali; Meah, M Bahadur; Islam, Md Rashidul

    2015-11-01

    Bacterial wilt caused by Ralstonia solanacearum is a destructive disease of many economically important crop species. A significant variation in wilt incidence and severity in eggplant and potato was observed among the growing areas surveyed. R. solanacearum isolates obtained both from eggplant and potato belong to biovar III, while isolates from eggplant belong to race 1 and isolates obtained from potato belong to race 3. Random amplified polymorphic DNA (RAPD) technique was used as a tool for assessing genetic variation and relationship among seven isolate groups of R. solanacearum viz., RsB-1, RsB-2, RsB-3, RsP-1, RsP-2, RsP-3 and RsP-4, consisting in a total of 28 isolates. Out of the RAPD markers used, amplification with four decamer primers produced 70 bands with sizes ranging from 100 to 1400 bp. Out of 70 bands, 68 bands (97.06%) were polymorphic and two bands (2.94%) were monomorphic amongst the seven R. solanacearum isolates group. The Unweighted Pair Group Method of Arithmetic Means (UPGMA) dendrogram constructed from Nei's genetic distance produced two main clusters of the seven isolates of R. solanacearum. The isolates RsB-1, RsB-2, RsB-3 and R-4 grouped in cluster І, while RsP-2, RsP-3 and RsP-4 grouped in cluster ІІ. The highest intra-variety similarity index (Si) was found in RsB-1 isolate (86.35%) and the lowest one in RsP-2 (56.59%). The results indicated that relatively higher and lower levels of genetic variation were found in RsP-3 and RsB-3, respectively. The coefficient of gene differentiation (G(st)) was 0.5487, reflecting the existence of a high level of genetic variations among seven isolates of R. solanacearum. Comparatively higher genetic distance (0.4293) and lower genetic identity (0.6510) were observed between RsB-2 and RsP-4 combinations. The lowest genetic distance (0.0357) and highest genetic identity (0.9650) were found in RsB-1 vs. RsB-2 pair. Thus, RAPD offers a potentially simple, rapid and reliable method to evaluate genetic diversity analysis in R. solanacearum. PMID:26302834

  13. Fusarium Pathogenomics

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fusarium is a genus of filamentous fungi that contains many agronomically important plant pathogens, mycotoxin producers, and opportunistic human pathogens. Comparative analyses have revealed compartmentalization of genomes into regions responsible for metabolism and reproduction (core genome) and p...

  14. Effect of clove oil on plant pathogenic bacteria and bacterial wilt of tomato and geranium

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We determined the antibacterial activity of clove oil against seven different genera of plant pathogenic bacteria including Gram-negative Agrobacterium tumefaciens, Erwinia carotovora pv. carotovora, Pseudomonas syringae pv. syringae, Ralstonia solanacearum, and Xanthomonas campestris pv. pelargonii...

  15. Species or Genotypes? Reassessment of Four Recently Described Species of the Ceratocystis Wilt Pathogen, Ceratocystis fimbriata, on Mangifera indica.

    PubMed

    Oliveira, Leonardo S S; Harrington, Thomas C; Ferreira, Maria A; Damacena, Michelle B; Al-Sadi, Abdullah M; Al-Mahmooli, Issa H S; Alfenas, Acelino C

    2015-09-01

    Ceratocystis wilt is among the most important diseases on mango (Mangifera indica) in Brazil, Oman, and Pakistan. The causal agent was originally identified in Brazil as Ceratocystis fimbriata, which is considered by some as a complex of many cryptic species, and four new species on mango trees were distinguished from C. fimbriata based on variation in internal transcribed spacer sequences. In the present study, phylogenetic analyses using DNA sequences of mating type genes, TEF-1α, and β-tubulin failed to identify lineages corresponding to the four new species names. Further, mating experiments found that the mango isolates representing the new species were interfertile with each other and a tester strain from sweet potato (Ipomoea batatas), on which the name C. fimbriata is based, and there was little morphological variation among the mango isolates. Microsatellite markers found substantial differentiation among mango isolates at the regional and population levels, but certain microsatellite genotypes were commonly found in multiple populations, suggesting that these genotypes had been disseminated in infected nursery stock. The most common microsatellite genotypes corresponded to the four recently named species (C. manginecans, C. acaciivora, C. mangicola, and C. mangivora), which are considered synonyms of C. fimbriata. This study points to the potential problems of naming new species based on introduced genotypes of a pathogen, the value of an understanding of natural variation within and among populations, and the importance of phenotype in delimiting species. PMID:25822187

  16. HapX-Mediated Iron Homeostasis Is Essential for Rhizosphere Competence and Virulence of the Soilborne Pathogen Fusarium oxysporum[C][W][OA

    PubMed Central

    López-Berges, Manuel S.; Capilla, Javier; Turrà, David; Schafferer, Lukas; Matthijs, Sandra; Jöchl, Christoph; Cornelis, Pierre; Guarro, Josep; Haas, Hubertus; Di Pietro, Antonio

    2012-01-01

    Soilborne fungal pathogens cause devastating yield losses and are highly persistent and difficult to control. During the infection process, these organisms must cope with limited availability of iron. Here we show that the bZIP protein HapX functions as a key regulator of iron homeostasis and virulence in the vascular wilt fungus Fusarium oxysporum. Deletion of hapX does not affect iron uptake but causes derepression of genes involved in iron-consuming pathways, leading to impaired growth under iron-depleted conditions. F. oxysporum strains lacking HapX are reduced in their capacity to invade and kill tomato (Solanum lycopersicum) plants and immunodepressed mice. The virulence defect of ΔhapX on tomato plants is exacerbated by coinoculation of roots with a biocontrol strain of Pseudomonas putida, but not with a siderophore-deficient mutant, indicating that HapX contributes to iron competition of F. oxysporum in the tomato rhizosphere. These results establish a conserved role for HapX-mediated iron homeostasis in fungal infection of plants and mammals. PMID:22968717

  17. Use of molecular markers to compare Fusarium verticillioides pathogenic strains isolated from plants and humans.

    PubMed

    Chang, S C; Macêdo, D P C; Souza-Motta, C M; Oliveira, N T

    2013-01-01

    Fusarium verticillioides is a pathogen of agriculturally important crops, especially maize. It is considered one of the most important pathogens responsible for fumonisin contamination of food products, which causes severe, chronic, and acute intoxication in humans and animals. Moreover, it is recognized as a cause of localized infections in immunocompetent patients and disseminated infections among severely immunosuppressed patients. Several molecular tools have been used to analyze the intraspecific variability of fungi. The objective of this study was to use molecular markers to compare pathogenic isolates of F. verticillioides and isolates of the same species obtained from clinical samples of patients with Fusarium mycoses. The molecular markers that we used were inter-simple sequence repeat markers (primers GTG5 and GACA4), intron splice site primer (primer EI1), random amplified polymorphic DNA marker (primer OPW-6), and restriction fragment length polymorphism-internal transcribed spacer (ITS) from rDNA. From the data obtained, clusters were generated based on the UPGMA clustering method. The amplification products obtained using primers ITS4 and ITS5 and loci ITS1-5.8-ITS2 of the rDNA yielded fragments of approximately 600 bp for all the isolates. Digestion of the ITS region fragment using restriction enzymes such as EcoRI, DraI, BshI, AluI, HaeIII, HinfI, MspI, and PstI did not permit differentiation among pathogenic and clinical isolates. The inter-simple sequence repeat, intron splice site primer, and random amplified polymorphic DNA markers presented high genetic homogeneity among clinical isolates in contrast to the high variability found among the phytopathogenic isolates of F. verticillioides. PMID:24065642

  18. In vitro antifugal activity of medicinal plant extract against Fusarium oxysporum f. sp. lycopersici race 3 the causal agent of tomato wilt.

    PubMed

    Isaac, G S; Abu-Tahon, M A

    2014-03-01

    Medicinal plant extracts of five plants; Adhatoda vasica, Eucalyptus globulus, Lantana camara, Nerium oleander and Ocimum basilicum collected from Cairo, Egypt were evaluated against Fusarium oxysporum f. sp. lycopersici race 3 in vitro conditions using water and certain organic solvents. The results revealed that cold distilled water extracts of O. basilicum and E. globulus were the most effective ones for inhibiting the growth of F. oxysporum f. sp. lycopersici. Butanolic and ethanolic extracts of the tested plants inhibited the pathogen growth to a higher extent than water extracts. Butanolic extract of O. basilicum completely inhibited the growth of F. oxysporum f. sp. lycopersici at concentrations 1.5 and 2.0% (v/v). Butanolic extracts (2.0%) of tested plants had a strong inhibitory effect on hydrolytic enzymes; β-glucosidase, pectin lyase and protease of F. oxysporum f. sp. lycopersici. This study has confirmed that the application of plant extracts, especially from O. basilicum for controlling F. oxysporum f. sp. lycopersici is environmentally safe, cost effective and does not disturb ecological balance. Investigations are in progress to test the efficacy of O. basilicum extract under in vivo conditions. PMID:24561899

  19. Widespread Occurrence of Diverse Human Pathogenic Types of the Fungus Fusarium Detected in Plumbing Drains ▿ †

    PubMed Central

    Short, Dylan P. G.; O'Donnell, Kerry; Zhang, Ning; Juba, Jean H.; Geiser, David M.

    2011-01-01

    It has been proposed that plumbing systems might serve as a significant environmental reservoir of human-pathogenic isolates of Fusarium. We tested this hypothesis by performing the first extensive multilocus sequence typing (MLST) survey of plumbing drain-associated Fusarium isolates and comparing the diversity observed to the known diversity of clinical Fusarium isolates. We sampled 471 drains, mostly in bathroom sinks, from 131 buildings in the United States using a swabbing method. We found that 66% of sinks and 80% of buildings surveyed yielded at least one Fusarium culture. A total of 297 isolates of Fusarium collected were subjected to MLST to identify the phylogenetic species and sequence types (STs) of these isolates. Our survey revealed that the six most common STs in sinks were identical to the six most frequently associated with human infections. We speculate that the most prevalent STs, by virtue of their ability to form and grow in biofilms, are well adapted to plumbing systems. Six major Fusarium STs were frequently isolated from plumbing drains within a broad geographic area and were identical to STs frequently associated with human infections. PMID:21976755

  20. Surfactin A production and isoforms characterizations in strains of Bacillus mojavensis for control of a maize pathogen, Fusarium verticillioides

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The endophytic bacterium, Bacillus mojavensis, RRC 101 controls fungal diseases in maize and other plants. The bacterium and its cultural extracts have been shown to be antagonistic to the pathogenic and mycotoxic fungus, Fusarium verticillioides. An antifungal cyclic lipopeptide produced by B. moj...

  1. mRNA isoforms in the maize endophyte/pathogen Fusarium verticillioides: And a little story about KP4

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The filamentous fungus Fusarium verticillioides is a pathogen and endophyte of maize. At some stages of its life, it may synthesize a family of mycotoxins called fumonisins that may contaminate maize products. Ingestion of fumonisin is linked to a variety of animal diseases including cancer in som...

  2. Fusarium azukicola sp. nov., an exotic azuki bean root-rot pathogen in Hokkaido, Japan.

    PubMed

    Aoki, Takayuki; Tanaka, Fumio; Suga, Haruhisa; Hyakumachi, Mitsuro; Scandiani, María Mercedes; O'Donnell, Kerry

    2012-01-01

    We report on the phenotypic, molecular phylogenetic and pathogenic characterization of a novel azuki bean (Vigna angularis) root-rot (BRR) pathogen from Hokkaido, Japan, which formally is described herein as Fusarium azukicola. This species can be distinguished phenotypically from the other Phaseolus/Vigna BRR and soybean sudden-death syndrome (SDS) pathogens by the production of wider and longer four-septate conidia cultured on SNA. Molecular phylogenetic analyses of four anonymous intergenic loci, a portion of the translation elongation factor (EF-1α) gene and the nuclear ribosomal intergenic spacer region (IGS rDNA) strongly support the genealogical exclusivity of F. azukicola with respect to the other soybean SDS and BRR pathogens within Clade 2 of the F. solani species complex (FSSC). Evolutionary relationships of F. azukicola to other members of the SDS-BRR clade, however, are unresolved by phylogenetic analyses of the individual and combined datasets, with the exception of the IGS rDNA partition, which strongly supports it as a sister of the soybean SDS pathogen F. brasiliense. A multilocus genotyping assay is updated to include primer probes that successfully distinguish F. azukicola from the other soybean SDS and BRR pathogens. Results of a pathogenicity experiment reveal that the F. azukicola isolates are able to induce root-rot symptoms on azuki bean, mung bean (Vigna radiata), kidney bean (Phaseolus vulgaris) and soybean (Glycine max), as well as typical SDS foliar symptoms on soybean. Our hypothesis is that F. azukicola evolved in South America and was introduced to Hokkaido, Japan, on azuki bean but its possible route of introduction remains unknown. PMID:22492403

  3. Measuring protein kinase and sugar kinase activity in plant pathogenic fusarium species.

    PubMed

    Bluhm, Burton H; Zhao, Xinhua

    2010-01-01

    As ubiquitous metabolic and signaling intermediaries, kinases regulate innumerable aspects of fungal growth and development. At its simplest, the enzymatic function of a kinase is to transfer a phosphate from a donor molecule (such as adenosine triphosphate) to an acceptor molecule, such as a protein, carbohydrate, or lipid. Kinase activity is intricately interwoven into signal transduction, and ultimately modulates gene expression, downstream phosphorylation events, and other mechanisms of posttranslational modification. Therefore, sensitive and reproducible techniques to measure kinase activity are crucial to elucidate cellular signaling and for fungal functional genomics.Protein and sugar kinases regulate multiple aspects of pathogenesis in the mycotoxigenic, plant pathogenic fungi Fusarium graminearum, and Fusarium verticillioides. Here, we present protocols to (1) quantify phosphorylation of mitogen-activated protein kinases in F. graminearum, and (2) determine glucokinase activity in F. verticillioides. The mitogen-activated protein kinase phosphorylation assay utilizes immunological methods to quantify substrate phosphorylation, whereas the glucokinase assay is a coupled enzyme assay, in which phosphorylation of glucose by glucokinase is measured indirectly through the subsequent reduction of NADP+ to NADPH, a substrate more amenable for spectrophotometric detection. PMID:20238271

  4. Relationship between resistance to Stewart's wilt and Goss's wilt in dent corn inbreds

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Stewart's wilt, caused by Pantoea stewartii subsp. stewartii and Goss's wilt, caused by Clavibacter michiganensis ssp. nebraskensis (Cmn), are the two prominent bacterial leaf blight pathogens in maize in the US. Goss's wilt has become much more widespread in geographic range since 2008 and many pop...

  5. Tissue-specific and pathogen-inducible expression of a fusion protein containing a Fusarium-specific antibody and a fungal chitinase protects wheat against Fusarium pathogens and mycotoxins.

    PubMed

    Cheng, Wei; Li, He-Ping; Zhang, Jing-Bo; Du, Hong-Jie; Wei, Qi-Yong; Huang, Tao; Yang, Peng; Kong, Xian-Wei; Liao, Yu-Cai

    2015-06-01

    Fusarium head blight (FHB) in wheat and other small grain cereals is a globally devastating disease caused by toxigenic Fusarium pathogens. Controlling FHB is a challenge because germplasm that is naturally resistant against these pathogens is inadequate. Current control measures rely on fungicides. Here, an antibody fusion comprised of the Fusarium spp.-specific recombinant antibody gene CWP2 derived from chicken, and the endochitinase gene Ech42 from the biocontrol fungus Trichoderma atroviride was introduced into the elite wheat cultivar Zhengmai9023 by particle bombardment. Expression of this fusion gene was regulated by the lemma/palea-specific promoter Lem2 derived from barley; its expression was confirmed as lemma/palea-specific in transgenic wheat. Single-floret inoculation of independent transgenic wheat lines of the T3 to T6 generations revealed significant resistance (type II) to fungal spreading, and natural infection assays in the field showed significant resistance (type I) to initial infection. Gas chromatography-mass spectrometry analysis revealed marked reduction of mycotoxins in the grains of the transgenic wheat lines. Progenies of crosses between the transgenic lines and the FHB-susceptible cultivar Huamai13 also showed significantly enhanced FHB resistance. Quantitative real-time PCR analysis revealed that the tissue-specific expression of the antibody fusion was induced by salicylic acid drenching and induced to a greater extent by F. graminearum infection. Histochemical analysis showed substantial restriction of mycelial growth in the lemma tissues of the transgenic plants. Thus, the combined tissue-specific and pathogen-inducible expression of this Fusarium-specific antibody fusion can effectively protect wheat against Fusarium pathogens and reduce mycotoxin content in grain. PMID:25418882

  6. The Fusarium graminearum genome reveals a link between localized polymorphism and pathogen specialization.

    PubMed

    Cuomo, Christina A; Güldener, Ulrich; Xu, Jin-Rong; Trail, Frances; Turgeon, B Gillian; Di Pietro, Antonio; Walton, Jonathan D; Ma, Li-Jun; Baker, Scott E; Rep, Martijn; Adam, Gerhard; Antoniw, John; Baldwin, Thomas; Calvo, Sarah; Chang, Yueh-Long; Decaprio, David; Gale, Liane R; Gnerre, Sante; Goswami, Rubella S; Hammond-Kosack, Kim; Harris, Linda J; Hilburn, Karen; Kennell, John C; Kroken, Scott; Magnuson, Jon K; Mannhaupt, Gertrud; Mauceli, Evan; Mewes, Hans-Werner; Mitterbauer, Rudolf; Muehlbauer, Gary; Münsterkötter, Martin; Nelson, David; O'donnell, Kerry; Ouellet, Thérèse; Qi, Weihong; Quesneville, Hadi; Roncero, M Isabel G; Seong, Kye-Yong; Tetko, Igor V; Urban, Martin; Waalwijk, Cees; Ward, Todd J; Yao, Jiqiang; Birren, Bruce W; Kistler, H Corby

    2007-09-01

    We sequenced and annotated the genome of the filamentous fungus Fusarium graminearum, a major pathogen of cultivated cereals. Very few repetitive sequences were detected, and the process of repeat-induced point mutation, in which duplicated sequences are subject to extensive mutation, may partially account for the reduced repeat content and apparent low number of paralogous (ancestrally duplicated) genes. A second strain of F. graminearum contained more than 10,000 single-nucleotide polymorphisms, which were frequently located near telomeres and within other discrete chromosomal segments. Many highly polymorphic regions contained sets of genes implicated in plant-fungus interactions and were unusually divergent, with higher rates of recombination. These regions of genome innovation may result from selection due to interactions of F. graminearum with its plant hosts. PMID:17823352

  7. The Fusarium Graminearum Genome Reveals a Link Between Localized Polymorphism and Pathogen Specialization

    SciTech Connect

    Cuomo, Christina A.; Guldener, Ulrich; Xu, Jin Rong; Trail, Frances; Turgeon, Barbara G.; Di Pietro, Antonio; Walton, Johnathan D.; Ma, Li Jun; Baker, Scott E.; Rep, Martijn; Adam, Gerhard; Antoniw, John; Baldwin, Thomas; Calvo, Sarah; Chang, Yueh Long; DeCaprio, David; Gale, Liane R.; Gnerre, Sante; Goswami, Rubella S.; Hammond-Kossack, Kim; Harris, Linda J.; Hilburn, Karen; Kennell, John C.; Kroken, Scott; Magnuson, Jon K.; Mannhaupt, Gertrud; Mauceli, Evan; Mewes, Hans Werner; Mitterbauer, Rudolf; Muehlbauer, Gary; Munsterkotter, Martin; Nelson, David; O'Donnell, Kerry; Ouellet, Therese; Qi, Weihong; Quesneville, Hadi; Roncero, M. Isabel; Seong, Kye Yong; Tetko, Igor V.; Urban, Martin; Waalwijk, Cees; Ward, Todd J.; Yao, Jiqiang; Birren, Bruce W.; Kistler, H. Corby

    2007-09-07

    We sequenced and annotated the genome of the filamentous fungus Fusarium graminearum, a major pathogen of cultivated cereals. Very few repetitive sequences were detected, and the process of repeat-induced point mutation, in which duplicated sequences are subject to extensive mutation, may partially account for the reduced repeat content and apparent low number of paralogous (ancestrally duplicated) genes. A second strain of F. graminearum contained more than 10,000 single-nucleotide polymorphisms, which were frequently located near telomeres and within other discrete chromosomal segments. Many highly polymorphic regions contained sets of genes implicated in plant-fungus interactions and were unusually divergent, with higher rates of recombination. These regions of genome innovation may result from selection due to interactions of F. graminearum with its plant hosts.

  8. Pathological Relationship of Ditylenchus dipsaci and Fusarium oxysporum f. sp. medicaginis on alfalfa.

    PubMed

    Griffin, G D

    1990-07-01

    Ditylenchus dipsaci and Fusarium oxysporum f. sp. medicaginis synergistically affected the mortality and plant growth of Ranger alfalfa, a cultivar susceptible to stem nematode and Fusarium wilt. The nematode-fungus relationship had an additive effect on mortality and plant growth of Lahontan (nematode resistant and Fusarium wilt susceptible) and of Moapa 69 (nematode susceptible and Fusarium wilt resistant). Mortality rates were 13, 16, 46, and 49% for Ranger; 4, 18, 26, and 28% for Lahontan; and 19, 10, 32, and 30% for Moapa 69 inoculated with D. dipsaci, F. oxysporum f. sp. medicaginis, and simultaneously and sequentially with D. dipsaci and F. oxysporum f. sp. medicaginis, respectively. Shoot weights as a percentage of uninoculated controls for the same treatments were 52, 84, 26, and 28%, for Ranger; 74, 86, 64, and 64% for Lahontan; and 50, 95, 44, and 39% for Moapa 69. Plant growth suppression was related to vascular bundle infection and discoloration of alfalfa root tissue. Disease severity and plant growth of alfalfa did not differ with simultaneous or sequential inoculations of the two pathogens. Fusarium oxysporum f. sp. medicaginis affected alfalfa growth but not nematode reproduction. PMID:19287729

  9. Identification of I-7 expands the repertoire of genes for resistance to Fusarium wilt in tomato to three resistance gene classes.

    PubMed

    Gonzalez-Cendales, Yvonne; Catanzariti, Ann-Maree; Baker, Barbara; Mcgrath, Des J; Jones, David A

    2016-04-01

    The tomato I-3 and I-7 genes confer resistance to Fusarium oxysporum f. sp. lycopersici (Fol) race 3 and were introgressed into the cultivated tomato, Solanum lycopersicum, from the wild relative Solanum pennellii. I-3 has been identified previously on chromosome 7 and encodes an S-receptor-like kinase, but little is known about I-7. Molecular markers have been developed for the marker-assisted breeding of I-3, but none are available for I-7. We used an RNA-seq and single nucleotide polymorphism (SNP) analysis approach to map I-7 to a small introgression of S. pennellii DNA (c. 210 kb) on chromosome 8, and identified I-7 as a gene encoding a leucine-rich repeat receptor-like protein (LRR-RLP), thereby expanding the repertoire of resistance protein classes conferring resistance to Fol. Using an eds1 mutant of tomato, we showed that I-7, like many other LRR-RLPs conferring pathogen resistance in tomato, is EDS1 (Enhanced Disease Susceptibility 1) dependent. Using transgenic tomato plants carrying only the I-7 gene for Fol resistance, we found that I-7 also confers resistance to Fol races 1 and 2. Given that Fol race 1 carries Avr1, resistance to Fol race 1 indicates that I-7-mediated resistance, unlike I-2- or I-3-mediated resistance, is not suppressed by Avr1. This suggests that Avr1 is not a general suppressor of Fol resistance in tomato, leading us to hypothesize that Avr1 may be acting against an EDS1-independent pathway for resistance activation. The identification of I-7 has allowed us to develop molecular markers for marker-assisted breeding of both genes currently known to confer Fol race 3 resistance (I-3 and I-7). Given that I-7-mediated resistance is not suppressed by Avr1, I-7 may be a useful addition to I-3 in the tomato breeder's toolbox. PMID:26177154

  10. Response of tomato wilt pathogen Ralstonia solanacearum to the volatile organic compounds produced by a biocontrol strain Bacillus amyloliquefaciens SQR-9.

    PubMed

    Raza, Waseem; Ling, Ning; Yang, Liudong; Huang, Qiwei; Shen, Qirong

    2016-01-01

    It is important to study the response of plant pathogens to the antibiosis traits of biocontrol microbes to design the efficient biocontrol strategies. In this study, we evaluated the role of volatile organic compounds (VOCs) produced by a biocontrol strain Bacillus amyloliquefaciens SQR-9 on the growth and virulence traits of tomato wilt pathogen Ralstonia solanacearum (RS). The VOCs of SQR-9 significantly inhibited the growth of RS on agar medium and in soil. In addition, the VOCs significantly inhibited the motility traits, production of antioxidant enzymes and exopolysaccharides, biofilm formation and tomato root colonization by RS. The strain SQR-9 produced 22 VOCs, but only nine VOCs showed 1-11% antibacterial activity against RS in their corresponding amounts; however, the consortium of all VOCs showed 70% growth inhibition of RS. The proteomics analysis showed that the VOCs of SQR-9 downregulated RS proteins related to the antioxidant activity, virulence, carbohydrate and amino acid metabolism, protein folding and translation, while the proteins involved in the ABC transporter system, amino acid synthesis, detoxification of aldehydes and ketones, methylation, protein translation and folding, and energy transfer were upregulated. This study describes the significance and effectiveness of VOCs produced by a biocontrol strain against tomato wilt pathogen. PMID:27103342

  11. Response of tomato wilt pathogen Ralstonia solanacearum to the volatile organic compounds produced by a biocontrol strain Bacillus amyloliquefaciens SQR-9

    PubMed Central

    Raza, Waseem; Ling, Ning; Yang, Liudong; Huang, Qiwei; Shen, Qirong

    2016-01-01

    It is important to study the response of plant pathogens to the antibiosis traits of biocontrol microbes to design the efficient biocontrol strategies. In this study, we evaluated the role of volatile organic compounds (VOCs) produced by a biocontrol strain Bacillus amyloliquefaciens SQR-9 on the growth and virulence traits of tomato wilt pathogen Ralstonia solanacearum (RS). The VOCs of SQR-9 significantly inhibited the growth of RS on agar medium and in soil. In addition, the VOCs significantly inhibited the motility traits, production of antioxidant enzymes and exopolysaccharides, biofilm formation and tomato root colonization by RS. The strain SQR-9 produced 22 VOCs, but only nine VOCs showed 1–11% antibacterial activity against RS in their corresponding amounts; however, the consortium of all VOCs showed 70% growth inhibition of RS. The proteomics analysis showed that the VOCs of SQR-9 downregulated RS proteins related to the antioxidant activity, virulence, carbohydrate and amino acid metabolism, protein folding and translation, while the proteins involved in the ABC transporter system, amino acid synthesis, detoxification of aldehydes and ketones, methylation, protein translation and folding, and energy transfer were upregulated. This study describes the significance and effectiveness of VOCs produced by a biocontrol strain against tomato wilt pathogen. PMID:27103342

  12. First report of Fusarium decemcellulare causing inflorescence wilt, vascular and flower necrosis of rambutan (Nephelium lappaceum), longan (Dimocarpus longan) and mango (Mangifera indica)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Longan, mango and rambutan are very important fruit crops in Puerto Rico. During a disease survey in Puerto Rico conducted from 2008 to 2010, 50% of the inflorescences were affected with inflorescence wilt, flower and vascular necrosis at 70% of the fields of rambutan and longan at the USDA-ARS Rese...

  13. Slow sand filters effectively reduce Phytophthora after a pathogen switch from Fusarium and a simulated pump failure.

    PubMed

    Lee, Eric; Oki, Lorence R

    2013-09-15

    Slow sand filtration has been shown to effectively reduce Phytophthora zoospores in irrigation water. This experiment tested the reduction of Phytophthora colony forming units (CFUs) by slow sand filtration systems after switching the pathogen contaminating plant leachate from Fusarium to Phytophthora and the resilience of the system to a short period without water, as might be caused by a pump failure. The slow sand filtration system greatly reduced Phytophthora CFUs and transmission after switching the pathogens. In addition, Phytophthora reduction by the slow sand filter was equally effective before and after the simulated pump failure. Reduction of Fusarium was not seen by the SSFs, before or after the simulated pump failure. The results suggest that slow sand filters are effective at reducing larger organisms, such as Phytophthora zoospores, even after a pump failure or a change in pathogens. PMID:23866129

  14. Wildly Growing Asparagus (Asparagus officinalis L.) Hosts Pathogenic Fusarium Species and Accumulates Their Mycotoxins.

    PubMed

    Stępień, Łukasz; Waśkiewicz, Agnieszka; Urbaniak, Monika

    2016-05-01

    Asparagus officinalis L. is an important crop in many European countries, likely infected by a number of Fusarium species. Most of them produce mycotoxins in plant tissues, thus affecting the physiology of the host plant. However, there is lack of information on Fusarium communities in wild asparagus, where they would definitely have considerable environmental significance. Therefore, the main scientific aim of this study was to identify the Fusarium species and quantify their typical mycotoxins present in wild asparagus plants collected at four time points of the season. Forty-four Fusarium strains of eight species-Fusarium acuminatum, Fusarium avenaceum, Fusarium culmorum, Fusarium equiseti, Fusarium oxysporum, Fusarium proliferatum, Fusarium sporotrichioides, and Fusarium tricinctum-were isolated from nine wild asparagus plants in 2013 season. It is the first report of F. sporotrichioides isolated from this particular host. Fumonisin B1 was the most abundant mycotoxin, and the highest concentrations of fumonisins B1-B3 and beauvericin were found in the spears collected in May. Moniliformin and enniatins were quantified at lower concentrations. Mycotoxins synthesized by individual strains obtained from infected asparagus tissues were assessed using in vitro cultures on sterile rice grain. Most of the F. sporotrichioides strains synthesized HT-2 toxin and F. equiseti strains were found to be effective zearalenone producers. PMID:26687343

  15. Comparative genomics of the Fusarium fujikuroi species complex: biosynthetic pathways metabolite production and plant pathogenicity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fusarium is a huge genus of filamentous fungi causing plant diseases in a wide range of host plants that result in high economic losses to world agriculture every year. Phylogenetic studies have shown that the genus Fusarium consists of different species complexes. One of them is the “Fusarium fujik...

  16. Pathogenic and Phylogenetic analysis of Fusarium oxysporum from Sugarbeet in Michigan and Minnesota

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fusarium yellows of sugarbeet (Beta vulgaris L.), caused by Fusarium oxysporum Schlechtend:FR. f. sp. betae (Stewart) Snyd & Hans, can lead to significant reduction in root yield sucrose percentage, and juice purity. Fusarium yellows has become increasingly common in both Michigan and Minnesota sug...

  17. Phenotypic, molecular phylogenetic, and pathogenetic characterization of Fusarium crassistipitatum sp. nov., a novel soybean sudden death syndrome pathogen from Argentina and Brazil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A novel soybean sudden death syndrome (SDS) pathogen from Argentina and Brazil is formally described herein as Fusarium crassistipitatum based on detailed phenotypic analyses of macro- and microscopic characters and phylogenetic analyses of multilocus Deoxyribonucleic acid (DNA) sequence data. Fusar...

  18. Fusarium-induced diseases of tropical, perennial crops.

    PubMed

    Ploetz, Randy C

    2006-06-01

    ABSTRACT The world's oldest ecosystems are found in the tropics. They are diverse, highly evolved, but barely understood. This and subsequent papers describe diseases of tropical, perennial plants that are caused by Fusarium spp. Many of these are economically significant, difficult to manage, and of scientific interest. Some represent coevolved patho-systems (e.g., Panama disease, tracheomycosis of coffee, fusariosis of pineapple, and Fusarium wilt of oil palm), whereas others may be new-encounter diseases or are caused by generalist pathogens (cushion gall of cacao). New vector relationships are evident in other pathosystems (e.g., mango malformation), and two or more pathogens have been shown to cause some of the diseases (Panama disease and tracheomycosis of coffee). More work on these pathosystems is warranted as they could reveal much about the evolution of plant pathogens and the important diseases they cause. PMID:18943183

  19. Identification of I-7 expands the repertoire of genes for resistance to Fusarium wilt in tomato to three resistance gene classes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The tomato I-3 and I-7 genes confer resistance to Fusarium oxysporum f. sp. lycopersici (Fol) race 3 and both genes were introgressed into the cultivated tomato, Solanum lycopersicum, from the wild relative Solanum pennellii. I-3 was identified previously and encodes a S-receptor-like kinase, but li...

  20. Development of a physical map of the soybean pathogen Fusarium virguliforme based on synteny with Fusarium graminearum genomic DNA

    PubMed Central

    Shultz, Jeffry L; Ali, Sikander; Ballard, Linda; Lightfoot, David A

    2007-01-01

    Background Reference genome sequences within the major taxa can be used to assist the development of genomic tools for related organisms. A major constraint in the use of these sequenced and annotated genomes is divergent evolution. Divergence of organisms from a common ancestor may have occurred millions of years ago, leading to apparently un-related and un-syntenic genomes when sequence alignment is attempted. Results A series of programs were written to prepare 36 Mbp of Fusarium graminearum sequence in 19 scaffolds as a reference genome. Exactly 4,152 Bacterial artificial chromosome (BAC) end sequences from 2,178 large-insert Fusarium virguliforme clones were tested against this sequence. A total of 94 maps of F. graminearum sequence scaffolds, annotated exonic fragments and associated F. virguliforme sequences resulted. Conclusion Developed here was a technique that allowed the comparison of genomes based on small, 15 bp regions of shared identity. The main power of this method lay in its ability to align diverged sequences. This work is unique in that discontinuous sequences were used for the analysis and information not readily apparent, such as match direction, are presented. The 94 maps and JAVA programs are freely available on the Web and by request. PMID:17683537

  1. Impact of water potential on growth and germination of Fusarium solani soilborne pathogen of peanut

    PubMed Central

    Palacios, Sofia; Casasnovas, Francisco; Ramirez, María L.; Reynoso, María. M.; Torres, Adriana M.

    2014-01-01

    Studies were conducted to determine the effect of osmotic and matric stress on germination and growth of two Fusarium solani strains, the etiological agent responsible of peanut brown root rot. Both strains had similar osmotic and matric potential ranges that allowed growth, being the latter one narrower. F. solani showed the ability to grow down to −14 MPa at 25 °C in non-ionic modified osmotic medium, while under matric stress this was limited to −8.4 MPa at 25 °C. However, both strains were seen to respond differently to decreasing osmotic and matric potentials, during early stages of germination. One strain (RC 338) showed to be more sensitive to matric than osmotic (non ionic) and the other one (RC 386) showed to be more sensitive to osmotic than matric imposed water stress. After 24 h of incubation, both isolates behaved similarly. The minimum water potential for germination was −8.4 MPa on glycerol amended media and −5.6 MPa for NaCl and PEG amended media, respectively. The knowledge of the water potential range which allow mycelia growth and spore germination of F. solani provides an inside to the likely behaviour of this devastating soilborne plant pathogen in nature and has important practical implications. PMID:25477950

  2. Rab GTPases are essential for membrane trafficking-dependent growth and pathogenicity in Fusarium graminearum.

    PubMed

    Zheng, Huawei; Zheng, Wenhui; Wu, Congxian; Yang, Jie; Xi, Yang; Xie, Qiurong; Zhao, Xu; Deng, Xiaolong; Lu, Guodong; Li, Guangpu; Ebbole, Daniel; Zhou, Jie; Wang, Zonghua

    2015-11-01

    Rab GTPases represent the largest subfamily of Ras-related small GTPases and regulate membrane trafficking. Vesicular transport is a general mechanism that governs intracellular membrane trafficking along the endocytic and exocytic pathways in all eukaryotic cells. Fusarium graminearum is a filamentous fungus and causes the devastating and economically important head blight of wheat and related species. The mechanism of vesicular transport is not well understood, and little is known about Rab GTPases in F. graminearum. In this study, we systematically characterized all eleven FgRabs by live cell imaging and genetic analysis. We find that FgRab51 and FgRab52 are important for the endocytosis, FgRab7 localizes to the vacuolar membrane and regulates the fusion of vacuoles and autophagosomes, and FgRab8 and FgRab11 are important for polarized growth and/or exocytosis. Furthermore, both endocytic and exocytic FgRabs are required for vegetative growth, conidiogenesis, sexual reproduction, as well as pathogenesis and deoxynivalenol metabolism in F. graminearum. Thus, we conclude that Rab GTPases are essential for membrane trafficking-dependent growth and pathogenicity in F. graminearum. PMID:26177389

  3. Real-time imaging of hydrogen peroxide dynamics in vegetative and pathogenic hyphae of Fusarium graminearum

    PubMed Central

    Mentges, Michael; Bormann, Jörg

    2015-01-01

    Balanced dynamics of reactive oxygen species in the phytopathogenic fungus Fusarium graminearum play key roles for development and infection. To monitor those dynamics, ratiometric analysis using the novel hydrogen peroxide (H2O2) sensitive fluorescent indicator protein HyPer-2 was established for the first time in phytopathogenic fungi. H2O2 changes the excitation spectrum of HyPer-2 with an excitation maximum at 405 nm for the reduced and 488 nm for the oxidized state, facilitating ratiometric readouts with maximum emission at 516 nm. HyPer-2 analyses were performed using a microtiter fluorometer and confocal laser scanning microscopy (CLSM). Addition of external H2O2 to mycelia caused a steep and transient increase in fluorescence excited at 488 nm. This can be reversed by the addition of the reducing agent dithiothreitol. HyPer-2 in F. graminearum is highly sensitive and specific to H2O2 even in tiny amounts. Hyperosmotic treatment elicited a transient internal H2O2 burst. Hence, HyPer-2 is suitable to monitor the intracellular redox balance. Using CLSM, developmental processes like nuclear division, tip growth, septation, and infection structure development were analyzed. The latter two processes imply marked accumulations of intracellular H2O2. Taken together, HyPer-2 is a valuable and reliable tool for the analysis of environmental conditions, cellular development, and pathogenicity. PMID:26446493

  4. The prevalence and impact of Fusarium head blight pathogens and mycotoxins on malting barley quality in UK.

    PubMed

    Nielsen, L K; Cook, D J; Edwards, S G; Ray, R V

    2014-06-01

    Fusarium head blight (FHB) caused by Fusarium and Microdochium species can significantly affect the yield of barley grain as well as the quality and safety of malt and beer. The present study provides new knowledge on the impacts of the FHB pathogen complex on the malting and brewing quality parameters of naturally infected barley. Quantitative real-time PCR and liquid chromatography double mass spectrometry were used to quantify the predominant FHB pathogens and Fusarium mycotoxins, respectively, in commercially grown UK malting barley samples collected between 2007 and 2011. The predominant Fusarium species identified across the years were F. poae, F. tricinctum and F. avenaceum. Microdochium majus was the predominant Microdochium species in 2007, 2008, 2010 and 2011 whilst Microdochium nivale predominated in 2009. Deoxynivalenol and zearalenone quantified in samples collected between 2007 and 2009 were associated with F. graminearum and F. culmorum, whilst HT-2 and T-2, and nivalenol in samples collected between 2010 and 2011 correlated positively with F. langsethiae and F. poae, respectively. Analysis of the regional distribution and yearly variation in samples from 2010 to 2011 showed significant differences in the composition of the FHB species complex. In most regions (Scotland, the South and North of England) the harvest in 2010 had higher concentrations of Fusarium spp. than in 2011, although no significant difference was observed in the Midlands between the two years. Microdochium DNA was significantly higher in 2011 and in the North of England and Scotland compared to the South or Midlands regions. Pathogens of the FHB complex impacted negatively on grain yield and quality parameters. Thousand grain weight of malting barley was affected significantly by M. nivale and M. majus whilst specific weight correlated negatively with F. avenaceum and F. graminearum. To determine the impact of sub-acute infections of the identified Fusarium and Microdochium species on malting and brewing quality of naturally infected samples, selected malting barley cultivars (Optic, Quench and Tipple) were micromalted and subjected to malt and wort analysis of key quality parameters. F. poae and M. nivale decreased germinative energy and increased water sensitivity of barley. The fungal biomass of F. poae and F. langsethiae correlated with increased wort free amino nitrogen and with decreased extract of malt. DNA of M. nivale correlated with increased malt friability as well as decreased wort filtration volume. The findings of this study indicate that the impact of species such as the newly emerging F. langsethiae, as well as F. poae and the two non-toxigenic Microdochium species should be considered when evaluating the quality of malting barley. PMID:24727381

  5. The prevalence and impact of Fusarium head blight pathogens and mycotoxins on malting barley quality in UK

    PubMed Central

    Nielsen, L.K.; Cook, D.J.; Edwards, S.G.; Ray, R.V.

    2014-01-01

    Fusarium head blight (FHB) caused by Fusarium and Microdochium species can significantly affect the yield of barley grain as well as the quality and safety of malt and beer. The present study provides new knowledge on the impacts of the FHB pathogen complex on the malting and brewing quality parameters of naturally infected barley. Quantitative real-time PCR and liquid chromatography double mass spectrometry were used to quantify the predominant FHB pathogens and Fusarium mycotoxins, respectively, in commercially grown UK malting barley samples collected between 2007 and 2011. The predominant Fusarium species identified across the years were F. poae, F. tricinctum and F. avenaceum. Microdochium majus was the predominant Microdochium species in 2007, 2008, 2010 and 2011 whilst Microdochium nivale predominated in 2009. Deoxynivalenol and zearalenone quantified in samples collected between 2007 and 2009 were associated with F. graminearum and F. culmorum, whilst HT-2 and T-2, and nivalenol in samples collected between 2010 and 2011 correlated positively with F. langsethiae and F. poae, respectively. Analysis of the regional distribution and yearly variation in samples from 2010 to 2011 showed significant differences in the composition of the FHB species complex. In most regions (Scotland, the South and North of England) the harvest in 2010 had higher concentrations of Fusarium spp. than in 2011, although no significant difference was observed in the Midlands between the two years. Microdochium DNA was significantly higher in 2011 and in the North of England and Scotland compared to the South or Midlands regions. Pathogens of the FHB complex impacted negatively on grain yield and quality parameters. Thousand grain weight of malting barley was affected significantly by M. nivale and M. majus whilst specific weight correlated negatively with F. avenaceum and F. graminearum. To determine the impact of sub-acute infections of the identified Fusarium and Microdochium species on malting and brewing quality of naturally infected samples, selected malting barley cultivars (Optic, Quench and Tipple) were micromalted and subjected to malt and wort analysis of key quality parameters. F. poae and M. nivale decreased germinative energy and increased water sensitivity of barley. The fungal biomass of F. poae and F. langsethiae correlated with increased wort free amino nitrogen and with decreased extract of malt. DNA of M. nivale correlated with increased malt friability as well as decreased wort filtration volume. The findings of this study indicate that the impact of species such as the newly emerging F. langsethiae, as well as F. poae and the two non-toxigenic Microdochium species should be considered when evaluating the quality of malting barley. PMID:24727381

  6. THE ROLE OF FUSARIUM BIODIVERSITY IN PLANT PATHOGENICITY AND BIOLOGICAL CONTROL

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Fusarium disease complexes of maize, wheat, and other cereal grains are biologically highly diverse. This biodiversity is believed to have a major impact on the types and levels of mycotoxins in food grains. The first dimension of complexity is at the Fusarium species level. Identification an...

  7. Systematics, Phylogeny and Trichothecene Mycotoxin Potential of Fusarium Head Blight Cereal Pathogens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Economically devastating outbreaks and epidemics of Fusarium head blight (FHB) or scab of wheat and barley have occurred worldwide over the past two decades. Although the primary etiological agent of FHB was thought to comprise a single panmictic species, Fusarium graminearum, a series of studies we...

  8. Species diversity, pathogenicity and toxigenicity of Fusarium associated with rice seeds in Brazil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fusarium is commonly reported in association with rice seeds in Brazil, but knowledge on the species diversity and toxigenic potential is lacking. Such information is critical because maximum limits for Fusarium mycotoxins were set for Brazilian rice in 2011. Ninety-eight rice seed samples from the ...

  9. Systematics, phylogeny and trichothecene mycotoxin potential of fusarium head blight cereal pathogens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fusarium head blight(FHB)or scab of cereals is one of the most economically devastating plant diseases in the world today. Prior to 2000, the primary etiological agent of FHB was thought to comprise a single panmictic species,Fusarium graminearum. However, a series of studies we conducted over the p...

  10. Novel fusarium head blight pathogens from Nepal and Louisiana revealed by multilocus genealogical concordance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study was conducted to assess evolutionary relationships, species diversity, and trichothecene toxin potential of five Fusarium graminearum complex (FGSC) isolates identified as genetically novel during prior Fusarium head blight (FHB) surveys in Nepal and Louisiana. Results of a multilocus gen...

  11. Systematics, Phylogeny and Trichothecene Mycotoxin potential of Fusarium head blight cereal pathogens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fusarium head blight (FHB) or scab of cereals is one of the most economically devastating plant diseases in the world today. Prior to 2000, the primary etiological agent of FHB was thought to comprise a single panmictic species, Fusarium graminearum. However, a series of studies we conducted over th...

  12. Host extract modulates metabolism and fumonisin biosynthesis by the plant-pathogenic fungus Fusarium proliferatum.

    PubMed

    Stępień, Łukasz; Waśkiewicz, Agnieszka; Wilman, Karolina

    2015-01-16

    Fusarium proliferatum is a common pathogen able to infect a broad range of agriculturally important crops. Recently, some evidence for genetic variance among the species genotypes in relation to their plant origin has been reported. Mycotoxin contamination of plant tissues is the most important threat caused by F. proliferatum and fumonisins B (FBs) are the principal mycotoxins synthesized. The toxigenic potential of the pathogen genotypes is variable and also the reaction of different host plant species on the infection by pathogen is different. The objective of present study was to evaluate the impact of the extracts on the growth and fumonisin biosynthesis by 32 F. proliferatum strains originating from different host species (A-asparagus, M-maize, G-garlic, PS-pea and P-pineapple), and how it changes the secondary metabolism measured by fumonisin biosynthesis. The average strain dry weight was 65.2 mg for control conditions and it reached 180.7 mg, 100.5 mg, 76.6 mg, 126.2 mg and 51.1 mg when pineapple, asparagus, maize, garlic and pea extracts were added, respectively. In the second experiment the extracts were added after 5 days of culturing of the representative group of strains, displaying diverse reaction to the extract presence. Also, the influence of stationary vs. shaken culture was examined. Mean biomass amounts for shaken cultures of 15 chosen strains were as follows: 37.4 mg of dry weight for control culture (C), 219.6 mg (P), 113 mg (A), 93.6 mg (M), 62 mg (G) and 48 mg (PS), respectively. For stationary cultures, the means were as follows: C-57.4 mg, P-355.6 mg, A-291.6 mg, M-191.1 mg, G-171.1 mg and PS-58.9 mg. Few strains showed differential growth when stationary/shaken culture conditions were applied. Almost all strains synthesized moderate amounts of fumonisins in control conditions-less than 10 ng/μL, regardless of the origin and host species. Few strains were able to produce over 100 ng/μL of FBs when pineapple extract was added, twelve strains synthesized more than 10 ng/μL under asparagus extract induction and the pea extract was the most efficient inhibitor of fumonisin biosynthesis. The general impact of the extracts on the fungal biomass amounts was similar, regardless of the host plant origin of the fungal genotypes studied. The evaluation of FBs content has shown differential reaction of some strains, which may contribute to their aggressiveness and pathogenicity. PMID:25462926

  13. The silencing suppressor (NSs) protein of the plant virus Tomato spotted wilt virus enhances heterologous protein expression and baculovirus pathogenicity in cells and lepidopteran insects.

    PubMed

    de Oliveira, Virgínia Carla; da Silva Morgado, Fabricio; Ardisson-Araújo, Daniel Mendes Pereira; Resende, Renato Oliveira; Ribeiro, Bergmann Morais

    2015-11-01

    In this work, we showed that cell death induced by a recombinant (vAcNSs) Autographa californica multiple nucleopolyhedrovirus (AcMNPV) expressing the silencing suppressor (NSs) protein of Tomato spotted wilt virus (TSWV) was enhanced on permissive and semipermissive cell lines. The expression of a heterologous gene (firefly luciferase) during co-infection of insect cells with vAcNSs and a second recombinant baculovirus (vAgppolhfluc) was shown to increase when compared to single vAgppolhfluc infections. Furthermore, the vAcNSs mean time-to-death values were significantly lower than those for wild-type AcMNPV on larvae of Spodoptera frugiperda and Anticarsia gemmatalis. These results showed that the TSWV-NSs protein could efficiently increase heterologous protein expression in insect cells as well as baculovirus pathogenicity and virulence, probably by suppressing the gene-silencing machinery in insects. PMID:26323262

  14. Comparative secretome analysis of Fusarium graminearum and two of its non-pathogenic mutants upon deoxynivalenol induction in vitro.

    PubMed

    Rampitsch, Christof; Day, Jacqueline; Subramaniam, Rajagopal; Walkowiak, Sean

    2013-06-01

    To understand early events in plant-pathogen interactions, it is necessary to explore the pathogen secretome to identify secreted proteins that help orchestrate pathology. The secretome can be obtained from pathogens grown in vitro, and then characterized using standard proteomic approaches based on protein extraction and subsequent identification of tryptic peptides by LC-MS. A subset of the secretome is composed of proteins whose presence is required to initiate infection and their removal from the secretome would result in pathogens with reduced or no virulence. We present here comparative secretome from Fusarium graminearum. This filamentous fungus causes Fusarium head blight on wheat, a serious cereal disease found in many cereal-growing regions. Affected grain is contaminated with mycotoxins and cannot be used for food or feed. We used label-free quantitative MS to compare the secretomes of wild-type with two nonpathogenic deletion mutants of F. graminearum, Δtri6, and Δtri10. These mutations in mycotoxin-regulating transcription factors revealed a subset of 29 proteins whose relative abundance was affected in their secretomes, as measured by spectral counting. Proteins that decreased in abundance are potential candidate virulence factors and these included cell wall-degrading enzymes, metabolic enzymes, pathogenesis-related proteins, and proteins of unknown function. PMID:23512867

  15. The Wor1-like Protein Fgp1 Regulates Pathogenicity, Toxin Synthesis and Reproduction in the Phytopathogenic Fungus Fusarium graminearum

    PubMed Central

    Jonkers, Wilfried; Dong, Yanhong; Broz, Karen; Corby Kistler, H.

    2012-01-01

    WOR1 is a gene for a conserved fungal regulatory protein controlling the dimorphic switch and pathogenicity determents in Candida albicans and its ortholog in the plant pathogen Fusarium oxysporum, called SGE1, is required for pathogenicity and expression of key plant effector proteins. F. graminearum, an important pathogen of cereals, is not known to employ switching and no effector proteins from F. graminearum have been found to date that are required for infection. In this study, the potential role of the WOR1-like gene in pathogenesis was tested in this toxigenic fungus. Deletion of the WOR1 ortholog (called FGP1) in F. graminearum results in greatly reduced pathogenicity and loss of trichothecene toxin accumulation in infected wheat plants and in vitro. The loss of toxin accumulation alone may be sufficient to explain the loss of pathogenicity to wheat. Under toxin-inducing conditions, expression of genes for trichothecene biosynthesis and many other genes are not detected or detected at lower levels in Δfgp1 strains. FGP1 is also involved in the developmental processes of conidium formation and sexual reproduction and modulates a morphological change that accompanies mycotoxin production in vitro. The Wor1-like proteins in Fusarium species have highly conserved N-terminal regions and remarkably divergent C-termini. Interchanging the N- and C- terminal portions of proteins from F. oxysporum and F. graminearum resulted in partial to complete loss of function. Wor1-like proteins are conserved but have evolved to regulate pathogenicity in a range of fungi, likely by adaptations to the C-terminal portion of the protein. PMID:22693448

  16. Characterization of RNA silencing components in the plant pathogenic fungus Fusarium graminearum.

    PubMed

    Chen, Yun; Gao, Qixun; Huang, Mengmeng; Liu, Ye; Liu, Zunyong; Liu, Xin; Ma, Zhonghua

    2015-01-01

    The RNA interference (RNAi) plays a critical role in gene regulation in a variety of eukaryotic organisms. However, the role of RNAi remains largely unclear in plant pathogenic fungi. In this study, we explored the roles of core components of the RNAi pathway in Fusarium graminearum, the major causal agent of wheat head blight. Our results demonstrated that the hairpin RNA (hpRNA) can efficiently silence the expression level of target gene, and the argonaute protein FgAgo1 and dicer protein FgDicer2 are important in this silencing process. RNAi machinery was not involved in growth, abiotic stress and pathogenesis in F. graminearum under tested conditions. We firstly applied high-throughput sequencing technology to elucidate small RNA (17-40 nucleotides) (sRNA) transcriptome in F. graminearum, and found that a total of forty-nine micro-like-RNA (milRNA) candidates were identified in the wild-type and ∆FgDICER2, and twenty-four of them were FgDicer2-dependent. Fg-milRNA-4 negatively regulated expression of its target gene. Taken together, our results indicated that the hpRNA-induced gene silencing was a valuable genetic tool for exploring gene function in F. graminearum. FgAgo1 and FgDicer2 proteins played a critical role in the hpRNA mediated gene silencing process. In addition, FgDicer2 was involved in sRNA transcription and milRNA generation in this fungus. PMID:26212591

  17. MYT3, a Myb-like transcription factor, affects fungal development and pathogenicity of Fusarium graminearum.

    PubMed

    Kim, Yongsoo; Kim, Hun; Son, Hokyoung; Choi, Gyung Ja; Kim, Jin-Cheol; Lee, Yin-Won

    2014-01-01

    We previously characterized members of the Myb protein family, MYT1 and MYT2, in Fusarium graminearum. MYT1 and MYT2 are involved in female fertility and perithecium size, respectively. To expand knowledge of Myb proteins in F. graminearum, in this study, we characterized the functions of the MYT3 gene, which encodes a putative Myb-like transcription factor containing two Myb DNA-binding domains and is conserved in the subphylum Pezizomycotina of Ascomycota. MYT3 proteins were localized in nuclei during most developmental stages, suggesting the role of MYT3 as a transcriptional regulator. Deletion of MYT3 resulted in impairment of conidiation, germination, and vegetative growth compared to the wild type, whereas complementation of MYT3 restored the wild-type phenotype. Additionally, the Δmyt3 strain grew poorly on nitrogen-limited media; however, the mutant grew robustly on minimal media supplemented with ammonium. Moreover, expression level of nitrate reductase gene in the Δmyt3 strain was decreased in comparison to the wild type and complemented strain. On flowering wheat heads, the Δmyt3 strain exhibited reduced pathogenicity, which corresponded with significant reductions in trichothecene production and transcript levels of trichothecene biosynthetic genes. When the mutant was selfed, mated as a female, or mated as a male for sexual development, perithecia were not observed on the cultures, indicating that the Δmyt3 strain lost both male and female fertility. Taken together, these results demonstrate that MYT3 is required for pathogenesis and sexual development in F. graminearum, and will provide a robust foundation to establish the regulatory networks for all Myb-like proteins in F. graminearum. PMID:24722578

  18. The Predicted Secretome of the Plant Pathogenic Fungus Fusarium graminearum: A Refined Comparative Analysis

    PubMed Central

    Brown, Neil A.; Antoniw, John; Hammond-Kosack, Kim E.

    2012-01-01

    The fungus Fusarium graminearum forms an intimate association with the host species wheat whilst infecting the floral tissues at anthesis. During the prolonged latent period of infection, extracellular communication between live pathogen and host cells must occur, implying a role for secreted fungal proteins. The wheat cells in contact with fungal hyphae subsequently die and intracellular hyphal colonisation results in the development of visible disease symptoms. Since the original genome annotation analysis was done in 2007, which predicted the secretome using TargetP, the F. graminearum gene call has changed considerably through the combined efforts of the BROAD and MIPS institutes. As a result of the modifications to the genome and the recent findings that suggested a role for secreted proteins in virulence, the F. graminearum secretome was revisited. In the current study, a refined F. graminearum secretome was predicted by combining several bioinformatic approaches. This strategy increased the probability of identifying truly secreted proteins. A secretome of 574 proteins was predicted of which 99% was supported by transcriptional evidence. The function of the annotated and unannotated secreted proteins was explored. The potential role(s) of the annotated proteins including, putative enzymes, phytotoxins and antifungals are discussed. Characterisation of the unannotated proteins included the analysis of Pfam domains and features associated with known fungal effectors, for example, small size, cysteine-rich and containing internal amino acid repeats. A comprehensive comparative genomic analysis involving 57 fungal and oomycete genomes revealed that only a small number of the predicted F. graminearum secreted proteins can be considered to be either species or sequenced strain specific. PMID:22493673

  19. Protein phosphatase 2A regulatory subunits perform distinct functional roles in the maize pathogen Fusarium verticillioides.

    TOXLINE Toxicology Bibliographic Information

    Shin JH; Kim JE; Malapi-Wight M; Choi YE; Shaw BD; Shim WB

    2013-06-01

    Fusarium verticillioides is a pathogen of maize causing ear rot and stalk rot. The fungus also produces fumonisins, a group of mycotoxins linked to disorders in animals and humans. A cluster of genes, designated FUM genes, plays a key role in the synthesis of fumonisins. However, our understanding of the regulatory mechanism of fumonisin biosynthesis is still incomplete. We have demonstrated previously that Cpp1, a protein phosphatase type 2A (PP2A) catalytic subunit, negatively regulates fumonisin production and is involved in cell shape maintenance. In general, three PP2A subunits, structural A, regulatory B and catalytic C, make up a heterotrimer complex to perform regulatory functions. Significantly, we identified two PP2A regulatory subunits in the F. verticillioides genome, Ppr1 and Ppr2, which are homologous to Saccharomyces cerevisiae Cdc55 and Rts1, respectively. In this study, we hypothesized that Ppr1 and Ppr2 are involved in the regulation of fumonisin biosynthesis and/or cell development in F. verticillioides, and generated a series of mutants to determine the functional role of Ppr1 and Ppr2. The PPR1 deletion strain (Δppr1) resulted in drastic growth defects, but increased microconidia production. The PPR2 deletion mutant strain (Δppr2) showed elevated fumonisin production, similar to the Δcpp1 strain. Germinating Δppr1 conidia formed abnormally swollen cells with a central septation site, whereas Δppr2 showed early hyphal branching during conidia germination. A kernel rot assay showed that the mutants were slow to colonize kernels, but this is probably a result of growth defects rather than a virulence defect. Results from this study suggest that two PP2A regulatory subunits in F. verticillioides carry out distinct roles in the regulation of fumonisin biosynthesis and fungal development.

  20. Protein phosphatase 2A regulatory subunits perform distinct functional roles in the maize pathogen Fusarium verticillioides.

    PubMed

    Shin, Joon-Hee; Kim, Jung-Eun; Malapi-Wight, Martha; Choi, Yoon-E; Shaw, Brian D; Shim, Won-Bo

    2013-06-01

    Fusarium verticillioides is a pathogen of maize causing ear rot and stalk rot. The fungus also produces fumonisins, a group of mycotoxins linked to disorders in animals and humans. A cluster of genes, designated FUM genes, plays a key role in the synthesis of fumonisins. However, our understanding of the regulatory mechanism of fumonisin biosynthesis is still incomplete. We have demonstrated previously that Cpp1, a protein phosphatase type 2A (PP2A) catalytic subunit, negatively regulates fumonisin production and is involved in cell shape maintenance. In general, three PP2A subunits, structural A, regulatory B and catalytic C, make up a heterotrimer complex to perform regulatory functions. Significantly, we identified two PP2A regulatory subunits in the F. verticillioides genome, Ppr1 and Ppr2, which are homologous to Saccharomyces cerevisiae Cdc55 and Rts1, respectively. In this study, we hypothesized that Ppr1 and Ppr2 are involved in the regulation of fumonisin biosynthesis and/or cell development in F. verticillioides, and generated a series of mutants to determine the functional role of Ppr1 and Ppr2. The PPR1 deletion strain (Δppr1) resulted in drastic growth defects, but increased microconidia production. The PPR2 deletion mutant strain (Δppr2) showed elevated fumonisin production, similar to the Δcpp1 strain. Germinating Δppr1 conidia formed abnormally swollen cells with a central septation site, whereas Δppr2 showed early hyphal branching during conidia germination. A kernel rot assay showed that the mutants were slow to colonize kernels, but this is probably a result of growth defects rather than a virulence defect. Results from this study suggest that two PP2A regulatory subunits in F. verticillioides carry out distinct roles in the regulation of fumonisin biosynthesis and fungal development. PMID:23452277

  1. Characterization of RNA silencing components in the plant pathogenic fungus Fusarium graminearum

    PubMed Central

    Chen, Yun; Gao, Qixun; Huang, Mengmeng; Liu, Ye; Liu, Zunyong; Liu, Xin; Ma, Zhonghua

    2015-01-01

    The RNA interference (RNAi) plays a critical role in gene regulation in a variety of eukaryotic organisms. However, the role of RNAi remains largely unclear in plant pathogenic fungi. In this study, we explored the roles of core components of the RNAi pathway in Fusarium graminearum, the major causal agent of wheat head blight. Our results demonstrated that the hairpin RNA (hpRNA) can efficiently silence the expression level of target gene, and the argonaute protein FgAgo1 and dicer protein FgDicer2 are important in this silencing process. RNAi machinery was not involved in growth, abiotic stress and pathogenesis in F. graminearum under tested conditions. We firstly applied high-throughput sequencing technology to elucidate small RNA (17–40 nucleotides) (sRNA) transcriptome in F. graminearum, and found that a total of forty-nine micro-like-RNA (milRNA) candidates were identified in the wild-type and ∆FgDICER2, and twenty-four of them were FgDicer2-dependent. Fg-milRNA-4 negatively regulated expression of its target gene. Taken together, our results indicated that the hpRNA-induced gene silencing was a valuable genetic tool for exploring gene function in F. graminearum. FgAgo1 and FgDicer2 proteins played a critical role in the hpRNA mediated gene silencing process. In addition, FgDicer2 was involved in sRNA transcription and milRNA generation in this fungus. PMID:26212591

  2. MYT3, A Myb-Like Transcription Factor, Affects Fungal Development and Pathogenicity of Fusarium graminearum

    PubMed Central

    Son, Hokyoung; Choi, Gyung Ja; Kim, Jin-Cheol; Lee, Yin-Won

    2014-01-01

    We previously characterized members of the Myb protein family, MYT1 and MYT2, in Fusarium graminearum. MYT1 and MYT2 are involved in female fertility and perithecium size, respectively. To expand knowledge of Myb proteins in F. graminearum, in this study, we characterized the functions of the MYT3 gene, which encodes a putative Myb-like transcription factor containing two Myb DNA-binding domains and is conserved in the subphylum Pezizomycotina of Ascomycota. MYT3 proteins were localized in nuclei during most developmental stages, suggesting the role of MYT3 as a transcriptional regulator. Deletion of MYT3 resulted in impairment of conidiation, germination, and vegetative growth compared to the wild type, whereas complementation of MYT3 restored the wild-type phenotype. Additionally, the Δmyt3 strain grew poorly on nitrogen-limited media; however, the mutant grew robustly on minimal media supplemented with ammonium. Moreover, expression level of nitrate reductase gene in the Δmyt3 strain was decreased in comparison to the wild type and complemented strain. On flowering wheat heads, the Δmyt3 strain exhibited reduced pathogenicity, which corresponded with significant reductions in trichothecene production and transcript levels of trichothecene biosynthetic genes. When the mutant was selfed, mated as a female, or mated as a male for sexual development, perithecia were not observed on the cultures, indicating that the Δmyt3 strain lost both male and female fertility. Taken together, these results demonstrate that MYT3 is required for pathogenesis and sexual development in F. graminearum, and will provide a robust foundation to establish the regulatory networks for all Myb-like proteins in F. graminearum. PMID:24722578

  3. Pathogenicity of Fusarium semitectum against crop pests and its biosafety to non-target organisms.

    PubMed

    Mikunthan, G; Manjunatha, M

    2006-01-01

    Microbial control is receiving more attention, since these alternative tactics, compared to chemical control methods, are energy saving, non polluting, ecologically sound and sustainable. A mycopathogen, Fusarium semitectum Berk. and Rav. (ARSEF 7233) was isolated from diseased cadavers of aphid (Aphis gossypii) and cultured in Saboraud Maltose Agar supplemented with Yeast extract medium (SMAY). Being isolated first time from the chilli ecosystem its potential was evaluated. Experiments were conducted to understand its pathogenicity against crop pests as well as to ensure its safety to non target organisms such as silk worm (Bombyx mor), honey bee (Apis indica) and earthworm (Eisenia foetida). A paper-thrips-paper sandwich method for thrips and detached-leaf bioassay method for mites were used. Test insects and mites either reared in laboratory or obtained from the field were topically applied with spore suspension of F. semitectum (1x10(9) spores/ml). Mortality was recorded and dead animals were surface sterilized with 0.5% NaOCl and placed in SMAY medium to confirm pathogenicity. Mulberry leaves sprayed with the fungal suspension were fed to larvae of B. mori and reared. Newly emerged A. indica were topically applied with fungus. The fungus grown in cow dung for two weeks was used to assess the composting ability of E. foetida. F. semitectum produced mycosis and caused mortality to sucking pests such as chilli thrips (Scirtothrips dorsalis), broad mite (Polyphagotarsonemus latus), sugarcane wooly aphid (Ceratavacuna lanigera), spiraling whitefly (Aleyrodicus disperses), whitefly (Bemisia tabaci, A. gossypii and coconut mite (Aceria guerroronis). The fungus did not cause mortality on larvae of lepidopteran insect pests and ladybird beetle (Menochilus sexmaculatus), predatory mite (Amblysius ovalis) and larval parasitoid (Goniozus nephantidis). F. semitectum failed to infect the larvae of B. mori and newly emerged A. indica and its brood. The mycopathogen had no influence on the composting ability and growth of E. foetida. F. semitectum, in general, expressed its selectivity against sucking pests and proved its eco-friendly characteristics to the beneficial organisms and especially safe to Sericulture, Apiculture and Vermiculture industries in Karnataka, India. This novel fungus can be well incorporated as a viable tactics into the integrated management programmes of crop pests. PMID:17385514

  4. Antifungal Activity of a Synthetic Cationic Peptide against the Plant Pathogens Colletotrichum graminicola and Three Fusarium Species

    PubMed Central

    Johnson, Eric T.; Evans, Kervin O.; Dowd, Patrick F.

    2015-01-01

    A small cationic peptide (JH8944) was tested for activity against a number of pathogens of agricultural crops. JH8944 inhibited conidium growth in most of the tested plant pathogens with a dose of 50 μg/ml, although one isolate of Fusarium oxysporum was inhibited at 5 μg/ml of JH8944. Most conidia of Fusarium graminearum were killed within 6 hours of treatment with 50 μg/ml of JH8944. Germinating F. graminearum conidia required 238 μg/ml of JH8944 for 90% growth inhibition. The peptide did not cause any damage to tissues surrounding maize leaf punctures when tested at a higher concentration of 250 μg/ml even after 3 days. Liposomes consisting of phosphatidylglycerol were susceptible to leakage after treatment with 25 and 50 μg/ml of JH8944. These experiments suggest this peptide destroys fungal membrane integrity and could be utilized for control of crop fungal pathogens. PMID:26361481

  5. Transgenic expression of polygalacturonase-inhibiting proteins in Arabidopsis and wheat increases resistance to the flower pathogen Fusarium graminearum.

    PubMed

    Ferrari, S; Sella, L; Janni, M; De Lorenzo, G; Favaron, F; D'Ovidio, R

    2012-03-01

    Fusarium head blight (FHB), caused by Fusarium graminearum, is one of the most important diseases of wheat worldwide, resulting in yield losses and mycotoxin contamination. The molecular mechanisms regulating Fusarium penetration and infection are poorly understood. Beside mycotoxin production, cell wall degradation may play a role in the development of FHB. Many fungal pathogens secrete polygalacturonases (PGs) during the early stages of infection, and plants have evolved polygalacturonase-inhibiting proteins (PGIPs) to restrict pectin degradation during fungal infection. To investigate the role of plant PGIPs in restricting the development of FHB symptoms, we first used Arabidopsis thaliana, whose genome encodes two PGIPs (AtPGIP1 and AtPGIP2). Arabidopsis transgenic plants expressing either of these PGIPs under control of the CaMV 35S promoter accumulate inhibitory activity against F. graminearum PG in their inflorescences, and show increased resistance to FHB. Second, transgenic wheat plants expressing the bean PvPGIP2 in their flowers also had a significant reduction of symptoms when infected with F. graminearum. Our data suggest that PGs likely play a role in F. graminearum infection of floral tissues, and that PGIPs incorporated into wheat may be important for increased resistance to FHB. PMID:21974721

  6. Molecular diagnostics on the toxigenic potential of Fusarium spp. plant pathogens

    PubMed Central

    Dawidziuk, A; Koczyk, G; Popiel, D; Kaczmarek, J; Buśko, M

    2014-01-01

    Aims We propose and test an efficient and rapid protocol for the detection of toxigenic Fusarium isolates producing three main types of Fusarium-associated mycotoxins (fumonisins, trichothecenes and zearelanone). Methods and Results The novel approach utilizes partially multiplexed markers based on genes essential for mycotoxin biosynthesis (fumonisin—fum6, fum8; trichothecenes—tri5, tri6; zearalenone, zea2) in Fusarium spp. The protocol has been verified by screening a collection of 96 isolates representing diverse species of filamentous fungi. Each Fusarium isolate was taxonomically identified through both molecular and morphological techniques. The results demonstrate a reliable detection of toxigenic potential for trichothecenes (sensitivity 100%, specificity 95%), zearalenone (sensitivity 100%, specificity 100%) and fumonisins (sensitivity 94%, specificity 88%). Both presence and identity of toxin biosynthetic genes were further confirmed by direct sequencing of amplification products. Conclusions The cross-species-specific PCR markers for key biosynthetic genes provide a sensitive detection of toxigenic fungal isolates, contaminating biological material derived from agricultural fields. Significance and Impact of the Study The conducted study shows that a PCR-based assay of biosynthetic genes is a reliable, cost-effective, early warning system against Fusarium contamination. Its future use as a high-throughput detection strategy complementing chemical assays enables effective targeted application of crop protection products. PMID:24575830

  7. Fusaric acid is a crucial factor in the disturbance of leaf water imbalance in Fusarium-infected banana plants.

    PubMed

    Dong, Xian; Ling, Ning; Wang, Min; Shen, Qirong; Guo, Shiwei

    2012-11-01

    Fusarium wilt of banana is caused by Fusarium oxysporum f. sp. cubense infection. The initial chlorosis symptoms occur progressively from lower to upper leaves, with wilt symptoms subsequently occurring in the whole plant. To determine the effect of the pathogen infection on the gas exchange characteristics and water content in banana leaves, hydroponic experiments with pathogen inoculation were conducted in a greenhouse. Compared with control plants, infected banana seedlings showed a higher leaf temperature as determined by thermal imaging. Reduced stomatal conductance (g(s)) and transpiration rate (E) in infected plants resulted in lower levels of water loss than in control plants. Water potential in heavily diseased plants (II) was significantly reduced and the E/g(s) ratio was higher than in noninfected plants, indicating the occurrence of uncontrolled water loss not regulated by stomata in diseased plants. As no pathogen colonies were detected from the infected plant leaves, the crude toxin was extracted from the pathogen culture and evaluated about the effect on banana plant to further investigate the probable reason of these physiological changes in Fusarium-infected banana leaf. The phytotoxin fusaric acid (FA) was found in the crude toxin, and both crude toxin and pure FA had similar effects as the pathogen infection on the physiological changes in banana leaf. Additionally, FA was present at all positions in diseased plants and its concentration was positively correlated with the incidence of disease symptoms. Taken together, these observations indicated that FA secreted by the pathogen is an important factor involved in the disturbance of leaf temperature, resulting in uncontrolled leaf water loss and electrolyte leakage due to damaging the cell membrane. In conclusion, FA plays a critical role in accelerating the development of Fusarium wilt in banana plants by acting as a phytotoxin. PMID:22964424

  8. Candida and Fusarium species known as opportunistic human pathogens from customer-accessible parts of residential washing machines.

    PubMed

    Babič, Monika Novak; Zalar, Polona; Ženko, Bernard; Schroers, Hans-Josef; Džeroski, Sašo; Gunde-Cimerman, Nina

    2015-03-01

    Energy constraints have altered consumer practice regarding the use of household washing machines. Washing machines were developed that use lower washing temperatures, smaller amounts of water and biodegradable detergents. These conditions may favour the enrichment of opportunistic human pathogenic fungi. We focused on the isolation of fungi from two user-accessible parts of washing machines that often contain microbial biofilms: drawers for detergents and rubber door seals. Out of 70 residential washing machines sampled in Slovenia, 79% were positive for fungi. In total, 72 strains belonging to 12 genera and 26 species were isolated. Among these, members of the Fusarium oxysporum and Fusarium solani species complexes, Candida parapsilosis and Exophiala phaeomuriformis represented 44% of fungi detected. These species are known as opportunistic human pathogens and can cause skin, nail or eye infections also in healthy humans. A machine learning analysis revealed that presence of detergents and softeners followed by washing temperature, represent most critical factors for fungal colonization. Three washing machines with persisting malodour that resulted in bad smelling laundry were analysed for the presence of fungi and bacteria. In these cases, fungi were isolated in low numbers (7.5 %), while bacteria Micrococcus luteus, Pseudomonas aeruginosa, and Sphingomonas species prevailed. PMID:25749362

  9. Release of pea germplasm with Fusarium resistance combined with desirable yield and anti-lodging traits

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fusarium root rot caused by Fusarium solani f. sp. pisi (Fsp) and Fusarium wilt caused by Fusarium oxysporum f. sp. pisi (Fop) races 1, 2 and 5, negatively impact the pea industry worldwide. Limited pea germplasm with agronomically acceptable characteristics combined with resistance to these disease...

  10. Effects of arbuscular mycorrhizal fungi and a non-pathogenic Fusarium oxysporum on Meloidogyne incognita infestation of tomato.

    PubMed

    Diedhiou, P M; Hallmann, J; Oerke, E-C; Dehne, H-W

    2003-08-01

    Arbuscular mycorrhizal (AM) fungi and non-pathogenic strains of soil-borne pathogens have been shown to control plant parasitic nematodes. As AM fungi and non-pathogenic fungi improve plant health by different mechanisms, combination of two such partners with complementary mechanisms might increase overall control efficacy and, therefore, provide an environmentally safe alternative to nematicide application. Experiments were conducted to study possible interactions between the AM fungus Glomus coronatum and the non-pathogenic Fusarium oxysporum strain Fo162 in the control of Meloidogyne incognita on tomato. Pre-inoculation of tomato plants with G. coronatum or Fo162 stimulated plant growth and reduced M. incognita infestation. Combined application of the AM fungus and Fo162 enhanced mycorrhization of tomato roots but did not increase overall nematode control or plant growth. A higher number of nematodes per gall was found for mycorrhizal than non-mycorrhizal plants. In synergisms between biocontrol agents, differences in their antagonistic mechanisms seem to be less important than their effects on different growth stages of the pathogen. PMID:12938032

  11. Species composition, toxigenic potential and pathogenicity of Fusarium graminearum species complex isolates from southern Brazilian rice

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study aimed to assess the extent and distribution of Fusarium graminearum species complex (FGSC) diversity in Brazilian rice. Four species and two trichothecene genotypes were found among 89 FGSC isolates obtained from infected seeds: F. asiaticum with the nivalenol (NIV) genotype (69%), F. gra...

  12. Control of Root Rot and Wilt Diseases of Roselle under Field Conditions

    PubMed Central

    Hassan, Naglaa; Elsharkawy, Mohsen Mohamed; Shimizu, Masafumi

    2014-01-01

    Roselle (Hibiscus sabdariffa L.) is one of the most important medicinal crops in many parts of the world. In this study, the effects of microelements, antioxidants, and bioagents on Fusarium oxysporum, F. solani, and Macrophomina phaseolina, the causal pathogens of root rot and wilt diseases in roselle, were examined under field conditions. Preliminary studies were carried out in vitro in order to select the most effective members to be used in field control trials. Our results showed that microelements (copper and manganese), antioxidants (salicylic acid, ascorbic acid, and EDTA), a fungicide (Dithane M45) and biological control agents (Trichoderma harzianum and Bacillus subtilis) were significantly reduced the linear growth of the causal pathogens. Additionally, application of the previous microelements, antioxidants, a fungicide and biological control agents significantly reduced disease incidence of root rot and wilt diseases under field conditions. Copper, salicylic acid, and T. harzianum showed the best results in this respect. In conclusion, microelements, antioxidants, and biocontrol agents could be used as alternative strategies to fungicides for controlling root rot and wilt diseases in roselle. PMID:25606010

  13. Control of Root Rot and Wilt Diseases of Roselle under Field Conditions.

    PubMed

    Hassan, Naglaa; Elsharkawy, Mohsen Mohamed; Shimizu, Masafumi; Hyakumachi, Mitsuro

    2014-12-01

    Roselle (Hibiscus sabdariffa L.) is one of the most important medicinal crops in many parts of the world. In this study, the effects of microelements, antioxidants, and bioagents on Fusarium oxysporum, F. solani, and Macrophomina phaseolina, the causal pathogens of root rot and wilt diseases in roselle, were examined under field conditions. Preliminary studies were carried out in vitro in order to select the most effective members to be used in field control trials. Our results showed that microelements (copper and manganese), antioxidants (salicylic acid, ascorbic acid, and EDTA), a fungicide (Dithane M45) and biological control agents (Trichoderma harzianum and Bacillus subtilis) were significantly reduced the linear growth of the causal pathogens. Additionally, application of the previous microelements, antioxidants, a fungicide and biological control agents significantly reduced disease incidence of root rot and wilt diseases under field conditions. Copper, salicylic acid, and T. harzianum showed the best results in this respect. In conclusion, microelements, antioxidants, and biocontrol agents could be used as alternative strategies to fungicides for controlling root rot and wilt diseases in roselle. PMID:25606010

  14. Effect of different ecological conditions on secondary metabolite production and gene expression in two mycotoxigenic plant pathogen Fusarium species: F. verticillioides and F. equiseti

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The genus Fusarium includes many species that are plant pathogens and many produce harmful secondary metabolites including fumonisins and trichothecenes. These mycotoxins can cause disease in animals and have been associated with cancers and birth defects in humans. Many factors influence the produc...

  15. Fusarium torreyae sp. nov., a pathogen causing canker disease of Florida torreya (Torreya taxifolia), a critically endangered conifer restricted to northern Florida and southwestern Georgia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    During a survey for pathogens of Florida torreya (Torreya taxifolia) conducted in 2009, a novel Fusarium species was isolated from cankers affecting this critically endangered conifer whose current range is restricted to northern Florida and southwestern Georgia. Published multilocus molecular phylo...

  16. Evaluation of a triplex real-time PCR system to detect the plant-pathogenic molds Alternaria spp., Fusarium spp. and C. purpurea.

    PubMed

    Grube, Sabrina; Schönling, Jutta; Prange, Alexander

    2015-12-01

    This article describes the development of a triplex real-time PCR system for the simultaneous detection of three major plant-pathogenic mold genera (Alternaria spp., Fusarium spp. and the species Claviceps purpurea). The designed genus-specific primer-probe systems were validated for sensitivity, specificity and amplification in the presence of background DNA. PMID:26545945

  17. Comparison of inoculation methods for characterizing relative aggressiveness of two soybean sudden-death syndrome pathogens, Fusarium virguliforme and F. tucumaniae

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fusarium tucumaniae and F. virguliforme are the primary etiological agents of sudden-death syndrome (SDS) of soybean in Argentina and the United States, respectively. Five isolates of F. tucumaniae and four of F. virguliforme were tested for pathogenicity to soybeans, by comparing a toothpick method...

  18. Colonization of Flax Roots and Early Physiological Responses of Flax Cells Inoculated with Pathogenic and Nonpathogenic Strains of Fusarium oxysporum

    PubMed Central

    Olivain, Chantal; Trouvelot, Sophie; Binet, Marie-Noëlle; Cordier, Christelle; Pugin, Alain; Alabouvette, Claude

    2003-01-01

    Fusarium oxysporum includes nonpathogenic strains and pathogenic strains that can induce necrosis or tracheomycosis in plants. The objective of this study was to compare the abilities of a pathogenic strain (Foln3) and a nonpathogenic strain (Fo47) to colonize flax roots and to induce early physiological responses in flax cell culture suspensions. Both strains colonized the outer cortex of the root; however, plant defense reactions, i.e., the presence of wall appositions, osmiophilic material, and collapsed cells, were less frequent and less intense in a root colonized by Foln3 than by Fo47. Early physiological responses were measured in flax cell suspensions confronted with germinated microconidia of both strains. Both pathogenic (Foln3) and nonpathogenic strains (Fo47) triggered transient H2O2 production in the first few minutes of the interaction, but the nonpathogenic strain also induced a second burst 3 h postinoculation. Ca2+ influx was more intense in cells inoculated with Fo47 than in cells inoculated with Foln3. Similarly, alkalinization of the extracellular medium was higher with Fo47 than with Foln3. Inoculation of the fungi into flax cell suspensions induced cell death 10 to 20 h postinoculation, with a higher percentage of dead cells observed with Fo47 than with Foln3 beginning at 14 h. This is the first report showing that early physiological responses of flax cells can be used to distinguish pathogenic and nonpathogenic strains of the soil-borne fungus F. oxysporum. PMID:12957934

  19. MANAGEMENT OF SCLEROTINIA BLIGHT AND VERTICILLIUM WILT IN PEANUTS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Some of the objectives of this research are to study the biology of economically important peanut pathogens including Tomato Spotted Wilt Virus (TSWV), and to determine the role of disease resistance in managing soil-borne peanut pathogens, particularly Sclerotinia blight, Verticillium wilt, and Sou...

  20. Transcription factors spt3 and spt8 are associated with conidiation, mycelium growth, and pathogenicity in Fusarium graminearum.

    PubMed

    Gao, Tao; Zheng, Zhitian; Hou, Yiping; Zhou, Mingguo

    2014-02-01

    Fusarium graminearum (teleomorph: Gibberella zeae), the dominant pathogen of Fusarium head blight (FHB) on wheat, can cause substantial economic losses. The Spt-Ada-Gcn5-acetyltransferase (SAGA) transcription coactivator plays multiple roles in regulating transcription because of the presence of functionally independent modules of subunits within the complex. The transcription factors spt3 and spt8 are components of the SAGA complex and they are important in yeasts and filamentous fungi including F. graminearum. In this study, we identified Fgspt3 and Fgspt8, homologs of Saccharomyces cerevisiae spt3 and spt8 from F. graminearum using the blastp program. The aim of the present study was to investigate the functions of Fgspt3 and Fgspt8 in F. graminearum. The deletion mutants grew significantly more slowly than the wild-type parent and did not produce conidia. Expression of the sporulation-related genes FgFlbC and FgRen1 were significantly down-regulated in the mutants. The mutants exhibited no sexual reproduction on infected wheat kernels and a 90% decrease in virulence on wheat. Pigment formation was also greatly altered in the mutants. All of the defects were restored by genetic complementation of the mutant with wild-type Fgspt3 and Fgspt8 genes. Overall, Fgspt3 and Fgspt8 are essential genes in F. graminearum. PMID:24289742

  1. Accumulation of β-Fructosidase in the Cell Walls of Tomato Roots following Infection by a Fungal Wilt Pathogen 1

    PubMed Central

    Benhamou, Nicole; Grenier, Jean; Chrispeels, Maarten J.

    1991-01-01

    Active defense in plants is associated with marked metabolic alterations, but little is known about the exact role of the reported changes in specific activity of several enzymes in infected plant tissues. β-Fructosidase (invertase), the enzyme that converts sucrose into glucose and fructose, increases upon infection by fungi and bacteria. To understand the relationship between fungal growth and β-fructosidase accumulation, we used an antiserum raised against a purified deglycosylated carrot cell wall β-fructosidase to study by immunogold labeling the spatial and temporal distribution of the enzyme in susceptible and resistant tomato (Lycopersicon esculentum) root tissues infected with the necrotrophic fungus, Fusarium oxysporum f. sp. racidis-lycopersici. In susceptible plants, the enzyme started to accumulate in host cell walls about 72 hours after inoculation. Accumulation occurred only in colonized cells and was mainly restricted to areas where the walls of both partners contacted each other. In resistant plants, accumulation of β-fructosidase was noticeable as soon as 48 hours after inoculation and appeared to reach an optimum by 72 hours after inoculation. Increase in wall-bound β-fructosidase was not restricted to infected cells but occurred also, to a large extent, in tissues that remained uncolonized during the infection process. The enzyme also accumulated in wall appositions (papillae) and intercellular spaces. This pattern of enzyme distribution suggests that induction of β-fructosidase upon fungal infection is part of the plant's defense response. The possible physiological role(s) of this enzyme in infected tomato plants is discussed in relation to the high demand in energy and carbon sources during pathogenesis. ImagesFigure 1Figure 2Figure 3Figure 4Figure 5 PMID:16668461

  2. Phylogenetics and Taxonomy of the Fungal Vascular Wilt Pathogen Verticillium, with the Descriptions of Five New Species

    PubMed Central

    Inderbitzin, Patrik; Bostock, Richard M.; Davis, R. Michael; Usami, Toshiyuki; Platt, Harold W.; Subbarao, Krishna V.

    2011-01-01

    Knowledge of pathogen biology and genetic diversity is a cornerstone of effective disease management, and accurate identification of the pathogen is a foundation of pathogen biology. Species names provide an ideal framework for storage and retrieval of relevant information, a system that is contingent on a clear understanding of species boundaries and consistent species identification. Verticillium, a genus of ascomycete fungi, contains important plant pathogens whose species boundaries have been ill defined. Using phylogenetic analyses, morphological investigations and comparisons to herbarium material and the literature, we established a taxonomic framework for Verticillium comprising ten species, five of which are new to science. We used a collection of 74 isolates representing much of the diversity of Verticillium, and phylogenetic analyses based on the ribosomal internal transcribed spacer region (ITS), partial sequences of the protein coding genes actin (ACT), elongation factor 1-alpha (EF), glyceraldehyde-3-phosphate dehydrogenase (GPD) and tryptophan synthase (TS). Combined analyses of the ACT, EF, GPD and TS datasets recognized two major groups within Verticillium, Clade Flavexudans and Clade Flavnonexudans, reflecting the respective production and absence of yellow hyphal pigments. Clade Flavexudans comprised V. albo-atrum and V. tricorpus as well as the new species V. zaregamsianum, V. isaacii and V. klebahnii, of which the latter two were morphologically indistinguishable from V. tricorpus but may differ in pathogenicity. Clade Flavnonexudans comprised V. nubilum, V. dahliae and V. longisporum, as well as the two new species V. alfalfae and V. nonalfalfae, which resembled the distantly related V. albo-atrum in morphology. Apart from the diploid hybrid V. longisporum, each of the ten species corresponded to a single clade in the phylogenetic tree comprising just one ex-type strain, thereby establishing a direct link to a name tied to a herbarium specimen. A morphology-based key is provided for identification to species or species groups. PMID:22174791

  3. Arabidopsis defense response against Fusarium oxysporum.

    PubMed

    Berrocal-Lobo, Marta; Molina, Antonio

    2008-03-01

    The plant fungal pathogen Fusarium oxysporum (Fox) is the causal agent of root rot or wilt diseases in several plant species, including crops such as tomato (Solanum lycopersicum), banana (Musa sapientum) and asparagus (Asparagus officinalis). Colonization of plants by Fox leads to the necrosis of the infected tissues, a subsequent collapse of vascular vessels and decay of the plant. Plant resistance to Fox appears to be monogenic or oligogenic depending on the host. Perception of Fox by plants follows the concept of elicitor-induced immune response, which in turn activates several plant defense signaling pathways. Here, we review the Fox-derived elicitors identified so far and the interaction among the different signaling pathways mediating plant resistance to Fox. PMID:18289920

  4. Illumina-based analysis of the rhizosphere microbial communities associated with healthy and wilted Lanzhou lily (Lilium davidii var. unicolor) plants grown in the field.

    PubMed

    Shang, Qianhan; Yang, Guo; Wang, Yun; Wu, Xiukun; Zhao, Xia; Hao, Haiting; Li, Yuyao; Xie, Zhongkui; Zhang, Yubao; Wang, Ruoyu

    2016-06-01

    Lanzhou lily (Liliumdavidii var. unicolor) is the best edible lily as well as a traditional medicinal plant in China. The microbes associated with plant roots play crucial roles in plant growth and health. However, little is known about the differences of rhizosphere microbes between healthy and wilted Lanzhou lily (Lilium davidii var. unicolor) plants. The objective of this study was to compare the rhizosphere microbial community and functional diversity of healthy and wilted plants, and to identify potential biocontrol agents with significant effect. Paired end Illumina Mi-Seq sequencing of 16S rRNA and ITS gene amplicons was employed to study the bacterial and fungal communities in the rhizosphere soil of Lanzhou lily plants. BIOLOG technology was adopted to investigate the microbial functional diversity. Our results indicated that there were major differences in the rhizosphere microbial composition and functional diversity of wilted samples compared with healthy samples. Healthy Lanzhou lily plants exhibited lower rhizosphere-associated bacterial diversity than diseased plants, whereas fungi exhibited the opposite trend. The dominant phyla in both the healthy and wilted samples were Proteobacteria and Ascomycota, i.e., 34.45 and 64.01 %, respectively. The microbial functional diversity was suppressed in wilted soil samples. Besides Fusarium, the higher relative abundances of Rhizoctonia, Verticillium, Penicillium, and Ilyonectria (Neonectria) in the wilted samples suggest they may pathogenetic root rot fungi. The high relative abundances of Bacillus in Firmicutes in healthy samples may have significant roles as biological control agents against soilborne pathogens. This is the first study to find evidence of major differences between the microbial communities in the rhizospheric soil of healthy and wilted Lanzhou lily, which may be linked to the health status of plants. PMID:27116961

  5. Biological Efficacy of Streptomyces sp. Strain BN1 against the Cereal Head Blight Pathogen Fusarium graminearum

    PubMed Central

    Jung, Boknam; Park, Sook-Young; Lee, Yin-Won; Lee, Jungkwan

    2013-01-01

    Fusarium head blight (FHB) caused by the filamentous fungus Fusarium graminearum is one of the most severe diseases threatening the production of small grains. Infected grains are often contaminated with mycotoxins such as zearalenone and trichothecences. During survey of contamination by FHB in rice grains, we found a bacterial isolate, designated as BN1, antagonistic to F. graminearum. The strain BN1 had branching vegetative hyphae and spores, and its aerial hyphae often had long, straight filaments bearing spores. The 16S rRNA gene of BN1 had 100% sequence identity with those found in several Streptomyces species. Phylogenetic analysis of ITS regions showed that BN1 grouped with S. sampsonii with 77% bootstrap value, suggesting that BN1 was not a known Streptomyces species. In addition, the efficacy of the BN1 strain against F. graminearum strains was tested both in vitro and in vivo. Wheat seedling length was significantly decreased by F. graminearum infection. However, this effect was mitigated when wheat seeds were treated with BN1 spore suspension prior to F. graminearum infection. BN1 also significantly decreased FHB severity when it was sprayed onto wheat heads, whereas BN1 was not effective when wheat heads were point inoculated. These results suggest that spraying of BN1 spores onto wheat heads during the wheat flowering season can be efficient for plant protection. Mechanistic studies on the antagonistic effect of BN1 against F. graminearum remain to be analyzed. PMID:25288928

  6. Effect of Elevated Atmospheric CO2 and Temperature on the Disease Severity of Rocket Plants Caused by Fusarium Wilt under Phytotron Conditions

    PubMed Central

    Chitarra, Walter; Siciliano, Ilenia; Ferrocino, Ilario; Gullino, Maria Lodovica; Garibaldi, Angelo

    2015-01-01

    The severity of F. oxysporum f.sp. conglutinans on rocket plants grown under simulated climate change conditions has been studied. The rocket plants were cultivated on an infested substrate (4 log CFU g-1) and a non-infested substrate over three cycles. Pots were placed in six phytotrons in order to simulate different environmental conditions: 1) 400–450 ppm CO2, 18–22°C; 2) 800–850 ppm CO2, 18–22°C; 3) 400–450 ppm CO2, 22–26°C, 4) 800–850 ppm CO2, 22–26°C, 5) 400–450 ppm CO2, 26–30°C; 6) 800–850 ppm CO2, 26–30°C. Substrates from the infested and control samples were collected from each phytotron at 0, 60 and 120 days after transplanting. The disease index, microbial abundance, leaf physiological performances, root exudates and variability in the fungal profiles were monitored. The disease index was found to be significantly influenced by higher levels of temperature and CO2. Plate counts showed that fungal and bacterial development was not affected by the different CO2 and temperature levels, but a significant decreasing trend was observed from 0 up to 120 days. Conversely, the F. oxysporum f.sp. conglutinans plate counts did not show any significantly decrease from 0 up to 120 days. The fungal profiles, evaluated by means of polymerase chain reaction denaturing gradient gel electrophoresis (PCR-DGGE), showed a relationship to temperature and CO2 on fungal diversity profiles. Different exudation patterns were observed when the controls and infested plants were compared, and it was found that both CO2 and temperature can influence the release of compounds from the roots of rocket plants. In short, the results show that global climate changes could influence disease incidence, probably through plant-mediated effects, caused by soilborne pathogens. PMID:26469870

  7. Effect of Elevated Atmospheric CO2 and Temperature on the Disease Severity of Rocket Plants Caused by Fusarium Wilt under Phytotron Conditions.

    PubMed

    Chitarra, Walter; Siciliano, Ilenia; Ferrocino, Ilario; Gullino, Maria Lodovica; Garibaldi, Angelo

    2015-01-01

    The severity of F. oxysporum f.sp. conglutinans on rocket plants grown under simulated climate change conditions has been studied. The rocket plants were cultivated on an infested substrate (4 log CFU g-1) and a non-infested substrate over three cycles. Pots were placed in six phytotrons in order to simulate different environmental conditions: 1) 400-450 ppm CO2, 18-22°C; 2) 800-850 ppm CO2, 18-22°C; 3) 400-450 ppm CO2, 22-26°C, 4) 800-850 ppm CO2, 22-26°C, 5) 400-450 ppm CO2, 26-30°C; 6) 800-850 ppm CO2, 26-30°C. Substrates from the infested and control samples were collected from each phytotron at 0, 60 and 120 days after transplanting. The disease index, microbial abundance, leaf physiological performances, root exudates and variability in the fungal profiles were monitored. The disease index was found to be significantly influenced by higher levels of temperature and CO2. Plate counts showed that fungal and bacterial development was not affected by the different CO2 and temperature levels, but a significant decreasing trend was observed from 0 up to 120 days. Conversely, the F. oxysporum f.sp. conglutinans plate counts did not show any significantly decrease from 0 up to 120 days. The fungal profiles, evaluated by means of polymerase chain reaction denaturing gradient gel electrophoresis (PCR-DGGE), showed a relationship to temperature and CO2 on fungal diversity profiles. Different exudation patterns were observed when the controls and infested plants were compared, and it was found that both CO2 and temperature can influence the release of compounds from the roots of rocket plants. In short, the results show that global climate changes could influence disease incidence, probably through plant-mediated effects, caused by soilborne pathogens. PMID:26469870

  8. Individual and combined roles of malonichrome, ferricrocin, and TAFC siderophores in Fusarium graminearum pathogenic and sexual development

    PubMed Central

    Oide, Shinichi; Berthiller, Franz; Wiesenberger, Gerlinde; Adam, Gerhard; Turgeon, B. Gillian

    2015-01-01

    Intra- and extracellular iron-chelating siderophores produced by fungal non-ribosomal peptide synthetases have been shown to be involved in reproductive and pathogenic developmental processes and in iron and oxidative stress management. Here we report individual and combined contributions of three of these metabolites to developmental success of the destructive cereal pathogen Fusarium graminearum. In previous work, we determined that deletion of the NPS2 gene, responsible for intracellular siderophore biosynthesis, results in inability to produce sexual spores when mutants of this homothallic ascomycete are selfed. Deletion of the NPS6 gene, required for extracellular siderophore biosynthesis, does not affect sexual reproduction but results in sensitivity to iron starvation and oxidative stress and leads to reduced virulence to the host. Building on this, we report that double mutants lacking both NPS2 and NPS6 are augmented in all collective phenotypes of single deletion strains (i.e., abnormal sexual and pathogenic development, hypersensitivity to oxidative and iron-depletion stress), which suggests overlap of function. Using comparative biochemical analysis of wild-type and mutant strains, we show that NPS1, a third gene associated with siderophore biosynthesis, is responsible for biosynthesis of a second extracellular siderophore, malonichrome. nps1 mutants fail to produce this metabolite. Phenotypic characterization reveals that, although single nps1 mutants are like wild-type with respect to sexual development, hypersensitivity to ROS and iron-depletion stress, and virulence to the host, triple nps1nps2nps6 deletion strains, lacking all three siderophores, are even more impaired in these attributes than double nps2nps6 strains. Thus, combinatorial mutants lacking key iron-associated genes uncovered malonichrome function. The intimate connection between presence/absence of siderophores and resistance/sensitivity to ROS is central to sexual and pathogenic development. PMID:25628608

  9. Individual and combined roles of malonichrome, ferricrocin, and TAFC siderophores in Fusarium graminearum pathogenic and sexual development.

    PubMed

    Oide, Shinichi; Berthiller, Franz; Wiesenberger, Gerlinde; Adam, Gerhard; Turgeon, B Gillian

    2014-01-01

    Intra- and extracellular iron-chelating siderophores produced by fungal non-ribosomal peptide synthetases have been shown to be involved in reproductive and pathogenic developmental processes and in iron and oxidative stress management. Here we report individual and combined contributions of three of these metabolites to developmental success of the destructive cereal pathogen Fusarium graminearum. In previous work, we determined that deletion of the NPS2 gene, responsible for intracellular siderophore biosynthesis, results in inability to produce sexual spores when mutants of this homothallic ascomycete are selfed. Deletion of the NPS6 gene, required for extracellular siderophore biosynthesis, does not affect sexual reproduction but results in sensitivity to iron starvation and oxidative stress and leads to reduced virulence to the host. Building on this, we report that double mutants lacking both NPS2 and NPS6 are augmented in all collective phenotypes of single deletion strains (i.e., abnormal sexual and pathogenic development, hypersensitivity to oxidative and iron-depletion stress), which suggests overlap of function. Using comparative biochemical analysis of wild-type and mutant strains, we show that NPS1, a third gene associated with siderophore biosynthesis, is responsible for biosynthesis of a second extracellular siderophore, malonichrome. nps1 mutants fail to produce this metabolite. Phenotypic characterization reveals that, although single nps1 mutants are like wild-type with respect to sexual development, hypersensitivity to ROS and iron-depletion stress, and virulence to the host, triple nps1nps2nps6 deletion strains, lacking all three siderophores, are even more impaired in these attributes than double nps2nps6 strains. Thus, combinatorial mutants lacking key iron-associated genes uncovered malonichrome function. The intimate connection between presence/absence of siderophores and resistance/sensitivity to ROS is central to sexual and pathogenic development. PMID:25628608

  10. Shifts in banana root exudate profiles after colonization with the non-pathogenic Fusarium oxysporum strain Fo162.

    PubMed

    Kurtz, Andreas; Schouten, Alexander

    2009-01-01

    The non-pathogenic fungus Fusorium oxysporum strain Fo162 can efficiently colonize banana roots and reduce infecting by the burrowing nematode Radopholus similis. It is assumed that the fungus triggers a systemic reaction in the plant, which is affecting the biochemical composition of the root exudates and is thus causing the reduction in nematode colonization. To characterize these shifts, a continuous flow experiment was set up to collect root metabolites on a matrix (XAD-4). Based on HPLC analysis, the extracts, collected from the XAD-4, showed no differences in the composition of the root exudates between plants colonized by the endophyte and the controls. However, the accumulation of several compounds differed significantly. When these extracts were used in a bioassay with Radopholus similis none of the sample-treatment combinations had a significant attracting or repelling effect on the nematodes. This experiment shows that non-pathogenic Fusarium oxysporum strain Fo162 is able to upregulate the synthesis of at least some, so far unidentified compounds released by banana roots under hydroponic conditions. Further studies and optimization of the experimental setup are required to determine whether or not increase in metabolite concentration can affect nematode responses in vitro and ultimately in vivo. PMID:20222617

  11. Characterization of a JAZ7 activation-tagged Arabidopsis mutant with increased susceptibility to the fungal pathogen Fusarium oxysporum.

    PubMed

    Thatcher, Louise F; Cevik, Volkan; Grant, Murray; Zhai, Bing; Jones, Jonathan D G; Manners, John M; Kazan, Kemal

    2016-04-01

    In Arabidopsis, jasmonate (JA)-signaling plays a key role in mediatingFusarium oxysporumdisease outcome. However, the roles of JASMONATE ZIM-domain (JAZ) proteins that repress JA-signaling have not been characterized in host resistance or susceptibility to this pathogen. Here, we found mostJAZgenes are induced followingF. oxysporumchallenge, and screening T-DNA insertion lines in Arabidopsis JAZ family members identified a highly disease-susceptibleJAZ7mutant (jaz7-1D). This mutant exhibited constitutiveJAZ7expression and conferred increased JA-sensitivity, suggesting activation of JA-signaling. Unlikejaz7loss-of-function alleles,jaz7-1Dalso had enhanced JA-responsive gene expression, altered development and increased susceptibility to the bacterial pathogenPstDC3000 that also disrupts host JA-responses. We also demonstrate that JAZ7 interacts with transcription factors functioning as activators (MYC3, MYC4) or repressors (JAM1) of JA-signaling and contains a functional EAR repressor motif mediating transcriptional repression via the co-repressor TOPLESS (TPL). We propose through direct TPL recruitment, in wild-type plants JAZ7 functions as a repressor within the JA-response network and that injaz7-1Dplants, misregulated ectopic JAZ7 expression hyper-activates JA-signaling in part by disturbing finely-tuned COI1-JAZ-TPL-TF complexes. PMID:26896849

  12. Characterization of a JAZ7 activation-tagged Arabidopsis mutant with increased susceptibility to the fungal pathogen Fusarium oxysporum

    PubMed Central

    Thatcher, Louise F.; Cevik, Volkan; Grant, Murray; Zhai, Bing; Jones, Jonathan D.G.; Manners, John M.; Kazan, Kemal

    2016-01-01

    In Arabidopsis, jasmonate (JA)-signaling plays a key role in mediating Fusarium oxysporum disease outcome. However, the roles of JASMONATE ZIM-domain (JAZ) proteins that repress JA-signaling have not been characterized in host resistance or susceptibility to this pathogen. Here, we found most JAZ genes are induced following F. oxysporum challenge, and screening T-DNA insertion lines in Arabidopsis JAZ family members identified a highly disease-susceptible JAZ7 mutant (jaz7-1D). This mutant exhibited constitutive JAZ7 expression and conferred increased JA-sensitivity, suggesting activation of JA-signaling. Unlike jaz7 loss-of-function alleles, jaz7-1D also had enhanced JA-responsive gene expression, altered development and increased susceptibility to the bacterial pathogen Pst DC3000 that also disrupts host JA-responses. We also demonstrate that JAZ7 interacts with transcription factors functioning as activators (MYC3, MYC4) or repressors (JAM1) of JA-signaling and contains a functional EAR repressor motif mediating transcriptional repression via the co-repressor TOPLESS (TPL). We propose through direct TPL recruitment, in wild-type plants JAZ7 functions as a repressor within the JA-response network and that in jaz7-1D plants, misregulated ectopic JAZ7 expression hyper-activates JA-signaling in part by disturbing finely-tuned COI1-JAZ-TPL-TF complexes. PMID:26896849

  13. Loop-Mediated Isothermal Amplification of Specific Endoglucanase Gene Sequence for Detection of the Bacterial Wilt Pathogen Ralstonia solanacearum

    PubMed Central

    Pirc, Manca; Llop, Pablo; Ravnikar, Maja; Dreo, Tanja

    2014-01-01

    The increased globalization of crops production and processing industries also promotes the side-effects of more rapid and efficient spread of plant pathogens. To prevent the associated economic losses, and particularly those related to bacterial diseases where their management relies on removal of the infected material from production, simple, easy-to-perform, rapid and cost-effective tests are needed. Loop-mediated isothermal amplification (LAMP) assays that target 16S rRNA, fliC and egl genes were compared and evaluated as on-site applications. The assay with the best performance was that targeted to the egl gene, which shows high analytical specificity for diverse strains of the betaproteobacterium Ralstonia solanacearum, including its non-European and non-race 3 biovar 2 strains. The additional melting curve analysis provides confirmation of the test results. According to our extensive assessment, the egl LAMP assay requires minimum sample preparation (a few minutes of boiling) for the identification of pure cultures and ooze from symptomatic material, and it can also be used in a high-throughput format in the laboratory. This provides sensitive and reliable detection of R. solanacearum strains of different phylotypes. PMID:24763488

  14. The endophytic strain Fusarium oxysporum Fo47: a good candidate for priming the defense responses in tomato roots.

    PubMed

    Aim, Sbastien; Alabouvette, Claude; Steinberg, Christian; Olivain, Chantal

    2013-08-01

    The protective Fusarium oxysporum strain Fo47 is effective in controlling Fusarium wilt in tomato. Previous studies have demonstrated the role of direct antagonism and involvement of induced resistance. The aim of the present study was to investigate whether priming of plant defense responses is a mechanism by which Fo47 controls Fusarium wilt. An in vitro design enabled inoculation of the tap root with Fo47 and the pathogenic strain (Fol8) at different locations and different times. The expression levels of six genes known to be involved in tomato defense responses were quantified using reverse-transcription quantitative polymerase chain reaction (qPCR). Three genes-CHI3, GLUA, and PR-1a-were overexpressed in the root preinoculated with Fo47, and then challenged with Fol8. The genes GLUA and PR-1a were upregulated in cotyledons after inoculation of Fo47. Fungal growth in the root was assessed by qPCR, using specific markers for Fo47 and Fol8. Results showed a reduction of the pathogen growth in the root of the tomato plant preinoculated with Fo47. This study demonstrated that priming of tomato defense responses is one of the mechanisms of action of Fo47, which induces a reduced colonization of the root by the pathogen. PMID:23617416

  15. Molecular phylogeny, pathogenicity and toxigenicity of Fusarium oxysporum f. sp. lycopersici.

    PubMed

    Nirmaladevi, D; Venkataramana, M; Srivastava, Rakesh K; Uppalapati, S R; Gupta, Vijai Kumar; Yli-Mattila, T; Clement Tsui, K M; Srinivas, C; Niranjana, S R; Chandra, Nayaka S

    2016-01-01

    The present study aimed at the molecular characterization of pathogenic and non pathogenic F. oxysporum f. sp. lycopersici strains isolated from tomato. The causal agent isolated from symptomatic plants and soil samples was identified based on morphological and molecular analyses. Pathogenicity testing of 69 strains on five susceptible tomato varieties showed 45% of the strains were highly virulent and 30% were moderately virulent. Molecular analysis based on the fingerprints obtained through ISSR indicated the presence of wide genetic diversity among the strains. Phylogenetic analysis based on ITS sequences showed the presence of at least four evolutionary lineages of the pathogen. The clustering of F. oxysporum with non pathogenic isolates and with the members of other formae speciales indicated polyphyletic origin of F. oxysporum f. sp. lycopersici. Further analysis revealed intraspecies variability and nucleotide insertions or deletions in the ITS region among the strains in the study and the observed variations were found to be clade specific. The high genetic diversity in the pathogen population demands for development of effective resistance breeding programs in tomato. Among the pathogenic strains tested, toxigenic strains harbored the Fum1 gene clearly indicating that the strains infecting tomato crops have the potential to produce Fumonisin. PMID:26883288

  16. Molecular phylogeny, pathogenicity and toxigenicity of Fusarium oxysporum f. sp. lycopersici

    PubMed Central

    Nirmaladevi, D.; Venkataramana, M.; Srivastava, Rakesh K.; Uppalapati, S. R.; Gupta, Vijai Kumar; Yli-Mattila, T.; Clement Tsui, K. M.; Srinivas, C.; Niranjana, S. R.; Chandra, Nayaka S.

    2016-01-01

    The present study aimed at the molecular characterization of pathogenic and non pathogenic F. oxysporum f. sp. lycopersici strains isolated from tomato. The causal agent isolated from symptomatic plants and soil samples was identified based on morphological and molecular analyses. Pathogenicity testing of 69 strains on five susceptible tomato varieties showed 45% of the strains were highly virulent and 30% were moderately virulent. Molecular analysis based on the fingerprints obtained through ISSR indicated the presence of wide genetic diversity among the strains. Phylogenetic analysis based on ITS sequences showed the presence of at least four evolutionary lineages of the pathogen. The clustering of F. oxysporum with non pathogenic isolates and with the members of other formae speciales indicated polyphyletic origin of F. oxysporum f. sp. lycopersici. Further analysis revealed intraspecies variability and nucleotide insertions or deletions in the ITS region among the strains in the study and the observed variations were found to be clade specific. The high genetic diversity in the pathogen population demands for development of effective resistance breeding programs in tomato. Among the pathogenic strains tested, toxigenic strains harbored the Fum1 gene clearly indicating that the strains infecting tomato crops have the potential to produce Fumonisin. PMID:26883288

  17. Comparative study of the pathogenicity of seabed isolates of Fusarium equiseti and the effect of the composition of the mineral salt medium and temperature on mycelial growth

    PubMed Central

    Palmero, D.; de Cara, M.; Iglesias, C.; Gálvez, L.; Tello, J.C.

    2011-01-01

    The pathogenicity of seven strains of Fusarium equiseti isolated from seabed soil was evaluated on different host plants showing pre and post emergence damage. Radial growth of 27 strains was measured on culture media previously adjusted to different osmotic potentials with either KCl or NaCl (-1.50 to -144.54 bars) at 15°, 25° and 35° C. Significant differences and interactive effects were observed in the response of mycelia to osmotic potential and temperature. PMID:24031710

  18. Wheat kernel black point and fumonisin contamination by Fusarium Proliferatum

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fumonisins are mycotoxins produced by several Fusarium species, especially Fusarium proliferatum and Fusarium verticillioides, which are common pathogens of maize worldwide. Consumption of fumonisins has been shown to cause a number of mycotoxicoses, including leucoencephalomalacia in horses, pulmon...

  19. The Sfp-Type 4′-Phosphopantetheinyl Transferase Ppt1 of Fusarium fujikuroi Controls Development, Secondary Metabolism and Pathogenicity

    PubMed Central

    Wiemann, Philipp; Albermann, Sabine; Niehaus, Eva-Maria; Studt, Lena; von Bargen, Katharina W.; Brock, Nelson L.; Humpf, Hans-Ulrich; Dickschat, Jeroen S.; Tudzynski, Bettina

    2012-01-01

    The heterothallic ascomycete Fusarium fujikuroi is a notorious rice pathogen causing super-elongation of plants due to the production of terpene-derived gibberellic acids (GAs) that function as natural plant hormones. Additionally, F. fujikuroi is able to produce a variety of polyketide- and non-ribosomal peptide-derived metabolites such as bikaverins, fusarubins and fusarins as well as metabolites from yet unidentified biosynthetic pathways, e.g. moniliformin. The key enzymes needed for their production belong to the family of polyketide synthases (PKSs) and non-ribosomal peptide synthases (NRPSs) that are generally known to be post-translationally modified by a Sfp-type 4′phosphopantetheinyl transferase (PPTase). In this study we provide evidence that the F. fujikuroi Sfp-type PPTase FfPpt1 is essentially involved in lysine biosynthesis and production of bikaverins, fusarubins and fusarins, but not moniliformin as shown by analytical methods. Concomitantly, targeted Ffppt1 deletion mutants reveal an enhancement of terpene-derived metabolites like GAs and volatile substances such as α-acorenol. Pathogenicity assays on rice roots using fluorescent labeled wild-type and Ffppt1 mutant strains indicate that lysine biosynthesis and iron acquisition but not PKS and NRPS metabolism is essential for establishment of primary infections of F. fujikuroi. Additionally, FfPpt1 is involved in conidiation and sexual mating recognition possibly by activating PKS- and/or NRPS-derived metabolites that could act as diffusible signals. Furthermore, the effect on iron acquisition of Ffppt1 mutants led us to identify a previously uncharacterized putative third reductive iron uptake system (FfFtr3/FfFet3) that is closely related to the FtrA/FetC system of A. fumigatus. Functional characterization provides evidence that both proteins are involved in iron acquisition and are liable to transcriptional repression of the homolog of the Aspergillus GATA-type transcription factor SreA under iron-replete conditions. Targeted deletion of the first Fusarium homolog of this GATA-type transcription factor-encoding gene, Ffsre1, strongly indicates its involvement in regulation of iron homeostasis and oxidative stress resistance. PMID:22662164

  20. Molecular identification of Fusarium species isolated from transgenic insect-resistant cotton plants in Mexicali valley, Baja California.

    PubMed

    Gonzalez-Soto, T; González-Mendoza, D; Troncoso-Rojas, R; Morales-Trejo, A; Ceceña-Duran, C; Garcia-Lopez, A; Grimaldo-Juarez, O

    2015-01-01

    Cotton production in the Mexicali valley is adversely affected by wilt and root rot disease associated with Fusarium species. In the present study, we sought to isolate and identify the Fusarium species in the rhizosphere of transgenic insect-resistant cotton plants grown in the Mexicali valley. Our analyses isolated four native fungi from the rhizosphere of cotton plants, namely, T-ICA01, T-ICA03, T-ICA04, and T-ICA08. These fungal isolates were categorized as belonging to Fusarium solani using their phenotypic characteristics and ITS region sequence data. Examination of the infection index showed that T-ICA03 and T-ICA04 caused systemic colonization (90%) of seeds followed by the occurrence of radicle and coleoptile decay. In contrast, T-ICA08 strain was less pathogenic against seed tissues (40%) in comparison to the other strains isolated. Our study showed that in transgenic insect-resistant cotton the disease "Fusarium wilt" is caused by the fungus, F. solani. Future studies are necessary to characterize the F. solani populations to determine whether phenological stages might influence the genetic diversity of the fungal populations present. PMID:26436498

  1. An adaptive evolutionary shift in Fusarium head blight pathogen populations is driving the rapid spread of more toxigenic Fusarium graminerarum in North America

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Toxigenic fungi responsible for Fusarium head blight (FHB) place significant constraints on the production of cereals worldwide and contaminate grain with trichothecene mycotoxins that pose a serious threat to food safety. A fraction of the global FHB species and trichothecene chemotype diversity i...

  2. Diversity of laccase-coding genes in Fusarium oxysporum genomes.

    PubMed

    Kwiatos, Natalia; Ryngajłło, Małgorzata; Bielecki, Stanisław

    2015-01-01

    Multiple studies confirm laccase role in fungal pathogenicity and lignocellulose degradation. In spite of broad genomic research, laccases from plant wilt pathogen Fusarium oxysporum are still not characterized. The study aimed to identify F. oxysporum genes that may encode laccases sensu stricto and to characterize the proteins in silico in order to facilitate further research on their impact on the mentioned processes. Twelve sequenced F. oxysporum genomes available on Broad Institute of Harvard and MIT (2015) website were analyzed and three genes that may encode laccases sensu stricto were found. Their amino acid sequences possess all features essential for their catalytic activity, moreover, the homology models proved the characteristic 3D laccase structures. The study shades light on F. oxysporum as a new source of multicopper oxidases, enzymes with possible high redox potential and broad perspective in biotechnological applications. PMID:26441870

  3. Targeting Iron Acquisition Blocks Infection with the Fungal Pathogens Aspergillus fumigatus and Fusarium oxysporum

    PubMed Central

    Leal, Sixto M.; Roy, Sanhita; Vareechon, Chairut; Carrion, Steven deJesus; Clark, Heather; Lopez-Berges, Manuel S.; diPietro, Antonio; Schrettl, Marcus; Beckmann, Nicola; Redl, Bernhard; Haas, Hubertus; Pearlman, Eric

    2013-01-01

    Filamentous fungi are an important cause of pulmonary and systemic morbidity and mortality, and also cause corneal blindness and visual impairment worldwide. Utilizing in vitro neutrophil killing assays and a model of fungal infection of the cornea, we demonstrated that Dectin-1 dependent IL-6 production regulates expression of iron chelators, heme and siderophore binding proteins and hepcidin in infected mice. In addition, we show that human neutrophils synthesize lipocalin-1, which sequesters fungal siderophores, and that topical lipocalin-1 or lactoferrin restricts fungal growth in vivo. Conversely, we show that exogenous iron or the xenosiderophore deferroxamine enhances fungal growth in infected mice. By examining mutant Aspergillus and Fusarium strains, we found that fungal transcriptional responses to low iron levels and extracellular siderophores are essential for fungal growth during infection. Further, we showed that targeting fungal iron acquisition or siderophore biosynthesis by topical application of iron chelators or statins reduces fungal growth in the cornea by 60% and that dual therapy with the iron chelator deferiprone and statins further restricts fungal growth by 75%. Together, these studies identify specific host iron-chelating and fungal iron-acquisition mediators that regulate fungal growth, and demonstrate that therapeutic inhibition of fungal iron acquisition can be utilized to treat topical fungal infections. PMID:23853581

  4. Heterochromatin influences the secondary metabolite profile in the plant pathogen Fusarium graminearum

    PubMed Central

    Reyes-Dominguez, Yazmid; Boedi, Stefan; Sulyok, Michael; Wiesenberger, Gerlinde; Stoppacher, Norbert; Krska, Rudolf; Strauss, Joseph

    2012-01-01

    Chromatin modifications and heterochromatic marks have been shown to be involved in the regulation of secondary metabolism gene clusters in the fungal model system Aspergillus nidulans. We examine here the role of HEP1, the heterochromatin protein homolog of Fusarium graminearum, for the production of secondary metabolites. Deletion of Hep1 in a PH-1 background strongly influences expression of genes required for the production of aurofusarin and the main tricothecene metabolite DON. In the Hep1 deletion strains AUR genes are highly up-regulated and aurofusarin production is greatly enhanced suggesting a repressive role for heterochromatin on gene expression of this cluster. Unexpectedly, gene expression and metabolites are lower for the trichothecene cluster suggesting a positive function of Hep1 for DON biosynthesis. However, analysis of histone modifications in chromatin of AUR and DON gene promoters reveals that in both gene clusters the H3K9me3 heterochromatic mark is strongly reduced in the Hep1 deletion strain. This, and the finding that a DON-cluster flanking gene is up-regulated, suggests that the DON biosynthetic cluster is repressed by HEP1 directly and indirectly. Results from this study point to a conserved mode of secondary metabolite (SM) biosynthesis regulation in fungi by chromatin modifications and the formation of facultative heterochromatin. PMID:22100541

  5. Development of the molecular methods for rapid detection and differentiation of Fusarium oxysporum and F. oxysporum f. sp. niveum in Taiwan.

    PubMed

    Lin, Ying-Hong; Chen, Kan-Shu; Chang, Jing-Yi; Wan, Yu-Ling; Hsu, Ching-Chi; Huang, Jenn-Wen; Chang, Pi-Fang Linda

    2010-09-30

    Fusarium wilt, caused by Fusarium oxysporum (Fo), is one of the most important fungal diseases worldwide. Like other plant pathogens, Fo displays specialized forms in association with its hosts. For example, F. oxysporum f. sp. niveum (Fon) is the damaging pathogen causing Fusarium wilt disease on watermelon, whereas F. oxysporum f. sp. cubense is the pathogen that infects banana. A rapid and reliable pathogen identification or disease diagnosis is essential for the integrated disease management practices in many crops. In this study, two new primer sets, Fon-1/Fon-2 and FnSc-1/FnSc-2, were developed to differentiate Fon and Fo, respectively. The PCR method using the novel primer sets has high sensitivity to detect Fon when the DNA concentration was as low as 0.01 pg or when the conidia number was as few as 5. In comparison with the published primer set, the Fon-1/Fon-2 primer set, derived from the sequence of OP-M12 random primer-amplified fragment, produced a 174 bp DNA fragment, and was more specific to Fon in Taiwan. In addition, with optimized PCR parameters, the molecular method using the Fon-1/Fon-2 primer set could directly detect Fon even when watermelon samples were collected in its early stage of disease development. PMID:20471505

  6. Deep mRNA sequencing reveals stage-specific transcriptome alterations during microsclerotia development in the smoke tree vascular wilt pathogen, Verticillium dahliae

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Verticillium dahliae is a soil-borne fungus that causes vascular wilt diseases in a wide range of plant hosts. V. dahliae produces multicelled, melanized resting bodies, also known as microsclerotia (MS) that can survive for years in the soil. Thus, MS formation marks an important event in the disea...

  7. The velvet gene, FgVe1, affects fungal development and positively regulates trichothecene biosynthesis and pathogenicity in Fusarium graminearum.

    PubMed

    Merhej, Jawad; Urban, Martin; Dufresne, Marie; Hammond-Kosack, Kim E; Richard-Forget, Florence; Barreau, Christian

    2012-05-01

    Trichothecenes are a group of toxic secondary metabolites produced mainly by Fusarium graminearum (teleomorph: Gibberella zeae) during the infection of crop plants, including wheat, maize, barley, oats, rye and rice. Some fungal genes involved in trichothecene biosynthesis have been shown to encode regulatory proteins. However, the global regulation of toxin biosynthesis is still enigmatic. In addition to the production of secondary metabolites belonging to the trichothecene family, F. graminearum produces the red pigment aurofusarin. The gene regulation underlying the production of aurofusarin is not well understood. The velvet gene (veA) is conserved in various genera of filamentous fungi. Recently, the veA gene from Aspergillus nidulans has been shown to be the key component of the velvet complex regulating development and secondary metabolism. Using blast analyses, we identified the velvet gene from F. graminearum, FgVe1. Disruption of FgVe1 causes several phenotypic effects. However, the complementation of this mutant with the FgVe1 gene restores the wild-type phenotypes. The in vitro phenotypes include hyperbranching of the mycelium, suppression of aerial hyphae formation, reduced hydrophobicity of the mycelium and highly reduced sporulation. Our data also show that FgVe1 modulates the production of the aurofusarin pigment and is essential for the expression of Tri genes and the production of trichothecenes. Pathogenicity studies performed on flowering wheat plants indicate that FgVe1 is a positive regulator of virulence in F. graminearum. PMID:22013911

  8. Silver nanoparticle production by the fungus Fusarium oxysporum: nanoparticle characterisation and analysis of antifungal activity against pathogenic yeasts.

    PubMed

    Ishida, Kelly; Cipriano, Talita Ferreira; Rocha, Gustavo Miranda; Weissmüller, Gilberto; Gomes, Fabio; Miranda, Kildare; Rozental, Sonia

    2014-04-01

    The microbial synthesis of nanoparticles is a green chemistry approach that combines nanotechnology and microbial biotechnology. The aim of this study was to obtain silver nanoparticles (SNPs) using aqueous extract from the filamentous fungus Fusarium oxysporum as an alternative to chemical procedures and to evaluate its antifungal activity. SNPs production increased in a concentration-dependent way up to 1 mM silver nitrate until 30 days of reaction. Monodispersed and spherical SNPs were predominantly produced. After 60 days, it was possible to observe degenerated SNPs with in additional needle morphology. The SNPs showed a high antifungal activity against Candida and Cryptococcus , with minimum inhibitory concentration values ≤ 1.68 µg/mL for both genera. Morphological alterations of Cryptococcus neoformans treated with SNPs were observed such as disruption of the cell wall and cytoplasmic membrane and lost of the cytoplasm content. This work revealed that SNPs can be easily produced by F. oxysporum aqueous extracts and may be a feasible, low-cost, environmentally friendly method for generating stable and uniformly sized SNPs. Finally, we have demonstrated that these SNPs are active against pathogenic fungi, such as Candida and Cryptococcus. PMID:24714966

  9. Silver nanoparticle production by the fungus Fusarium oxysporum: nanoparticle characterisation and analysis of antifungal activity against pathogenic yeasts

    PubMed Central

    Ishida, Kelly; Cipriano, Talita Ferreira; Rocha, Gustavo Miranda; Weissmüller, Gilberto; Gomes, Fabio; Miranda, Kildare; Rozental, Sonia

    2013-01-01

    The microbial synthesis of nanoparticles is a green chemistry approach that combines nanotechnology and microbial biotechnology. The aim of this study was to obtain silver nanoparticles (SNPs) using aqueous extract from the filamentous fungus Fusarium oxysporum as an alternative to chemical procedures and to evaluate its antifungal activity. SNPs production increased in a concentration-dependent way up to 1 mM silver nitrate until 30 days of reaction. Monodispersed and spherical SNPs were predominantly produced. After 60 days, it was possible to observe degenerated SNPs with in additional needle morphology. The SNPs showed a high antifungal activity against Candida and Cryptococcus , with minimum inhibitory concentration values ≤ 1.68 µg/mL for both genera. Morphological alterations of Cryptococcus neoformans treated with SNPs were observed such as disruption of the cell wall and cytoplasmic membrane and lost of the cytoplasm content. This work revealed that SNPs can be easily produced by F. oxysporum aqueous extracts and may be a feasible, low-cost, environmentally friendly method for generating stable and uniformly sized SNPs. Finally, we have demonstrated that these SNPs are active against pathogenic fungi, such as Candida and Cryptococcus . PMID:24714966

  10. LDS1-produced oxylipins are negative regulators of growth, conidiation and fumonisin synthesis in the fungal maize pathogen Fusarium verticillioides

    PubMed Central

    Scala, Valeria; Giorni, Paola; Cirlini, Martina; Ludovici, Matteo; Visentin, Ivan; Cardinale, Francesca; Fabbri, Anna A.; Fanelli, Corrado; Reverberi, Massimo; Battilani, Paola; Galaverna, Gianni; Dall'Asta, Chiara

    2014-01-01

    Oxylipins are fatty acid-derived signaling compounds produced by all eukaryotes so far investigated; in mycotoxigenic fungi, they modulate toxin production and interactions with the host plants. Among the many enzymes responsible for oxylipin generation, Linoleate Diol Synthase 1 (LDS1) produces mainly 8-hydroperoxyoctadecenoic acid and subsequently different di-hydroxyoctadecenoic acids. In this study, we inactivated a copy of the putative LDS1 ortholog (acc. N. FVEG_09294.3) of Fusarium verticillioides, with the aim to investigate its influence on the oxylipin profile of the fungus, on its development, secondary metabolism and virulence. LC-MS/MS oxylipin profiling carried out on the selected mutant strain revealed significant quali-quantitative differences for several oxylipins when compared to the WT strain. The Fvlds1-deleted mutant grew better, produced more conidia, synthesized more fumonisins and infected maize cobs faster than the WT strain. We hypothesize that oxylipins may act as regulators of gene expression in the toxigenic plant pathogen F. verticillioides, in turn causing notable changes in its phenotype. These changes could relate to the ability of oxylipins to re-shape the transcriptional profile of F. verticillioides by inducing chromatin modifications and exerting a direct control on the transcription of secondary metabolism in fungi. PMID:25566199

  11. Detoxification of nitric oxide by flavohemoglobin and the denitrification pathway in the maize pathogen Fusarium verticillioides

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The ephemeral nitric oxide (NO) is a free radical, highly reactive, environmentally rare, and a potent signaling molecule in organisms across kingdoms of life. This gaseous small molecule can freely transverse membranes and has been implicated in aspects of pathogenicity both in animal and plant ho...

  12. Fusarium oxysporum f. sp. vasinfectum race 4 in California

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A brief review of research on Fusarium oxysporum Schlechtend.:Fr. f. sp. vasinfectum (Atk.) W.C. Snyder & H.N. Hans. race 4 in California is presented. Fusarium wilt has recently emerged as the dominant disease concern for cotton (Gossypium hirsutum L., G. barbadense L.) growers in California. An es...

  13. Dry heat treatment of Fusarium-infected cotton seed

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fusarium wilt caused by Fusarium oxysporum f. sp. vasinfectum (FOV) race 4 has emerged as the dominant disease concern for cotton growers in California. Originally described from Asia, race 4 has spread into multiple counties in the San Joaquin Valley (SJV) since its discovery in one California fiel...

  14. Fusarium Race 4: Commercial cultivar screening for resistance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fusarium wilt (FOV) of cotton in California has been considered a potentially serious fungal disease for many decades in areas of the San Joaquin Valley (SJV). In the past, damage from Fusarium has been notable only in areas with the combination of: (a) moderate to high populations of one or more sp...

  15. Molecular characterization of a novel mycovirus of the family Tymoviridae isolated from the plant pathogenic fungus Fusarium graminearum.

    PubMed

    Li, Pengfei; Lin, Yanhong; Zhang, Hailong; Wang, Shuangchao; Qiu, Dewen; Guo, Lihua

    2016-02-01

    We isolated a novel mycovirus, Fusarium graminearum mycotymovirus 1 (FgMTV1/SX64), which is related to members of the family Tymoviridae, from the plant pathogenic fungus F. graminearum strain SX64. The complete 7863 nucleotide sequence of FgMTV1/SX64, excluding the poly (A) tail, was determined. The genome of FgMTV1/SX64 is predicted to contain four open reading frames (ORFs). The largest ORF1 is 6723 nucleotides (nt) in length and encodes a putative polyprotein of 2242 amino acids (aa), which contains four conserved domains, a methyltransferase (Mtr), tymovirus endopeptidase (Pro), viral RNA helicase (Hel), and RNA-dependent RNA polymerase (RdRp), of the replication-associated proteins (RPs) of the positive-strand RNA viruses. ORFs 2-4 putatively encode three putative small hypothetical proteins, but their functions are still unknown. Sequence alignments and phylogenetic analyses based on the putative RP protein and the three conserved domains (Mtr, Hel and RdRp) showed that FgMTV1/SX64 is most closely related to, but distinctly branched from, the viruses from the family Tymoviridae. Although FgMTV1/SX64 infection caused mild or no effect on conidia production, biomass and virulence of its host F. graminearum strain SX64, its infection had significant effects on the growth rate, colony diameter and deoxynivalenol (DON) production. This is the first molecular characterization of a tymo-like mycovirus isolated from a plant pathogenic fungus. It is proposed that the mycovirus FgMTV1/SX64 is a representative member of new proposed lineage Mycotymovirus in the family Tymoviridae. PMID:26744993

  16. Impact of transgenic Bt maize residues on the mycotoxigenic plant pathogen Fusarium graminearum and the biocontrol agent Trichoderma atroviride.

    PubMed

    Naef, Andreas; Zesiger, Thierry; Défago, Geneviève

    2006-01-01

    Transformation of maize with genes encoding for insecticidal crystal (Cry) proteins from Bacillus thuringiensis (Bt) could have an impact on the saprophytic survival of plant pathogens and their antagonists on crop residues. We assessed potential effects on the mycotoxin deoxynivalenol (DON)-producing wheat and maize pathogen Fusarium graminearum and on the biocontrol agent Trichoderma atroviride. Purified Cry1Ab protein caused no growth inhibition of these fungi on agar plates. Cry1Ab concentrations above levels common in Bt maize tissue stimulated the growth of F. graminearum. The fungi were also grown on gamma-radiation-sterilized leaf tissue of four Bt maize hybrids and their non transgenic isolines collected at maize maturity on a field trial in 2002 and 2003. Both fungi degraded the Cry1Ab protein in Bt maize tissue. Fungal biomass quantification with microsatellite-based polymerase chain reaction (PCR) assays revealed differential fungal growth on leaf tissue of different maize varieties but no consistent difference between corresponding Bt and non-Bt hybrids. Generally, year of maize tissue collection had a greater impact on biomass production than cultivar or Bt transformation. The mycotoxin DON levels observed in maize tissue experiments corresponded with patterns in F. graminearum biomass, indicating that Bt transformation has no impact on DON production. In addition to bioassays, maize leaf tissue was analyzed with a mass spectrometer-based electronic nose, generating fingerprints of volatile organic compounds. Chemical fingerprints of corresponding Bt and non-Bt leaf tissues differed only for those hybrid pairs that caused differential fungal biomass production in the bioassays. Our results suggest that Cry1Ab protein in maize residues has no direct effect on F. graminearum and T. atroviride but some corresponding Bt/non-Bt maize hybrids differ more in composition than Cry protein content alone, which can affect the saprophytic growth of fungi on crop residues. PMID:16738384

  17. Fusarium symbionts of an ambrosia beetle (Euwallacea sp.) in southern Florida are pathogens of avocado, Persea americana

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fusarium dieback, a destructive disease of avocado (Persea americana), was reported in California and Israel in 2012. It is associated with an ambrosia beetle, Euwallacea sp., and damage caused by an unnamed symbiont of the beetle in Clade 3 of the Fusarium solani species complex (FSSC) designated p...

  18. Multilocus Genotyping and Molecular Phylogenetics Resolve a Novel Head Blight Pathogen within the Fusarium graminearum Species Complex from Ethiopia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A survey of Fusarium head blight (FHB)-contaminated wheat in Ethiopia recovered 31 isolates resembling members of the Fusarium graminearum species complex. Results of a multilocus genotyping (MLGT) assay for FHB species and trichothecene chemotype determination suggested that 22 of these isolates m...

  19. Clonality, recombination, and hybridization in the plumbing-inhabiting human pathogen Fusarium keratoplasticum inferred from multilocus sequence typing

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Recent work has shown that Fusarium species and genotypes most commonly associated with human infections, particularly of the cornea (mycotic keratitis), are the same as those most commonly isolated from plumbing systems. The species most dominant in plumbing biofilms is Fusarium keratoplasticum, a ...

  20. First report of Fusarium graminearum, F. asiaticum and F. cortaderiae as head blight pathogens of annual ryegrass in Brazil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Members of the Fusarium graminearum species complex (FGSC) cause Fusarium head blight (FHB) of small grains and several grasses, including annual ryegrass (Lolium multiflorum Lam.), an important forage crop, but also a common weed in wheat, rice and maize agroecosystem in southern Brazil. Although i...

  1. Enhanced Control of Cucumber Wilt Disease by Bacillus amyloliquefaciens SQR9 by Altering the Regulation of Its DegU Phosphorylation

    PubMed Central

    Xu, Zhihui; Zhang, Ruifu; Wang, Dandan; Qiu, Meihua; Feng, Haichao; Zhang, Nan

    2014-01-01

    Bacillus amyloliquefaciens strain SQR9, isolated from the cucumber rhizosphere, suppresses the growth of Fusarium oxysporum in the cucumber rhizosphere and protects the host plant from pathogen invasion through efficient root colonization. In the Gram-positive bacterium Bacillus, the response regulator DegU regulates genetic competence, swarming motility, biofilm formation, complex colony architecture, and protease production. In this study, we report that stepwise phosphorylation of DegU in B. amyloliquefaciens SQR9 can influence biocontrol activity by coordinating multicellular behavior and regulating the synthesis of antibiotics. Results from in vitro and in situ experiments and quantitative PCR (qPCR) studies demonstrate the following: (i) that the lowest level of phosphorylated DegU (DegU?P) (the degQ mutation) impairs complex colony architecture, biofilm formation, colonization activities, and biocontrol efficiency of Fusarium wilt disease but increases the production of macrolactin and bacillaene, and (ii) that increasing the level of DegU?P by degQ and degSU overexpression significantly improves complex colony architecture, biofilm formation, colonization activities, production of the antibiotics bacillomycin D and difficidin, and efficiency of biocontrol of Fusarium wilt disease. The results offer a new strategy to enhance the biocontrol efficacy of Bacillus amyloliquefaciens SQR9. PMID:24584252

  2. Jasmonic Acid, Abscisic Acid, and Salicylic Acid Are Involved in the Phytoalexin Responses of Rice to Fusarium fujikuroi, a High Gibberellin Producer Pathogen.

    PubMed

    Siciliano, Ilenia; Amaral Carneiro, Greice; Spadaro, Davide; Garibaldi, Angelo; Gullino, Maria Lodovica

    2015-09-23

    Fusarium fujikuroi, the causal agent of bakanae disease, is the main seedborne pathogen on rice. To understand the basis of rice resistance, a quantitative method to simultaneously detect phytohormones and phytoalexins was developed by using HPLC-MS/MS. With this method dynamic profiles and possible interactions of defense-related phytohormones and phytoalexins were investigated on two rice cultivars, inoculated or not with F. fujikuroi. In the resistant cultivar Selenio, the presence of pathogen induced high production of phytoalexins, mainly sakuranetin, and symptoms of bakanae were not observed. On the contrary, in the susceptible genotype Dorella, the pathogen induced the production of gibberellin and abscisic acid and inhibited jasmonic acid production, phytoalexins were very low, and bakanae symptoms were observed. The results suggested that a wide range of secondary metabolites are involved in plant defense against pathogens and phytoalexin synthesis could be an important factor for rice resistance against bakanae disease. PMID:26323788

  3. Evidence for a reversible drought induced shift in the species composition of mycotoxin producing Fusarium head blight pathogens isolated from symptomatic wheat heads.

    PubMed

    Beyer, Marco; Pogoda, Friederike; Pallez, Marine; Lazic, Joëlle; Hoffmann, Lucien; Pasquali, Matias

    2014-07-16

    Fusarium species are fungal plant pathogens producing toxic secondary metabolites such as deoxynivalenol (DON), 15-acetyl-deoxynivalenol (15AcDON) and nivalenol (NIV). In Luxembourg, the Fusarium species composition isolated from symptomatic winter wheat heads was dominated by Fusarium graminearum sensu stricto strains (genetic 15AcDON chemotype) between the years 2009 and 2012, except for 2011, when Fusarium culmorum strains (genetic NIV chemotype) dominated the pathogen complex. Previous reports indicated that F. graminearum sensu stricto (genetic 15AcDON chemotype) was also most frequently isolated from randomly sampled winter wheat kernels including symptomatic as well as asymptomatic kernels in 2007 and 2008. The annual precipitation (average of 10 weather stations scattered across the country) decreased continuously from 924.31mm in 2007 over 917.15mm in 2008, to 843.38mm in 2009, 736.24mm in 2010, and 575.09mm in 2011. In 2012, the annual precipitation increased again to 854.70mm. Hardly any precipitation was recorded around the time of wheat anthesis in the years 2010 and 2011, whereas precipitation levels >50mm within the week preceding anthesis plus the week post anthesis were observed in the other years. The shift to genetic NIV chemotype F. culmorum strains in 2011 was accompanied by a very minor elevation of average NIV contents (2.9ngg(-1)) in the grain. Our data suggest that high NIV levels in Luxembourgish winter wheat are at present rather unlikely, because the indigenous F. culmorum strains with the genetic NIV chemotype seem to be outcompeted under humid in vivo conditions by F. graminearum DON producing strains on the one hand and seem to be inhibited - even though to a lower extent than DON producing strains - under dry in vivo conditions on the other hand. PMID:24859190

  4. Induction of Defense-Related Enzymes in Banana Plants: Effect of Live and Dead Pathogenic Strain of Fusarium oxysporum f. sp. cubense

    PubMed Central

    Thakker, Janki N.; Patel, Samiksha; Dhandhukia, Pinakin C.

    2013-01-01

    The aim of the present study was to scrutinize the response of banana (Grand Naine variety) plants when interacting with dead or live pathogen, Fusarium oxysporum f.sp. cubense, a causative agent of Panama disease. Response of plants was evaluated in terms of induction of defense-related marker enzyme activity, namely, peroxidase (POX), polyphenol oxidase (PPO), β-1,3 glucanase, chitinase, and phenolics. Plant's interaction with live pathogen resulted in early induction of defense to restrain penetration as well as antimicrobial productions. However, pathogen overcame the defense of plant and caused disease. Interaction with dead pathogen resulted in escalating defense response in plants. Later on plants inoculated with dead pathogen showed resistance to even forced inoculation of live pathogen. Results obtained in the present study suggest that dead pathogen was able to mount defense response in plants and provide resistance to Panama disease upon subsequent exposure. Therefore, preparation from dead pathogen could be a potential candidate as a biocontrol agent or plant vaccine to combat Panama disease. PMID:25969777

  5. Fot 1 Insertions in the Fusarium oxysporum f. sp. albedinis Genome Provide Diagnostic PCR Targets for Detection of the Date Palm Pathogen

    PubMed Central

    Fernandez, Diana; Ouinten, Mohamed; Tantaoui, Abdelaziz; Geiger, Jean-Paul; Daboussi, Marie-Josée; Langin, Thierry

    1998-01-01

    Populations of Fusarium oxysporum f. sp. albedinis, the causal agent of Bayoud disease of date palm, are derivatives of a single clonal lineage and exhibit very similar Fot 1 hybridization patterns. In order to develop a sensitive diagnostic tool for F. oxysporum f. sp. albedinis detection, we isolated several DNA clones containing a copy of the transposable element Fot 1 from a genomic library of the date palm pathogen. Regions flanking the insertion sites were sequenced, and these sequences were used to design PCR primers that amplify the DNA regions at several Fot 1 insertion sites. When tested on a large sample of Fusarium isolates, including 286 F. oxysporum f. sp. albedinis isolates, 17 other special forms, nonpathogenic F. oxysporum isolates from palm grove soils, and 8 other Fusarium species, the primer pair TL3-FOA28 allowed amplification of a 400-bp fragment found only in F. oxysporum f. sp. albedinis. Sequence analysis showed that one of the Fot 1 copies was truncated, lacking 182 bp at its 3′ terminus. The primer pair BI03-FOA1 amplified a 204-bp fragment which overlapped the Fot 1 truncated copy and its 3′ site of insertion in the F. oxysporum f. sp. albedinis genome and identified 95% of the isolates. The primer pairs BIO3-FOA1 and TL3-FOA28 used in PCR assays thus provide a useful diagnostic tool for F. oxysporum f. sp. albedinis isolates. PMID:9464402

  6. Contamination of Bananas with Beauvericin and Fusaric Acid Produced by Fusarium oxysporum f. sp. cubense

    PubMed Central

    Kuang, Ruibin; Yang, Qiaosong; Hu, Chunhua; Sheng, Ou; Zhang, Sheng; Ma, Lijun; Wei, Yuerong; Yang, Jing; Liu, Siwen; Biswas, Manosh Kumar; Viljoen, Altus; Yi, Ganjun

    2013-01-01

    Background Fusarium wilt, caused by the fungal pathogen Fusarium oxysporum f. sp. cubense (Foc), is one of the most destructive diseases of banana. Toxins produced by Foc have been proposed to play an important role during the pathogenic process. The objectives of this study were to investigate the contamination of banana with toxins produced by Foc, and to elucidate their role in pathogenesis. Methodology/Principal Findings Twenty isolates of Foc representing races 1 and 4 were isolated from diseased bananas in five Chinese provinces. Two toxins were consistently associated with Foc, fusaric acid (FA) and beauvericin (BEA). Cytotoxicity of the two toxins on banana protoplast was determined using the Alamar Blue assay. The virulence of 20 Foc isolates was further tested by inoculating tissue culture banana plantlets, and the contents of toxins determined in banana roots, pseudostems and leaves. Virulence of Foc isolates correlated well with toxin deposition in the host plant. To determine the natural occurrence of the two toxins in banana plants with Fusarium wilt symptoms, samples were collected before harvest from the pseudostems, fruit and leaves from 10 Pisang Awak ‘Guangfen #1’ and 10 Cavendish ‘Brazilian’ plants. Fusaric acid and BEA were detected in all the tissues, including the fruits. Conclusions/Signficance The current study provides the first investigation of toxins produced by Foc in banana. The toxins produced by Foc, and their levels of contamination of banana fruits, however, were too low to be of concern to human and animal health. Rather, these toxins appear to contribute to the pathogenicity of the fungus during infection of banana plants. PMID:23922960

  7. A Deoxynivalenol-Activated Methionyl-tRNA Synthetase Gene from Wheat Encodes a Nuclear Localized Protein and Protects Plants Against Fusarium Pathogens and Mycotoxins.

    PubMed

    Zuo, Dong-Yun; Yi, Shu-Yuan; Liu, Rong-Jing; Qu, Bo; Huang, Tao; He, Wei-Jie; Li, Cheng; Li, He-Ping; Liao, Yu-Cai

    2016-06-01

    Fusarium graminearum is the fungal pathogen that causes globally important diseases of cereals and produces mycotoxins such as deoxynivalenol (DON). Owing to the dearth of available sources of resistance to Fusarium pathogens, characterization of novel genes that confer resistance to mycotoxins and mycotoxin-producing fungi is vitally important for breeding resistant crop varieties. In this study, a wheat methionyl-tRNA synthetase (TaMetRS) gene was identified from suspension cell cultures treated with DON. It shares conserved aminoacylation catalytic and tRNA anticodon binding domains with human MetRS and with the only previously characterized plant MetRS, suggesting that it functions in aminoacylation in the cytoplasm. However, the TaMetRS comprises a typical nuclear localization signal and cellular localization studies with a TaMetRS::GFP fusion protein showed that TaMetRS is localized in the nucleus. Expression of TaMetRS was activated by DON treatment and by infection with a DON-producing F. graminearum strain in wheat spikes. No such activation was observed following infection with a non-DON-producing F. graminearum strain. Expression of TaMetRS in Arabidopsis plants conferred significant resistance to DON and F. graminearum. These results indicated that this DON-activated TaMetRS gene may encode a novel type of MetRS in plants that has a role in defense and detoxification. PMID:26882849

  8. Unravelling the Microbiome of Eggs of the Endangered Sea Turtle Eretmochelys imbricata Identifies Bacteria with Activity against the Emerging Pathogen Fusarium falciforme

    PubMed Central

    Sarmiento-Ramírez, Jullie M.; van der Voort, Menno; Raaijmakers, Jos M.; Diéguez-Uribeondo, Javier

    2014-01-01

    Habitat bioaugmentation and introduction of protective microbiota have been proposed as potential conservation strategies to rescue endangered mammals and amphibians from emerging diseases. For both strategies, insight into the microbiomes of the endangered species and their habitats is essential. Here, we sampled nests of the endangered sea turtle species Eretmochelys imbricata that were infected with the fungal pathogen Fusarium falciforme. Metagenomic analysis of the bacterial communities associated with the shells of the sea turtle eggs revealed approximately 16,664 operational taxonomic units, with Proteobacteria, Actinobacteria, Firmicutes and Bacteroidetes as the most dominant phyla. Subsequent isolation of Actinobacteria from the eggshells led to the identification of several genera (Streptomyces, Amycolaptosis, Micromomospora Plantactinospora and Solwaraspora) that inhibit hyphal growth of the pathogen F. falciforme. These bacterial genera constitute a first set of microbial indicators to evaluate the potential role of microbiota in conservation of endangered sea turtle species. PMID:24743166

  9. Role of ethylene in the protection of tomato plants against soil-borne fungal pathogens conferred by an endophytic Fusarium solani strain.

    PubMed

    Kavroulakis, Nektarios; Ntougias, Spyridon; Zervakis, Georgios I; Ehaliotis, Constantinos; Haralampidis, Kosmas; Papadopoulou, Kalliope K

    2007-01-01

    An endophytic fungal isolate (Fs-K), identified as a Fusarium solani strain, was obtained from root tissues of tomato plants grown on a compost which suppressed soil and foliar pathogens. Strain Fs-K was able to colonize root tissues and subsequently protect plants against the root pathogen Fusarium oxysporum f.sp. radicis-lycopersici (FORL), and elicit induced systemic resistance against the tomato foliar pathogen Septoria lycopersici. Interestingly, attenuated expression of certain pathogenesis-related genes, i.e. PR5 and PR7, was detected in tomato roots inoculated with strain Fs-K compared with non-inoculated plants. The expression pattern of PR genes was either not affected or aberrant in leaves. A genetic approach, using mutant tomato plant lines, was used to determine the role of ethylene and jasmonic acid in the plant's response to infection by the soil-borne pathogen F. oxysporum f.sp. radicis-lycopersici (FORL), in the presence or absence of isolate Fs-K. Mutant tomato lines Never ripe (Nr) and epinastic (epi1), both impaired in ethylene-mediated plant responses, inoculated with FORL are not protected by isolate Fs-K, indicating that the ethylene signalling pathway is required for the mode of action used by the endophyte to confer resistance. On the contrary, def1 mutants, affected in jasmonate biosynthesis, show reduced susceptibility to FORL, in the presence Fs-K, which suggests that jasmonic acid is not essential for the mediation of biocontrol activity of isolate Fs-K. PMID:18048373

  10. A Multilocus Genealogical Concordance Approach to Species Delimitation within the Fusarium graminearum Species Complex of Cereal Head Blight Pathogens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fusarium head blight (FHB) of wheat and barley currently ranks as one of the most destructive and economically devastating plant diseases worldwide. Outbreaks and epidemics of FHB pose a double threat to cereal production: (i) the disease is frequently responsible for poor seed quality and reductio...

  11. FUBT, a putative MFS transporter, promotes secretion of fusaric acid in the cotton pathogen Fusarium oxysporum f. sp. vasinfectum

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fusaric acid (FA) is a key component in virulence and symptom development in cotton during infection by Fusarium oxysporum. A putative MFS transporter gene was identified upstream of the polyketide synthase gene responsible for the biosynthesis of FA. Disruption of the transporter gene, designated...

  12. Analysis of transporter responsible for the secretion of fusaric acid from the plant pathogen Fusarium oxysporum f. sp. vasinfectum

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fusaric acid (FA), a phytotoxic polyketide produced by Fusarium oxysporum f. sp. vasinfectum (Fov), has been suggested to be associated with disease symptoms on cotton. In response to a potential threat on cotton production by the introduction of high FA producing strains from Australia, new sources...

  13. A Two-locus DNA Sequence Database for Typing Plant and Human Pathogens Within the Fusarium oxysporum Species Complex

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We constructed a two-locus database, comprising partial translation elongation factor (EF-1alpha) gene sequences and nearly full-length sequences of the nuclear ribosomal intergenic spacer region (IGS rDNA) for 850 isolates spanning the phylogenetic breadth of the Fusarium oxysporum species complex ...

  14. The transcription factor FgStuAp influences spore development, pathogenicity, and secondary metabolism in Fusarium graminearum

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Members of the APSES family of fungal proteins regulate morphogenesis and virulence in ascomycetes. We deleted the FgStuA gene in Fusarium graminearum and demonstrate its involvement in several different processes. FgStuA is closely related to FoStuA in F. oxysporum and StuA in Aspergillus. Unlike F...

  15. Diversity of Fusarium head blight populations and trichothecene toxin types reveals regional differences in pathogen composition and temporal dynamics

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Analyses of genetic diversity, trichothecene genotype composition, and population structure were conducted using 4,086 Fusarium graminearum isolates collected from wheat in eight Canadian provinces over a three year period between 2005 and 2007. The results revealed substantial regional differences ...

  16. Characterization of the Maize Stalk Rot Pathogens Fusarium subglutinans and F. temperatum and the Effect of Fungicides on Their Mycelial Growth and Colony Formation

    PubMed Central

    Shin, Jong-Hwan; Han, Joon-Hee; Lee, Ju Kyong; Kim, Kyoung Su

    2014-01-01

    Maize is a socioeconomically important crop in many countries. Recently, a high incidence of stalk rot disease has been reported in several maize fields in Gangwon province. In this report, we show that maize stalk rot is associated with the fungal pathogens Fusarium subglutinans and F. temperatum. Since no fungicides are available to control these pathogens on maize plants, we selected six fungicides (tebuconazole, difenoconazole, fluquinconazole, azoxystrobin, prochloraz and kresoxim-methyl) and examined their effectiveness against the two pathogens. The in vitro antifungal effects of the six fungicides on mycelial growth and colony formation were investigated. Based on the inhibition of mycelial growth, the most toxic fungicide was tebuconazole with 50% effective concentrations (EC50) of <0.1 μg/ml and EC90 values of 0.9 μg/ml for both pathogens, while the least toxic fungicide was azoxystrobin with EC50 values of 0.7 and 0.5 μg/ml for F. subglutinans and F. temperatum, respectively, and EC90 values of >3,000 μg/ml for both pathogens. Based on the inhibition of colony formation by the two pathogens, kresoxim-methyl was the most toxic fungicide with complete inhibition of colony formation at concentrations of 0.1 and 0.01 μg/ml for F. subglutinans and F. temperatum, respectively, whereas azoxystrobin was the least toxic fungicide with complete inhibition of colony formation at concentrations >3,000 μg/ml for both pathogens. PMID:25506304

  17. Identification of a cis-acting factor modulating the transcription of FUM1, a key fumonisin-biosynthetic gene in the fungal maize pathogen Fusarium verticillioides.

    PubMed

    Montis, V; Pasquali, M; Visentin, I; Karlovsky, P; Cardinale, F

    2013-02-01

    Fumonisins, toxic secondary metabolites produced by some Fusarium spp. and Aspergillus niger, have strong agro-economic and health impacts. The genes needed for their biosynthesis, named FUM, are clustered and co-expressed in fumonisin producers. In eukaryotes, coordination of transcription can be attained through shared transcription factors, whose specificity relies on the recognition of cis-regulatory elements on target promoters. A bioinformatic analysis on FUM promoters in the maize pathogens Fusarium verticillioides and Aspergillus niger identified a degenerated, over-represented motif potentially involved in the cis-regulation of FUM genes, and of fumonisin biosynthesis. The same motif was not found in various FUM homologues of fungi that do not produce fumonisins. Comparison of the transcriptional strength of the intact FUM1 promoter with a synthetic version, where the motif had been mutated, was carried out in vivo and in planta for F. verticillioides. The results showed that the motif is important for efficient transcription of the FUM1 gene. PMID:23219667

  18. Update of Commercial Cultivar Screening for Resistance to Race 4 Fusarium oxysporum vasinfectum.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fusarium wilt impacts on cotton in the San Joaquin Valley of California focused mostly on race 1 Fusarium oxysporum vasinfectum (FOV), with most economic impacts occurring when the disease was present in association with nematode damage. During the past five years, field investigations have found Fu...

  19. Observations on the effect of lower-temperature dry heat treatments on Fusarium in cotton seed

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fusarium wilt caused by Fusarium oxysporum f. sp. vasinfectum (FOV) race 4 has emerged as the dominant disease concern for cotton growers in California. Originally described from Asia, race 4 has spread into multiple counties in the San Joaquin Valley (SJV) since its discovery in one California fiel...

  20. New genotypes of Fusarium oxysporum f. sp. vasinfectum from the Southeastern United States

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sixty-one isolates of Fusarium oxysporum f. sp. vasinfectum were collected from cotton plants (Gossypium spp.) with symptoms of Fusarium wilt to determine the composition of races present in the southeastern U.S. Analysis of partial sequences of the translation elongation factor gene revealed four n...

  1. NMR Structural Studies on the Biosynthesis of Fusaric Acid from Fusarium oxysporum f. sp. vasinfectum

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fusarium wilt of cotton is caused by Fusarium oxysporum Sclecht f. sp. vasinfectum (Atk.) Sny. and Hans (F.o.v.). F.o.v. occurs in most countries where cotton is grown. Losses in cotton yield can be especially devastating on farms where soil conditions, nematode populations, and indigenous populat...

  2. Comparison of sugar beet responses at different ages to isolates of Fusarium oxysporum

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fusarium oxysporum has been reported to cause several diseases of sugar beet, including seedling damping-off, a mature plant wilt (Fusarium yellows), a mature plant root rot, and seed stalk blight. Recent work in our lab and others has shown a great deal of diversity in F. oxysporum from sugar beet....

  3. Efficacy of four soil treatments against Fusarium oxysporum f. sp. vasinfectum race 4 on cotton

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fusarium wilt caused by race 4 of Fusarium oxysporum f. sp. vasinfectum is a critically important disease problem in California cotton (Gossypium spp.). Because few cultivars with resistance to race 4 are available, management alternatives for this disease are needed. Four soil treatments (50:50 met...

  4. Fusarium graminearum Isolates from Wheat and Maize in New York Show Similar Range of Aggressiveness and Toxigenicity in Cross-Species Pathogenicity Tests.

    PubMed

    Kuhnem, Paulo R; Del Ponte, Emerson M; Dong, Yanhong; Bergstrom, Gary C

    2015-04-01

    This study aimed to assess whether pathogenic Fusarium graminearum isolates from wheat and maize were more aggressive on their host of origin and whether aggressiveness was influenced further by B-trichothecene chemotype. Fifteen isolates were selected from a contemporary collection of isolates surveyed in New York in 2011 to 2012 to represent diversity of host of origin and chemotype. Three pathogenicity assays were used to evaluate and compare these isolates. Fusarium head blight (FHB) severity and trichothecene production in wheat, and maize seedling blight were evaluated in greenhouse inoculation experiments, and Gibberella ear rot (GER) severity and trichothecene production were evaluated in maize ears inoculated in the field. Our results showed among F. graminearum isolates a wide variation in aggressiveness and mycotoxin production toward wheat and maize and these isolates could not be structured by their host of origin or by chemotype. Moreover, aggressiveness rank order changed according to the host/organ evaluated. This indicates that relative susceptibility at the seedling stage may not predict susceptibility of ears. Significant correlations were observed of total trichothecenes (deoxynivalenol [DON] and its acetylated derivatives) produced with FHB and GER severity on wheat and maize, respectively. One isolate did not produce DON or ADON in wheat or maize kernels, yet was aggressive on both hosts. Nine of the fifteen isolates produced small amounts of zearalenone (ZON) in maize kernels, but not in wheat kernels, and ZON level was not correlated with GER severity. F. graminearum isolates from New York showed wide variation in aggressiveness and mycotoxin production toward susceptible wheat and maize. Neither host of origin nor trichothecene chemotype appeared to structure the populations we sampled. PMID:25338173

  5. Antifungal activity of ZnO nanoparticles and their interactive effect with a biocontrol bacterium on growth antagonism of the plant pathogen Fusarium graminearum.

    PubMed

    Dimkpa, Christian O; McLean, Joan E; Britt, David W; Anderson, Anne J

    2013-12-01

    Fungal plant pathogens such as Fusarium graminearum cause severe global economic losses in cereals crops, and current control measures are limited. This work addresses the potential for ZnO nanoparticles (NPs) and biocontrol bacteria to be used in plant fungal control strategies. Growth of F. graminearum was significantly (p = 0.05) inhibited by inclusion of the NPs in a mung bean broth agar and in sand. Suspension in mung bean broth medium modified the surface charge, dissolution, and aggregation state of the ZnO NPs, in comparison to processes occurring in water suspension. The ZnO NPs were significantly more inhibitory to fungal growth than micro-sized particles of ZnO, although both types of particles released similar levels of soluble Zn, indicating size-dependent toxicity of the particles. Zn ions produced dose-dependent inhibition, noticeable at the level of soluble Zn released from NPs after seven-day suspension in medium; inhibitory levels caused acidification of the growth medium. Transfer of fungal inoculum after exposure to the ZnO NPs to fresh medium did not indicate adaptation to the stress because growth was still inhibited by the NPs. The ZnO NPs did not prevent metabolites from a biocontrol bacterium, Pseudomonas chlororaphis O6, from inhibiting Fusarium growth: no synergism was observed in the mung bean agar. Because other studies find that soil amendment with ZnO NPs required high doses for inhibition of plant growth, the findings of pathogen growth control reported in this paper open the possibility of using ZnO NP-based formulations to complement existing strategies for improving crop health in field settings. PMID:23933719

  6. Host perception of jasmonates promotes infection by Fusarium oxysporum formae speciales that produce isoleucine- and leucine-conjugated jasmonates

    PubMed Central

    Cole, Stephanie J.; Yoon, Alexander J.; Faull, Kym F.; Diener, Andrew C.

    2014-01-01

    Summary Three pathogenic forms, or formae speciales, of Fusarium oxysporum infect the roots of Arabidopsis thaliana belowground, instigating symptoms of wilt disease in leaves aboveground. In prior reports, Arabidopsis mutants that are deficient in the biosynthesis of abscisic acid or salicylic acid or insensitive to ethylene or jasmonates exhibit more or less wilt disease than wild type, implicating the involvement of hormones in the normal host response to F. oxysporum. Our analysis of hormone-related mutants finds no evidence that endogenous hormones contribute to infection in roots. Mutants that are deficient in abscisic acid and insensitive to ethylene have no less infection than wild type, though they exhibit less disease. Whether a mutant that is insensitive to jasmonates affects infection depends on which forma specialis is infecting roots. Insensitivity to jasmonates suppresses infection by F. oxysporum forma specialis conglutinans and F. oxysporum forma specialis matthioli, which produce isoleucine- and leucine-conjugated jasmonate (JA-Ile/Leu) in culture filtrates; whereas, insensitivity to jasmonates has no effect on infection by F. oxysporum forma specialis raphani, which produces no detectable JA-Ile/Leu. Furthermore, insensitivity to jasmonates has no effect on wilt disease of tomato, and the tomato pathogen F. oxysporum forma specialis lycopersici produces no detectable jasmonates. Thus, some but not all F. oxysporum pathogens appear to utilize jasmonates as effectors, promoting infection in roots and/or development of symptoms in shoots. Only when infection of roots is promoted by jasmonates is wilt disease enhanced in a mutant deficient in salicylic acid biosynthesis. PMID:24387225

  7. A nitrogen response pathway regulates virulence in plant pathogenic fungi: role of TOR and the bZIP protein MeaB.

    PubMed

    López-Berges, Manuel S; Rispail, Nicolas; Prados-Rosales, Rafael C; Di Pietro, Antonio

    2010-12-01

    Virulence in plant pathogenic fungi is controlled through a variety of cellular pathways in response to the host environment. Nitrogen limitation has been proposed to act as a key signal to trigger the in planta expression of virulence genes. Moreover, a conserved Pathogenicity mitogen activated protein kinase (MAPK) cascade is strictly required for plant infection in a wide range of pathogens. We investigated the relationship between nitrogen signaling and the Pathogenicity MAPK cascade in controlling infectious growth of the vascular wilt fungus Fusarium oxysporum. Several MAPK-activated virulence functions such as invasive growth, vegetative hyphal fusion and host adhesion were strongly repressed in the presence of the preferred nitrogen source ammonium. Repression of these functions by ammonium was abolished by L-Methionine sulfoximine (MSX) or rapamycin, two specific inhibitors of Gln synthetase and the protein kinase TOR (Target Of Rapamycin), respectively, and was dependent on the bZIP protein MeaB. Supplying tomato plants with ammonium rather than nitrate resulted in a significant delay of vascular wilt symptoms caused by the F. oxysporum wild type strain, but not by the ΔmeaB mutant. Ammonium also repressed invasive growth in two other pathogens, the rice blast fungus Magnaporthe oryzae and the wheat head blight pathogen Fusarium graminearum. Our results suggest the presence of a conserved nitrogen-responsive pathway that operates via TOR and MeaB to control infectious growth in plant pathogenic fungi. PMID:21139428

  8. Retrograde trafficking from the endosome to the trans-Golgi network mediated by the retromer is required for fungal development and pathogenicity in Fusarium graminearum.

    PubMed

    Zheng, Wenhui; Zheng, Huawei; Zhao, Xu; Zhang, Ying; Xie, Qiurong; Lin, Xiaolian; Chen, Ahai; Yu, Wenying; Lu, Guodong; Shim, Won-Bo; Zhou, Jie; Wang, Zonghua

    2016-06-01

    In eukaryotes, the retromer is an endosome-localized complex involved in protein retrograde transport. However, the role of such intracellular trafficking events in pathogenic fungal development and pathogenicity remains unclear. The role of the retromer complex in Fusarium graminearum was investigated using cell biological and genetic methods. We observed the retromer core component FgVps35 (Vacuolar Protein Sorting 35) in the cytoplasm as fast-moving puncta. FgVps35-GFP co-localized with both early and late endosomes, and associated with the trans-Golgi network (TGN), suggesting that FgVps35 functions at the donor endosome membrane to mediate TGN trafficking. Disruption of microtubules with nocodazole significantly restricted the transportation of FgVps35-GFP and resulted in severe germination and growth defects. Mutation of FgVPS35 not only mimicked growth defects induced by pharmacological treatment, but also affected conidiation, ascospore formation and pathogenicity. Using yeast two-hybrid assays, we determined the interactions among FgVps35, FgVps26, FgVps29, FgVps17 and FgVps5 which are analogous to the yeast retromer complex components. Deletion of any one of these genes resulted in similar phenotypic defects to those of the ΔFgvps35 mutant and disrupted the stability of the complex. Overall, our results provide the first clear evidence of linkage between the retrograde transport mediated by the retromer complex and virulence in F. graminearum. PMID:26875543

  9. Molecular research and genetic engineering of resistance to Verticillium wilt in cotton: A review

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Verticillium dahliae, a soil-borne pathogen, causes Verticillium wilt, one of the most serious diseases in cotton, deleteriously influencing the crop’s production and quality. Verticillium wilt has become a major obstacle in cotton production since Helicoverpa armigera, the cotton bollworm, became e...

  10. Transcriptome Profiling of Resistance to Fusarium oxysporum f. sp. conglutinans in Cabbage (Brassica oleracea) Roots

    PubMed Central

    Xing, Miaomiao; Lv, Honghao; Ma, Jian; Xu, Donghui; Li, Hailong; Yang, Limei; Kang, Jungen; Wang, Xiaowu; Fang, Zhiyuan

    2016-01-01

    Fusarium wilt caused by Fusarium oxysporum f. sp. conglutinans (FOC) is a destructive disease of Brassica crops, which results in severe yield losses. There is little information available about the mechanism of disease resistance. To obtain an overview of the transcriptome profiles in roots of R4P1, a Brassica oleracea variety that is highly resistant to fusarium wilt, we compared the transcriptomes of samples inoculated with FOC and samples inoculated with distilled water. RNA-seq analysis generated more than 136 million 100-bp clean reads, which were assembled into 62,506 unigenes (mean size = 741 bp). Among them, 49,959 (79.92%) genes were identified based on sequence similarity searches, including SwissProt (29,050, 46.47%), Gene Ontology (GO) (33,767, 54.02%), Clusters of Orthologous Groups (KOG) (14,721, 23.55%) and Kyoto Encyclopedia of Genes and Genomes Pathway database (KEGG) (12,974, 20.76%) searches; digital gene expression analysis revealed 885 differentially expressed genes (DEGs) between infected and control samples at 4, 12, 24 and 48 hours after inoculation. The DEGs were assigned to 31 KEGG pathways. Early defense systems, including the MAPK signaling pathway, calcium signaling and salicylic acid-mediated hypersensitive response (SA-mediated HR) were activated after pathogen infection. SA-dependent systemic acquired resistance (SAR), ethylene (ET)- and jasmonic (JA)-mediated pathways and the lignin biosynthesis pathway play important roles in plant resistance. We also analyzed the expression of defense-related genes, such as genes encoding pathogenesis-related (PR) proteins, UDP-glycosyltransferase (UDPG), pleiotropic drug resistance, ATP-binding cassette transporters (PDR-ABC transporters), myrosinase, transcription factors and kinases, which were differentially expressed. The results of this study may contribute to efforts to identify and clone candidate genes associated with disease resistance and to uncover the molecular mechanism underlying FOC resistance in cabbage. PMID:26849436

  11. Transcriptome Profiling of Resistance to Fusarium oxysporum f. sp. conglutinans in Cabbage (Brassica oleracea) Roots.

    PubMed

    Xing, Miaomiao; Lv, Honghao; Ma, Jian; Xu, Donghui; Li, Hailong; Yang, Limei; Kang, Jungen; Wang, Xiaowu; Fang, Zhiyuan

    2016-01-01

    Fusarium wilt caused by Fusarium oxysporum f. sp. conglutinans (FOC) is a destructive disease of Brassica crops, which results in severe yield losses. There is little information available about the mechanism of disease resistance. To obtain an overview of the transcriptome profiles in roots of R4P1, a Brassica oleracea variety that is highly resistant to fusarium wilt, we compared the transcriptomes of samples inoculated with FOC and samples inoculated with distilled water. RNA-seq analysis generated more than 136 million 100-bp clean reads, which were assembled into 62,506 unigenes (mean size = 741 bp). Among them, 49,959 (79.92%) genes were identified based on sequence similarity searches, including SwissProt (29,050, 46.47%), Gene Ontology (GO) (33,767, 54.02%), Clusters of Orthologous Groups (KOG) (14,721, 23.55%) and Kyoto Encyclopedia of Genes and Genomes Pathway database (KEGG) (12,974, 20.76%) searches; digital gene expression analysis revealed 885 differentially expressed genes (DEGs) between infected and control samples at 4, 12, 24 and 48 hours after inoculation. The DEGs were assigned to 31 KEGG pathways. Early defense systems, including the MAPK signaling pathway, calcium signaling and salicylic acid-mediated hypersensitive response (SA-mediated HR) were activated after pathogen infection. SA-dependent systemic acquired resistance (SAR), ethylene (ET)- and jasmonic (JA)-mediated pathways and the lignin biosynthesis pathway play important roles in plant resistance. We also analyzed the expression of defense-related genes, such as genes encoding pathogenesis-related (PR) proteins, UDP-glycosyltransferase (UDPG), pleiotropic drug resistance, ATP-binding cassette transporters (PDR-ABC transporters), myrosinase, transcription factors and kinases, which were differentially expressed. The results of this study may contribute to efforts to identify and clone candidate genes associated with disease resistance and to uncover the molecular mechanism underlying FOC resistance in cabbage. PMID:26849436

  12. The global regulator FfSge1 is required for expression of secondary metabolite gene clusters but not for pathogenicity in Fusarium fujikuroi.

    PubMed

    Michielse, Caroline B; Studt, Lena; Janevska, Slavica; Sieber, Christian M K; Arndt, Birgit; Espino, Jose Juan; Humpf, Hans-Ulrich; Güldener, Ulrich; Tudzynski, Bettina

    2015-08-01

    The plant pathogenic fungus Fusarium fujikuroi is the causal agent of bakanae disease on rice due to its ability to produce gibberellins. Besides these phytohormones, F. fujikuroi is able to produce several other secondary metabolites (SMs). Although much progress has been made in the field of secondary metabolism, the transcriptional regulation of SM biosynthesis is complex and still incompletely understood. Environmental conditions, global as well as pathway-specific regulators and chromatin remodelling have been shown to play major roles. Here, the role of FfSge1, a homologue of the morphological switch regulators Wor1 and Ryp1 in Candida albicans and Histoplasma capsulatum, respectively, is explored with emphasis on secondary metabolism. FfSge1 is not required for formation of conidia and pathogenicity but is involved in vegetative growth. Transcriptome analysis of the mutant Δffsge1 compared with the wild type, as well as comparative chemical analysis between the wild type, Δffsge1 and OE:FfSGE1, revealed that FfSge1 functions as a global activator of secondary metabolism in F. fujikuroi. Double mutants of FfSGE1 and other SM regulatory genes brought insights into the hierarchical regulation of secondary metabolism. In addition, FfSge1 is also required for expression of a yet uncharacterized SM gene cluster containing a non-canonical non-ribosomal peptide synthetase. PMID:25115968

  13. Deciphering the Cryptic Genome: Genome-wide Analyses of the Rice Pathogen Fusarium fujikuroi Reveal Complex Regulation of Secondary Metabolism and Novel Metabolites

    PubMed Central

    Studt, Lena; Niehaus, Eva-Maria; Espino, Jose J.; Huß, Kathleen; Michielse, Caroline B.; Albermann, Sabine; Wagner, Dominik; Bergner, Sonja V.; Connolly, Lanelle R.; Fischer, Andreas; Reuter, Gunter; Kleigrewe, Karin; Bald, Till; Wingfield, Brenda D.; Ophir, Ron; Freeman, Stanley; Hippler, Michael; Smith, Kristina M.; Brown, Daren W.; Proctor, Robert H.; Münsterkötter, Martin; Freitag, Michael; Humpf, Hans-Ulrich; Güldener, Ulrich; Tudzynski, Bettina

    2013-01-01

    The fungus Fusarium fujikuroi causes “bakanae” disease of rice due to its ability to produce gibberellins (GAs), but it is also known for producing harmful mycotoxins. However, the genetic capacity for the whole arsenal of natural compounds and their role in the fungus' interaction with rice remained unknown. Here, we present a high-quality genome sequence of F. fujikuroi that was assembled into 12 scaffolds corresponding to the 12 chromosomes described for the fungus. We used the genome sequence along with ChIP-seq, transcriptome, proteome, and HPLC-FTMS-based metabolome analyses to identify the potential secondary metabolite biosynthetic gene clusters and to examine their regulation in response to nitrogen availability and plant signals. The results indicate that expression of most but not all gene clusters correlate with proteome and ChIP-seq data. Comparison of the F. fujikuroi genome to those of six other fusaria revealed that only a small number of gene clusters are conserved among these species, thus providing new insights into the divergence of secondary metabolism in the genus Fusarium. Noteworthy, GA biosynthetic genes are present in some related species, but GA biosynthesis is limited to F. fujikuroi, suggesting that this provides a selective advantage during infection of the preferred host plant rice. Among the genome sequences analyzed, one cluster that includes a polyketide synthase gene (PKS19) and another that includes a non-ribosomal peptide synthetase gene (NRPS31) are unique to F. fujikuroi. The metabolites derived from these clusters were identified by HPLC-FTMS-based analyses of engineered F. fujikuroi strains overexpressing cluster genes. In planta expression studies suggest a specific role for the PKS19-derived product during rice infection. Thus, our results indicate that combined comparative genomics and genome-wide experimental analyses identified novel genes and secondary metabolites that contribute to the evolutionary success of F. fujikuroi as a rice pathogen. PMID:23825955

  14. Native cell-death genes as candidates for developing wilt resistance in transgenic banana plants

    PubMed Central

    Ghag, Siddhesh B.; Shekhawat, Upendra K. Singh; Ganapathi, Thumballi R.

    2014-01-01

    In order to feed an ever-increasing world population, there is an urgent need to improve the production of staple food and fruit crops. The productivity of important food and fruit crops is constrained by numerous biotic and abiotic factors. The cultivation of banana, which is an important fruit crop, is severely threatened by Fusarium wilt disease caused by infestation by an ascomycetes fungus Fusarium oxysporum f. sp. cubense (Foc). Since there are no established edible cultivars of banana resistant to all the pathogenic races of Foc, genetic engineering is the only option for the generation of resistant cultivars. Since Foc is a hemibiotrophic fungus, investigations into the roles played by different cell-death-related genes in the progression of Foc infection on host banana plants are important. Towards this goal, three such genes namely MusaDAD1, MusaBAG1 and MusaBI1 were identified in banana. The study of their expression pattern in banana cells in response to Foc inoculation (using Foc cultures or fungal toxins like fusaric acid and beauvericin) indicated that they were indeed differentially regulated by fungal inoculation. Among the three genes studied, MusaBAG1 showed the highest up-regulation upon Foc inoculation. Further, in order to characterize these genes in the context of Foc infection in banana, we generated transgenic banana plants constitutively overexpressing the three genes that were later subjected to Foc bioassays in a contained greenhouse. Among the three groups of transgenics tested, transformed banana plants overexpressing MusaBAG1 demonstrated the best resistance towards Foc infection. Further, these plants also showed the highest relative overexpression of the transgene (MusaBAG1) among the three groups of transformed plants generated. Our study showed for the first time that native genes like MusaBAG1 can be used to develop transgenic banana plants with efficient resistance towards pathogens like Foc. PMID:24996429

  15. Native cell-death genes as candidates for developing wilt resistance in transgenic banana plants.

    PubMed

    Ghag, Siddhesh B; Shekhawat, Upendra K Singh; Ganapathi, Thumballi R

    2014-01-01

    In order to feed an ever-increasing world population, there is an urgent need to improve the production of staple food and fruit crops. The productivity of important food and fruit crops is constrained by numerous biotic and abiotic factors. The cultivation of banana, which is an important fruit crop, is severely threatened by Fusarium wilt disease caused by infestation by an ascomycetes fungus Fusarium oxysporum f. sp. cubense (Foc). Since there are no established edible cultivars of banana resistant to all the pathogenic races of Foc, genetic engineering is the only option for the generation of resistant cultivars. Since Foc is a hemibiotrophic fungus, investigations into the roles played by different cell-death-related genes in the progression of Foc infection on host banana plants are important. Towards this goal, three such genes namely MusaDAD1, MusaBAG1 and MusaBI1 were identified in banana. The study of their expression pattern in banana cells in response to Foc inoculation (using Foc cultures or fungal toxins like fusaric acid and beauvericin) indicated that they were indeed differentially regulated by fungal inoculation. Among the three genes studied, MusaBAG1 showed the highest up-regulation upon Foc inoculation. Further, in order to characterize these genes in the context of Foc infection in banana, we generated transgenic banana plants constitutively overexpressing the three genes that were later subjected to Foc bioassays in a contained greenhouse. Among the three groups of transgenics tested, transformed banana plants overexpressing MusaBAG1 demonstrated the best resistance towards Foc infection. Further, these plants also showed the highest relative overexpression of the transgene (MusaBAG1) among the three groups of transformed plants generated. Our study showed for the first time that native genes like MusaBAG1 can be used to develop transgenic banana plants with efficient resistance towards pathogens like Foc. PMID:24996429

  16. Comparative genomics of Fusarium oxysporum f. sp. melonis reveals the secreted protein recognized by the Fom-2 resistance gene in melon.

    PubMed

    Schmidt, Sarah Maria; Lukasiewicz, Joanna; Farrer, Rhys; van Dam, Peter; Bertoldo, Chiara; Rep, Martijn

    2016-01-01

    Development of resistant crops is the most effective way to control plant diseases to safeguard food and feed production. Disease resistance is commonly based on resistance genes, which generally mediate the recognition of small proteins secreted by invading pathogens. These proteins secreted by pathogens are called 'avirulence' proteins. Their identification is important for being able to assess the usefulness and durability of resistance genes in agricultural settings. We have used genome sequencing of a set of strains of the melon wilt fungus Fusarium oxysporum f. sp. melonis (Fom), bioinformatics-based genome comparison and genetic transformation of the fungus to identify AVRFOM2, the gene that encodes the avirulence protein recognized by the melon Fom-2 gene. Both an unbiased and a candidate gene approach identified a single candidate for the AVRFOM2 gene. Genetic complementation of AVRFOM2 in three different race 2 isolates resulted in resistance of Fom-2-harbouring melon cultivars. AvrFom2 is a small, secreted protein with two cysteine residues and weak similarity to secreted proteins of other fungi. The identification of AVRFOM2 will not only be helpful to select melon cultivars to avoid melon Fusarium wilt, but also to monitor how quickly a Fom population can adapt to deployment of Fom-2-containing cultivars in the field. PMID:26305378

  17. Mitogen-activated protein kinases are associated with the regulation of physiological traits and virulence in Fusarium oxysporum f. sp. cubense.

    PubMed

    Ding, Zhaojian; Li, Minhui; Sun, Fei; Xi, Pinggen; Sun, Longhua; Zhang, Lianhui; Jiang, Zide

    2015-01-01

    Fusarium oxysporum f. sp. cubense (FOC) is an important soil-borne fungal pathogen causing devastating vascular wilt disease of banana plants and has become a great concern threatening banana production worldwide. However, little information is known about the molecular mechanisms that govern the expression of virulence determinants of this important fungal pathogen. In this study, we showed that null mutation of three mitogen-activated protein (MAP) kinase genes, designated as FoSlt2, FoMkk2 and FoBck1, respectively, led to substantial attenuation in fungal virulence on banana plants. Transcriptional analysis revealed that the MAP kinase signaling pathway plays a key role in regulation of the genes encoding production of chitin, peroxidase, beauvericin and fusaric acid. Biochemical analysis further confirmed the essential role of MAP kinases in modulating the production of fusaric acid, which was a crucial phytotoxin in accelerating development of Fusarium wilt symptoms in banana plants. Additionally, we found that the MAP kinase FoSlt2 was required for siderophore biosynthesis under iron-depletion conditions. Moreover, disruption of the MAP kinase genes resulted in abnormal hypha and increased sensitivity to Congo Red, Calcofluor White and H2O2. Taken together, these results depict the critical roles of MAP kinases in regulation of FOC physiology and virulence. PMID:25849862

  18. Mitogen-Activated Protein Kinases Are Associated with the Regulation of Physiological Traits and Virulence in Fusarium oxysporum f. sp. cubense

    PubMed Central

    Ding, Zhaojian; Li, Minhui; Sun, Fei; Xi, Pinggen; Sun, Longhua; Zhang, Lianhui; Jiang, Zide

    2015-01-01

    Fusarium oxysporum f. sp. cubense (FOC) is an important soil-borne fungal pathogen causing devastating vascular wilt disease of banana plants and has become a great concern threatening banana production worldwide. However, little information is known about the molecular mechanisms that govern the expression of virulence determinants of this important fungal pathogen. In this study, we showed that null mutation of three mitogen-activated protein (MAP) kinase genes, designated as FoSlt2, FoMkk2 and FoBck1, respectively, led to substantial attenuation in fungal virulence on banana plants. Transcriptional analysis revealed that the MAP kinase signaling pathway plays a key role in regulation of the genes encoding production of chitin, peroxidase, beauvericin and fusaric acid. Biochemical analysis further confirmed the essential role of MAP kinases in modulating the production of fusaric acid, which was a crucial phytotoxin in accelerating development of Fusarium wilt symptoms in banana plants. Additionally, we found that the MAP kinase FoSlt2 was required for siderophore biosynthesis under iron-depletion conditions. Moreover, disruption of the MAP kinase genes resulted in abnormal hypha and increased sensitivity to Congo Red, Calcofluor White and H2O2. Taken together, these results depict the critical roles of MAP kinases in regulation of FOC physiology and virulence. PMID:25849862

  19. Cytotoxicity and Phytotoxicity of Trichothecene Mycotoxins Produced by Fusarium spp.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Trichothecenes, a major class of mycotoxins produced by Fusarium, Myrothecium, and Stachybotrys species, are toxic to plants, causing blights, wilts and other economically-important plant diseases, and to mammals, for example feed-refusal caused by deoxynivalenol (vomitoxin). Macrocyclic trichothec...

  20. Root Rot of Balloon Flower (Platycodon grandiflorum) Caused by Fusarium solani and Fusarium oxysporum.

    PubMed

    Jeon, Chi Sung; Kim, Gyoung Hee; Son, Kyeong In; Hur, Jae-Seoun; Jeon, Kwon-Seok; Yoon, Jun-Hyuck; Koh, Young Jin

    2013-12-01

    Balloon flower (Platycodon grandiflorum) is a kind of mountain herbs whose roots have restorative properties and the cultivating acreage of balloon flower has been steadily increasing in Korea. More frequent rain and high amount of rainfalls as a result of climate changes predisposed balloon flower to the outbreaks of root rot at high-density cultivation area in recent years. Root crowns were usually discolored into brown to blackish brown at first and the infected plants showed slight wilting symptom at early infection stage. Severely infected roots were entirely rotted and whole plants eventually died at late infection stage. The overall disease severities of root rot of balloon flower were quite variable according to the surveyed fields in Jeonnam, Gyeongnam and Jeju Provinces, which ranged from 0.1% to 40%. The root rot occurred more severely at the paddy or clay soils than the sandy soils and their severities were much higher at lowland than upland in the same localty. The disease increased with aging of the balloon flower. The causal fungi were identified as Fusarium solani and F. oxysporum on the basis of their mycological characteristics. The optimum temperature ranges of their mycelial growths was found to be 24°C. The pathogenic characters of F. solani and F. oxysporum treated by artificial wounding inoculation on healthy roots of balloon flower revealed that F. solani was more virulent than F. oxysporum. This study identified the causal agents of root rot of balloon flower as Fusarium solani and F. oxysporum, probably for the first time. PMID:25288973

  1. The need for culture collections to support plant pathogen diagnostic networks.

    PubMed

    Barba, Marina; Van den Bergh, Inge; Belisario, Alessandra; Beed, Fen

    2010-01-01

    Plant-pathogenic microorganisms, by virtue of their size, similarity in disease symptoms and closely related morphologies, are notoriously difficult to diagnose and detect. Diagnosis gives proof as to the causal agent of disease and is important for developing appropriate control measures. Detection shows the presence of a microorganism and is of importance for safeguarding national and international trade. Live reference collections are required to characterize the taxonomy and function of microorganisms as a prerequisite to development of tools for diagnosis and detection. Two case studies will be presented in this paper to demonstrate the importance of microorganism collections for facilitating knowledge sharing and the development of identification methods. Fusarium wilt of banana caused by Fusarium oxysporum f. sp. cubense and sharka disease of stone fruits caused by plum pox virus (PPV) are considered. Both diseases consist of different races/strains with different host specificities, but Fusarium wilt poses a threat to food security, while PPV poses a threat to trade due to its classification as a quarantine pest, since there is no anti-virus treatment available to control sharka disease in orchards. It is only through comprehensive collections of correctly identified and well-maintained strains representing the genetic diversity of a target organism that robust, specific, reliable and efficient diagnostic and detection tools can be developed. PMID:20457251

  2. A novel Asian clade within the Fusarium graminearum species complex includes a newly discovered cereal head blight pathogen from the Russian Far East.

    PubMed

    Yli-Mattila, Tapani; Gagkaeva, Tatiana; Ward, Todd J; Aoki, Takayuki; Kistler, H Corby; O'Donnell, Kerry

    2009-01-01

    We investigated Fusarium graminearum complex (Fg complex) species diversity and toxin potential in European and Asian regions of the Russian Federation and adjoining regions northwest to Finland and south near Harbin, Heilongjiang Province, China, to expand our knowledge of the host range and geographic distribution of these economically devastating cereal head blight pathogens. Results of a recently described multilocus genotyping (MLGT) assay revealed that F. graminearum was the sole Fg complex pathogen in northern Europe and the predominant one in Asia (90.5%). Even though isolates of F. graminearum were segregating for 3-acetyldeoxynivalenol (3ADON) and 15-acetyldeoxynivalenol (15ADON) chemotype in nearly equal frequencies in the regions sampled on both continents, significant differences in the geographic distribution of isolates producing these acetyl ester derivatives of deoxynivalenol (DON) were observed in Europe. While 93.5% of the isolates in southern Russia (n = 43 of 46) possessed the 15ADON chemotype, isolates of F. graminearum recovered in Finland and northwestern Russia (n = 40) were exclusively 3ADON producers. Based on results of the MLGT assay, species identity of 10 genetically novel Fg complex isolates from the Russian Far East was investigated further via molecular phylogenetic analyses of multilocus DNA sequence data. Results of these analyses resolved these isolates as a phylogenetically distinct, reciprocally monophyletic sister lineage of F. asiaticum, which together with F. vorosii form a newly discovered Asian clade within the Fg complex. Because this novel lineage fulfills the highly conservative criterion of genealogical exclusivity under phylogenetic species recognition it is formally described herein as F. ussurianum. In addition to morphologically characterizing isolates of F. ussurianum, experiments were conducted to assess pathogenicity to wheat and trichothecene toxin potential in planta. PMID:19927749

  3. Surface Survival and Internalization of Salmonella through Natural Cracks on Developing Cantaloupe Fruits, Alone or in the Presence of the Melon Wilt Pathogen Erwinia tracheiphila

    PubMed Central

    Gautam, Dhiraj; Dobhal, Shefali; Payton, Mark E.; Fletcher, Jacqueline; Ma, Li Maria

    2014-01-01

    Outbreaks of foodborne illness attributed to the consumption of Salmonella-tainted cantaloupe have occurred repeatedly, but understanding of the ecology of Salmonella on cantaloupe fruit surfaces is limited. We investigated the interactions between Salmonella enterica Poona, the plant pathogenic bacterium Erwinia tracheiphila, and cantaloupe fruit. Fruit surfaces were inoculated at the natural cracking stage by spreading S. enterica and E. tracheiphila, 20 µl at 107 cfu/ml, independently or together, over a 2×2 cm rind area containing a crack. Microbial and microscopic analyses were performed at 0, 9 and 24 days post inoculation (DPI). Even at 24 DPI (fruit maturity) S. enterica was detected on 14% and 40% of the fruit inoculated with S. enterica alone and the two-pathogen mixture, respectively. However, the population of S. enterica declined gradually after initial inoculation. E. tracheiphila, inoculated alone or together with Salmonella, caused watersoaked lesions on cantaloupe fruit; but we could not conclude in this study that S. enterica survival on the fruit surface was enhanced by the presence of those lesions. Of fruit inoculated with E. tracheiphila alone and sampled at 24 DPI, 61% had watersoaked lesions on the surface. In nearly half of those symptomatic fruits the watersoaking extended into the sub-rind mesocarp, and E. tracheiphila was recovered from that tissue in 50% of the symptomatic fruit. In this work, E. tracheiphila internalized through natural cracks on developing fruits. S. enterica was never detected in the fruit interior (ca. 2–3 mm below rind surface) under the limited conditions of our experiments, but the possibility that it, or other human pathogens that contaminate fresh produce, might also do so should be investigated under a wider range of conditions and produce types. PMID:25147942

  4. Surface survival and internalization of salmonella through natural cracks on developing cantaloupe fruits, alone or in the presence of the melon wilt pathogen Erwinia tracheiphila.

    PubMed

    Gautam, Dhiraj; Dobhal, Shefali; Payton, Mark E; Fletcher, Jacqueline; Ma, Li Maria

    2014-01-01

    Outbreaks of foodborne illness attributed to the consumption of Salmonella-tainted cantaloupe have occurred repeatedly, but understanding of the ecology of Salmonella on cantaloupe fruit surfaces is limited. We investigated the interactions between Salmonella enterica Poona, the plant pathogenic bacterium Erwinia tracheiphila, and cantaloupe fruit. Fruit surfaces were inoculated at the natural cracking stage by spreading S. enterica and E. tracheiphila, 20 µl at 107 cfu/ml, independently or together, over a 2×2 cm rind area containing a crack. Microbial and microscopic analyses were performed at 0, 9 and 24 days post inoculation (DPI). Even at 24 DPI (fruit maturity) S. enterica was detected on 14% and 40% of the fruit inoculated with S. enterica alone and the two-pathogen mixture, respectively. However, the population of S. enterica declined gradually after initial inoculation. E. tracheiphila, inoculated alone or together with Salmonella, caused watersoaked lesions on cantaloupe fruit; but we could not conclude in this study that S. enterica survival on the fruit surface was enhanced by the presence of those lesions. Of fruit inoculated with E. tracheiphila alone and sampled at 24 DPI, 61% had watersoaked lesions on the surface. In nearly half of those symptomatic fruits the watersoaking extended into the sub-rind mesocarp, and E. tracheiphila was recovered from that tissue in 50% of the symptomatic fruit. In this work, E. tracheiphila internalized through natural cracks on developing fruits. S. enterica was never detected in the fruit interior (ca. 2-3 mm below rind surface) under the limited conditions of our experiments, but the possibility that it, or other human pathogens that contaminate fresh produce, might also do so should be investigated under a wider range of conditions and produce types. PMID:25147942

  5. Regional and field-specific factors affect the composition of fusarium head blight pathogens in subtropical no-till wheat agroecosystem of Brazil.

    PubMed

    Del Ponte, Emerson M; Spolti, Piérri; Ward, Todd J; Gomes, Larissa B; Nicolli, Camila P; Kuhnem, Paulo R; Silva, Cleiltan N; Tessmann, Dauri J

    2015-02-01

    A multiyear survey of >200 wheat fields in Paraná (PR) and Rio Grande do Sul (RS) states was conducted to assess the extent and distribution of Fusarium graminearum species complex (FGSC) diversity in the southern Brazilian wheat agroecosystem. Five species and three trichothecene genotypes were found among 671 FGSC isolates from Fusarium head blight (FHB)-infected wheat heads: F. graminearum (83%) of the 15-acetyldeoxynivalenol (15-ADON) genotype, F. meridionale (12.8%) and F. asiaticum (0.4%) of the nivalenol (NIV) genotype, and F. cortaderiae (2.5%) and F. austroamericanum (0.9%) with either the NIV or the 3-ADON genotype. Regional differences in FGSC composition were observed, with F. meridionale and the NIV type being significantly (P<0.001) more prevalent in PR (>28%) than in RS (≤9%). Within RS, F. graminearum was overrepresented in fields below 600 m in elevation and in fields with higher levels of FHB incidence (P<0.05). Species composition was not significantly influenced by previous crop or the stage of grain development at sampling. Habitat-specific differences in FGSC composition were evaluated in three fields by characterizing a total of 189 isolates collected from corn stubble, air above the wheat canopy, and symptomatic wheat kernels. Significant differences in FGSC composition were observed among these habitats (P<0.001). Most strikingly, F. meridionale and F. cortaderiae of the NIV genotype accounted for the vast majority (>96%) of isolates from corn stubble, whereas F. graminearum with the 15-ADON genotype was dominant (>84%) among isolates from diseased wheat kernels. Potential differences in pathogenic fitness on wheat were also suggested by a greenhouse competitiveness assay in which F. graminearum was recovered at much higher frequency (>90%) than F. meridionale from four wheat varieties inoculated with an equal mixture of F. graminearum and F. meridionale isolates. Taken together, the data presented here suggest that FGSC composition and, consequently, the trichothecene contamination in wheat grown in southern Brazil is influenced by host adaptation and pathogenic fitness. Evidence that F. meridionale and F. cortaderiae with the NIV genotype are regionally significant contributors to FHB may have significant implications for food safety and the economics of cereal production. PMID:25121641

  6. Virulence and secondary metabolite profiles of vascular competent and vascular incompetent pathotypes of Fusarium oxysporum f. sp. vasinfectum

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fusarium wilt of cotton, caused by Fusarium oxysporum f. sp. vasinfectum (Fov), occurs in most cotton growing areas of the world. Pathotypes of Fov have been categorized into eight races based on virulence to different hosts. However, lack of reciprocal resistance reactions among cotton cultivars t...

  7. Identification of resistance to fusarium oxysporum f. sp. niveum Race 2 in citrullus lanatus var. citroides plant introductions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fusarium wilt is a major disease of watermelon in North America and around the world. Control of this disease is difficult, because the soil-borne causal agent Fusarium oxysporum f. sp. niveum (Fon), produces resilient spores that remain infectious for many years. Although various levels of resist...

  8. Trichoderma harzianum and Glomus intraradices modify the hormone disruption induced by Fusarium oxysporum infection in melon plants.

    PubMed

    Martínez-Medina, Ainhoa; Pascual, Jose Antonio; Pérez-Alfocea, Francisco; Albacete, Alfonso; Roldán, Antonio

    2010-07-01

    The plant hormones salicylic acid (SA), jasmonic acid (JA), ethylene (ET), and abscisic acid (ABA) are known to play crucial roles in plant disease and pest resistance. Changes in the concentrations of these plant hormones in melon plant shoots, as a consequence of the interaction between the plant, the pathogen Fusarium oxysporum, the antagonistic microorganism Trichoderma harzianum, and the arbuscular mycorrhizal fungus Glomus intraradices were investigated. Attack by F. oxysporum activated a defensive response in the plant, mediated by the plant hormones SA, JA, ET, and ABA, similar to the one produced by T. harzianum. When inoculated with the pathogen, both T. harzianum and G. intraradices attenuated the plant response mediated by the hormones ABA and ET elicited by the pathogen attack. T. harzianum was also able to attenuate the SA-mediated response. In the three-way interaction (F. oxysporum-T. harzianum-G. intraradices), although a synergistic effect in reducing disease incidence was found, no synergistic effect on the modulation of the hormone disruption induced by the pathogen was observed. These results suggest that the induction of plant basal resistance and the attenuation of the hormonal disruption caused by F. oxysporum are both mechanisms by which T. harzianum can control Fusarium wilt in melon plants; while the mechanisms involving G. intraradices seem to be independent of SA and JA signaling. PMID:20528186

  9. The Genome of the Generalist Plant Pathogen Fusarium avenaceum Is Enriched with Genes Involved in Redox, Signaling and Secondary Metabolism

    PubMed Central

    Lysøe, Erik; Harris, Linda J.; Walkowiak, Sean; Subramaniam, Rajagopal; Divon, Hege H.; Riiser, Even S.; Llorens, Carlos; Gabaldón, Toni; Kistler, H. Corby; Jonkers, Wilfried; Kolseth, Anna-Karin; Nielsen, Kristian F.; Thrane, Ulf; Frandsen, Rasmus J. N.

    2014-01-01

    Fusarium avenaceum is a fungus commonly isolated from soil and associated with a wide range of host plants. We present here three genome sequences of F. avenaceum, one isolated from barley in Finland and two from spring and winter wheat in Canada. The sizes of the three genomes range from 41.6–43.1 MB, with 13217–13445 predicted protein-coding genes. Whole-genome analysis showed that the three genomes are highly syntenic, and share>95% gene orthologs. Comparative analysis to other sequenced Fusaria shows that F. avenaceum has a very large potential for producing secondary metabolites, with between 75 and 80 key enzymes belonging to the polyketide, non-ribosomal peptide, terpene, alkaloid and indole-diterpene synthase classes. In addition to known metabolites from F. avenaceum, fuscofusarin and JM-47 were detected for the first time in this species. Many protein families are expanded in F. avenaceum, such as transcription factors, and proteins involved in redox reactions and signal transduction, suggesting evolutionary adaptation to a diverse and cosmopolitan ecology. We found that 20% of all predicted proteins were considered to be secreted, supporting a life in the extracellular space during interaction with plant hosts. PMID:25409087

  10. Candidate genes associated with QTL controlling resistance to fusarium root rot in pea

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fusarium root rot (FRR) of pea (Pisum sativum L.) is a serious pathogen in the USA and Europe and genetic resistance offers an effective and economical control for this pathogen. Fusarium root rot is caused by the fungus pathogen (Haematonectria haematococca (Berk. & Broome) (Anamorph): Fusarium sol...

  11. Verticillium Wilt Resistance Evaluation of Wisconsin Breeding Clones

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Verticillium wilt is one of the most widespread and persistent problems encountered by potato producers. In Wisconsin, it is caused in large part by the fungal pathogen Verticillium dahliae. Soil fumigation is currently the only consistently effective control measure. However, host plant resistan...

  12. Natural and natural-like phenolic inhibitors of type B trichothecene in vitro production by the wheat (Triticum sp.) pathogen Fusarium culmorum.

    PubMed

    Pani, Giovanna; Scherm, Barbara; Azara, Emanuela; Balmas, Virgilio; Jahanshiri, Zahra; Carta, Paola; Fabbri, Davide; Dettori, Maria Antonietta; Fadda, Angela; Dessì, Alessandro; Dallocchio, Roberto; Migheli, Quirico; Delogu, Giovanna

    2014-06-01

    Fusarium culmorum, a fungal pathogen of small grain cereals, produces 4-deoxynivalenol and its acetylated derivatives that may cause toxicoses on humans or animals consuming contaminated food or feed. Natural and natural-like compounds belonging to phenol and hydroxylated biphenyl structural classes were tested in vitro to determine their activity on vegetative growth and trichothecene biosynthesis by F. culmorum. Most of the compounds tested at 1.5 or 1.0 mM reduced 3-acetyl-4-deoxynivalenol production by over 70% compared to the control, without affecting fungal growth significantly. Furthermore, several compounds retained their ability to inhibit toxin in vitro production at the lowest concentrations of 0.5 and 0.25 mM. Magnolol 27 showed fungicidal activity even at 0.1 mM. No linear correlation was observed between antioxidant properties of the compounds and their ability to inhibit fungal growth and mycotoxigenic capacity. A guaiacyl unit in the structure may play a key role in trichothecene inhibition. PMID:24820850

  13. TRANSFORMATION TO PRODUCE BARLEY RESISTANT TO FUSARIUM GRAMINEARUM

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The fungal pathogen Fusarium graminearum destroys barley and wheat crops by causing scab disease (Fusarium head blight, FHB). Spores infect seed spike tissues, leading to production of mycotoxins. There are no known barleys with biochemical resistance to Fusarium, although some have various levels ...

  14. RNA-Seq analysis reveals new gene models and alternative splicing in the fungal pathogen Fusarium graminearum

    PubMed Central

    2013-01-01

    Background The genome of Fusarium graminearum has been sequenced and annotated previously, but correct gene annotation remains a challenge. In addition, posttranscriptional regulations, such as alternative splicing and RNA editing, are poorly understood in F. graminearum. Here we took advantage of RNA-Seq to improve gene annotations and to identify alternative splicing and RNA editing in F. graminearum. Results We identified and revised 655 incorrectly predicted gene models, including revisions of intron predictions, intron splice sites and prediction of novel introns. 231 genes were identified with two or more alternative splice variants, mostly due to intron retention. Interestingly, the expression ratios between different transcript isoforms appeared to be developmentally regulated. Surprisingly, no RNA editing was identified in F. graminearum. Moreover, 2459 novel transcriptionally active regions (nTARs) were identified and our analysis indicates that many of these could be missed genes. Finally, we identified the 5′ UTR and/or 3′ UTR sequences of 7666 genes. A number of representative novel gene models and alternatively spliced genes were validated by reverse transcription polymerase chain reaction and sequencing of the generated amplicons. Conclusions We have developed novel and efficient strategies to identify alternatively spliced genes and incorrect gene models based on RNA-Seq data. Our study identified hundreds of alternatively spliced genes in F. graminearum and for the first time indicated that alternative splicing is developmentally regulated in filamentous fungi. In addition, hundreds of incorrect predicted gene models were identified and revised and thousands of nTARs were discovered in our study, which will be helpful for the future genomic and transcriptomic studies in F. graminearum. PMID:23324402

  15. The transmembrane protein FgSho1 regulates fungal development and pathogenicity via the MAPK module Ste50-Ste11-Ste7 in Fusarium graminearum.

    PubMed

    Gu, Qin; Chen, Yun; Liu, Ye; Zhang, Chengqi; Ma, Zhonghua

    2015-04-01

    The mitogen-activated protein kinase (MAPK) signaling pathways have been characterized in Fusarium graminearum. Currently, the upstream sensors of these pathways are unknown. Biological functions of a transmembrane protein FgSho1 were investigated using a target gene deletion strategy. The relationship between FgSho1 and the MAPK cassette FgSte50-Ste11-Ste7 was analyzed in depth. The transmembrane protein FgSho1 is required for conidiation, full virulence, and deoxynivalenol (DON) biosynthesis in F. graminearum. Furthermore, FgSho1 and FgSln1 have an additive effect on virulence of F. graminearum. The yeast two-hybrid, coimmunoprecipitation, colocalization and affinity capture-mass spectrometry analyses strongly indicated that FgSho1 physically interacts with the MAPK module FgSte50-Ste11-Ste7. Similar to the FgSho1 mutant, the mutants of FgSte50, FgSte11, and FgSte7 were defective in conidiation, pathogenicity, and DON biosynthesis. In addition, FgSho1 plays a minor role in the response to osmotic stress but it is involved in the cell wall integrity pathway, which is independent of the module FgSte50-Ste11-Ste7 in F. graminearum. Collectively, results of this study strongly indicate that FgSho1 regulates fungal development and pathogenicity via the MAPK module FgSte50-Ste11-Ste7 in F. graminearum, which is different from what is known in the budding yeast Saccharomyces cerevisiae. PMID:25388878

  16. The Adenylyl Cyclase Plays a Regulatory Role in the Morphogenetic Switch from Vegetative to Pathogenic Lifestyle of Fusarium graminearum on Wheat

    PubMed Central

    Bormann, Jörg; Boenisch, Marike Johanne; Brückner, Elena; Firat, Demet; Schäfer, Wilhelm

    2014-01-01

    Cyclic 3′,5′-adenosine monophosphate (cAMP) is a nucleotide derived from adenosine triphosphate that acts as a second messenger throughout all kingdoms. Intracellular cAMP levels are synthesized by a membrane-bound protein, the adenylyl cyclase. In order to analyze the function of this gene and the importance of cAMP in the life cycle of the cereal pathogen Fusarium graminearum, the adenylyl cyclase gene (FGSG_01234) was deleted by gene replacement (ΔFgac1). The ΔFgac1 mutant displayed a drastically reduced growth on agar medium which could be rescued by a cAMP analogon. Furthermore, the ΔFgac1 mutant was unable to produce perithecia on detached wheat nodes. However, artificial conditions like carrot agar allowed perithecia development. Pathogenicity towards wheat was drastically reduced in ΔFgac1 compared to the wild type. Point-inoculated spikelets showed only small lesions but no typical head blight disease symptoms. Fluorescence microscopy using dsRed-expressing strains revealed that the ΔFgac1 strain was unable to develop any complex infection structures like lobate appressoria and infection cushions. Instead, hyphal anastomosis occurs frequently. Scanning electron microscopy demonstrated the lack of fungal penetration. Hence, the formation of compound appressoria seems to be essential for infection of wheat. Hyphae on flower leaves produced huge amounts of new conidia, thereby circumventing the infection cycle. This abundant sporulation on wheat epidermis was not observed in wild type. Intriguingly, the Fgac1 deletion mutant was able to infect maize cobs as wild type, indicating that cAMP signaling is not important for maize infection. The ΔFgac1 mutant was unable to produce the mycotoxin deoxynivalenol both in vitro and during wheat infection. In this study, we show that cAMP signaling controls important cellular processes such as development of infection structures, pathogenicity, secondary metabolite production and sexual reproduction. For the first time, we show that cAMP regulates the switch from vegetative to pathogenic lifestyle of F. graminearum on wheat. PMID:24603887

  17. The adenylyl cyclase plays a regulatory role in the morphogenetic switch from vegetative to pathogenic lifestyle of Fusarium graminearum on wheat.

    PubMed

    Bormann, Jörg; Boenisch, Marike Johanne; Brückner, Elena; Firat, Demet; Schäfer, Wilhelm

    2014-01-01

    Cyclic 3',5'-adenosine monophosphate (cAMP) is a nucleotide derived from adenosine triphosphate that acts as a second messenger throughout all kingdoms. Intracellular cAMP levels are synthesized by a membrane-bound protein, the adenylyl cyclase. In order to analyze the function of this gene and the importance of cAMP in the life cycle of the cereal pathogen Fusarium graminearum, the adenylyl cyclase gene (FGSG_01234) was deleted by gene replacement (ΔFgac1). The ΔFgac1 mutant displayed a drastically reduced growth on agar medium which could be rescued by a cAMP analogon. Furthermore, the ΔFgac1 mutant was unable to produce perithecia on detached wheat nodes. However, artificial conditions like carrot agar allowed perithecia development. Pathogenicity towards wheat was drastically reduced in ΔFgac1 compared to the wild type. Point-inoculated spikelets showed only small lesions but no typical head blight disease symptoms. Fluorescence microscopy using dsRed-expressing strains revealed that the ΔFgac1 strain was unable to develop any complex infection structures like lobate appressoria and infection cushions. Instead, hyphal anastomosis occurs frequently. Scanning electron microscopy demonstrated the lack of fungal penetration. Hence, the formation of compound appressoria seems to be essential for infection of wheat. Hyphae on flower leaves produced huge amounts of new conidia, thereby circumventing the infection cycle. This abundant sporulation on wheat epidermis was not observed in wild type. Intriguingly, the Fgac1 deletion mutant was able to infect maize cobs as wild type, indicating that cAMP signaling is not important for maize infection. The ΔFgac1 mutant was unable to produce the mycotoxin deoxynivalenol both in vitro and during wheat infection. In this study, we show that cAMP signaling controls important cellular processes such as development of infection structures, pathogenicity, secondary metabolite production and sexual reproduction. For the first time, we show that cAMP regulates the switch from vegetative to pathogenic lifestyle of F. graminearum on wheat. PMID:24603887

  18. Root Exudates from Grafted-Root Watermelon Showed a Certain Contribution in Inhibiting Fusarium oxysporum f. sp. niveum

    PubMed Central

    Wang, Dongsheng; Mao, Jiugeng; Huang, Qiwei; Guo, Shiwei; Shen, Qirong

    2013-01-01

    Grafting watermelon onto bottle gourd rootstock is commonly used method to generate resistance to Fusarium oxysporum f. sp. niveum (FON), but knowledge of the effect of the root exudates of grafted watermelon on this soil-borne pathogen in rhizosphere remains limited. To investigate the root exudate profiles of the own-root bottle gourd, grafted-root watermelon and own-root watermelon, recirculating hydroponic culture system was developed to continuously trap these root exudates. Both conidial germination and growth of FON were significantly decreased in the presence of root exudates from the grafted-root watermelon compared with the own-root watermelon. HPLC analysis revealed that the composition of the root exudates released by the grafted-root watermelon differed not only from the own-root watermelon but also from the bottle gourd rootstock plants. We identified salicylic acid in all 3 root exudates, chlorogenic acid and caffeic acid in root exudates from own-root bottle gourd and grafted-root watermelon but not own-root watermelon, and abundant cinnamic acid only in own-root watermelon root exudates. The chlorogenic and caffeic acid were candidates for potentiating the enhanced resistance of the grafted watermelon to FON, therefore we tested the effects of the two compounds on the conidial germination and growth of FON. Both phenolic acids inhibited FON conidial germination and growth in a dose-dependent manner, and FON was much more susceptible to chlorogenic acid than to caffeic acid. In conclusion, the key factor in attaining the resistance to Fusarium wilt is grafting on the non-host root stock, however, the root exudates profile also showed some contribution in inhibiting FON. These results will help to better clarify the disease resistance mechanisms of grafted-root watermelon based on plant-microbe communication and will guide the improvement of strategies against Fusarium-mediated wilt of watermelon plants. PMID:23700421

  19. Root exudates from grafted-root watermelon showed a certain contribution in inhibiting Fusarium oxysporum f. sp. niveum.

    PubMed

    Ling, Ning; Zhang, Wenwen; Wang, Dongsheng; Mao, Jiugeng; Huang, Qiwei; Guo, Shiwei; Shen, Qirong

    2013-01-01

    Grafting watermelon onto bottle gourd rootstock is commonly used method to generate resistance to Fusarium oxysporum f. sp. niveum (FON), but knowledge of the effect of the root exudates of grafted watermelon on this soil-borne pathogen in rhizosphere remains limited. To investigate the root exudate profiles of the own-root bottle gourd, grafted-root watermelon and own-root watermelon, recirculating hydroponic culture system was developed to continuously trap these root exudates. Both conidial germination and growth of FON were significantly decreased in the presence of root exudates from the grafted-root watermelon compared with the own-root watermelon. HPLC analysis revealed that the composition of the root exudates released by the grafted-root watermelon differed not only from the own-root watermelon but also from the bottle gourd rootstock plants. We identified salicylic acid in all 3 root exudates, chlorogenic acid and caffeic acid in root exudates from own-root bottle gourd and grafted-root watermelon but not own-root watermelon, and abundant cinnamic acid only in own-root watermelon root exudates. The chlorogenic and caffeic acid were candidates for potentiating the enhanced resistance of the grafted watermelon to FON, therefore we tested the effects of the two compounds on the conidial germination and growth of FON. Both phenolic acids inhibited FON conidial germination and growth in a dose-dependent manner, and FON was much more susceptible to chlorogenic acid than to caffeic acid. In conclusion, the key factor in attaining the resistance to Fusarium wilt is grafting on the non-host root stock, however, the root exudates profile also showed some contribution in inhibiting FON. These results will help to better clarify the disease resistance mechanisms of grafted-root watermelon based on plant-microbe communication and will guide the improvement of strategies against Fusarium-mediated wilt of watermelon plants. PMID:23700421

  20. Effects of water regime, crop residues, and application rates on control of Fusarium oxysporum f. sp. cubense.

    PubMed

    Wen, Teng; Huang, Xinqi; Zhang, Jinbo; Zhu, Tongbin; Meng, Lei; Cai, Zucong

    2015-05-01

    Biological soil disinfestation is an effective method to control soil-borne disease by flooding and incorporating with organic amendments, but field conditions and resources sometimes limited its practical application. A laboratory experiment was conducted to develop practice guidelines on controlling Fusarium wilt, a widespread banana disease caused by Fusarium oxysporum f. sp. cubense (FOC). FOC infested soil incorporated with rice or maize straw at rates of 1.5 tons/ha and 3.0 tons/ha was incubated under flooded or water-saturated (100% water holding capacity) conditions at 30°C for 30 days. Results showed that FOC populations in the soils incorporated with either rice or maize straw rapidly reduced more than 90% in the first 15 days and then fluctuated till the end of incubation, while flooding alone without organic amendment reduced FOC populations slightly. The rapid and dramatic decrease of redox potential (down to -350 mV) in straw-amended treatments implied that both anaerobic condition and strongly reductive soil condition would contribute to pathogen inactivation. Water-saturation combined with straw amendments had the comparable effects on reduction of FOC, indicating that flooding was not indispensable for inactivating FOC. There was no significant difference in the reduction of FOC observed in the straw amendments at between 1.5 and 3 tons/ha. Therefore, incorporating soil with straw (rice or maize straw) at a rate of 3.0 tons/ha under 100% water holding capacity or 1.5 tons/ha under flooding, would effectively alleviate banana Fusarium wilt caused by FOC after 15-day treating under 30°C. PMID:25968255

  1. Fusariosis associated with pathogenic fusarium species colonization of a hospital water system: a new paradigm for the epidemiology of opportunistic mold infections.

    PubMed

    Anaissie, E J; Kuchar, R T; Rex, J H; Francesconi, A; Kasai, M; Müller, F M; Lozano-Chiu, M; Summerbell, R C; Dignani, M C; Chanock, S J; Walsh, T J

    2001-12-01

    We sought the reservoir of Fusarium species in a hospital with cases of known fusarial infections. Cultures of samples from patients and the environment were performed and evaluated for relatedness by use of molecular methods. Fusarium species was recovered from 162 (57%) of 283 water system samples. Of 92 sink drains tested, 72 (88%) yielded Fusarium solani; 12 (16%) of 71 sink faucet aerators and 2 (8%) of 26 shower heads yielded Fusarium oxysporum. Fusarium solani was isolated from the hospital water tank. Aerosolization of Fusarium species was documented after running the showers. Molecular biotyping revealed multiple distinct genotypes among the isolates from the environment and patients. Eight of 20 patients with F. solani infections had isolates with a molecular match with either an environmental isolate (n=2) or another patient isolate (n=6). The time interval between the 2 matched patient-environment isolates pairs was 5 and 11 months, and 2, 4, and 5.5 years for the 3 patient-patient isolate pairs. The water distribution system of a hospital was identified as a reservoir of Fusarium species. PMID:11692299

  2. EVOLUTION OF THE FUSARIUM GRAMINEARUM SPECIES COMPLEX

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fusarium head blight or scab of cereals is one of the most devastating plant diseases worldwide. These pathogens cause significant reduction in seed quality and yields and often contaminate seeds with trichothecene and estrogenic mycotoxins. Genealogical concordance phylogenetic species recognitio...

  3. Transcription of Genes in the Biosynthetic Pathway for Fumonisin Mycotoxins Is Epigenetically and Differentially Regulated in the Fungal Maize Pathogen Fusarium verticillioides

    PubMed Central

    Visentin, I.; Montis, V.; Döll, K.; Alabouvette, C.; Tamietti, G.; Karlovsky, P.

    2012-01-01

    When the fungal pathogen Gibberella moniliformis (anamorph, Fusarium verticillioides) colonizes maize and maize-based products, it produces class B fumonisin (FB) mycotoxins, which are a significant threat to human and animal health. FB biosynthetic enzymes and accessory proteins are encoded by a set of clustered and cotranscribed genes collectively named FUM, whose molecular regulation is beginning to be unraveled by researchers. FB accumulation correlates with the amount of transcripts from the key FUM genes, FUM1, FUM21, and FUM8. In fungi in general, gene expression is often partially controlled at the chromatin level in secondary metabolism; when this is the case, the deacetylation and acetylation (and other posttranslational modifications) of histones are usually crucial in the regulation of transcription. To assess whether epigenetic factors regulate the FB pathway, we monitored FB production and FUM1, FUM21, and FUM8 expression in the presence of a histone deacetylase inhibitor and verified by chromatin immunoprecipitation the relative degree of histone acetylation in the promoter regions of FUM1, FUM21, and FUM8 under FB-inducing and noninducing conditions. Moreover, we generated transgenic F. verticillioides strains expressing GFP under the control of the FUM1 promoter to determine whether its strength under FB-inducing and noninducing conditions was influenced by its location in the genome. Our results indicate a clear and differential role for chromatin remodeling in the regulation of FUM genes. This epigenetic regulation can be attained through the modulation of histone acetylation at the level of the promoter regions of the key biosynthetic genes FUM1 and FUM21, but less so for FUM8. PMID:22117026

  4. Evolutionary relationships among the Fusarium oxysporum f. sp. cubense vegetative compatibility groups.

    PubMed

    Fourie, Gerda; Steenkamp, E T; Gordon, T R; Viljoen, A

    2009-07-01

    Fusarium oxysporum f. sp. cubense, the causal agent of fusarium wilt of banana (Musa spp.), is one of the most destructive strains of the vascular wilt fungus F. oxysporum. Genetic relatedness among and within vegetative compatibility groups (VCGs) of F. oxysporum f. sp. cubense was studied by sequencing two nuclear and two mitochondrial DNA regions in a collection of 70 F. oxysporum isolates that include representatives of 20 VCGs of F. oxysporum f. sp. cubense, other formae speciales, and nonpathogens. To determine the ability of F. oxysporum f. sp. cubense to sexually recombine, crosses were made between isolates of opposite mating types. Phylogenetic analysis separated the F. oxysporum isolates into two clades and eight lineages. Phylogenetic relationships between F. oxysporum f. sp. cubense and other formae speciales of F. oxysporum and the relationships among VCGs and races of F. oxysporum f. sp. cubense clearly showed that F. oxysporum f. sp. cubense's ability to cause disease on banana has emerged multiple times, independently, and that the ability to cause disease to a specific banana cultivar is also a polyphyletic trait. These analyses further suggest that both coevolution with the host and horizontal gene transfer may have played important roles in the evolutionary history of the pathogen. All examined isolates harbored one of the two mating-type idiomorphs, but never both, which suggests a heterothallic mating system should sexual reproduction occur. Although, no sexual structures were observed, some lineages of F. oxysporum f. sp. cubense harbored MAT-1 and MAT-2 isolates, suggesting a potential that these lineages have a sexual origin that might be more recent than initially anticipated. PMID:19482953

  5. Increased resistance to fungal wilts in transgenic eggplant expressing alfalfa glucanase gene.

    PubMed

    Singh, Deepali; Ambroise, Annick; Haicour, Robert; Sihachakr, Darasinh; Rajam, Manchikatla Venkat

    2014-04-01

    The wilt diseases caused by Verticillium dahliae and Fusarium oxysporum are the major diseases of eggplant (Solanum melongena L.). In order to generate transgenic resistance against the wilt diseases, Agrobacterium-mediated gene transfer was performed to introduce alfalfa glucanase gene encoding an acidic glucanase into eggplant using neomycin phosphotransferase (npt-II) gene as a plant selection marker. The transgene integration into eggplant genome was confirmed by Polymerase chain reaction (PCR) and Southern blot analysis and transgene expression by the glucanase activity and western blot analysis. The selected transgenic lines were challenged with V. dahliae and F. oxysporum under in vitro and in vivo growth conditions, and transgenic lines showed enhanced resistance against the wilt-causing fungi with a delay of 5-7 days in the disease development as compared to wild-type plants. PMID:24757318

  6. Transcriptome profiling of resistant and susceptible Cavendish banana roots following inoculation with Fusarium oxysporum f. sp. cubense tropical race 4

    PubMed Central

    2012-01-01

    Background Fusarium wilt, caused by the fungal pathogen Fusarium oxysporum f. sp. cubense tropical race 4 (Foc TR4), is considered the most lethal disease of Cavendish bananas in the world. The disease can be managed in the field by planting resistant Cavendish plants generated by somaclonal variation. However, little information is available on the genetic basis of plant resistance to Foc TR4. To a better understand the defense response of resistant banana plants to the Fusarium wilt pathogen, the transcriptome profiles in roots of resistant and susceptible Cavendish banana challenged with Foc TR4 were compared. Results RNA-seq analysis generated more than 103 million 90-bp clean pair end (PE) reads, which were assembled into 88,161 unigenes (mean size = 554 bp). Based on sequence similarity searches, 61,706 (69.99%) genes were identified, among which 21,273 and 50,410 unigenes were assigned to gene ontology (GO) categories and clusters of orthologous groups (COG), respectively. Searches in the Kyoto Encyclopedia of Genes and Genomes Pathway database (KEGG) mapped 33,243 (37.71%) unigenes to 119 KEGG pathways. A total of 5,008 genes were assigned to plant-pathogen interactions, including disease defense and signal transduction. Digital gene expression (DGE) analysis revealed large differences in the transcriptome profiles of the Foc TR4-resistant somaclonal variant and its susceptible wild-type. Expression patterns of genes involved in pathogen-associated molecular pattern (PAMP) recognition, activation of effector-triggered immunity (ETI), ion influx, and biosynthesis of hormones as well as pathogenesis-related (PR) genes, transcription factors, signaling/regulatory genes, cell wall modification genes and genes with other functions were analyzed and compared. The results indicated that basal defense mechanisms are involved in the recognition of PAMPs, and that high levels of defense-related transcripts may contribute to Foc TR4 resistance in banana. Conclusions This study generated a substantial amount of banana transcript sequences and compared the defense responses against Foc TR4 between resistant and susceptible Cavendish bananas. The results contribute to the identification of candidate genes related to plant resistance in a non-model organism, banana, and help to improve the current understanding of host-pathogen interactions. PMID:22863187

  7. The development and application of a plant bioassay to elucidate toxic principles directed at watermelon by Fusarium Oxysporum f. sp. niveum

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Formae speciales of Fusarium oxysporum cause wilt and death of numerous agronomic crops worldwide. The objective of this research was to develop a bioassay for Fusarium toxins directed toward watermelon. Watermelon seedlings were grown to the two leaf stage; the roots were washed and trimmed. Two...

  8. Root defense analysis against Fusarium oxysporum reveals new regulators to confer resistance

    PubMed Central

    Chen, Yi Chung; Wong, Chin Lin; Muzzi, Frederico; Vlaardingerbroek, Ido; Kidd, Brendan N.; Schenk, Peer M.

    2014-01-01

    Fusarium oxysporum is a root-infecting fungal pathogen that causes wilt disease on a broad range of plant species, including Arabidopsis thaliana. Investigation of the defense response against this pathogen had primarily been conducted using leaf tissue and little was known about the root defense response. In this study, we profiled the expression of root genes after infection with F. oxysporum by microarray analysis. In contrast to the leaf response, root tissue did not show a strong induction of defense-associated gene expression and instead showed a greater proportion of repressed genes. Screening insertion mutants from differentially expressed genes in the microarray uncovered a role for the transcription factor ETHYLENE RESPONSE FACTOR72 (ERF72) in susceptibility to F. oxysporum. Due to the role of ERF72 in suppressing programmed cell death and detoxifying reactive oxygen species (ROS), we examined the pub22/pub23/pub24 U-box type E3 ubiquitin ligase triple mutant which is known to possess enhanced ROS production in response to pathogen challenge. We found that the pub22/23/24 mutant is more resistant to F. oxysporum infection, suggesting that a heightened innate immune response provides protection against F. oxysporum. We conclude that root-mediated defenses against soil-borne pathogens can be provided at multiple levels. PMID:24998294

  9. GENOMIC ANALYSIS OF FUSARIUM VERTICILLIOIDES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fusarium verticillioides (teleomorph Gibberella moniliformis) can be either an endophyte of maize, causing no visible disease, or a pathogen causing disease of ears, stalks, roots and seedlings. At any stage, this fungus can synthesize fumonisins, a family of mycotoxins structurally similar to the ...

  10. Genetic Variability Among Isolates of Fusarium oxysporum from Sugar Beet

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fusarium Yellows, caused by the fungus Fusarium oxysporum f. sp. betae (FOB), can lead to significant yield losses for sugar beet growers. This fungus is variable in pathogenicity, morphology, host range, and symptoms; and, it is not a well characterized pathogen on sugar beet. From 1998 – 2003, 8...

  11. Cerebroside elicitor confers resistance to fusarium disease in various plant species.

    PubMed

    Umemura, Kenji; Tanino, Shigeki; Nagatsuka, Tadako; Koga, Jinichiro; Iwata, Michiaki; Nagashima, Kenji; Amemiya, Yoshimiki

    2004-08-01

    ABSTRACT In the rice blast fungus pathosystem, cerebroside, a compound categorized as a sphingolipid, was found in our previous study to be a non-racespecific elicitor, which elicits defense responses in rice. Here we describe that cerebroside C is produced in diverse strains of Fusarium oxysporum, a common soilborne agent of wilt disease affecting a wide range of plant species. In addition, some type of cerebroside elicitor involving cerebroside A, B, or C was detected in other soilborne phytopathogens, such as Pythium and Botrytis. Treatment of lettuce (Lactuca sativa), tomato (Lycopersicon esculentum), melon (Cucumis melo), and sweet potato (Ipomoea batatas) with cerebroside B resulted in resistance to infection by each pathogenic strain of F. oxysporum. Induction of pathogenesis-related genes and H(2)O(2) production by treatment with cerebroside B were observed in tomato root tissues. The cerebroside elicitor showed no antifungal activity against F. oxysporum in vitro, indicating that the cerebroside elicitor activates defense mechanisms to confer resistance to Fusarium disease. These results suggest that cerebroside functions as a non-race-specific elicitor in a wide range of plant-phytopathogenic fungus interactions. Additionally, cerebroside elicitor serves as a potential biologically derived control agent. PMID:18943100

  12. The Fusarium oxysporum effector Six6 contributes to virulence and suppresses I-2-mediated cell death.

    PubMed

    Gawehns, F; Houterman, P M; Ichou, F Ait; Michielse, C B; Hijdra, M; Cornelissen, B J C; Rep, M; Takken, F L W

    2014-04-01

    Plant pathogens secrete effectors to manipulate their host and facilitate colonization. Fusarium oxysporum f. sp. lycopersici is the causal agent of Fusarium wilt disease in tomato. Upon infection, F. oxysporum f. sp. lycopersici secretes numerous small proteins into the xylem sap (Six proteins). Most Six proteins are unique to F. oxysporum, but Six6 is an exception; a homolog is also present in two Colletotrichum spp. SIX6 expression was found to require living host cells and a knockout of SIX6 in F. oxysporum f. sp. lycopersici compromised virulence, classifying it as a genuine effector. Heterologous expression of SIX6 did not affect growth of Agrobacterium tumefaciens in Nicotiana benthamiana leaves or susceptibility of Arabidopsis thaliana toward Verticillium dahliae, Pseudomonas syringae, or F. oxysporum, suggesting a specific function for F. oxysporum f. sp. lycopersici Six6 in the F. oxysporum f. sp. lycopersici- tomato pathosystem. Remarkably, Six6 was found to specifically suppress I-2-mediated cell death (I2CD) upon transient expression in N. benthamiana, whereas it did not compromise the activity of other cell-death-inducing genes. Still, this I2CD suppressing activity of Six6 does not allow the fungus to overcome I-2 resistance in tomato, suggesting that I-2-mediated resistance is independent from cell death. PMID:24313955

  13. Onychomycosis caused by Fusarium solani and Fusarium oxysporum in São Paulo, Brazil.

    PubMed

    Godoy, P; Nunes, E; Silva, V; Tomimori-Yamashita, J; Zaror, L; Fischman, O

    2004-04-01

    Fusarium species are common soil saprophytes and plant pathogens that have been frequently reported as etiologic agents of opportunistic infections in humans. We report eight cases of onychomycosis caused by Fusarium solani (4) and Fusarium oxysporum (4) in São Paulo, Brazil. These species were isolated from toenails in all cases. The infections were initially considered to be caused by dermatophytes. The clinical appearance of the affected toenails was leukonychia or distal subungual hyperkeratosis with yellowish brown coloration. The eight cases reported here suggest that Fusarium spp. should be taken into consideration in the differential diagnosis of tinea unguium. PMID:15180157

  14. Detection of Fusarium oxysporum f.sp. basilici in substrates and roots by PCR.

    PubMed

    Pugliese, M; Ferrocino, I; Gullino, M L; Garibaldi, A

    2013-01-01

    Fusarium oxysporum is a soil-borne fungus that causes vascular wilts in a wide variety of plant species. Basil is recognized as an ecological niche for Fusarium oxysporum f.sp. basilici (FOB) and this fungus is now present in most countries where basil is cultivated. The rapid identification of the species affecting basil plants is necessary to define a successful method for crop protection. The aim of this study was to develop a PCR method for the rapid detection of Fusarium oxysporum f. sp. basilici in substrates. The specificity of the primers used was tested using the DNA extracted directly from substrate samples. Fusarium oxysporum f.sp. basilici was artificially inoculated with decreasing amounts in a commercial substrate (sphagnum peat moss) and in a mixture with 40% of municipal compost, after steam disinfestation. Basil seeds (cv. Fine verde) were sown in pots that were laid on a bench in the greenhouse. At time 0 and after 7, 14 and 21 days from the inoculation, substrate and root samples were collected and prepared for microbial analysis and for the DNA extraction. DNA extraction was carried out using NucleoSpin Soil Kit (Macherey-Nagel, Germany). PCR amplification for the specific detection was carried out using primer sets Bik 1 (5'-ATT CAA GAG CTA AAG GTC C-3') and Bik 4 (5'-TTT GAC CAA GAT AGA TGC C-3') for the first PCR, while primers Bik 1 + Bik 2 (5'-AAA GGT AGT ATA TCG GAG G-3') for the nested PCR to increase detection sensitivity. Disease incidence was also assessed 21 days after seeding. The results showed the presence of amplified fragments of the expected size when the concentration of F. oxysporum f.sp. basilici was at least 3.5 Log CFU g(-1) by using DNA extract directly from substrate, before roots were infected by the pathogen. The detection of Fusarium oxysporum f. sp. basilici by PCR method developed in this study is certainly simple and fast and can be useful for its reliable detection in substrate samples, but not to guarantee that the substrate is totally free of pathogens. PMID:25151841

  15. Fusarium Wilt and Yellows of Sugar Beet and Dry Bean

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Central High Plains (Colorado, Nebraska and Wyoming) is among the largest producer of dry edible beans and sugar beets in the United States. Sugar beet is an important cash crop in northeastern Colorado with approximately 30,000 acres planted and 944,000 tons harvested in 2012. Approximately 250...

  16. Systemic ketoconazole treatment for Fusarium leg ulcers.

    PubMed

    Landau, M; Srebrnik, A; Wolf, R; Bashi, E; Brenner, S

    1992-07-01

    Fusarium oxysporum was isolated from a large foot ulcer in an otherwise healthy 69-year-old man. Although tissue invasion could not be proven histologically, systemic antifungal treatment was administered with satisfactory response. Fusarium species are common soil-inhabiting organisms and plant pathogens. In humans, Fusarium is considered an opportunistic agent in skin ulcers, interdigital spaces, and burned skin, but can also cause mycotic keratitis, onychomycosis, and rarely deep-seated or disseminated infections, especially in an immunocompromised host. The distinction between skin infection and saprophytic growth, as well as optimal treatment regimens for the two types of infection, have not been clearly defined. We describe a case of leg ulcers caused by Fusarium oxysporum in a 69-year-old man treated successfully with oral ketoconazole. "Silent" immunologic disturbances were found in this apparently healthy patient. The case illustrates a relatively benign infection caused by Fusarium that responded to systemic antifungal drug treatment. PMID:1500248

  17. Fusarium euwallaceae sp. nov.--a symbiotic fungus of Euwallacea sp., an invasive ambrosia beetle in Israel and California.

    PubMed

    Freeman, S; Sharon, M; Maymon, M; Mendel, Z; Protasov, A; Aoki, T; Eskalen, A; O'Donnell, K

    2013-01-01

    The invasive Asian ambrosia beetle Euwallacea sp. (Coleoptera, Scolytinae, Xyleborini) and a novel Fusarium sp. that it farms in its galleries as a source of nutrition causes serious damage to more than 20 species of live trees and pose a serious threat to avocado production (Persea americana) in Israel and California. Adult female beetles are equipped with mandibular mycangia in which its fungal symbiont is transported within and from the natal galleries. Damage caused to the xylem is associated with disease symptoms that include sugar or gum exudates, dieback, wilt and ultimately host tree mortality. In 2012 the beetle was recorded on more than 200 and 20 different urban landscape species in southern California and Israel respectively. Euwallacea sp. and its symbiont are closely related to the tea shot-hole borer (E. fornicatus) and its obligate symbiont, F. ambrosium occurring in Sri Lanka and India. To distinguish these beetles, hereafter the unnamed xyleborine in Israel and California will be referred to as Euwallacea sp. IS/CA. Both fusaria exhibit distinctive ecologies and produce clavate macroconidia, which we think might represent an adaption to the species-specific beetle partner. Both fusaria comprise a genealogically exclusive lineage within Clade 3 of the Fusarium solani species complex (FSSC) that can be differentiated with arbitrarily primed PCR. Currently these fusaria can be distinguished only phenotypically by the abundant production of blue to brownish macroconidia in the symbiont of Euwallacea sp. IS/CA and their rarity or absence in F. ambrosium. We speculate that obligate symbiosis of Euwallacea and Fusarium, might have driven ecological speciation in these mutualists. Thus, the purpose of this paper is to describe and illustrate the novel, economically destructive avocado pathogen as Fusarium euwallaceae sp. nov. S. Freeman et al. PMID:23928415

  18. Functional characterization of the gene FoOCH1 encoding a putative ?-1,6-mannosyltransferase in Fusarium oxysporum f. sp. cubense.

    PubMed

    Li, Min-Hui; Xie, Xiao-Ling; Lin, Xian-Feng; Shi, Jin-Xiu; Ding, Zhao-Jian; Ling, Jin-Feng; Xi, Ping-Gen; Zhou, Jia-Nuan; Leng, Yueqiang; Zhong, Shaobin; Jiang, Zi-De

    2014-04-01

    Fusarium oxysporum f. sp. cubense (FOC) is the causal agent of banana Fusarium wilt and has become one of the most destructive pathogens threatening the banana production worldwide. However, few genes related to morphogenesis and pathogenicity of this fungal pathogen have been functionally characterized. In this study, we identified and characterized the disrupted gene in a T-DNA insertional mutant (L953) of FOC with significantly reduced virulence on banana plants. The gene disrupted by T-DNA insertion in L953 harbors an open reading frame, which encodes a protein with homology to ?-1,6-mannosyltransferase (OCH1) in fungi. The deletion mutants (?FoOCH1) of the OCH1 orthologue (FoOCH1) in FOC were impaired in fungal growth, exhibited brighter staining with fluorescein isothiocyanate (FITC)-Concanavalin A, had less cell wall proteins and secreted more proteins into liquid media than the wild type. Furthermore, the mutation or deletion of FoOCH1 led to loss of ability to penetrate cellophane membrane and decline in hyphal attachment and colonization as well as virulence to the banana host. The mutant phenotypes were fully restored by complementation with the wild type FoOCH1 gene. Our data provide a first evidence for the critical role of FoOCH1 in maintenance of cell wall integrity and virulence of F. oxysporum f. sp. cubense. PMID:24503549

  19. Deciphering the cryptic genome: Genome-wide analyses of the rice pathogen Fusarium fujikuroi reveal complex regulation of secondary metabolism and novel metabolites

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The fungus Fusarium fujikuroi is agriculturally important because it produces the phytohormones gibberellic acids (GAs) and causes bakanae (“foolish seedling”) disease of rice. The fungus also produces multiple other secondary metabolites, including pigments and mycotoxins. Here, we present a high-q...

  20. Regional and field-specific factors affect the composition of Fusarium head blight pathogens in subtropical no-till wheat agroecosystem of Brazil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A multiyear survey of >200 wheat fields in Paraná (PR) and Rio Grande do Sul (RS) states was conducted to assess the extent and distribution of Fusarium graminearum species complex (FGSC) diversity in the southern Brazilian wheat agroecosystem. Five species and three trichothecene genotypes were fou...

  1. Survey and competition assay data suggest species-specific difference in host/niche adaptation influence the distribution of Fusarium graminearum species complex pathogens in Brazil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Fusarium graminearum species complex (FGSC) comprises at least 16 toxigenic species of economic concern to cereal crops. In Brazil, six species of the FGSC have been identified, but their frequencies vary according to the host species. Although F. graminearum (Fgra) is dominant in wheat (>90%) a...

  2. A Novel Asian Clade Within the Fusarium graminearum Species Complex Includes a Newly Discovered Cereal Head Blight Pathogen from the Far East of Russia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We investigated B-trichothecene toxin-producing Fusarium head blight (B-FHB) species and their toxin potential in European and Asian regions of the Russian Federation, and adjoining regions to the Northwest in Finland and the South near Harbin, in the Heilongjiang Province of China to expand our kno...

  3. The genome of the of the generalist plant pathogenic fungus Fusarium avenaceum is enriched with genes involved in redox, signaling and secondary metabolism

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fusarium avenaceum is a fungus commonly isolated from soil and with a wide range of host plants. We present here three genome sequences of F. avenaceum, one isolated from barley in Finland and two from spring and winter wheat in Canada. The physical sizes of the three genomes range from 41.6-43.2 MB...

  4. Relationships among vegetative compatibility grouping, toxin production, and virulence of Fusarium Oxysporum to cotton

    Technology Transfer Automated Retrieval System (TEKTRAN)

    More than 1200 isolates of Fusarium oxysporum obtained from cotton were used in a series of studies over 20 years. These isolates were obtained from wilted plants, roots of plants without symptoms, and live seed imported into the U.S. In some cases, these isolates were associated with the severe da...

  5. Laurel wilt: Understanding an unusual and exotic vascular wilt disease

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Laurel wilt kills American members of the Lauraceae plant family (Laurales, Magnoliid complex). These include significant components of Coastal Plain forest communities in the southeastern USA, most importantly redbay, as well as the commercial crop avocado. The disease has decimated redbay, swamp ...

  6. First Report of Bacterial Wilt Caused by Ralstonia solanacearum Biovar 2 Race 1 on Tomato in Egypt

    PubMed Central

    Seleim, Mohamed A. A.; Abo-Elyousr, Kamal A. M.; Abd-El-Moneem, Kenawy M.; Saead, Farag A.

    2014-01-01

    This study aims to isolate and identify the causal pathogen of tomato bacterial wilt in Egypt. In 2008, tomato plants showing typical symptoms of bacterial wilt disease with no foliar yellowing were observed in Minia, Assiut and Sohag governorates, Egypt. When cut stems of symptomatic plants were submerged in water, whitish ooze was evident and longitudinal sections showed a brown discoloration in the vascular tissues. Bacteria were isolated on triphenyl tetrazolium chloride medium and fifteen isolates shown typical morphological and cultural characteristics were confirmed as Ralstonia solanacearum biovar 2 race 1. Pathogenicity tests showed that all isolates proved to be pathogenic to tomato plants, varied from 52 to 97% wilting. This is the first report of R. solanacearum biovar 2 race 1 causing bacterial wilt in tomato crop in Egypt. PMID:25289016

  7. Detection of tomatinase from Fusarium oxysporum f. sp. lycopersici in infected tomato plants.

    PubMed

    Lairini, K; Ruiz-Rubio, M

    1997-08-01

    The antifungal glycoalkaloid alpha-tomatine of the tomato plant (Lycopersicon esculentum) is proposed to protect the plant against phytopathogenic fungi. Fusarium oxysporum f. sp. lycopersici, a vascular pathogen of tomato, produces a tomatinase enzyme which hydrolyses the glycoalkaloid into non-fungitoxic compounds. Detoxification of alpha-tomatine may be how this fungus avoids the plant glycoalkaloid barrier. As an initial step to evaluate this possibility we have studied the induction of tomatinase; (i) in fungal cultures containing extracts from leaf, stem or root of tomato plants; and (ii) in stem and root of tomato plants infected with the pathogen at different infection stages. The kinetics of tomatinase induction with leaf extract (0.6% dry weight) was similar to that observed with 20 micrograms ml-1 of alpha-tomatine. In the presence of stem extract, tomatinase activity was less than 50% of that induced with leaf extract, whereas in the presence of root extract tomatinase activity was very low. In the stem of infected tomato plants tomatinase activity was higher at the wilt stage than in previous infections stages and in root, tomatinase activity appeared with the first symptoms and was maintained until wilting. TLC analysis showed that the tomatinase induced in culture medium with plant extracts and in infected tomato plants had the same mode of action as the enzyme induced with pure alpha-tomatine, hydrolysing the glycoalkaloid into its non-fungitoxic forms, tomatidine and beta-lycotetraose. The antisera raised against purified tomatinase recognized in extracts of root and stem of infected tomato plants a protein of 50000 (45000 when proteins were deglycosylated), corresponding to the tomatinase enzyme. Therefore, it is concluded that F. oxysporum f. sp. lycopersici express tomatinase in vivo as a result of the infection of tomato plant. PMID:9237400

  8. Rainfall Effects on Wilting Forages

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Given the uncertainty of the weather and inherent differences between forage crops, specific recommendations for managing potential rain damage to wilting forages are difficult. However, there are a number of principles that can be applied to best manage the potential for rain damage. These science-...

  9. Isolation and Heterologous Expression of a Polygalacturonase Produced by Fusarium oxysporum f. sp. cubense Race 1 and 4

    PubMed Central

    Dong, Zhangyong; Wang, Zhenzhong

    2015-01-01

    Fusarium wilt (Panama disease) caused by Fusarium oxysporum f. sp. cubense (FOC) represents a significant threat to banana (Musa spp.) production. Musa AAB is susceptible to Race 1 (FOC1) and Race 4 (FOC4), while Cavendish Musa AAA is found to be resistant to FOC1 but still susceptible to Race 4. A polygalacturonase (PGC3) was purified from the supernatant of Fusarium oxysporum f. sp. cubense race 4 (FOC4), which is the pathogen of Fusarium wilt. PGC3 had an apparent molecular weight of 45 kDa according to SDS-PAGE. The enzyme hydrolyzed polygalacturonic acid in an exo-manner, as demonstrated by analysis of degradation products. The Km and Vmax values of PGC3 from FOC4 were determined to be 0.70 mg·mL−1 and 101.01 Units·mg·protein−1·min−1, respectively. Two pgc3 genes encoding PGC3 from FOC4 and FOC1, both genes of 1368 bp in length encode 456 amino-acid residues with a predicted signal peptide sequence of 21 amino acids. There are 16 nucleotide sites difference between FOC4-pgc3 and FOC1-pgc3, only leading to four amino acid residues difference. In order to obtain adequate amounts of protein required for functional studies, two genes were cloned into the expression vector pPICZaA and then expressed in Pichia pastoris strains of SMD1168. The recombinant PGC3, r-FOC1-PGC3 and r-FOC4-PGC3, were expressed and purified as active proteins. The optimal PGC3 activity was observed at 50 °C and pH 4.5. Both recombinant PGC3 retained >40% activity at pH 3–7 and >50% activity in 10–50 °C. Both recombinant PGC3 proteins could induce a response but with different levels of tissue maceration and necrosis in banana plants. In sum, our results indicate that PGC3 is an exo-PG and can be produced with full function in P. pastoris. PMID:25854430

  10. Isolation and heterologous expression of a polygalacturonase produced by Fusarium oxysporum f. sp. cubense race 1 and 4.

    PubMed

    Dong, Zhangyong; Wang, Zhenzhong

    2015-01-01

    Fusarium wilt (Panama disease) caused by Fusarium oxysporum f. sp. cubense (FOC) represents a significant threat to banana (Musa spp.) production. Musa AAB is susceptible to Race 1 (FOC1) and Race 4 (FOC4), while Cavendish Musa AAA is found to be resistant to FOC1 but still susceptible to Race 4. A polygalacturonase (PGC3) was purified from the supernatant of Fusarium oxysporum f. sp. cubense race 4 (FOC4), which is the pathogen of Fusarium wilt. PGC3 had an apparent molecular weight of 45 kDa according to SDS-PAGE. The enzyme hydrolyzed polygalacturonic acid in an exo-manner, as demonstrated by analysis of degradation products. The Km and Vmax values of PGC3 from FOC4 were determined to be 0.70 mg·mL-1 and 101.01 Units·mg·protein-1·min-1, respectively. Two pgc3 genes encoding PGC3 from FOC4 and FOC1, both genes of 1368 bp in length encode 456 amino-acid residues with a predicted signal peptide sequence of 21 amino acids. There are 16 nucleotide sites difference between FOC4-pgc3 and FOC1-pgc3, only leading to four amino acid residues difference. In order to obtain adequate amounts of protein required for functional studies, two genes were cloned into the expression vector pPICZaA and then expressed in Pichia pastoris strains of SMD1168. The recombinant PGC3, r-FOC1-PGC3 and r-FOC4-PGC3, were expressed and purified as active proteins. The optimal PGC3 activity was observed at 50 °C and pH 4.5. Both recombinant PGC3 retained >40% activity at pH 3-7 and >50% activity in 10-50 °C. Both recombinant PGC3 proteins could induce a response but with different levels of tissue maceration and necrosis in banana plants. In sum, our results indicate that PGC3 is an exo-PG and can be produced with full function in P. pastoris. PMID:25854430

  11. A major QTL associated with Fusarium oxysporum race 1 resistance identified in genetic populations derived from closely related watermelon lines using selective genotyping and genotyping-by-sequencing for SNP discovery

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fusarium wilt is a major soil-borne disease of watermelon caused by the fungus Fusarium oxysporum Schlechtend.:Fr. f. sp. niveum (E.F. Sm.) W.C. Snyder & H.N. Hans (Fon). In this study, a genetic population of 186 F3 families (24 plants in each family) exhibited continuous distribution for Fon race ...

  12. Three improved Citrullus lanatus var. citroides lines USVL246-FR2, USVL252-FR2, and USVL335-FR2, with resistance to Fusarium oxysporum f. sp. niveum race 2

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fusarium wilt (FW) is a major disease of watermelon in North America and around the world. Control of this disease is difficult because the soil-borne causal agent Fusarium oxysporum f. sp. niveum (Fon) produces chlamydospores that remain infectious in the soil for many years. Although, various le...

  13. Distinct colonization patterns and cDNA-AFLP transcriptome profiles in compatible and incompatible interactions between melon and different races of Fusarium oxysporum f. sp. melonis

    PubMed Central

    2011-01-01

    Background Fusarium oxysporum f. sp. melonis Snyd. & Hans. (FOM) causes Fusarium wilt, the most important infectious disease of melon (Cucumis melo L.). The four known races of this pathogen can be distinguished only by infection on appropriate cultivars. No molecular tools are available that can discriminate among the races, and the molecular basis of compatibility and disease progression are poorly understood. Resistance to races 1 and 2 is controlled by a single dominant gene, whereas only partial polygenic resistance to race 1,2 has been described. We carried out a large-scale cDNA-AFLP analysis to identify host genes potentially related to resistance and susceptibility as well as fungal genes associated with the infection process. At the same time, a systematic reisolation procedure on infected stems allowed us to monitor fungal colonization in compatible and incompatible host-pathogen combinations. Results Melon plants (cv. Charentais Fom-2), which are susceptible to race 1,2 and resistant to race 1, were artificially infected with a race 1 strain of FOM or one of two race 1,2 w strains. Host colonization of stems was assessed at 1, 2, 4, 8, 14, 16, 18 and 21 days post inoculation (dpi), and the fungus was reisolated from infected plants. Markedly different colonization patterns were observed in compatible and incompatible host-pathogen combinations. Five time points from the symptomless early stage (2 dpi) to obvious wilting symptoms (21 dpi) were considered for cDNA-AFLP analysis. After successful sequencing of 627 transcript-derived fragments (TDFs) differentially expressed in infected plants, homology searching retrieved 305 melon transcripts, 195 FOM transcripts expressed in planta and 127 orphan TDFs. RNA samples from FOM colonies of the three strains grown in vitro were also included in the analysis to facilitate the detection of in planta-specific transcripts and to identify TDFs differentially expressed among races/strains. Conclusion Our data suggest that resistance against FOM in melon involves only limited transcriptional changes, and that wilting symptoms could derive, at least partially, from an active plant response. We discuss the pathogen-derived transcripts expressed in planta during the infection process and potentially related to virulence functions, as well as transcripts that are differentially expressed between the two FOM races grown in vitro. These transcripts provide candidate sequences that can be further tested for their ability to distinguish between races. Sequence data from this article have been deposited in GenBank, Accession Numbers: HO867279-HO867981. PMID:21338485

  14. Hyperkeratotic Warty Skin Lesion of Foot Caused by Fusarium oxysporum

    PubMed Central

    Kaur, Ravinder; Maheshwari, Megha

    2013-01-01

    Fusarium species are common soil-inhabiting organisms and plant pathogens. Human infections are usually precipitated by local or systemic predisposing factors, and disseminated infection is associated with impaired immune responses. Skin infections caused by Fusarium spp. include keratitis, onychomycosis, mycetoma, painful discrete erythematous nodules. Hyperkeratotic skin lesions caused by Fusarium spp. are, however, rarely reported. We report a case of hyperkeratotic verrucous warty skin lesion in the foot of a 50-year-old immunocompetent male, farmer by occupation. PMID:23716829

  15. Water balance altered in cucumber plants infected with Fusarium oxysporum f. sp. cucumerinum

    PubMed Central

    Wang, Min; Sun, Yuming; Sun, Guomei; Liu, Xiaokang; Zhai, Luchong; Shen, Qirong; Guo, Shiwei

    2015-01-01

    Fusarium wilt is caused by the infection and growth of the fungus Fusarium oxysporum in the xylem of host plants. The physiological responses of cucumbers that are infected with Fusarium oxysporum f. sp. cucumerinum (FOC) was studied in pot and hydroponic experiments in a greenhouse. The results showed that although water absorption and stem hydraulic conductance decreased markedly in infected plants, large amounts of red ink accumulated in the leaves of infected cucumber plants. The transpiration rate (E) and stomatal conductance (gs) of the infected plants were significantly reduced, but the E/gs was higher than healthy plants. We further found that there was a positive correlation between leaf membrane injury and E/gs, indicating that the leaf cell membrane injury increased the non-stomatal water loss from infected plants. The fusaric acid (FA), which was detected in the infected plant, resulted in damage to the leaf cell membranes and an increase in E/gs, suggesting that FA plays an important role in non-stomatal water loss. In conclusion, leaf cell membrane injury in the soil-borne Fusarium wilt of cucumber plants induced uncontrolled water loss from damaged cells. FA plays a critical role in accelerating the development of Fusarium wilt in cucumber plants. PMID:25579504

  16. Water balance altered in cucumber plants infected with Fusarium oxysporum f. sp. cucumerinum.

    PubMed

    Wang, Min; Sun, Yuming; Sun, Guomei; Liu, Xiaokang; Zhai, Luchong; Shen, Qirong; Guo, Shiwei

    2015-01-01

    Fusarium wilt is caused by the infection and growth of the fungus Fusarium oxysporum in the xylem of host plants. The physiological responses of cucumbers that are infected with Fusarium oxysporum f. sp. cucumerinum (FOC) was studied in pot and hydroponic experiments in a greenhouse. The results showed that although water absorption and stem hydraulic conductance decreased markedly in infected plants, large amounts of red ink accumulated in the leaves of infected cucumber plants. The transpiration rate (E) and stomatal conductance (gs) of the infected plants were significantly reduced, but the E/gs was higher than healthy plants. We further found that there was a positive correlation between leaf membrane injury and E/gs, indicating that the leaf cell membrane injury increased the non-stomatal water loss from infected plants. The fusaric acid (FA), which was detected in the infected plant, resulted in damage to the leaf cell membranes and an increase in E/gs, suggesting that FA plays an important role in non-stomatal water loss. In conclusion, leaf cell membrane injury in the soil-borne Fusarium wilt of cucumber plants induced uncontrolled water loss from damaged cells. FA plays a critical role in accelerating the development of Fusarium wilt in cucumber plants. PMID:25579504

  17. FocVel1 influences asexual production, filamentous growth, biofilm formation, and virulence in Fusarium oxysporum f. sp. cucumerinum

    PubMed Central

    Li, Peiqian; Pu, Xiaoming; Feng, Baozhen; Yang, Qiyun; Shen, Huifang; Zhang, Jingxin; Lin, Birun

    2015-01-01

    Velvet genes play critical roles in the regulation of diverse cellular processes. In current study, we identified the gene FocVel1, a homolog of Fusarium graminearum VelA, in the plant pathogenic fungus F. oxysporum f. sp. cucumerinum. This pathogen causes the destructive disease called cucumber Fusarium wilt (CFW), which severely affects the production and marketing of this vegetable worldwide. Transcript analyses revealed high expression of FocVel1 during conidiophore development. Disruption of the FocVel1 gene led to several phenotypic defects, including reduction in aerial hyphal formation and conidial production. The deletion mutant ΔFocVel1 showed increased resistance to both osmotic stress and cell wall-damaging agents, but increased sensitivity to iprodione and prochloraz fungicides, which may be related to changes in cell wall components. In the process of biofilm formation in vitro, the mutant strain ΔFocVel1 displayed not only a reduction in spore aggregation but also a delay in conidial germination on the polystyrene surface, which may result in defects in biofilm formation. Moreover, pathogenicity assays showed that the mutant ΔFocVel1 exhibited impaired virulence in cucumber seedlings. And the genetic complementation of the mutant with the wild-type FocVel1 gene restored all the defects of the ΔFocVel1. Taken together, the results of this study indicated that FocVel1 played a critical role in the regulation of various cellular processes and pathogenicity in F. oxysporum f. sp. cucumerinum. PMID:25999976

  18. FocVel1 influences asexual production, filamentous growth, biofilm formation, and virulence in Fusarium oxysporum f. sp. cucumerinum.

    PubMed

    Li, Peiqian; Pu, Xiaoming; Feng, Baozhen; Yang, Qiyun; Shen, Huifang; Zhang, Jingxin; Lin, Birun

    2015-01-01

    Velvet genes play critical roles in the regulation of diverse cellular processes. In current study, we identified the gene FocVel1, a homolog of Fusarium graminearum VelA, in the plant pathogenic fungus F. oxysporum f. sp. cucumerinum. This pathogen causes the destructive disease called cucumber Fusarium wilt (CFW), which severely affects the production and marketing of this vegetable worldwide. Transcript analyses revealed high expression of FocVel1 during conidiophore development. Disruption of the FocVel1 gene led to several phenotypic defects, including reduction in aerial hyphal formation and conidial production. The deletion mutant ΔFocVel1 showed increased resistance to both osmotic stress and cell wall-damaging agents, but increased sensitivity to iprodione and prochloraz fungicides, which may be related to changes in cell wall components. In the process of biofilm formation in vitro, the mutant strain ΔFocVel1 displayed not only a reduction in spore aggregation but also a delay in conidial germination on the polystyrene surface, which may result in defects in biofilm formation. Moreover, pathogenicity assays showed that the mutant ΔFocVel1 exhibited impaired virulence in cucumber seedlings. And the genetic complementation of the mutant with the wild-type FocVel1 gene restored all the defects of the ΔFocVel1. Taken together, the results of this study indicated that FocVel1 played a critical role in the regulation of various cellular processes and pathogenicity in F. oxysporum f. sp. cucumerinum. PMID:25999976

  19. Cyber-infrastructure for Fusarium (CiF): Three integrated platforms supporting strain identification, phylogenetics, comparative genomics, and knowledge sharing

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The fungal genus Fusarium includes many plant and/or animal pathogenic species and produces diverse toxins. Although accurate identification is critical for managing such threats, it is difficult to identify Fusarium morphologically. Fortunately, extensive molecular phylogenetic studies, founded on ...

  20. ALTERATIONS IN B VERSUS C FUMONISIN PRODUCTION BY TRANSFORMATION OF THE FUSARIUM OXYSPORUM FUM8 CODING REGION INTO GIBBERELLA MONILIFORMIS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fumonisins are mycotoxins that cause several animal diseases, including cancer in rodents. These toxins are produced by the maize pathogen Gibberella moniliformis (anamorph Fusarium verticillioides), several closely related Fusarium species, and at least one isolate of F. oxysporum. G. moniliformi...

  1. Variation in the Trichothecene Mycotoxin Biosynthetic Gene Cluster in Fusarium

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Trichothecene mycotoxins are produced by some plant pathogenic species of the fungus Fusarium and can contribute to its virulence on some plants. In Fusarium graminearum and F. sporotrichioides trichothecene biosynthetic enzymes are encoded at three loci: the single-gene TRI101 locus; the two-gene ...

  2. Diversity of the Fusarium graminearum species complex on French cereals

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fusarium graminearum is an important pathogen causing Fusarium head blight (FHB) on wheat and barley and Gibberella ear rot (GER) on maize, and harvested grains often are contaminated with trichothecenes such as deoxynivalenol (DON) and nivalenol (NIV) that are a major health and food safety concern...

  3. Fusarium seed stalk blight and rot in sugar beet

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fusarium can cause damage to seed stalks that can cause reductions or complete loss of seed production. Fusarium oxysporum has been the reported cause of seed stalk blight, which is characterized by vascular discoloration. We sampled diseased seed stalks and examined isolates for their pathogenicity...

  4. Fusarium oxysporum Triggers Tissue-Specific Transcriptional Reprogramming in Arabidopsis thaliana

    PubMed Central

    Lyons, Rebecca; Stiller, Jiri; Powell, Jonathan; Rusu, Anca; Manners, John M.; Kazan, Kemal

    2015-01-01

    Some of the most devastating agricultural diseases are caused by root-infecting pathogens, yet the majority of studies on these interactions to date have focused on the host responses of aerial tissues rather than those belowground. Fusarium oxysporum is a root-infecting pathogen that causes wilt disease on several plant species including Arabidopsis thaliana. To investigate and compare transcriptional changes triggered by F. oxysporum in different Arabidopsis tissues, we infected soil-grown plants with F. oxysporum and subjected root and leaf tissue harvested at early and late timepoints to RNA-seq analyses. At least half of the genes induced or repressed by F. oxysporum showed tissue-specific regulation. Regulators of auxin and ABA signalling, mannose binding lectins and peroxidases showed strong differential expression in root tissue. We demonstrate that ARF2 and PRX33, two genes regulated in the roots, promote susceptibility to F. oxysporum. In the leaves, defensins and genes associated with the response to auxin, cold and senescence were strongly regulated while jasmonate biosynthesis and signalling genes were induced throughout the plant. PMID:25849296

  5. Fusarium oxysporum triggers tissue-specific transcriptional reprogramming in Arabidopsis thaliana.

    PubMed

    Lyons, Rebecca; Stiller, Jiri; Powell, Jonathan; Rusu, Anca; Manners, John M; Kazan, Kemal

    2015-01-01

    Some of the most devastating agricultural diseases are caused by root-infecting pathogens, yet the majority of studies on these interactions to date have focused on the host responses of aerial tissues rather than those belowground. Fusarium oxysporum is a root-infecting pathogen that causes wilt disease on several plant species including Arabidopsis thaliana. To investigate and compare transcriptional changes triggered by F. oxysporum in different Arabidopsis tissues, we infected soil-grown plants with F. oxysporum and subjected root and leaf tissue harvested at early and late timepoints to RNA-seq analyses. At least half of the genes induced or repressed by F. oxysporum showed tissue-specific regulation. Regulators of auxin and ABA signalling, mannose binding lectins and peroxidases showed strong differential expression in root tissue. We demonstrate that ARF2 and PRX33, two genes regulated in the roots, promote susceptibility to F. oxysporum. In the leaves, defensins and genes associated with the response to auxin, cold and senescence were strongly regulated while jasmonate biosynthesis and signalling genes were induced throughout the plant. PMID:25849296

  6. Fusarium Infection

    PubMed Central

    Muhammed, Maged; Anagnostou, Theodora; Desalermos, Athanasios; Kourkoumpetis, Themistoklis K.; Carneiro, Herman A.; Glavis-Bloom, Justin; Coleman, Jeffrey J.

    2013-01-01

    Abstract Fusarium species is a ubiquitous fungus that causes opportunistic infections. We present 26 cases of invasive fusariosis categorized according to the European Organization for Research and Treatment of Cancer/Mycoses Study Group (EORTC/MSG) criteria of fungal infections. All cases (20 proven and 6 probable) were treated from January 2000 until January 2010. We also review 97 cases reported since 2000. The most important risk factors for invasive fusariosis in our patients were compromised immune system, specifically lung transplantation (n = 6) and hematologic malignancies (n = 5), and burns (n = 7 patients with skin fusariosis), while the most commonly infected site was the skin in 11 of 26 patients. The mortality rates among our patients with disseminated, skin, and pulmonary fusariosis were 50%, 40%, and 37.5%, respectively. Fusarium solani was the most frequent species, isolated from 49% of literature cases. Blood cultures were positive in 82% of both current study and literature patients with disseminated fusariosis, while the remaining 16% had 2 noncontiguous sites of infection but negative blood cultures. Surgical removal of focal lesions was effective in both current study and literature cases. Skin lesions in immunocompromised patients should raise the suspicion for skin or disseminated fusariosis. The combination of medical monotherapy with voriconazole or amphotericin B and surgery in such cases is highly suggested. PMID:24145697

  7. Pathogenicity of Aseptic Bursaphelenchus xylophilus

    PubMed Central

    Zhu, Li-hua; Ye, Jianren; Negi, Sapna; Xu, Xu-ling; Wang, Zhang-li; Ji, Jin-yi

    2012-01-01

    Pine wilt is a disease of pine (Pinus spp.) caused by the pine wood nematode (PWN), Bursaphelenchus xylophilus. However, the pathogenic mechanism of pine wilt disease (PWD) remains unclear. Although the PWN was thought to be the only pathogenic agent associated with this disease, a potential role for bacterial symbionts in the disease process was recently proposed. Studies have indicated that aseptic PWNs do not cause PWD in aseptic pine trees, while PWNs associated with bacteria cause wilting symptoms. To investigate the pathogenicity of the PWN and its associated bacteria, 3-month-old microcuttings derived from certain clones of Pinus densiflora Siebold & Zucc. produced in vitro were inoculated under aseptic conditions with aseptic PWNs, non-aseptic PWNs and bacteria isolated from the nematodes. Six-month-old aseptic P. densiflora microcuttings and 7-month-old P. massoniana seedlings were also inoculated under aseptic conditions with aseptic PWNs and non-aseptic PWNs. The results showed that the aseptic microcuttings and seedlings inoculated with aseptic PWNs or non-aseptic PWNs wilted, while those inoculated with bacterial isolates did not wilt. Nematodes were recovered from wilted microcuttings and seedlings inoculated with aseptic PWNs and non-aseptic PWNs, and the asepsis of nematodes recovered from aseptic PWN-inoculated microcuttings and seedlings was reconfirmed by culturing them in NB liquid medium at 30°C for more than 7 days. Taken together, the results indicate that the asepsis of PWN did not cause the loss of pathogenicity. PMID:22662271

  8. Diversity of endophytic fungi from different Verticillium-wilt-resistant Gossypium hirsutum and evaluation of antifungal activity against Verticillium dahliae in vitro.

    PubMed

    Li, Zhi-Fang; Wang, Ling-Fei; Feng, Zi-Li; Zhao, Li-Hong; Shi, Yong-Qiang; Zhu, He-Qin

    2014-09-01

    Cotton plants were sampled and ranked according to their resistance to Verticillium wilt. In total, 642 endophytic fungi isolates representing 27 genera were recovered from Gossypium hirsutum root, stem, and leaf tissues, but were not uniformly distributed. More endophytic fungi appeared in the leaf (391) compared with the root (140) and stem (111) sections. However, no significant difference in the abundance of isolated endophytes was found among resistant cotton varieties. Alternaria exhibited the highest colonization frequency (7.9%), followed by Acremonium (6.6%) and Penicillium (4.8%). Unlike tolerant varieties, resistant and susceptible ones had similar endophytic fungal population compositions. In three Verticillium-wilt-resistant cotton varieties, fungal endophytes from the genus Alternaria were most frequently isolated, followed by Gibberella and Penicillium. The maximum concentration of dominant endophytic fungi was observed in leaf tissues (0.1797). The evenness of stem tissue endophytic communities (0.702) was comparatively more uniform than the other two tissues. Eighty endophytic fungi selected from 27 genera were evaluated for their inhibition activity against highly virulent Verticillium dahliae isolate Vd080 in vitro. Thirty-nine isolates exhibited fungistasis against the pathogen at varying degrees. Seven species, having high growth inhibition rates (≥75%), exhibited strong antifungal activity against V. dahliae. The antifungal activity of both volatile and nonvolatile metabolites was also investigated. The nonvolatile substances produced by CEF-818 (Penicillium simplicissimum), CEF-325 (Fusarium solani), CEF-714 (Leptosphaeria sp.), and CEF-642 (Talaromyces flavus) completely inhibited V. dahliae growth. These findings deepen our understanding of cotton-endophyte interactions and provide a platform for screening G. hirsutum endophytes with biocontrol potential. PMID:24836187

  9. Molecular characterization of Fusarium oxysporum f. sp. vasinfectum isolates from cottonseed imported from Australia into California for dairy feed

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bell et al. recovered 17 Fusarium oxysporum f. sp. vasinfectum (Fov) isolates from cottonseed imported from Australia into California for dairy feed in 2003. These isolates and four isolates obtained from wilted plants in Australia by Kochman in 1994 are distinct from American Fov isolates in that ...

  10. Molecular characterization of Fusarium oxysporum f. sp. Vasinfectum isolates recovered from cottonseed imported from Australia into California for cattle feed

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bell et al. recovered 17 Fusarium oxysporum f. sp. vasinfectum (Fov) isolates from cottonseed imported from Australia into California for cattle feed in 2003. These isolates and four isolates obtained from wilted plants in Australia by Kochman in 1994 are distinct from American Fov isolates in that...

  11. Resistance to tomato spotted wilt virus and root-knot nematode in peanut interspecific breeding lines

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The peanut root-knot nematode [Meloidogyne arenaria (Neal) Chitwood race 1] and tomato spotted wilt virus Tospovirus (TSWV) are economically significant pathogens of peanut in the southeastern United States. Peanut cultivars are available that have resistance to either the peanut root-knot nematode...

  12. INTRODUCTION OF THE TOMATO SPOTTED WILT VIRUS NUCLEOCAPSID GENE INTO A RUNNER-TYPE PEANUT

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Tomato Spotted Wilt Virus (TSWV) infects over 400 species of plants, including peanut. TSWV is a widespread peanut pathogen in the Southeastern United States causing significant losses to producers in that region. Although not yet a problem to peanut producers in the Southwester United States, TSW...

  13. Differential acquisition and transmission of Florida Tomato spotted wilt virus isolates by Western flower thrips

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Thrips-vectored Tomato spotted wilt virus (TSWV) is one of the most important insect-vectored plant pathogens globally. The virus host range encompasses many key vegetable, ornamental and agronomic crops. TSWV populations are highly heterogeneous, which has important implications for vector relati...

  14. Comparison of ambrosia beetle communities in two host with laurel wilt: swampbay vs. avocado

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The invasive redbay ambrosia beetle, Xyleborus glabratus (Coleoptera: Curculionidae: Scolytinae), is an exotic wood-boring pest first detected in 2002 near Savannah, Georgia. The beetle’s dominant fungal symbiont, Raffaelea lauricola, is the pathogen that causes laurel wilt, a lethal disease of tre...

  15. Ambrosia beetle communities in forest and agriculture ecosystems with laurel wilt disease

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The invasive redbay ambrosia beetle, Xyleborus glabratus, is an exotic wood-boring pest first detected in 2002 near Savannah, Georgia. The beetle’s dominant fungal symbiont, Raffaelea lauricola, is the pathogen that causes laurel wilt, a lethal disease of trees in the family Lauraceae. Redbay ambro...

  16. New outbreaks of verticillium wilt on Hop in Oregon caused by nonlethal verticillium albo-atrum

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In 2006 and 2007, new outbreaks of Verticillium wilt on hop were detected on two farms in Oregon. Verticillium pathogens vary in their virulence to hop; some strains cause minor damage but others can kill susceptible cultivars. Studies were conducted to determine the identity of the Verticillium sp...

  17. Progress Toward Breeding for Verticillium Wilt Resistance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Verticillium wilt is a persistent and serious problem in potato production. Host plant resistance offers an attractive long-term control method. Breeding progress depends on access to germplasm carrying resistance genes. This study was carried out to identify sources of Verticillium wilt resistan...

  18. Progress toward breeding for Verticillium wilt resistance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Verticillium wilt is a persistent and serious problem in potato production. Host plant resistance offers an attractive long-term control method. Breeding progress depends on access to germplasm carrying resistance genes. This study was carried out to identify sources of Verticillium wilt resistan...

  19. Dispersal of Formulations of Fusarium oxysporum f. sp. erythroxyli and F. oxysporum f. sp. melonis by Ants.

    PubMed

    Gracia-Garza, J A; Fravel, D R; Bailey, B A; Hebbar, P K

    1998-03-01

    ABSTRACT A natural epidemic of Fusarium wilt on coca (Erythroxylum coca) in Peru prompted the suggestion of possibly using the pathogen Fusarium oxysporum f. sp. erythroxyli as a mycoherbicide against this narcotic plant. During field trials conducted in Kauai, HI, to test the pathogenicity of the coca wilt pathogen, ants were observed removing formulations from test plots. While removal of formulations by ants was considered detrimental with respect to conducting field tests, ant removal was considered potentially beneficial in disseminating the mycoherbicide. Thus, research was initiated to assess the ability of formulation additives to alter the preference of ants for the formulated mycoherbicide. In Hawaii, preference of indigenous ants for removing formulations was tested using three different food bases (rice, rice plus canola oil, and wheat flour [gluten]). Similar tests were conducted at Beltsville, MD, using F. oxysporum f. sp. melonis, in which the formulation based on wheat flour was replaced by a formulation based on canola meal. Formulations based on wheat were preferred by ants in both locations; up to 90% of the wheat plus rice flour granules (C-6) and the wheat gluten plus kaolin granules (pesta) were removed within 24 h, while only 20% of those containing rice without oils were taken. However, when either canola, sunflower (Maryland only), or olive oil was added to the rice formulation, up to 90% of the granules were taken. The formulation based on canola meal was less attractive to ants, as only 65% of the granules were removed within a period of 24 h. Ants showed no preference with respect to presence or absence of fungal biomass. To alter the attractiveness of the C-6 formulation to ants, C-6 was amended with three natural products. Canna and tansy leaves were added to C-6 at a ratio of 1:5 (wt/wt), while chili powder was added at 1:25 or 1:2.5 (wt/wt). Canna, tansy, and the higher rate of chili powder significantly reduced the number of C-6 granules removed by ants. Canna and tansy leaves affected neither germination nor sporulation of the mycoherbicide, while the high concentration of chili powder reduced viability of propagules in the formulation. More F. oxysporum f. sp. erythroxyli-type colonies were recovered from inside ant nests (9 cm depth) than from nest surfaces, indicating that ants may distribute the mycoherbicide in the soil profile. Ants passively carried propagules of F. oxysporum f. sp. erythroxyli outside their bodies, as well as either very closely adhering to the outside or within their bodies. PMID:18944963

  20. Systemic acquired resistance in Cavendish banana induced by infection with an incompatible strain of Fusarium oxysporum f. sp. cubense.

    PubMed

    Wu, Yuanli; Yi, Ganjun; Peng, Xinxiang; Huang, Bingzhi; Liu, Ee; Zhang, Jianjun

    2013-07-15

    Fusarium wilt of banana is caused by the soil-borne fungus Fusarium oxysporum f. sp. cubense (Foc). The fact that there are no economically viable biological, chemical, or cultural measures of controlling the disease in an infected field leads to search for alternative strategies involving activation of the plant's innate defense system. The mechanisms underlying systemic acquired resistance (SAR) are much less understood in monocots than in dicots. Since systemic protection of plants by attenuated or avirulent pathogens is a typical SAR response, the establishment of a biologically induced SAR model in banana is helpful to investigate the mechanism of SAR to Fusarium wilt. This paper described one such model using incompatible Foc race 1 to induce resistance against Foc tropical race 4 in an in vitro pathosystem. Consistent with the observation that the SAR provided the highest level of protection when the time interval between primary infection and challenge inoculation was 10d, the activities of defense-related enzymes such as phenylalanine ammonia lyase (PAL, EC 4.3.1.5), peroxidase (POD, EC 1.11.1.7), polyphenol oxidase (PPO, EC 1.14.18.1), and superoxide dismutase (SOD, EC 1.15.1.1) in systemic tissues also reached the maximum level and were 2.00-2.43 times higher than that of the corresponding controls on the tenth day. The total salicylic acid (SA) content in roots of banana plantlets increased from about 1 to more than 5 μg g⁻¹ FW after the second leaf being inoculated with Foc race 1. The systemic up-regulation of MaNPR1A and MaNPR1B was followed by the second up-regulation of PR-1 and PR-3. Although SA and jasmonic acid (JA)/ethylene (ET) signaling are mostly antagonistic, systemic expression of PR genes regulated by different signaling pathways were simultaneously up-regulated after primary infection, indicating that both pathways are involved in the activation of the SAR. PMID:23702248

  1. Fusarium verticillioides: Talking to Friends and Enemies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fusarium verticillioides is both a symptomless endophyte and a pathogen of maize. At some point, the fungus may synthesize fumonisins which have been linked to a variety of animal diseases including cancer in some animals. In order to minimize losses due to contaminated food or feed, we are workin...

  2. HISTOLOGY AND PHYSIOLOGY OF FUSARIUM HEAD BLIGHT

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fusarium head blight re-emerged as a devastating disease of wheat and barley in the 1990s in the midwestern U.S. Research efforts to control the disease have been hampered by limited knowledge of how the fungal head blight pathogens infect and damage head tissue and what natural defenses the plant h...

  3. Fusarium Race 4: Management Recommendations for Growers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Over the past five to seven years, race 4 of the fungal pathogen Fusarium oxysporum spp. vasinfectum (race 4 FOV) has been widely studied and has increasingly impacted cotton fields in California’s San Joaquin Valley. Findings from field and greenhouse research and observations can be summarized as:...

  4. FUMONISIN MYCOTOXIN BIOSYNTHESIS IN FUSARIUM VERTICILLIOIDES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fumonsins are mycotoxins produced by the maize pathogen Fusarium verticillioides. These toxins are of concern because of their association with cancer in experimental rodents and the epidemiological correlation between consumption of fumonisin-contaminated maize and human esophageal cancer. We hav...

  5. Molecular Identification and Databases in Fusarium

    Technology Transfer Automated Retrieval System (TEKTRAN)

    DNA sequence-based methods for identifying pathogenic and mycotoxigenic Fusarium isolates have become the gold standard worldwide. Moreover, fusarial DNA sequence data are increasing rapidly in several web-accessible databases for comparative purposes. Unfortunately, the use of Basic Alignment Sea...

  6. Mycotoxigenic Fusarium species in animal feed

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fusarium species are among the most studied plant pathogenic fungi, with several species causing diseases on corn, wheat, barley, and other food and feed grains. Decreased yield, as well as diminished quality and value of the grain, results in significant worldwide economic losses. Additionally, ...

  7. Investigating Spore killer of Fusarium verticillioides

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Maize is one of the most important crops in the world. Fusarium verticillioides may colonize maize as an endophyte or as a pathogen, causing disease at any life stage of the plant. During growth on maize, F. verticillioides can synthesis a number of mycotoxins including fumonisins, which have been l...

  8. A novel transcriptional factor important for pathogenesis and ascosporogenesis in Fusarium graminearum

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fusarium head blight or scab caused by Fusarium graminearum is an important disease of wheat and barley. The pathogen not only causes severe yield losses but also contaminates infested grains with mycotoxins. In a previous study we identified several pathogenicity mutants by random insertional mutag...

  9. Phylogenetically marking the limits of the genus Fusarium for post-Article 59 usage

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fusarium (Hypocreales, Nectriaceae) is one of the most important and systematically challenging groups of mycotoxigenic, plant pathogenic, and human pathogenic fungi. We conducted maximum likelihood (ML), maximum parsimony (MP) and Bayesian (B) analyses on partial nucleotide sequences of genes encod...

  10. Activity of Haliscosamine against Fusarium oxysporum f.sp. melonis: in vitro and in vivo analysis.

    PubMed

    El Amraoui, Belakssem; Biard, Jean François; Ikbal, Fatima Ez-Zohra; El Wahidi, Majida; Kandil, Mostafa; El Amraoui, Mohammed; Fassouane, Aziz

    2015-01-01

    Marine sponges are a potential source of new molecules with diverse biological activities. We have previously isolated a sphingosine derivative, (9Z)-2-amino-docos-9-ene-1,3,13,14-tetraol (Haliscosamine) from the Moroccan sea sponge Haliclona viscosa. The aim of this study was to test Haliscosamine in vitro and in vivo for its antifungal activity against Fusarium oxysporum f.sp. melonis causing fusarium wilt of melon. Overall, in vitro test showed that haliscosamine has a similar effect as DESOGERME SP VEGETAUX®. In addition, in vivo showed a significant effect against Fusarium oxysporum f.sp. melonis. Taking to gather, our results suggest that haliscosamine constitutes a potential candidate against Fusarium oxysporum f.sp. melonis and the possibility to use in phytopathology. PMID:25625038

  11. Identification of tolerance to Fusarium root rot in wild pea germplasm with high levels of partial resistance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fusarium root rot, caused by Fusarium solani f. sp. pisi, is a serious root rot pathogen affecting peas in all pea growing areas of the USA and is damaging in both dryland and irrigated pea fields. Partial resistance to Fusarium root rot in 44 accessions from the Pisum Core Collection located in Pu...

  12. Biosynthesis of DON/15-ADON and NX-2 by different variants of TRI1 from Fusarium graminearum

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fusarium graminearum is one of the econimically most important plant pathogens causing diseases such as Fusarium Head Blight (FHB) of small grain cereals and ear rot of maize. During a large scale survey of Fusarium graminearum (sensu strictu) in the northern United States strains (termed N-strains)...

  13. Inoculation of tomato seedlings with Trichoderma Harzianum and Arbuscular Mycorrhizal Fungi and their effect on growth and control of wilt in tomato seedlings

    PubMed Central

    Mwangi, Margaret W.; Monda, Ethel O.; Okoth, Sheila A.; Jefwa, Joyce M.

    2011-01-01

    A green house study was conducted to investigate the ability of an isolate of Trichoderma harzianum (P52) and arbuscular mycorrhizal fungi (AMF) in enhancing growth and control of a wilt pathogen caused by Fusarium oxysporum f. sp. lycopersici in tomato seedlings. The plants were grown in plastic pots filled with sterilized soils. There were four treatments applied as follows; P52, AMF, AMF + P52 and a control. A completely randomized design was used and growth measurements and disease assessment taken after 3, 6 and 9 weeks. Treatments that significantly (P < 0.05) enhanced heights and root dry weights were P52, AMF and a treatment with a combination of both P52 and AMF when compared the control. The treatment with both P52 and AMF significantly (P < 0.05) enhanced all growth parameters (heights; shoot and root dry weight) investigated compared to the control. Disease severity was generally lower in tomato plants grown with isolate P52 and AMF fungi either individually or when combined together, though the effect was not statistically significant (P≥ 0.05). A treatment combination of P52 + AMF had less trend of severity as compared to each individual fungus. T. harzianum and AMF can be used to enhance growth in tomato seedlings. PMID:24031662

  14. Inoculation of tomato seedlings with Trichoderma Harzianum and Arbuscular Mycorrhizal Fungi and their effect on growth and control of wilt in tomato seedlings.

    PubMed

    Mwangi, Margaret W; Monda, Ethel O; Okoth, Sheila A; Jefwa, Joyce M

    2011-04-01

    A green house study was conducted to investigate the ability of an isolate of Trichoderma harzianum (P52) and arbuscular mycorrhizal fungi (AMF) in enhancing growth and control of a wilt pathogen caused by Fusarium oxysporum f. sp. lycopersici in tomato seedlings. The plants were grown in plastic pots filled with sterilized soils. There were four treatments applied as follows; P52, AMF, AMF + P52 and a control. A completely randomized design was used and growth measurements and disease assessment taken after 3, 6 and 9 weeks. Treatments that significantly (P < 0.05) enhanced heights and root dry weights were P52, AMF and a treatment with a combination of both P52 and AMF when compared the control. The treatment with both P52 and AMF significantly (P < 0.05) enhanced all growth parameters (heights; shoot and root dry weight) investigated compared to the control. Disease severity was generally lower in tomato plants grown with isolate P52 and AMF fungi either individually or when combined together, though the effect was not statistically significant (P≥ 0.05). A treatment combination of P52 + AMF had less trend of severity as compared to each individual fungus. T. harzianum and AMF can be used to enhance growth in tomato seedlings. PMID:24031662

  15. Spatial Pattern of Verticillium dahliae Microsclerotia and Cotton Plants with Wilt Symptoms in Commercial Plantations

    PubMed Central

    Yang, Jiarong; Hu, Xiaoping; Xu, Xiangming

    2015-01-01

    Spatial patterns of pathogen inoculum in field soils and the resulting patterns of disease may reflect the underlying mechanisms of pathogen dispersal. This knowledge can be used to design more efficient sampling schemes for assessing diseases. Spatial patterns of Verticillium dahliae microsclerotia were characterized in commercial cotton fields through quadrat and point sampling in 1994 and 2013, respectively. Furthermore, cotton plants with wilt symptoms, caused by V. dahliae, were assessed in six commercial cotton fields in 2013. Soil samples were assayed for the density of microsclerotia (expressed as CFU g-1 of soil) using a wet-sieving plating method and a real-time quantitative PCR method for the 1994 and 2013 study, respectively. The estimated inoculum threshold for causing wilt development on individual plants varied with the three fields: ca. 1.6 CFU g-1 of soil for one field, and 7.2 CFU g-1 of soil for the other two. Both quadrat and point sampling spatial analyses showed that aggregation of V. dahliae inoculum in soils was usually not detected beyond 1.0 m. Similarly, the spatial patterns of wilted cotton plants indicated that spatial aggregation of diseased plants were only observed below the scale of 1.0 m in six commercial cotton plantations. Therefore, spatial aggregation of both V. dahliae inoculum and cotton plants with wilt symptoms is not likely to be detected above the scale of 1.0 m for most commercial cotton plantations. When designing schemes for assessing wilt inoculum and wilt development, this scale needs to be taken into consideration. PMID:26167868

  16. REN1 is required for development of microconidia and macroconidia, but not of chlamydospores, in the plant pathogenic fungus Fusarium oxysporum.

    PubMed Central

    Ohara, Toshiaki; Inoue, Iori; Namiki, Fumio; Kunoh, Hitoshi; Tsuge, Takashi

    2004-01-01

    The filamentous fungus Fusarium oxysporum is a soil-borne facultative parasite that causes economically important losses in a wide variety of crops. F. oxysporum exhibits filamentous growth on agar media and undergoes asexual development producing three kinds of spores: microconidia, macroconidia, and chlamydospores. Ellipsoidal microconidia and falcate macroconidia are formed from phialides by basipetal division; globose chlamydospores with thick walls are formed acrogenously from hyphae or by the modification of hyphal cells. Here we describe rensa, a conidiation mutant of F. oxysporum, obtained by restriction-enzyme-mediated integration mutagenesis. Molecular analysis of rensa identified the affected gene, REN1, which encodes a protein with similarity to MedA of Aspergillus nidulans and Acr1 of Magnaporthe grisea. MedA and Acr1 are presumed transcription regulators involved in conidiogenesis in these fungi. The rensa mutant and REN1-targeted strains lack normal conidiophores and phialides and form rod-shaped, conidium-like cells directly from hyphae by acropetal division. These mutants, however, exhibit normal vegetative growth and chlamydospore formation. Nuclear localization of Ren1 was verified using strains expressing the Ren1-green fluorescent protein fusions. These data strongly suggest that REN1 encodes a transcription regulator required for the correct differentiation of conidiogenesis cells for development of microconidia and macroconidia in F. oxysporum. PMID:15020411

  17. Hydrolysis of plant cuticle by plant pathogens. Properties of cutinase I, cutinase II, and a nonspecific esterase isolated from Fusarium solani pisi.

    PubMed

    Purdy, R E; Kolattukudy, P E

    1975-07-01

    The properties of the homogeneous cutinase I, cutinase II, and the nonspecific esterase isolated from the extracellular fluid of cutin-grown Fusarium solani F. pisi (R.E. Purdy and P.E. Kolattukudy (1975), Biochemistry, preceding paper in this issue) were investigated. Using tritiated apple cutin as substrate, the two cutinases showed similar substrate concentration dependence, protein concentration dependence, time course profiles, and pH dependence profiles with optimum near 10.0. Using unlabeled cutin, the rate of dihydroxyhexadecanoic acid release from apple fruit cutin by cutinase I was determined to be 4.4 mumol per min per mg. The cutinases hydrolyzed methyl hexadecanoate, cyclohexyl hexadecanoate, and to a much lesser extent hexadecyl hexadecanoate but not 9-hexadecanoyloxyheptadecane, cholesteryl hexadecanoate, or hexadecyl cinnamate. The extent of hydrolysis of these model substrates by cutinase I was at least three times that by cutinase II. The nonspecific esterase hydrolyzed all of the above esters except hexadecyl cinnamate, and did so to a much greater extent than did the cutinases. None of the enzymes hydrolyzed alpha- or beta-glucosides of p-nitrophenol. p-Nitrophenyl esters of fatty acids from C2 through C18 were used as substrates and V's and Kms were determined... PMID:239740

  18. Field resistance to Fusarium oxysporum and Verticillium dahliae in transgenic cotton expressing the plant defensin NaD1

    PubMed Central

    Anderson, Marilyn A.

    2014-01-01

    The plant defensin NaD1, from Nicotiana alata, has potent antifungal activity against a range of filamentous fungi including the two important cotton pathogens, Fusarium oxysporum f. sp. vasinfectum (Fov) and Verticillium dahliae. Transgenic cotton plants expressing NaD1 were produced and plants from three events were selected for further characterization. Homozygous plants were assessed in greenhouse bioassays for resistance to Fov. One line (D1) was selected for field trial testing over three growing seasons in soils naturally infested with Fov and over two seasons in soils naturally infested with V. dahliae. In the field trials with Fov-infested soil, line D1 had 2–3-times the survival rate, a higher tolerance to Fov (higher disease rank), and a 2–4-fold increase in lint yield compared to the non-transgenic Coker control. When transgenic line D1 was planted in V. dahliae-infested soil, plants had a higher tolerance to Verticillium wilt and up to a 2-fold increase in lint yield compared to the non-transgenic Coker control. Line D1 did not exhibit any detrimental agronomic features compared to the parent Coker control when plants were grown in non-diseased soil. This study demonstrated that the expression of NaD1 in transgenic cotton plants can provide substantial resistance to two economically important fungal pathogens. PMID:24502957

  19. Proteomic identification of potential target proteins regulated by the SCF(F) (bp1) -mediated proteolysis pathway in Fusarium oxysporum.

    PubMed

    Miguel-Rojas, Cristina; Hera, Concepcion

    2013-12-01

    F-box proteins function in the recruitment of proteins for SCF ubiquitination and proteasome degradation. Here, we studied the role of Fbp1, a nonessential F-box protein of the tomato pathogen Fusarium oxysporum f. sp. lycopersici. The Δfbp1 mutant showed a significant delay in the production of wilt symptoms on tomato plants and was impaired in invasive growth on cellophane membranes and on living plant tissue. To search for target proteins recruited by Fbp1, a combination of sodium dodecylsulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and matrix-assisted laser desorption/ionization time-of-flight/time-of-flight (MALDI-TOF/TOF) was used to compare proteins in mycelia of the wild-type and Δfbp1 mutant. The proteomic approach identified 41 proteins differing significantly in abundance between the two strains, 17 of which were more abundant in the Δfbp1 mutant, suggesting a possible regulation by proteasome degradation. Interestingly, several of the identified proteins were related to vesicle trafficking. Microscopic analysis revealed an impairment of the Δfbp1 strain in directional growth and in the structure of the Spitzenkörper, suggesting a role of Fbp1 in hyphal orientation. Our results indicate that Fbp1 regulates protein turnover and pathogenicity in F. oxysporum. PMID:23855991

  20. Native root-associated bacteria rescue a plant from a sudden-wilt disease that emerged during continuous cropping.

    PubMed

    Santhanam, Rakesh; Luu, Van Thi; Weinhold, Arne; Goldberg, Jay; Oh, Youngjoo; Baldwin, Ian T

    2015-09-01

    Plants maintain microbial associations whose functions remain largely unknown. For the past 15 y, we have planted the annual postfire tobacco Nicotiana attenuata into an experimental field plot in the plant's native habitat, and for the last 8 y the number of plants dying from a sudden wilt disease has increased, leading to crop failure. Inadvertently we had recapitulated the common agricultural dilemma of pathogen buildup associated with continuous cropping for this native plant. Plants suffered sudden tissue collapse and black roots, symptoms similar to a Fusarium-Alternaria disease complex, recently characterized in a nearby native population and developed into an in vitro pathosystem for N. attenuata. With this in vitro disease system, different protection strategies (fungicide and inoculations with native root-associated bacterial and fungal isolates), together with a biochar soil amendment, were tested further in the field. A field trial with more than 900 plants in two field plots revealed that inoculation with a mixture of native bacterial isolates significantly reduced disease incidence and mortality in the infected field plot without influencing growth, herbivore resistance, or 32 defense and signaling metabolites known to mediate resistance against native herbivores. Tests in a subsequent year revealed that a core consortium of five bacteria was essential for disease reduction. This consortium, but not individual members of the root-associated bacteria community which this plant normally recruits during germination from native seed banks, provides enduring resistance against fungal diseases, demonstrating that native plants develop opportunistic mutualisms with prokaryotes that solve context-dependent ecological problems. PMID:26305938

  1. Isolation and characterization of an exopolygalacturonase from Fusarium oxysporum f.sp. cubense race 1 and race 4

    PubMed Central

    2011-01-01

    Background Fusarium wilt is an economically devastating disease that affects banana production. Although Cavendish banana cultivars are resistant to Fusarium oxysporum f.sp. cubense race 1 (FOC1) and maitain banana production after Gros Michel was destructed by race 1, a new race race 4 (FOC4) was found to infect Cavendish. Results An exopolygalacturonase (PGC2) was isolated and purified from the supernatant of the plant pathogen Fusarium oxysporum f.sp. cubense race 4 (FOC4). PGC2 had an apparent Mr of 63 kDa by SDS-PAGE and 51.7 kDa by mass spectrometry. The enzyme was N-glycosylated. PGC2 hydrolyzed polygalacturonic acid in an exo-manner, as demonstrated by analysis of degradation products. To obtain adequate amounts of protein for functional studies between the PGC2 proteins of two races of the pathogen, pgc2 genes encoding PGC2 from race 4 (FOC4) and race 1 (FOC1), both 1395 bp in length and encoding 465 amino acids with a predicted amino-terminal signal sequence of 18 residues, were cloned into the expression vector pPICZaA and then expressed in Pichia pastoris strains of SMD1168. The recombinant PGC2 products, r-FOC1-PGC2 and r-FOC4-PGC2, were expressed and purified as active extracellular proteins. Optimal PGC2 activity was observed at 50°C and pH 5. The Km and Vmax values of purified r-FOC1-PGC2 were 0.43 mg.mL-1 and 94.34 units mg protein-1 min-1, respectively. The Km and Vmax values of purified r-FOC4-PGC2 were 0.48 mg.mL-1 and 95.24 units mg protein-1 min-1, respectively. Both recombinant PGC2 proteins could induce tissue maceration and necrosis in banana plants. Conclusions Collectively, these results suggest that PGC2 is the first exoPG reported from the pathogen FOC, and we have shown that fully functional PGC2 can be produced in the P. pastoris expression system. PMID:21920035

  2. New report of additional enterobacterial species causing wilt in West Bengal, India.

    PubMed

    Sarkar, Shamayeeta; Chaudhuri, Sujata

    2015-07-01

    Ralstonia solanacearum is known to be the most prominent causal agent of bacterial wilt worldwide. It has a wide host range comprising solanaceous and nonsolanaceous plants. Typical symptoms of the disease are leaf wilt, browning of vascular tissues, and collapsing of the plant. With the objective of studying the diversity of pathogens causing bacterial wilt in West Bengal, we collected samples of diseased symptomatic crops and adjacent symptomatic and asymptomatic weeds from widespread locations in West Bengal. By means of a routine molecular identification test specific to "R. solanacearum species complex", the majority of these strains (68 out of 71) were found to not be R. solanacearum. Presumptive identification of these isolates with conventional biochemicals, extensive testing of pathogenicity of a subset involving greenhouse trials fulfilling Koch's postulate test, and scanning electron microscopic analysis for the presence of pathogen in diseased plants were done. 16S rDNA sequencing of a subset of these strains (GenBank accession Nos. JX880249-JX880251) and analysis of sequences with the nBLAST programme showed a high similarity (97%-99%) to sequences of the Enterobacteriaceae group available in GenBank. Molecular phylogeny further established the taxonomic position of the strains. The 3 bacterial strain cultures have been submitted to MTCC, Institute of Microbial Technology, Chandigarh, India, and were identified as Klebsiella oxytoca, Enterobacter cowanii, and Klebsiella oxytoca, respectively. Although Enterobacter sp. has previously been reported to cause wilt in many plants, susceptibility of most of the dedicated hosts of R. solanacearum to wilt caused by Enterobacter and other bacteria from Enterobacteriaceae is being reported for the first time in this work. PMID:26040797

  3. Differentially Expressed Genes in Resistant and Susceptible Common Bean (Phaseolus vulgaris L.) Genotypes in Response to Fusarium oxysporum f. sp. phaseoli

    PubMed Central

    Xue, Renfeng; Wu, Jing; Zhu, Zhendong; Wang, Lanfen; Wang, Xiaoming; Wang, Shumin; Blair, Matthew W.

    2015-01-01

    Fusarium wilt of common bean (Phaseolus vulgaris L.), caused by Fusarium oxysporum Schlechtend.:Fr. f.sp. phaseoli (Fop), is one of the most important diseases of common beans worldwide. Few natural sources of resistance to Fop exist and provide only moderate or partial levels of protection. Despite the economic importance of the disease across multiple crops, only a few of Fop induced genes have been analyzed in legumes. Therefore, our goal was to identify transcriptionally regulated genes during an incompatible interaction between common bean and the Fop pathogen using the cDNA amplified fragment length polymorphism (cDNA-AFLP) technique. We generated a total of 8,730 transcript-derived fragments (TDFs) with 768 primer pairs based on the comparison of a moderately resistant and a susceptible genotype. In total, 423 TDFs (4.9%) displayed altered expression patterns after inoculation with Fop inoculum. We obtained full amplicon sequences for 122 selected TDFs, of which 98 were identified as annotated known genes in different functional categories based on their putative functions, 10 were predicted but non-annotated genes and 14 were not homologous to any known genes. The 98 TDFs encoding genes of known putative function were classified as related to metabolism (22), signal transduction (21), protein synthesis and processing (20), development and cytoskeletal organization (12), transport of proteins (7), gene expression and RNA metabolism (4), redox reactions (4), defense and stress responses (3), energy metabolism (3), and hormone responses (2). Based on the analyses of homology, 19 TDFs from different functional categories were chosen for expression analysis using quantitative RT-PCR. The genes found to be important here were implicated at various steps of pathogen infection and will allow a better understanding of the mechanisms of defense and resistance to Fop and similar pathogens. The differential response genes discovered here could also be used as molecular markers in association mapping or QTL analysis. PMID:26030070

  4. Differentially Expressed Genes in Resistant and Susceptible Common Bean (Phaseolus vulgaris L.) Genotypes in Response to Fusarium oxysporum f. sp. phaseoli.

    PubMed

    Xue, Renfeng; Wu, Jing; Zhu, Zhendong; Wang, Lanfen; Wang, Xiaoming; Wang, Shumin; Blair, Matthew W

    2015-01-01

    Fusarium wilt of common bean (Phaseolus vulgaris L.), caused by Fusarium oxysporum Schlechtend.:Fr. f.sp. phaseoli (Fop), is one of the most important diseases of common beans worldwide. Few natural sources of resistance to Fop exist and provide only moderate or partial levels of protection. Despite the economic importance of the disease across multiple crops, only a few of Fop induced genes have been analyzed in legumes. Therefore, our goal was to identify transcriptionally regulated genes during an incompatible interaction between common bean and the Fop pathogen using the cDNA amplified fragment length polymorphism (cDNA-AFLP) technique. We generated a total of 8,730 transcript-derived fragments (TDFs) with 768 primer pairs based on the comparison of a moderately resistant and a susceptible genotype. In total, 423 TDFs (4.9%) displayed altered expression patterns after inoculation with Fop inoculum. We obtained full amplicon sequences for 122 selected TDFs, of which 98 were identified as annotated known genes in different functional categories based on their putative functions, 10 were predicted but non-annotated genes and 14 were not homologous to any known genes. The 98 TDFs encoding genes of known putative function were classified as related to metabolism (22), signal transduction (21), protein synthesis and processing (20), development and cytoskeletal organization (12), transport of proteins (7), gene expression and RNA metabolism (4), redox reactions (4), defense and stress responses (3), energy metabolism (3), and hormone responses (2). Based on the analyses of homology, 19 TDFs from different functional categories were chosen for expression analysis using quantitative RT-PCR. The genes found to be important here were implicated at various steps of pathogen infection and will allow a better understanding of the mechanisms of defense and resistance to Fop and similar pathogens. The differential response genes discovered here could also be used as molecular markers in association mapping or QTL analysis. PMID:26030070

  5. Fusarium Infection in Lung Transplant Patients

    PubMed Central

    Carneiro, Herman A.; Coleman, Jeffrey J.; Restrepo, Alejandro; Mylonakis, Eleftherios

    2013-01-01

    Fusarium is a fungal pathogen of immunosuppressed lung transplant patients associated with a high mortality in those with severe and persistent neutropenia. The principle portal of entry for Fusarium species is the airways, and lung involvement almost always occurs among lung transplant patients with disseminated infection. In these patients, the immunoprotective mechanisms of the transplanted lungs are impaired, and they are, therefore, more vulnerable to Fusarium infection. As a result, fusariosis occurs in up to 32% of lung transplant patients. We studied fusariosis in 6 patients following lung transplantation who were treated at Massachusetts General Hospital during an 8-year period and reviewed 3 published cases in the literature. Cases were identified by the microbiology laboratory and through discharge summaries. Patients presented with dyspnea, fever, nonproductive cough, hemoptysis, and headache. Blood tests showed elevated white blood cell counts with granulocytosis and elevated inflammatory markers. Cultures of Fusarium were isolated from bronchoalveolar lavage, blood, and sputum specimens. Treatments included amphotericin B, liposomal amphotericin B, caspofungin, voriconazole, and posaconazole, either alone or in combination. Lung involvement occurred in all patients with disseminated disease and it was associated with a poor outcome. The mortality rate in this group of patients was high (67%), and of those who survived, 1 patient was treated with a combination of amphotericin B and voriconazole, 1 patient with amphotericin B, and 1 patient with posaconazole. Recommended empirical treatment includes voriconazole, amphotericin B or liposomal amphotericin B first-line, and posaconazole for refractory disease. High-dose amphotericin B is recommended for treatment of most cases of fusariosis. The echinocandins (for example, caspofungin, micafungin, anidulafungin) are generally avoided because Fusarium species have intrinsic resistance to them. Treatment should ideally be based on the Fusarium isolate, susceptibility testing, and host-specific factors. Prognosis of fusariosis in the immunocompromised is directly related to a patient’s immune status. Prevention of Fusarium infection is recommended with aerosolized amphotericin B deoxycholate, which also has activity against other important fungi. PMID:21200188

  6. An Asian ambrosia beetle Euwallacea fornicatus and its novel symbiotic fungus Fusarium sp. pose a serious threat to the Israeli avocado industry

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The ambrosia beetle Euwallacea fornicatus Einchoff was first recorded in Israel in 2009. A novel unnamed symbiotic species within Clade 3 of the Fusarium solani species complex, carried in the mandibular mycangia of the beetle, is responsible for the typical wilt symptoms inflicted on avocado (Perse...

  7. COMPLETE GENETIC LINKAGE MAPS FROM AN INTERSPECIFIC CROSS BETWEEN FUSARIUM CIRCINATUM AND FUSARIUM SUBGLUTINANS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fusarium isolates associated with the Gibberella fujikuroi species complex include many important fungal pathogens of agricultural crops and trees. In this study an interspecific hybrid between F. circinatum and F subglutinans was used to compile a genetic linkage map. A framework map was construc...

  8. Fusarium pathogenesis investigated using Galleria mellonella as a heterologous host

    PubMed Central

    Coleman, Jeffrey J.; Muhammed, Maged; Kasperkovitz, Pia V.; Vyas, Jatin M.; Mylonakis, Eleftherios

    2011-01-01

    Members of the fungal genus Fusarium are capable of manifesting in a multitude of clinical infections, most commonly in immunocompromised patients. In order to better understand the interaction between the fungus and host, we have developed the larvae of the greater wax moth, Galleria mellonella, as a heterologous host for fusaria. When conidia are injected into the hemocoel of this Lepidopteran system, both clinical and environmental isolates of the fungus are able to kill the larvae at 37°C, although killing occurs more rapidly when incubated at 30°C. This killing was dependent on several other factors besides temperature, including the Fusarium strain, the number of conidia injected, and the conidia morphology, where macroconidia are more virulent than their microconidia counterpart. There was a correlation in the killing rate of Fusarium spp. when evaluated in G. mellonella and a murine model. In vivo studies indicated G. mellonella hemocytes were capable of initially phagocytosing both conidial morphologies. The G. mellonella system was also used to evaluate antifungal agents, and amphotericin B was able to confer a significant increase in survival to Fusarium infected-larvae. The G. mellonella-Fusarium pathogenicity system revealed that virulence of Fusarium spp. is similar, regardless of the origin of the isolate, and that mammalian endothermy is a major deterrent for Fusarium infection and therefore provides a suitable alternative to mammalian models to investigate the interaction between the host and this increasingly important fungal pathogen. PMID:22115447

  9. Environmental conditions that contribute to development and severity of Sugar Beet Fusarium Yellows caused by Fusarium oxysporum f. sp. betae: temperature

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fusarium yellows in sugar beet, caused by Fusarium oxysporum f. sp. betae, continues to cause significant problems to sugar beet production by causing considerable reductions in root yield, sucrose percentage, and juice purity in affected sugar beets. Environment plays a critical role in pathogen i...

  10. Imaging O2 changes induced in tomato roots by fungal pathogen

    NASA Astrophysics Data System (ADS)

    Rubol, S.; Turco, E.; Rodeghiero, M.; Bellin, A.

    2014-12-01

    In the last decade, planar optodes have demonstrated to be a useful non-invasive tool to monitor real time oxygen concentrations in a wide range of applications. However, only limited investigations have been carried out to explore the use of optodes in plant respiration studies. In particular, their use to study plant-pathogen interactions has been not deeply investigated. Here, we present for the first time an in vitro experimental setup capable to depict the dynamical effects of the fungal pathogen Fusarium oxysporum f.sp. lycopersici (Fol) on tomato roots by the use of a recently developed optical non-invasive optode oxygen sensor (Visisens, Presens, Germany). Fol is a soil-borne pathogen and the causal agent of wilt in tomato plants, a destructive worldwide disease. The interaction Fol-tomato is widely accepted as a model system in plant pathology. In this work, oxygen concentrations are monitored continuously in time and considered a proxy for root respiration and metabolic activity. The experimental procedure reveals three different dynamic stages: 1) a uniform oxygen consumption in tomato roots earlier before pathogen colonization, 2) a progressive decrease in the oxygen concentration indicating a high metabolic activity as soon as the roots were surrounded and colonized by the fungal mycelium, and 3) absence of root respiration, as a consequence of root death. Our results suggest the ability of the fungal mycelium to move preferentially towards and along the root as a consequence of the recognition event.

  11. Onychomycosis by Fusarium oxysporum probably acquired in utero.

    PubMed

    Carvalho, Vania O; Vicente, Vania A; Werner, Betina; Gomes, Renata R; Fornari, Gheniffer; Herkert, Patricia F; Rodrigues, Cristina O; Abagge, Kerstin T; Robl, Renata; Camiña, Ricardo H

    2014-10-01

    Fusarium oxysporum has been described as a pathogen causing onychomycosis, its incidence has been increasing in immunocompetent and disseminated infection can occur in immunosuppressed individuals. We describe the first case of congenital onychomycosis in a child caused by Fusarium oxysporum. The infection being acquired in utero was proven by molecular methods with the identification of the fungus both in the nail and placenta, most probably as an ascending contamination/infection in a HIV-positive, immunosuppressed mother. PMID:25383318

  12. Phenylpropanoid pathway is potentiated by silicon in the roots of banana plants during the infection process of Fusarium oxysporum f. sp. cubense.

    PubMed

    Fortunato, Alessandro Antônio; da Silva, Washington Luís; Rodrigues, Fabrício Ávila

    2014-06-01

    Fusarium wilt, caused by Fusarium oxysporum f. sp. cubense, is a disease that causes large reductions in banana yield worldwide. Considering the importance of silicon (Si) to potentiate the resistance of several plant species to pathogen infection, this study aimed to investigate, at the histochemical level, whether this element could enhance the production of phenolics on the roots of banana plants in response to F. oxysporum f. sp. cubense infection. Plants of cultivar Maçã, which is susceptible to F. oxysporum f. sp. cubense, were grown in plastic pots amended with 0 (-Si) or 0.39 g of Si (+Si) per kilogram of soil and inoculated with race 1 of F. oxysporum f. sp. cubense. The root Si concentration was increased by 35.6% for +Si plants in comparison to the -Si plants, which contributed to a 27% reduction in the symptoms of Fusarium wilt on roots. There was an absence of fluorescence for the root sections of the -Si plants treated with the Neu and Wilson's reagents. By contrast, for the root sections obtained from the +Si plants treated with Neu's reagent, strong yellow-orange fluorescence was observed in the phloem, and lemon-yellow fluorescence was observed in the sclerenchyma and metaxylem vessels, indicating the presence of flavonoids. For the root sections of the +Si plants treated with Wilson's reagent, orange-yellowish autofluorescence was more pronounced around the phloem vessels, and yellow fluorescence was more pronounced around the metaxylem vessels, also indicating the presence of flavonoids. Lignin was more densely deposited in the cortex of the roots of the +Si plants than for the -Si plants. Dopamine was barely detected in the roots of the -Si plants after using the lactic and glyoxylic acid stain, but was strongly suspected to occur on the phloem and metaxylem vessels of the roots of the +Si plants as confirmed by the intense orange-yellow fluorescence. The present study provides new evidence of the pivotal role of the phenylpropanoid pathway in the resistance of banana plants to F. oxysporum f. sp. cubense infection when supplied with Si. PMID:24350769

  13. Effects of the tomato pathogen Fusarium oxysporum f. sp. radicis-lycopersici and of the biocontrol bacterium Pseudomonas fluorescens WCS365 on the composition of organic acids and sugars in tomato root exudate.

    PubMed

    Kamilova, Faina; Kravchenko, Lev V; Shaposhnikov, Alexander I; Makarova, Nataliya; Lugtenberg, Ben

    2006-10-01

    The effects of the pathogenic fungus Fusarium oxysporum f. sp. radicis-lycopersici and of the bacterial biocontrol strain Pseudomonas fluorescens WCS365, and of both microbes, on the amounts and composition of root exudate components of tomato plants grown in a gnotobiotic stonewool substrate system were studied. Conditions were selected under which introduction of F. oxysporum f. sp. radicis-lycopersici caused severe foot and root rot, whereas inoculation of the seed with P. fluorescens WCS365 decreased the percentage of diseased plants from 96 to 7%. This is a much better disease control level than was observed in potting soil. Analysis of root exudate revealed that the presence of F. oxysporum f. sp. radicis-lycopersici did not alter the total amount of organic acids, but that the amount of citric acid decreased and that of succinic acid increased compared with the nontreated control. In contrast, in the presence of the P. fluorescens biocontrol strain WCS365, the total amount of organic acid increased, mainly due to a strong increase of the amount of citric acid, whereas the amount of succinic acid decreased dramatically. Under biocontrol conditions, when both microbes are present, the content of succinic acid decreased and the level of citric acid was similar to that in the nontreated control. The amount of sugar was approximately half that of the control sample when either one of the microbes was present alone or when both were present. Analysis of the interactions between the two microbes grown together in sterile tomato root exudate showed that WCS365 inhibited multiplication of F. oxysporum f. sp. radicis-lycopersici, whereas the fungus did not affect the number of CFU of the bacterium. PMID:17022176

  14. Is California bay laurel a suitable host for the non-native redbay ambrosia beetle, vector of laurel wilt disease?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Laurel wilt is a deadly vascular disease of trees in the Lauraceae that kills healthy redbay (Persea borbonia), sassafras (Sassafras albidum), and other related hosts. The fungal pathogen (Raffaelea lauricola) and it vector, the redbay ambrosia beetle (Xyleborus glabratus) are native to Asia and ha...

  15. Quantitative trait locus analysis of Verticillium wilt resistance in an introgressed recombinant inbred population of Upland cotton

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Verticillium wilt (VW) of Upland cotton (Gossypium hirsutum L.) is caused by the soil-borne fungal pathogen Verticillium dahlia Kleb. The availability of VW-resistant cultivars is vital for control of this economically important disease, but there is a paucity of Upland cotton breeding lines and cul...

  16. Sclerotinia wilt of Hop (Humulus lupulus) caused by Sclerotinia sclerotiorum in the Pacific Northwest U.S.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sclerotinia sclerotiorum is a widespread, destructive pathogen with an exceptionally broad host range. During June 2011, wilted hop plants (Humulus lupulus cv. Nugget) were observed in a hop yard in Marion County, Oregon. Some affected plants had upward curled leaves with necrotic margins, whereas o...

  17. SEMIOCHEMICAL-MEDIATED FLIGHT RESPONSES OF SAP BEETLE (COLEOPTERA:NITDULIDAE) VECTORS OF OAK WILT, CERATOCYSTIS FAGACEARUM

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The sap beetle, Colopterus truncatus (Coleoptera:Nitidulidae), is one of the primary vectors of the oak wilt pathogen, Ceratocystis fagacearum, in the north central United States. Male beetles emit an aggregation pheromone that attracts both sexes. Field behavioral assays utilizing various release...

  18. DEVELOPMENT OF BREEDING LINES WITH RESISTANCE TO TOMATO SPOTTED WILT VIRUS AND THE PEANUT ROOT-KNOT NEMATODE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Tomato spotted wilt virus (TSWV) has become a major problem in peanut (Arachis hypogaea L.) production areas of the southern United States. The peanut root-knot nematode [Meloidogyne arenaria (Neal) Chitwood race 1] is also an important pathogen in this production area. Peanut cultivars are availa...

  19. Redbay ambrosia beetle/Laurel wilt: Overview of projects at the USDA-ARS Subtropical Horticulture Research Station

    Technology Transfer Automated Retrieval System (TEKTRAN)

    ABSTRACT Laurel wilt, a deadly fungal disease of avocado and other trees in the Lauraceae, is vectored by the redbay ambrosia beetle (Xyleborus glabratus). First detected near Savannah, GA in 2002, the beetle and its obligatory pathogen have since spread to South Carolina and Florida. Currently, t...

  20. Sequence composition of BAC clones and SSR markers mapped to Upland cotton chromosomes 11 and 21 targeting resistance to soil-borne pathogens

    PubMed Central

    Wang, Congli; Ulloa, Mauricio; Shi, Xinyi; Yuan, Xiaohui; Saski, Christopher; Yu, John Z.; Roberts, Philip A.

    2015-01-01

    Genetic and physical framework mapping in cotton (Gossypium spp.) were used to discover putative gene sequences involved in resistance to common soil-borne pathogens. Chromosome (Chr) 11 and its homoeologous Chr 21 of Upland cotton (G. hirsutum) are foci for discovery of resistance (R) or pathogen-induced R (PR) genes underlying QTLs involved in response to root-knot nematode (Meloidogyne incognita), reniform nematode (Rotylenchulus reniformis), Fusarium wilt (Fusarium oxysporum f.sp. vasinfectum), Verticillium wilt (Verticillium dahliae), and black root rot (Thielaviopsis basicola). Simple sequence repeat (SSR) markers and bacterial artificial chromosome (BAC) clones from a BAC library developed from the Upland cotton Acala Maxxa were mapped on Chr 11 and Chr 21. DNA sequence through Gene Ontology (GO) of 99 of 256 Chr 11 and 109 of 239 Chr 21 previously mapped SSRs revealed response elements to internal and external stimulus, stress, signaling process, and cell death. The reconciliation between genetic and physical mapping of gene annotations from new DNA sequences of 20 BAC clones revealed 467 (Chr 11) and 285 (Chr 21) G. hirsutum putative coding sequences, plus 146 (Chr 11) and 98 (Chr 21) predicted genes. GO functional profiling of Unigenes uncovered genes involved in different metabolic functions and stress response elements (SRE). Our results revealed that Chrs 11 and 21 harbor resistance gene rich genomic regions. Sequence comparisons with the ancestral diploid D5 (G. raimondii), A2 (G. arboreum) and domesticated tetraploid TM-1 AD1 (G. hirsutum) genomes revealed abundance of transposable elements and confirmed the richness of resistance gene motifs in these chromosomes. The sequence information of SSR markers and BAC clones and the genetic mapping of BAC clones provide enhanced genetic and physical frameworks of resistance gene-rich regions of the cotton genome, thereby aiding discovery of R and PR genes and breeding for resistance to cotton diseases. PMID:26483808

  1. Sequence composition of BAC clones and SSR markers mapped to Upland cotton chromosomes 11 and 21 targeting resistance to soil-borne pathogens.

    PubMed

    Wang, Congli; Ulloa, Mauricio; Shi, Xinyi; Yuan, Xiaohui; Saski, Christopher; Yu, John Z; Roberts, Philip A

    2015-01-01

    Genetic and physical framework mapping in cotton (Gossypium spp.) were used to discover putative gene sequences involved in resistance to common soil-borne pathogens. Chromosome (Chr) 11 and its homoeologous Chr 21 of Upland cotton (G. hirsutum) are foci for discovery of resistance (R) or pathogen-induced R (PR) genes underlying QTLs involved in response to root-knot nematode (Meloidogyne incognita), reniform nematode (Rotylenchulus reniformis), Fusarium wilt (Fusarium oxysporum f.sp. vasinfectum), Verticillium wilt (Verticillium dahliae), and black root rot (Thielaviopsis basicola). Simple sequence repeat (SSR) markers and bacterial artificial chromosome (BAC) clones from a BAC library developed from the Upland cotton Acala Maxxa were mapped on Chr 11 and Chr 21. DNA sequence through Gene Ontology (GO) of 99 of 256 Chr 11 and 109 of 239 Chr 21 previously mapped SSRs revealed response elements to internal and external stimulus, stress, signaling process, and cell death. The reconciliation between genetic and physical mapping of gene annotations from new DNA sequences of 20 BAC clones revealed 467 (Chr 11) and 285 (Chr 21) G. hirsutum putative coding sequences, plus 146 (Chr 11) and 98 (Chr 21) predicted genes. GO functional profiling of Unigenes uncovered genes involved in different metabolic functions and stress response elements (SRE). Our results revealed that Chrs 11 and 21 harbor resistance gene rich genomic regions. Sequence comparisons with the ancestral diploid D5 (G. raimondii), A2 (G. arboreum) and domesticated tetraploid TM-1 AD1 (G. hirsutum) genomes revealed abundance of transposable elements and confirmed the richness of resistance gene motifs in these chromosomes. The sequence information of SSR markers and BAC clones and the genetic mapping of BAC clones provide enhanced genetic and physical frameworks of resistance gene-rich regions of the cotton genome, thereby aiding discovery of R and PR genes and breeding for resistance to cotton diseases. PMID:26483808

  2. Taxonomy and phylogeny of the Fusarium dimerum species group.

    PubMed

    Schroers, Hans-Josef; O'Donnell, Kerry; Lamprecht, Sandra C; Kammeyer, Patricia L; Johnson, Stuart; Sutton, Deanna A; Rinaldi, Michael G; Geiser, David M; Summerbell, Richard C

    2009-01-01

    The morphospecies Fusarium dimerum, known only from its anamorph, comprises at least 12 phylogenetically distinct species. Analyses of the large subunit ribosomal DNA (LSU rDNA) show they are taxa of the Nectriaceae (Hypocreales), related to F. domesticum and form a phylogenetically distinct clade within Fusarium. Fusarium dimerum, for which no herbarium material could be located, is characterized by macroconidia with a single, median septum, according to the original description and illustration. Fusarium lunatum (= F. dimerum var. violaceum) forms similar but longer macroconidia and purple, catenate or clustered chlamydospores. Fusarium delphinoides sp. nov., F. biseptatum sp. nov., F. penzigii sp. nov., F. nectrioides comb. nov. (= F. dimerum var. nectrioides) and two unnamed Fusarium spp. produce macroconidia with mostly two or rarely three septa. The name F. dimerum, which originally was applied to a fungus from a citron, is used for a taxon including isolates causing infections in immunocompetent and immunocompromised patients. Fusarium nectrioides, F. delphinoides, F. penzigii and F. biseptatum are known from soil and dead plant substrata or rarely as agents of trauma-related eye infections of humans. Fusarium lunatum is an inhabitant of the cladodes of species within the cactus genera Opuntia and Gymnocalycium. Its unnamed closest sister taxon, which also forms 1-septate macroconidia and purple, clustered chlamydospores, was isolated from a human sinus. Fusarium delphinoides is a pathogen of the cactus-like African species Hoodia gordonii (Apocynaceae). Phylogenetic analyses based on combined sequences of the internal transcribed spacer region, LSU rDNA and partial sequences of the elongation factor 1-alpha and beta-tubulin genes identified a clade of several species producing predominately 2-septate macroconidia as the reciprocally monophyletic sister of F. dimerum. The basal sister group of the two aforementioned clades includes Fusarium lunatum and two undescribed species, all of which form 1-septate macroconidia. PMID:19271670

  3. Combined action of the major secreted exo- and endopolygalacturonases is required for full virulence of Fusarium oxysporum.

    PubMed

    Bravo Ruiz, Gustavo; Di Pietro, Antonio; Roncero, M Isabel G

    2016-04-01

    The genome of the tomato pathogen Fusarium oxysporum f. sp. lycopersici encodes eight different polygalacturonases (PGs): four endoPGs and four exoPGs. Quantitative real-time reverse transcription-polymerase chain reaction (RT-PCR) revealed that endoPGs pg1 and pg5 and exoPGs pgx4 and pgx6 are expressed at significant levels during growth on citrus pectin, polygalacturonic acid or the monomer galacturonic acid, as well as during the infection of tomato plants. The remaining PG genes exhibit low expression levels under all the conditions tested. Secreted PG activity was decreased significantly during growth on pectin in the single deletion mutants lacking either pg1 or pgx6, as well as in the double mutant. Although the single deletion mutants did not display a significant virulence reduction on tomato plants, the Δpg1Δpgx6 double mutant was significantly attenuated in virulence. The combined action of exoPGs and endoPGs is thus essential for plant infection by the vascular wilt fungus F. oxysporum. PMID:26060046

  4. A high efficiency gene disruption strategy using a positive-negative split selection marker and electroporation for Fusarium oxysporum.

    PubMed

    Liang, Liqin; Li, Jianqiang; Cheng, Lin; Ling, Jian; Luo, Zhongqin; Bai, Miao; Xie, Bingyan

    2014-11-01

    The Fusarium oxysporum species complex consists of fungal pathogens that cause serial vascular wilt disease on more than 100 cultivated species throughout the world. Gene function analysis is rapidly becoming more and more important as the whole-genome sequences of various F. oxysporum strains are being completed. Gene-disruption techniques are a common molecular tool for studying gene function, yet are often a limiting step in gene function identification. In this study we have developed a F. oxysporum high-efficiency gene-disruption strategy based on split-marker homologous recombination cassettes with dual selection and electroporation transformation. The method was efficiently used to delete three RNA-dependent RNA polymerase (RdRP) genes. The gene-disruption cassettes of three genes can be constructed simultaneously within a short time using this technique. The optimal condition for electroporation is 10μF capacitance, 300Ω resistance, 4kV/cm field strength, with 1μg of DNA (gene-disruption cassettes). Under these optimal conditions, we were able to obtain 95 transformants per μg DNA. And after positive-negative selection, the transformants were efficiently screened by PCR, screening efficiency averaged 85%: 90% (RdRP1), 85% (RdRP2) and 77% (RdRP3). This gene-disruption strategy should pave the way for high throughout genetic analysis in F. oxysporum. PMID:24755311

  5. Recent trends in control methods for bacterial wilt diseases caused by Ralstonia solanacearum.

    PubMed

    Yuliar; Nion, Yanetri Asi; Toyota, Koki

    2015-01-01

    Previous studies have described the development of control methods against bacterial wilt diseases caused by Ralstonia solanacearum. This review focused on recent advances in control measures, such as biological, physical, chemical, cultural, and integral measures, as well as biocontrol efficacy and suppression mechanisms. Biological control agents (BCAs) have been dominated by bacteria (90%) and fungi (10%). Avirulent strains of R. solanacearum, Pseudomonas spp., Bacillus spp., and Streptomyces spp. are well-known BCAs. New or uncommon BCAs have also been identified such as Acinetobacter sp., Burkholderia sp., and Paenibacillus sp. Inoculation methods for BCAs affect biocontrol efficacy, such as pouring or drenching soil, dipping of roots, and seed coatings. The amendment of different organic matter, such as plant residue, animal waste, and simple organic compounds, have frequently been reported to suppress bacterial wilt diseases. The combined application of BCAs and their substrates was shown to more effectively suppress bacterial wilt in the tomato. Suppression mechanisms are typically attributed to the antibacterial metabolites produced by BCAs or those present in natural products; however, the number of studies related to host resistance to the pathogen is increasing. Enhanced/modified soil microbial communities are also indirectly involved in disease suppression. New promising types of control measures include biological soil disinfection using substrates that release volatile compounds. This review described recent advances in different control measures. We focused on the importance of integrated pest management (IPM) for bacterial wilt diseases. PMID:25762345

  6. Recent Trends in Control Methods for Bacterial Wilt Diseases Caused by Ralstonia solanacearum

    PubMed Central

    Yuliar; Nion, Yanetri Asi; Toyota, Koki

    2015-01-01

    Previous studies have described the development of control methods against bacterial wilt diseases caused by Ralstonia solanacearum. This review focused on recent advances in control measures, such as biological, physical, chemical, cultural, and integral measures, as well as biocontrol efficacy and suppression mechanisms. Biological control agents (BCAs) have been dominated by bacteria (90%) and fungi (10%). Avirulent strains of R. solanacearum, Pseudomonas spp., Bacillus spp., and Streptomyces spp. are well-known BCAs. New or uncommon BCAs have also been identified such as Acinetobacter sp., Burkholderia sp., and Paenibacillus sp. Inoculation methods for BCAs affect biocontrol efficacy, such as pouring or drenching soil, dipping of roots, and seed coatings. The amendment of different organic matter, such as plant residue, animal waste, and simple organic compounds, have frequently been reported to suppress bacterial wilt diseases. The combined application of BCAs and their substrates was shown to more effectively suppress bacterial wilt in the tomato. Suppression mechanisms are typically attributed to the antibacterial metabolites produced by BCAs or those present in natural products; however, the number of studies related to host resistance to the pathogen is increasing. Enhanced/modified soil microbial communities are also indirectly involved in disease suppression. New promising types of control measures include biological soil disinfection using substrates that release volatile compounds. This review described recent advances in different control measures. We focused on the importance of integrated pest management (IPM) for bacterial wilt diseases. PMID:25762345

  7. Myosins FaMyo2B and Famyo2 Affect Asexual and Sexual Development, Reduces Pathogenicity, and FaMyo2B Acts Jointly with the Myosin Passenger Protein FaSmy1 to Affect Resistance to Phenamacril in Fusarium asiaticum.

    PubMed

    Zheng, Zhitian; Liu, Xiumei; Li, Bin; Cai, Yiqiang; Zhu, Yuanye; Zhou, Mingguo

    2016-01-01

    We previously reported that mutations occurred in the gene myosin5 were responsible for resistance to the fungicide phenamacril in Fusarium graminearum. Here, we determined whether there is a functional link between phenamacril resistance and the myosin proteins FaMyo2B and Famyo2 in Fusarium asiaticum, which is the major causal agent of Fusarium head blight in China. We found that FaMyo2B acts jointly with FaSmy1 to affect resistance to phenamacril in F. asiaticum. We also found that FaMyo2B disruption mutant and Famyo2 deletion mutant were defective in hyphal branching, conidiation, and sexual reproduction. ΔFamyo2 also had an enhanced sensitivity to cell wall damaging agents and an abnormal distribution of septa and nuclei. In addition, the FaMyo2B and Famyo2 mutants had reduced pathogenicity on wheat coleoptiles and flowering wheat heads. Taken together, these results reveal that FaMyo2B and Famyo2 are required for several F. asiaticum developmental processes and activities, which help us better understand the resistance mechanism and find the most effective approach to control FHB. PMID:27099966

  8. Myosins FaMyo2B and Famyo2 Affect Asexual and Sexual Development, Reduces Pathogenicity, and FaMyo2B Acts Jointly with the Myosin Passenger Protein FaSmy1 to Affect Resistance to Phenamacril in Fusarium asiaticum

    PubMed Central

    Zheng, Zhitian; Liu, Xiumei; Li, Bin; Cai, Yiqiang; Zhu, Yuanye; Zhou, Mingguo

    2016-01-01

    We previously reported that mutations occurred in the gene myosin5 were responsible for resistance to the fungicide phenamacril in Fusarium graminearum. Here, we determined whether there is a functional link between phenamacril resistance and the myosin proteins FaMyo2B and Famyo2 in Fusarium asiaticum, which is the major causal agent of Fusarium head blight in China. We found that FaMyo2B acts jointly with FaSmy1 to affect resistance to phenamacril in F. asiaticum. We also found that FaMyo2B disruption mutant and Famyo2 deletion mutant were defective in hyphal branching, conidiation, and sexual reproduction. ΔFamyo2 also had an enhanced sensitivity to cell wall damaging agents and an abnormal distribution of septa and nuclei. In addition, the FaMyo2B and Famyo2 mutants had reduced pathogenicity on wheat coleoptiles and flowering wheat heads. Taken together, these results reveal that FaMyo2B and Famyo2 are required for several F. asiaticum developmental processes and activities, which help us better understand the resistance mechanism and find the most effective approach to control FHB. PMID:27099966

  9. Variability in Fusarium oxysporum from sugar beets in the United States – Final Report

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fusarium yellows can cause significant reduction in root yield, sucrose percentage and juice purity in affected sugar beets. Research in our laboratory and others on variability in Fusarium oxysporum associated with sugar beets demonstrated that isolates that are pathogenic on sugar beet can be hig...

  10. Species diversity and toxigenic potential of Fusarium graminearum complex isolates from maize fields in northwest Argentina

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Members of the Fusarium graminearum species complex (Fg complex) are the causal agents of ear rot in maize and Fusarium head blight of wheat and other small grain cereals. The potential of these pathogens to contaminate cereals with trichothecene mycotoxins is a health risk for both humans and anima...

  11. Morphological and molecular variation among species of the Fusarium dimerum species group

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The name Fusarium dimerum has been used in the past for saprotrophic fungi and opportunistic human pathogens with up to 3-septate but mostly 0- or 1-septate Fusarium-like conidia. On the basis of narrowly defined morphological characters, the varieties Pusillum, Nectrioides and Violaceum were disti...

  12. Evolution of a Secondary Metabolite Biosynthetic Gene Cluster in Fusarium by Gene Relocation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Trichothecenes are secondary metabolites produced by multiple genera of fungi, including some plant pathogenic species of Fusarium. Trichothecenes contribute to virulence of Fusarium on some plants and are considered to be mycotoxins because of their human and animal toxicity. Previous analyses of...

  13. Characterization of Fusarium head blight (FHB) resistance and deoxynivalenol accumulation in hulled and hulless winter barley

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fusarium head blight (FHB), caused by Fusarium graminearum, is one of the most serious diseases impacting the U.S. barley (Hordeum vulgare L.) industry. The mycotoxin deoxynivalenol (DON) produced by the pathogen renders grain unmarketable if concentrations exceed threshold values set for end-use m...

  14. Composition of the Fusarium graminearum species complex populations in wheat cropping environments in Southern Brazil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Fusarium graminearum species complex (FGSC) comprises several toxigenic species that cause Fusarium head blight (FHB) in wheat. In this study, high number (n=671 isolates) of pathogenic isolates (isolated from infected spikes) was obtained from a 3-year large-scale survey (2009-2011) conducted o...

  15. Identification of candidate effector proteins potentially involved in Fusarium graminearum-wheat interactions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pathogen-derived small secreted cysteine-rich proteins (SSCPs) are known to be a common source of fungal effectors that trigger resistance or susceptibility in specific host plants. This group of proteins has not been well studied in Fusarium graminearum, the primary cause of Fusarium head blight (...

  16. Effect of soil biochar amendment on wheat resistance to Fusarium head blight and mycotoxin contamination

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Mycotoxin contamination of food and feed is among the top food safety concerns. Fusarium head blight (FHB) is one of the most important diseases of wheat and other cereal grains. Fusarium graminearum, the fungal pathogen responsible for FHB, reduces crop yield and results in contamination of grain w...

  17. Npc1 is involved in sterol trafficking in the filamentous fungus Fusarium graminearum

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The ortholog of the human gene NPC1 was identified in the plant pathogenic, filamentous fungus Fusarium graminearum by shared amino acid sequence, protein domain structure and cellular localization of the mature fungal protein. The Fusarium Npc1 gene shares 34% amino acid sequence identity and 51% s...

  18. Mid-Infrared and Near-Infrared Spectroscopic Properties of Fusarium Isolates: Effects of Culture Conditions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Fusarium genus includes soil saprobes as well as pathogenic or toxin-producing species. Traditional classification of Fusarium isolates is slow and requires a high level of expertise. The objective of this project is to describe culture condition effects on mid-infrared (MidIR) and near-infrared...

  19. Acid and neutral trehalase activities in mutants of the corn rot fungus Fusarium verticillioides

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fusarium verticillioides is a fungal pathogen known to cause corn rot and other plant diseases and to contaminate grain with toxic metabolites. We are characterizing trehalose metabolism in F. verticillioides with the hope that this pathway might serve as a target for controlling Fusarium disease. T...

  20. A North American isolate of Fusarium graminearum: toxicity and biosynthesis of a new type A trichothecene

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fusarium graminearum is one of the economically most important plant pathogens causing diseases such as Fusarium Head Blight (FHB) of small grain cereals and ear rot of maize. The mycotoxin deoxynivalenol (DON) produced by F. graminearum is a virulence factor in wheat and probably also on other host...