Nonpathogenic Fusarium Oxysporum Research Articles

Endophytic non-pathogenic Fusarium oxysporum reorganizes the cell wall in flax seedlings.

Flax (Linum usitatissimum) is a crop producing valuable products like seeds and fiber. However, its cultivation faces challenges from environmental stress factors and significant yield losses due to fungal infections. The major threat is Fusarium oxysporum f.sp lini, causing fusarium wilt of flax. Interestingly, within the Fusarium family, there are non-pathogenic strains known as biocontrols, which protect plants from infections caused by pathogenic strains. When exposed to a non-pathogenic strain, flax exhibits defense responses similar to those seen during pathogenic infections. This sensitization process activates immune reactions, preparing the plant to better combat potential pathogenic strains. The plant cell wall is crucial for defending against pathogens. It serves as the primary barrier, blocking pathogen entry into plant cells. The aim of the study was to investigate the effects of treating flax with a non-pathogenic Fusarium oxysporum strain, focusing on cell wall remodeling. The infection's progress was monitored by determining the fungal DNA content and microscopic observation. The plant defense response was confirmed by an increase in the level of Pathogenesis-Related (PR) genes transcripts. The reorganization of flax cell wall during non-pathogenic Fusarium oxysporum strain infection was examined using Infrared spectroscopy (IR), determination of cell wall polymer content, and analysis of mRNA level of genes involved in their metabolism. IR analysis revealed reduced cellulose content in flax seedlings after treatment with Fo47 and that the cellulose chains were shorter and more loosely bound. Hemicellulose content was also reduced but only after 12h and 36h. The total pectin content remained unchanged, while the relative share of simple sugars and uronic acids in the pectin fractions changed over time. In addition, a dynamic change in the level of methylesterification of carboxyl groups of pectin was observed in flax seedlings treated with Fo47 compared to untreated seedlings. The increase in lignin content was observed only 48 hours after the treatment with non-pathogenic Fusarium oxysporum. Analysis of mRNA levels of cell wall polymer metabolism genes showed significant changes over time in all analyzed genes. In conclusion, the research suggests that the rearrangement of the cell wall is likely one of the mechanisms behind flax sensitization by the non-pathogenic Fusarium oxysporum strain. Understanding these processes could help in developing strategies to enhance flax's resistance to fusarium wilt and improve its overall yield and quality.

Effect of the Nonpathogenic Strain Fusarium oxysporum FO12 on Fe Acquisition in Rice (Oryza sativa L.) Plants.

Rice (Oryza sativa L.) is a very important cereal worldwide, since it is the staple food for more than half of the world's population. Iron (Fe) deficiency is among the most important agronomical concerns in calcareous soils where rice plants may suffer from this deficiency. Current production systems are based on the use of high-yielding varieties and the application of large quantities of agrochemicals, which can cause major environmental problems. The use of beneficial rhizosphere microorganisms is considered a relevant sustainable alternative to synthetic fertilizers. The main goal of this study was to determine the ability of the nonpathogenic strain Fusarium oxysporum FO12 to induce Fe-deficiency responses in rice plants and its effects on plant growth and Fe chlorosis. Experiments were carried out under hydroponic system conditions. Our results show that the root inoculation of rice plants with FO12 promotes the production of phytosiderophores and plant growth while reducing Fe chlorosis symptoms after several days of cultivation. Moreover, Fe-related genes are upregulated by FO12 at certain times in inoculated plants regardless of Fe conditions. This microorganism also colonizes root cortical tissues. In conclusion, FO12 enhances Fe-deficiency responses in rice plants, achieves growth promotion, and reduces Fe chlorosis symptoms.

Biological and Urea Treatments Reduce the Primary Inoculum of Red Leaf Blotch of Almond Caused by Polystigma amygdalinum.

Red leaf blotch (RLB), caused by Polystigma amygdalinum, is considered the most prevalent foliar disease in both traditional and new intensive almond-growing areas in Spain. Since the disease is monocyclic, its control must be based on the reduction of the only source of inoculum-the leaves infected in the previous season and fallen to the ground in autumn. Thus, this study aimed to determine the effect of two microorganisms and urea on RLB inoculum reduction by evaluating different application modes to fallen leaves in field conditions. Leaves of almond cv. Guara showing symptoms of RLB were collected in autumn, placed into nylon mesh bags, and treated by dipping or spraying with conidial suspensions of Myrothecium inundatum or the nonpathogenic strain Fusarium oxysporum FO12. The bags were exposed on the ground or buried in an experimental almond field for 6 months in each experimental year. Bags treated with crystalline urea solution at 46% N or not treated were included as controls. The primary inoculum (number of ascospores per gram of leaf) and the development of fruiting bodies (maturity stages of perithecia) were monitored in the fallen leaves for each experimental treatment combination. M. inundatum significantly reduced the primary inoculum in comparison with the nontreated control or F. oxysporum FO12, showing a similar effect to that observed for urea in the 2 experimental years. The type of application (spraying or dipping) did not show any significant effect, whereas the inoculum was significantly reduced in buried leaves in comparison with leaves maintained on the ground for all the treatments tested. This study represents the first report evaluating management strategies against RLB based on the reduction of the primary inoculum of P. amygdalinum.

Evaluation of Pseudomonas and Bacillus Strains as Potential Biocontrol Agents against Fusarium Wilt of Chickpea

Evaluation of Pseudomonas and Bacillus Strains as Potential Biocontrol Agents against Fusarium Wilt of Chickpea

Endophytic Non-Pathogenic Fusarium oxysporum-Derived Dual Benefit for Nematode Management and Improved Banana (Musa spp.) Productivity

The banana weevil (Cosmopolites sordidus) and the burrowing nematode Radopholus similis represent two of the most important pests of bananas. Previously, colonization of banana plants by the non-pathogenic Fusarium oxysporum (isolate V5w2) and the entomopathogenic Beauveria bassiana (isolate WA) have been shown to increase host resistance to various banana pests and diseases. However, there is limited data on how the combined inoculation of these isolates would affect field performance of bananas. In this study, the fungal endophytes were inoculated separately and in combination. Tissue cultured plantlets of cooking banana cultivar Mbwazirume and dessert banana cultivar Grande Naine were inoculated by root drenching with a suspension of 1.0 × 107 spores mL−1 of the endophytes on three occasions, separated 4 weeks apart, before transplanting into the field. Each plantlet was further inoculated with 1800 nematodes, composed primarily of R. similis. Inoculation of banana plants with the fungal endophytes significantly reduced nematode densities by >34%. Similarly, plant toppling was lower in the endophyte-enhanced plants (<16.5%) compared with the control (23.3%). We also observed improved yield of the first crop cycle in the endophyte-enhanced plants, which yielded >11 t ha−1 year−1 versus 9 t ha−1 year−1 achieved in the non-inoculated plants. These findings demonstrate the benefits of fungal endophytes in improving the yield of both cooking and dessert bananas via suppression of nematode densities and nematode-related damage.

Development of PCR-Based Race-Specific Markers for Differentiation of Indian Fusarium oxysporum f. sp. cubense, the Causal Agent of Fusarium Wilt in Banana.

Fusarium wilt caused by Fusarium oxysporum f. sp. cubense (Foc), is the most lethal soil-borne fungal pathogen infecting bananas. Foc race 1 (R1) and 4 (R4) are the two most predominant races affecting the economically important Cavendish group of bananas in India. A total of seven vegetative compatibility groups (VCGs) from three pathogenic races were isolated during our field survey and were found to be highly virulent towards cv. Grande Naine. According to comparative genome analyses, these Indian Foc VCGs were diverse in genomic organization and effector gene profiles. As a result, false-positive results were obtained with currently available molecular markers. In this context, the study has been initiated to develop PCR-based molecular markers for the unambiguous identification of Indian Foc R1 and R4 isolates. Whole-genome sequences of Foc R1 (GCA_011316005.3), Foc TR4 (GCA_014282265.3), and Foc STR4 (GCA_016802205.1), as well as the reference genomes of Foc (ASM799451v1) and F. oxysporum f. sp. lycopersici (Fol; ASM14995v2), were aligned to identify unique variable regions among the Foc races. Using putative chromosome and predicted gene comparison, race-specific unique Foc virulence genes were identified. The putative lineage-specific identified genes encoding products secreted in xylem (SIX) that may be necessary for disease development in the banana. An in silico analysis was performed and primers were designed from a region where sequences were dissimilar with other races to develop a specific marker for Foc R1, R4, TR4, and STR4. These race-specific markers allowed target amplification in the characterized highly virulent Foc isolates, and did not show any cross-amplification to any other Foc races, VCGs or banana pathogens, Fusarium species, and non-pathogenic Fusarium oxysporum isolates. The study demonstrated that the molecular markers developed for all the three Foc races of India could detect the pathogen in planta and up to 0.025 pg µL−1 DNA levels. Thus, the markers developed in this study are novel and could potentially be useful for the accurate diagnosis and detection of the Indian Foc races which are important for the effective management of the disease.

English

Peas are growing all over the world as a leguminous crop due to high nutrients value. Fusarium wilt of peas is a destructive disease and causing deleterious loses in pea growing regions of the world. The fields were surveyed with disease incidence of Fusarium wilt in major pea growing areas. Fields with heavy pathogen infestation and natural disease suppressive were observed at District Sahiwal, Pakistan. The samples were collected to diagnose the disease and factors responsible in the suppression of disease. The results of soil physio-chemical properties showed no significant differences between diseased and suppressive soils. Pathogenicity assays both in-vitro and pot trial showed that suppressive soil has natural ability to suppress the disease. Furthermore, in-vitro and pot assays were designed with different soil treatments to investigate the factors responsible in the natural disease suppressiveness in suppressive soil. The results demonstrated that the mechanism involved in disease suppressive soil is biotic in nature. All isolated fungal strains from diseased and healthy roots of pea were subjected to biological assays to evaluate the virulence. The assays showed that isolate SAH09 is non-pathogenic Fusarium oxysporum which was isolated from the pea roots of suppressive soil. Isolate SAH09 was used in dual culturing technique and pot trial to evaluate the mycoparastism behavior against virulent pathogenic isolates SAH03, SAH05 and SAH10. Results concluded that isolate SAH09 of non-pathogenic Fusarium oxysporum has potential to suppress the growth of all isolates of pathogenic Fusarium and possibly play the role in natural disease suppression in suppressive soils

The Non-Pathogenic Fusarium oxysporum Fo47 Induces Distinct Responses in Two Closely Related Solanaceae Plants against the Pathogen Verticillium dahliae

The non-pathogenic Fusarium oxysporum Fo47 is able to protect Capsicum annuum (pepper) but not in Solanum lycopersicum (tomato) against the pathogen Verticillium dahliae. Transcriptomics of the plant during the interaction with Fo47 shows the induction of distinct set of genes in pepper and tomato. The number of differentially expressed (DE) genes in pepper (231 DE genes) is greater than the number of DE genes in tomato (39 DE genes) at 2 days after the treatment with Fo47. Ethylene related genes were present among the DE genes in both plants, and the up-regulation of ethylene biosynthetic genes was observed to be triggered during the interaction of both plants with Fo47. The treatment with MCP (1-Methylcyclopropene, an ethylene-competitive inhibitor) reduced the Fo47 protection in pepper against Verticillium dahliae. Intriguingly, Fo47 was able to protect the ethylene-insensitive tomato mutant Never-ripe (Nr) against Verticillium dahliae, but not the tomato wilt type cv Pearson. Overall, ethylene is shown to be an important player in the response to Fo47, but its role depends on the host species.

Induced Systemic Resistance to Fusarium Root Rot and Changes in Antioxidative Ability by Arbuscular Mycorrhizal Fungus and Non-pathogenic Fusarium oxysporum in Asparagus Plants

Induced Systemic Resistance to Fusarium Root Rot and Changes in Antioxidative Ability by Arbuscular Mycorrhizal Fungus and Non-pathogenic Fusarium oxysporum in Asparagus Plants

The development of a multiplex PCR assay for the detection of Fusarium oxysporum f. sp. cubense lineage VI strains in East and Central Africa

Banana is a staple food and cash crop grown in East and Central Africa (ECA). The main banana varieties grown in ECA are the East African highland bananas (EAHB), although dessert/beer bananas such as Sukari Ndizi, Kayinja (Pisang Awak) and Gros Michel are also produced due to their high value at local markets. The Fusarium wilt fungus Fusarium oxysporum f. sp. cubense (Foc) causes disease of susceptible dessert/beer bananas, which significantly reduces yields. Banana Fusarium wilt is managed by excluding the pathogen from disease-free areas and by planting disease-resistant varieties in infested fields. Six phylogenetically closely-related vegetative compatibility groups (VCGs) of Foc, VCGs 0124, 0125, 0128, 01212, 01220 and 01222 are present in ECA, which all group together in Foc Lineage VI. Rapid and accurate detection of Foc Lineage VI strains is thus important to prevent its spread to disease-free areas. In this study, molecular markers specific to Foc Lineage VI were therefore developed. Primer sets were then combined in a multiplex PCR assay, and validated on a worldwide population of 623 known Foc isolates, other formae speciales and non-pathogenic Fusarium oxysporum isolates. The Foc Lineage VI multiplex PCR was used to identify Foc isolates collected in banana fields at five locations in Uganda and Tanzania. Foc Lineage VI DNA was detected at a concentration as low as 0.1 ng/μl, both in the absence and presence of banana DNA, and can therefore be used as an accurate diagnostic tool for Foc Lineage VI strains.

Non-pathogenic Fusarium oxysporum as a biocontrol agent

Non-pathogenic Fusarium oxysporum are endophytes which can suppress disease development by pathogenic F. oxysporum isolates through plant growth promotion and local as well as systemic induced resistance. Competition for space and nutrients, production of secondary metabolites and induction of resistance are their different modes of action against pathogens. These have been reported to be compatible with biocontrol agents and selected fungicides. They were reported to be evolved from pathogenic isolates and transfer of specific genes encoding pathogenicity can convert them to pathogenic forms. There is the possibility of rapid emergence of new pathogenic lineages in distinct non-pathogenic strains by simple co-cultivation with pathogenic strains. Detailed studies are required to undermine the genes and the pathways involved in their antagonistic as well as plant growth promoting potential. This review paper attempts to describe various aspects of non-pathogenic F. oxysporum isolates and the possible threats in their usage as biocontrol agents.

Characterization of Pathogenic and Nonpathogenic Fusarium oxysporum Isolates Associated with Commercial Tomato Crops in the Andean Region of Colombia.

In Colombia, tomato production under protected conditions represents an important economic contribution to the agricultural sector. Fusarium wilt diseases, caused by pathogenic formae speciales of the soil-borne fungus Fusarium oxysporum Schltdl., cause significant yield losses in tomatoes throughout the world. Investigation of the F. oxysporum–tomato pathosystem in Colombia is required to develop appropriate alternative disease management. In this study, 120 fungal isolates were obtained from four different departments in the Central Andean Region in Colombia from tomato crops with symptoms of wilt disease. A molecular characterization of the fungal isolates was performed using the SIX1, SIX3, and SIX4 effector genes of Fusarium oxysporum f. sp. lycopersici W.C. Snyder & H.N. Hansen (Fol). Additionally, we developed a new specific marker to distinguish between Fusarium oxysporum f. sp. radicis-lycopersici Jarvis & Shoemaker (Forl) and Fol isolates. Furthermore, a phylogenetic analysis using the Translation Elongation Factor 1-alpha (EF1a) gene was performed with the collected isolates. Two isolates (named Fol59 and Fol-UDC10) were identified as Fol race 2, four isolates were identified as Forl, six isolates were identified as F. solani, and most of the isolates were grouped within the F. oxysporum species complex. The phylogenetic tree of EF1a showed that most of the isolates could potentially correspond to nonpathogenic strains of F. oxysporum. Additional pathogenicity assays carried out with Fol59 and Fol-UDC10 confirmed that both isolates were highly virulent strains. This study represents a contribution to the understanding of the local interaction between tomatoes and F. oxysporum in Colombia.

Seleksi Komposisi Medium Pertumbuhan dan Bahan Pembawa untuk Formulasi Cendawan Agens Hayati Fusarium oxysporum Non-Patogenik P21a

Selection of Compositions of Growth Medium and Carriers for Formulation of Biological Agents of Non-Pathogenic Fusarium oxysporum P21aThe potency of non-pathogenic Fusarium oxysporum P21a (NPFo P21a) as a biological control agent has prospect to be developed commercially. The growth medium and carrier are the critical factor to formulate biological control. This study aimed to obtain the best solid medium dan lighting type for mycelium growth and sporulation as well as to determine the carrier and storage temperature which is suitable for NPFo P21a toward the survival of propagule and germination of shallot. The results showed that M2 medium treatment (rice grain:rice bran; 20:1 w/w) was the best medium for mycelium growth. The M3 medium treatment (20:2 w/w) was the best medium for sporulation of NPFo P21a. The near-UV lighting treatment was able to stimulate the macroconidium production of NPFo P21a. Talc-based formulation and the storage at 20 °C showed the best shelf-life for NPFo P21a with density of viable propagule and shallot germination better.

DNA Methylation Profile of β-1,3-Glucanase and Chitinase Genes in Flax Shows Specificity Towards Fusarium Oxysporum Strains Differing in Pathogenicity.

Most losses in flax (Linum usitatissimum L.) crops are caused by fungal infections. The new epigenetic approach to improve plant resistance requires broadening the knowledge about the influence of pathogenic and non-pathogenic Fusarium oxysporum strains on changes in the profile of DNA methylation. Two contrasting effects on the levels of methylation in flax have been detected for both types of Fusarium strain infection: Genome-wide hypermethylation and hypomethylation of resistance-related genes (β-1,3-glucanase and chitinase). Despite the differences in methylation profile, the expression of these genes increased. Plants pretreated with the non-pathogenic strain memorize the hypomethylation pattern and then react more efficiently upon pathogen infection. The peak of demethylation correlates with the alteration in gene expression induced by the non-pathogenic strain. In the case of pathogen infection, the expression peak lags behind the gene demethylation. Dynamic changes in tetramer methylation induced by both pathogenic and non-pathogenic Fusarium strains are dependent on the ratio between the level of methyltransferase and demethylase gene expression. Infection with both Fusarium strains suppressed methyltransferase expression and increased the demethylase (demeter) transcript level. The obtained results provide important new information about changes in methylation profile and thus expression regulation of pathogenesis-related genes in the flax plant response to stressors.

The Role of Volatile Organic Compounds and Rhizosphere Competence in Mode of Action of the Non-pathogenic Fusarium oxysporum FO12 Toward Verticillium Wilt.

Verticillium wilts caused by Verticillium spp. are among the most challenging plant diseases to control and affect numerous hosts worldwide. Due to the lack of effective, conventional control methods, integrated control strategies provide a promising approach to manage these diseases. The non-pathogenic Fusarium oxysporum strain FO12 was reported in previous studies to be an effective biocontrol agent against Verticillium dahliae, however, its mode of action remains to be elucidated. In this study, complementary in vitro and in vivo experiments were conducted in order to explore the implications of inhibitory substances and rhizosphere competence in antagonistic effects of FO12 against V. dahliae and V. longisporum. Volatile organic compounds and soluble substances produced by FO12, which caused significant inhibition of mycelial growth and microsclerotia viability in the two tested Verticillium species, were identified by means of gas and liquid chromatography-mass spectrometry. We showed that the antagonistic effect of F. oxysporum FO12 is partially due to the production of bioactive compounds such as 3-methyl-1-butanol and 2-methyl-1-butanol, among others. Several metabolic pathways of FO12 were altered upon contact with V. dahliae ELV22 volatiles. The reduced production of alpha, alpha-trehalose, a metabolite used in starch and sucrose metabolism, suggests that the biocontrol agent activates its stress response in the presence of the phytopathogen. Microscopic analysis using sGFP-tagged FO12 on oil seed rape as a model plant suggests that the biocontrol strain is an efficient root colonizer, which could compete with V. dahliae in the same ecological niche. The findings obtained in this study provide new insights into the mode of action of this potential biocontrol agent, which are relevant for controlling Verticillium wilt through an ecologically friendly approach.

A non-pathogenic strain of Fusarium oxysporum as a potential biocontrol agent against Verticillium wilt of olive

The non-pathogenic Fusarium oxysporum FO12 strain isolated from cork (Quercus suber) was one of the most effective treatments against Verticillium dahliae from among more than 200 natural compounds evaluated in previous studies. Based on the results of previous work, the present study aims to determine the potential of FO12 as a biological control agent against Verticillium wilt of olive (VWO). To this end, several in vitro and in vivo experiments were carried out to evaluate the effectiveness of FO12 against V. dahliae. Dual cultures were conducted, showing a significant reduction in the mycelial growth of V. dahliae. However, inhibition zones were not observed in vitro. Four different culture fractions of FO12 were prepared to evaluate their effect on the reduction of viable propagules of V. dahliae in soil and on the disease progression in inoculated plants. Treatments with crude culture broth of FO12 resulted in a total reduction of the inoculum density of V. dahliae in naturally infested soils as well as in the progression of VWO under controlled conditions. Treatments with conidial suspension or chlamydospores were also effective in reducing the inoculum density in the soil and the disease severity in olive plants. This work provides useful information about the efficacy of several FO12-based culture fractions against VWO under controlled conditions, which could be the basis for the development of effective commercial formulations in the coming future.

Antiviral and Antifungal Activity of Biologically Active Recombinant Bouganin Protein from Bougainvillea spectabilis Willd

Bo uganin antiviral protein (BAP) gene, one of the ribosome inactivating proteins, isolated from Bougainvillea spectabilis Willd. was cloned, expressed and the antiviral and antifungal activities were investigated. The full-length bouganin antiviral protein gene was amplified by reverse transcription-PCR using mRNA as template extracted from mature leaves. The coding region of bouganin gene was cloned into prokaryotic expression vector pETDuet-1 after amplification with end to end gene specific primers. The recombinant plasmid was transformed into Escherichia coli cells BL21(DE3)pLysS and the expression of BAP gene was induced by isopropyl β-D thiogalactopyranoside (IPTG). Bouganin antiviral protein having a molecular mass of 28 kDa has been isolated from transformed bacterial colonies. Antiviral activity of bouganin was assayed against Zucchini yellow mosaic virus (ZYMV) by a mechanical inoculation test. The antifungal activity of purified recombinant protein was tested against pathogenic and non-pathogenic Rhizoctonia solani, Trichoderma harzianum, and Fusarium oxysporum fungi using disc diffusion method. The increased amount of antiviral protein reduced the disease severity caused by ZYMV. The bouganin antiviral protein was inhibited the growth of R. solani by 30.7% and of T. harzianum by 20% after 72 h compared to control. No growth inhibition was observed for F. oxyporum. All plants including controls treated with in vitro expressed BAP protein exhibited severe growth reduction compared with negative control (not treated) plants.

Suppression of plant wilt diseases by nonpathogenic Fusarium oxysporum Fo47 combined with actinomycete strains

ABSTRACTIn order to build integrated strains with superior growth-promoting and disease-suppression effects, the biological control efficacy of Fo47 solid agents combined with actinomycetes strains toward Fusarium oxysporum and Verticillium dahliae were investigated in experiments on watermelon, cotton and eggplant. Five actinomycetes strains were prepared by solid fermentation. The count of viable solid agents, initially with propagules at 107–1011 CFU/g, slowly decreased after being stored one year at room temperature. After being inoculated into sterile soil for 50 days, the viable count of strain Fo47 remained at a stable level. The suppressive effects of Fo47 combined with strain QLP12 on Fusarium wilt on watermelon and cotton, and Verticillium wilt on eggplant, reaching 58.47%, 50.73% and 58.82%, respectively. This was significantly better than the single strain Fo47 alone, and growth of these treated plants and the colonisation rate of Fo47 were increased substantially as well. These results indicate that solid integrated agents with a high viability count and superior stability in soil could increase disease suppression and promote plant growth by synergy with different strains. The increased suppression obtained by Fo47 combined with actinomycete strains was not due to a simple addition of different mechanisms of biocontrol agents. By being intelligently integrated, these combinations increase disease suppression and provide the best biocontrol effect.

Ability of Non-Pathogenic Fusarium oxysporum Strain Fo47 to Suppress Rhizomania Disease of Sugar Beets in Morocco

Rhizomania is one of the most devastating diseases of sugar beet worldwide. The disease poses a serious threat to Moroccan production and it is capable of significantly decreasing quality and yield of sugar beet plantations. The long-term survival of its fungal vector (Polymyxa betae) in soil makes it a very difficult disease to manage. Therefore, this study investigated the potential of a non-pathogenic fungal Fusarium oxysporum strain Fo47 to control Polymyxa betae. This biocontrol agent was applied as soil treatment, seed treatment, or a combination of the both treatments. A bio-test was performed on treated soil. After four weeks of culture, the roots of sugar beet seedlings were retrieved and analyzed by the DAS-ELISA test. Results indicated that F. oxysporium Fo47 reduced the activity and survival of P. betae when compared to a reference biocontrol agent Trichoderma harzianum, which only revealed significant in reducing the viral load of Beet Necrotic Yellow Vein Virus (BNYVV) as seed treatment. The non-pathogenic Fusarium oxysporum Fo47 was more effective as soil treatment and allowed almost the same reduction of BNYVV virus concentration as T. harzianum 908. Therefore, our findings emphasizes that the performance of the biocontrol agent depends on the method of application.

OPTIMIZATION OF PROTEIN ISOLATION AND PRELIMINARY COMPARATIVE PROTEOMICS OF PATHOGENIC FUSARIUM OXYSPORUM f. sp. CUBENSE (P-FOC) AND NON PATHOGENIC FUSARIUM OXYSPORUM (np-FO)

Panama wilt of banana caused by F. oxysporum f. sp. cubense (Foc) is a devastating disease of banana and in severe condition causes 100% yield loss. In order to understand the molecular mechanism of pathogenicity for the effective management of the wilt disease, three protocols (MgCl2/CHAPS, TCA-Acetone and TCA/Phenol-SDS) were evaluated to extract protein from Foc mycelial tissue. Comparatively, TCA/Phenol-SDS method of protein precipitation and extraction resulted in maximum protein quantity (0.76±0.025 mg/g of mycelial tissue) and ca.600 spots were identified in CBB stained gels. A comparative proteomic study conducted between pathogenic F. oxysporum f. sp. cubense (P-Foc) (race 1, VCG 0124) and non-pathogenic Fusarium oxysporum (np-Fo) revealed a difference at the proteome level. In the comparative proteomics study, 23 spots were found to be differentially expressed with ≥ 1.5 fold intensity differences between P-Foc and np-Fo. Preliminarily, six spots (5 significantly upregulated and 1 unique proteins) from P-Foc was randomly picked and subjected to MALDITOF/MS analysis. Further, MASCOT search and functional annotation revealed that these up regulated proteins identified in P-Foc may be involved in invasive growth, signal transduction and pathogen persistence during adverse condition.