Tomatinase from Fusarium oxysporum f. sp. lycopersici Is Required for Full Virulence on Tomato Plants

Saponin detoxification enzymes from pathogenic fungi are involved in the infection process of their host plants. Fusarium oxysporum f. sp lycopersici, a tomato pathogen, produces the tomatinase enzyme Tom1, which degrades α-tomatine to less toxic derivates. To study the role of the tom1 gene in the virulence of F. oxysporum, we performed targeted disruption and overexpression of the gene. The infection process of tomato plants inoculated with transformants constitutively producing Tom1 resulted in an increase of symptom development. By contrast, tomato plants infected with the knockout mutants showed a delay in the disease process, indicating that Tom1, although not essential for pathogenicity, is required for the full virulence of F. oxysporum. Total tomatinase activity in the disrupted strains was reduced only 25%, leading to β2-tomatine as the main hydrolysis product of the saponin in vitro. In silico analysis of the F. oxysporum genome revealed the existence of four additional putative tomatinase genes with identities to tomatinases from family 3 of glycosyl hydrolases. These might be responsible for the remaining tomatinase activity in the Δtom1 mutants. Our results indicate that detoxification of α-tomatine in F. oxysporum is carried out by several tomatinase activities, suggesting the importance of these enzymes during the infection process.

Download Full-text

A Composite Bioinoculant Based on the Combined Application of Beneficial Bacteria and Fungi

Agronomy ◽

10.3390/agronomy10020220 ◽

2020 ◽

Vol 10 (2) ◽

pp. 220 ◽

Cited By ~ 2

Author(s):

Henrietta Allaga ◽

Bettina Bóka ◽

Péter Poór ◽

Viktor Dávid Nagy ◽

Attila Szűcs ◽

...

Keyword(s):

Nitrogen Fixation ◽

Plant Pathogens ◽

Azotobacter Vinelandii ◽

Pathogenic Fungi ◽

Screening Strategy ◽

Plant Residues ◽

Beneficial Bacteria ◽

Tomato Plants ◽

Bacteria And Fungi

A composite soil bioinoculant containing beneficial bacteria and fungi was developed for biocontrol of plant pathogens, phosphorous mobilization, stem degradation, humification, and nitrogen fixation. A Trichoderma asperellum isolate with outstanding in vitro antagonistic abilities toward a series of plant pathogenic fungi was included as a potential biocontrol component. The selected strain was also shown to promote growth and increase photosynthetic activity of tomato plants. For phosphorous mobilization and stem degradation, a Trichoderma atrobrunneum strain was selected, which produced cellulose-degrading enzymes even in the absence of stem residues, while this ability increased 10–15-fold in the presence of ground maize stem. The strain was also shown to produce large amounts of enzymes liberating organically bound phosphorous, as well as cellulase and xylanase activities in solid-state fermentation on various plant residues. A Streptomyces albus strain with excellent peroxidase-producing abilities was selected as a potential humus-producing component, while an Azotobacter vinelandii strain with the potential to provide excess nitrogen for crops was included for nitrogen fixation. The assembled soil bioinoculant had positive effect on the uptake of certain important macro- and microelements (potassium, sodium, and manganese) from the soil by field-grown tomato plants. The applied screening strategy proved to be applicable for the assembly of a composite soil bioinoculant with notable application potentials.

Download Full-text

Functional Analyses of Laccase Genes from Fusarium oxysporum

Phytopathology ◽

10.1094/phyto-98-5-0509 ◽

2008 ◽

Vol 98 (5) ◽

pp. 509-518 ◽

Cited By ~ 34

Author(s):

D. Cordoba Cañero ◽

M. I. G. Roncero

Keyword(s):

Fusarium Oxysporum ◽

Phenol Oxidase ◽

Infection Process ◽

Copper Binding ◽

Tomato Plants ◽

Extracellular Laccase ◽

Polymerase Chain ◽

Laccase Genes ◽

Functional Analyses ◽

Targeted Inactivation

Six laccase genes, lcc1, lcc2, lcc3, lcc4, lcc5, and lcc9, of the vascular wilt fungus Fusarium oxysporum were isolated and characterized. All genes have the characteristic conserved domains for copper binding of phenol oxidase enzymes. Targeted inactivation of lcc1, lcc3, and lcc5 resulted in a significant decrease of extracellular laccase activity. Reverse transcription-polymerase chain reaction showed that lcc1, lcc2, and lcc9 were constitutively expressed in culture, whereas lcc3 and lcc5 appeared down and up-regulated, respectively, by PacC. Oxidative stress conditions and phenolic compounds altered the growth rate of the Δlcc3 mutant compared with the wild-type. lcc1, lcc3, and lcc9 were expressed in roots and stems during the infection process. However, inactivation of lcc1, lcc3, and lcc5 had no detectable effects on virulence on tomato plants.

Download Full-text

Antifungal activity of saponins originated from Medicago hybrida against some ornamental plant pathogens

Acta Agrobotanica ◽

10.5586/aa.2006.061 ◽

2012 ◽

Vol 59 (2) ◽

pp. 51-58 ◽

Cited By ~ 9

Author(s):

Alicja Saniewska ◽

Anna Jarecka ◽

Zbigniew Biały ◽

Marian Jurzysta

Keyword(s):

Antifungal Activity ◽

Fusarium Oxysporum ◽

Botrytis Cinerea ◽

Plant Pathogens ◽

Pathogenic Fungi ◽

Ornamental Plant ◽

Mycelium Growth ◽

Medicagenic Acid ◽

Fungitoxic Effect

Antifungal activity of total saponins originated from roots of Medicago hybrida (Pourret) Trautv. were evaluated in vitro against six pathogenic fungi and eight individual major saponin glycosides were tested against one of the most susceptible fungi. The total saponins showed fungitoxic effect at all investigated concentrations (0.01%, 0.05% and 0.1%) but their potency was different for individual fungi. The highest saponin concentration (0.1%) was the most effective and the inhibition of Fusarium oxysporum f. sp. callistephi, Botrytis cinerea, Botrytis tulipae, Phoma narcissi, Fusarium oxysporum f. sp. narcissi was 84.4%, 69.9%, 68.6%, 57.2%, 55.0%, respectively. While Fusarium oxysporum Schlecht., a pathogen of Muscari armeniacum, was inhibited by 9.5% only. Eight major saponin glycosides isolated from the total saponins of M. hybrida roots were tested against the mycelium growth of Botrytis tulipae. The mycelium growth of the pathogen was greatly inhibited by hederagenin 3-O-β-D-glucopyranoside and medicagenic acid 3-O-β-D-glucopyranoside. Medicagenic acid 3-O-β-D-glucuronopyranosyl-28-O-β-D-glucopyranoside and oleanolic acid 3-O-[β-D-glucuronopyranosyl(1→2)-α-L-galactopyranosyl]-28-O-β-D-glucopyranoside showed low fungitoxic activity. Medicagenic acid 3-O-a-D-glucopyranosyl- 28-O-β-D-glucopyranoside, hederagenin 3-O-[α-L- hamnopyranosyl(1→2)-β-D-glucopyranosyl(1→2)-β-D-glucopyranosyl]- 28-O-α-D-glucopyranoside and hederagenin 3-O-β-D-glucuronopyranosyl-28-O-β-D- lucopyranoside did not limit or only slightly inhibited growth of the tested pathogen. While 2β, 3β-dihydroxyolean-12 ene-23-al-28-oic acid 3-O-β-D-glucuronopyranosyl-28-O-β-D-glucopyranoside slightly stimulated mycelium growth of B. tulipae.

Download Full-text

The biological activity of subspecies Trichoderma harzianum against Fusarium oxysporum, the causative agent of fusarium wilt cucumber in vitro

BIO Web of Conferences ◽

10.1051/bioconf/20202100021 ◽

2020 ◽

Vol 21 ◽

pp. 00021

Author(s):

Ninel Pavlovskaya ◽

Irina Gneusheva ◽

Irina Solokhina ◽

Natalya Ageeva

Keyword(s):

Biological Activity ◽

Fusarium Oxysporum ◽

Trichoderma Harzianum ◽

Pathogenic Fungi ◽

Chitinase Activity ◽

Lytic Enzymes ◽

Growth Promoting ◽

Phytopathogenic Microorganisms ◽

Trichoderma Lixii

The study of the effect of the strains of the fungus Trichoderma: Trichoderma atrobrunneum VKPM F-1434, Trichoderma harzianum 5/14, Trichoderma Lixii T4/14 on the number of micromycetes populations of the pathogenic fungi Fusarium oxysporum isolate B/14, Fusarium oxysporum isolate MOS509, Fysarium oxysporum isolate IMI58289 in vitro. It was found that the Trichoderma atrobrunneum fungus strain VKPM F-1434 showed the highest degree of inhibition on 10 days of cultivation with phytopathogenic microorganisms, which was 100 %. The study revealed that all Trichoderma species are capable of producing lytic enzymes. Trichoderma atrobrunneum strain VKPM F-1434 exhibits strong lipase and chitinase activity and average proteinase activity. In addition, Trichoderma atrobrunneum strain VKPM F-1434 has a growth-promoting ability, which was reflected in the germination of seeds of cucumber “German F1”. The maximum values of indicators of germination energy were noted – 98.4 % and germination – 100 %.

Download Full-text

Fusarium oxysporum (F221-B) as biocontrol agent against plant pathogenic fungi in vitro and in hydroponics

Plant Protection Science ◽

10.17221/59/2016-pps ◽

2017 ◽

Vol 53 (No. 2) ◽

pp. 85-95 ◽

Cited By ~ 8

Author(s):

Thongkamngam Titi ◽

Jaenaksorn Tanimnun

Keyword(s):

Fusarium Oxysporum ◽

Fungal Pathogens ◽

Biocontrol Agent ◽

Disease Incidence ◽

Pathogenic Fungi ◽

Curvularia Lunata ◽

Plant Growth Promoting ◽

Healthy Control ◽

Further Development

Efficacy of non-pathogenic Fusarium oxysporum (F221-B) was assessed as a possible biocontrol agent against fungal pathogens, namely Curvularia lunata (C11, C12), F. semitectum (F113), F. oxysporum f.sp. lactucae (F221-R, F442-G), Rhizoctonia solani (R11, R12), Rhizoctonia sp. (R111, R112, R113) in vitro, while F221-B showed a moderate ability to inhibit the mycelial growth of tested fungi about 36–56%. Then, F221-B was further evaluated for its ability of controlling lettuce root rot and wilt caused by F442-G in hydroponics. It was revealed that F221-B reduced disease incidence and severity about 60–80% compared to the inoculated control and significantly promoted the growth of 3 lettuce varieties. Interestingly, using only F221-B gave the significantly highest fresh weight (twice over the healthy control). Conclusively, this study provides an important suggestion for further development of F221-B since it showed the ability of biocontrol agent and plant growth promoting fungus.

Download Full-text

A pair of effectors encoded on a conditionally dispensable chromosome of Fusarium oxysporum suppress host-specific immunity

Communications Biology ◽

10.1038/s42003-021-02245-4 ◽

2021 ◽

Vol 4 (1) ◽

Author(s):

Yu Ayukawa ◽

Shuta Asai ◽

Pamela Gan ◽

Ayako Tsushima ◽

Yasunori Ichihashi ◽

...

Keyword(s):

Arabidopsis Thaliana ◽

Fusarium Oxysporum ◽

Host Specificity ◽

Pathogenic Fungi ◽

Plant Pathogenic Fungi ◽

Effector Genes ◽

Dispensable Chromosome ◽

Genes Encoding ◽

Insight Into

AbstractMany plant pathogenic fungi contain conditionally dispensable (CD) chromosomes that are associated with virulence, but not growth in vitro. Virulence-associated CD chromosomes carry genes encoding effectors and/or host-specific toxin biosynthesis enzymes that may contribute to determining host specificity. Fusarium oxysporum causes devastating diseases of more than 100 plant species. Among a large number of host-specific forms, F. oxysporum f. sp. conglutinans (Focn) can infect Brassicaceae plants including Arabidopsis (Arabidopsis thaliana) and cabbage. Here we show that Focn has multiple CD chromosomes. We identified specific CD chromosomes that are required for virulence on Arabidopsis, cabbage, or both, and describe a pair of effectors encoded on one of the CD chromosomes that is required for suppression of Arabidopsis-specific phytoalexin-based immunity. The effector pair is highly conserved in F. oxysporum isolates capable of infecting Arabidopsis, but not of other plants. This study provides insight into how host specificity of F. oxysporum may be determined by a pair of effector genes on a transmissible CD chromosome.

Download Full-text

The effect of chitosan on limitation of growth and development of some pathogenic fungi for ornamental plants

Acta Agrobotanica ◽

10.5586/aa.2001.002 ◽

2013 ◽

Vol 54 (1) ◽

pp. 17-29 ◽

Cited By ~ 2

Author(s):

Alicja Saniewska

Keyword(s):

Fusarium Oxysporum ◽

Inhibitory Action ◽

Marked Effect ◽

Ornamental Plants ◽

Pathogenic Fungi ◽

Inhibitory Effect ◽

Crab Shell ◽

Necrotic Spots ◽

Tulip Bulbs

The inhibitory effect of crab-shell chitosan, medium (200-800 cps) and high molecular weight ( 800-2000 cps) (purchased from Sigma-Aldrich Chemicals) toward Alternaria alternata, Botrytis tulipae, Fiisarium oxysporum f. sp. callistephi, Fusarium oxysporum f. sp. tulipae, Phoma narcissi and Phoma poolensis was evaluated in vitro and in vivo. The chitosan evidently inhibited in vitro growth of all tested pathogens, with a marked effect at higher concentrations above 200 μg/cm3. Chitosan at a concentration of 1,25; 2,5 and 5,0 mg/cm3 didn't have inhibitory action in appearance of fungi growth on naturally contaminated Callistephus chinensis seeds. At the same concentrations, chitosan applied as bulb scales dressing of Hymenocallis narcissiflora bulbs, before inoculation or after inoculation with Phoma narcissi, inhibited the development of necrotic spots on scales. Chitosan used preventively or curatively at a concentrations of 1,25; 2,5 and 5,0 mg/cm3 indicated inhibitory effect on development of Fusarium oxysporum f. sp. tulipae on tulip bulbs. Chitosan at a concentration of 10 mg/cm3 applied preventively (first spray 12th June) was very effective in the control of Puccinia antirrhini on snapdragon in the field. The strongest inhibitory effect was observed on snapdragon treated 8 times at week intervals.

Download Full-text

ANTAGONISTIC TEST OF RIAU LOCAL FUNGAL ISOLATES AGAINST SOME PATHOGENIC IN CULTIVATED PLANTS

AL-Kauniyah Jurnal Biologi ◽

10.15408/kauniyah.v12i2.8730 ◽

2019 ◽

Vol 12 (2) ◽

pp. 124-132

Author(s):

Nia Safitri ◽

Atria Martina ◽

Rodesia Mustika Roza

Keyword(s):

Fusarium Oxysporum ◽

Crop Production ◽

Plant Pathogens ◽

Pathogenic Fungi ◽

Culture Method ◽

Antagonistic Activity ◽

Cultivated Plants ◽

Dual Culture ◽

Trichoderma Sp

Tanaman budi daya merupakan tanaman yang sering diserang oleh cendawan pathogen, sehingga mengakibatkan penurunan populasi dan produksi tanaman. Pengendalian hayati dengan cendawan antagonis merupakan salah satu metode yang paling efektif dan lebih ramah lingkungan dalam menekan pertumbuhan patogen tanaman. Penelitian ini bertujuan untuk menguji aktivitas antagonis cendawan isolat lokal Riau terhadap beberapa cendawan patogen pada tanaman budi daya. Uji antagonis dilakukan secara in vitro dengan metode dual culture menggunakan lima belas cendawan isolat lokal Riau terhadap Fusarium oxysporum f.sp. lycopersici, Ganoderma philippii, G. boninense, Rigidoporus microporus dan Colletotrichum sansevieria. Hasil penelitian menunjukkan bahwa Trichoderma sp. PNE 4 memiliki aktivitas antagonis tertinggi dan isolat FER C1 serta isolat LLB07 hanya memiliki aktivitas antagonis yang tinggi dalam menekan pertumbuhan cendawan patogen. Trichoderma sp. PNE 4 mampu menghambat pertumbuhan miselium F. oxysporum sebesar 85,30%, G. Philippii (100%), G. boninense (100%), dan C. sansevieria (100%). Isolat FER C1 hanya menghambat R. Microporus (50,39%) dan isolat LLB07 menghambat G. philippii (52,20%). Trichoderma sp. PNE 4 merupakan cendawan uji yang terpilih sebagai cendawan antagonis, karena memiliki kemampuan daya hambat >70%.Abstract Cultivated plants are often attacked by pathogenic fungi resulting in a decline of population and crop production. Biocontrol with antagonistic fungi is one of the most effective and environmentally friendly methods in suppressing the growth of plant pathogens. This study aims to examine the antagonistic activity of local isolates fungi Riau against some pathogenic fungi on cultivated plants. The antagonistic test was performed in vitro by dual culture method using fifteen local isolates fungal Riau against Fusarium oxysporum f.sp. lycopersici, Ganoderma philippii, G. boninense, Rigidoporus microporus and Colletotrichum sansevieria. The results showed that Trichoderma sp. PNE 4 isolate exhibited highest activites and FER C1 and LLB07 isolates exhibited high activities suppressed the growth of the fungal pathogen. Trichoderma sp. PNE 4 isolate inhibited mycelial growth F. oxysporum (85.30%), G. philippii (100%), G. boninense (100%) and C. sansevieria (100%). FER C1 isolate only inhibited R. microporus (50.39%), and LLB07 isolate inhibited G. philippii (52.20%). Trichoderma sp. PNE 4 isolate is test isolates as fungal antagonistic.

Download Full-text

SUMOylation in Human Pathogenic Fungi: Role in Physiology and Virulence

Journal of Fungi ◽

10.3390/jof6010032 ◽

2020 ◽

Vol 6 (1) ◽

pp. 32

Author(s):

Mahima Sagar Sahu ◽

Sandip Patra ◽

Kundan Kumar ◽

Rupinder Kaur

Keyword(s):

Protein Modification ◽

Sequence Similarity ◽

In Silico Analysis ◽

Pathogenic Fungi ◽

Mammalian Host ◽

Nuclear Pore ◽

Yeast Saccharomyces Cerevisiae ◽

Pathogenic Yeast ◽

Sumo Conjugation

The small ubiquitin-related modifier (SUMO) protein is an important component of the post-translational protein modification systems in eukaryotic cells. It is known to modify hundreds of proteins involved in diverse cellular processes, ranging from nuclear pore dynamics to signal transduction pathways. Owing to its reversible nature, the SUMO-conjugation of proteins (SUMOylation) holds a prominent place among mechanisms that regulate the functions of a wide array of cellular proteins. The dysfunctional SUMOylation system has been associated with many human diseases, including neurodegenerative and autoimmune disorders. Furthermore, the non-pathogenic yeast Saccharomyces cerevisiae has served as an excellent model to advance our understanding of enzymes involved in SUMOylation and proteins modified by SUMOylation. Taking advantage of the tools and knowledge obtained from the S. cerevisiae SUMOylation system, research on fungal SUMOylation is beginning to gather pace, and new insights into the role of SUMOylation in the pathobiology of medically important fungi are emerging. Here, we summarize the known information on components of the SUMOylation machinery, and consequences of overexpression or deletion of these components in the human pathogenic fungi, with major focus on two prevalent Candida bloodstream pathogens, C. albicans and C. glabrata. Additionally, we have identified SUMOylation components, through in silico analysis, in four medically relevant fungi, and compared their sequence similarity with S. cerevisiae counterparts. SUMOylation modulates the virulence of C. albicans and C. glabrata, while it is required for conidia production in Aspergillus nidulans and A. flavus. In addition to highlighting these recent developments, we discuss how SUMOylation fine tunes the expression of virulence factors, and influences survival of fungal cells under diverse stresses in vitro and in the mammalian host.

Download Full-text

Cloning and Disruption of pgx4 Encoding an In Planta Expressed Exopolygalacturonase from Fusarium oxysporum

Molecular Plant-Microbe Interactions ◽

10.1094/mpmi.2000.13.4.359 ◽

2000 ◽

Vol 13 (4) ◽

pp. 359-365 ◽

Cited By ~ 57

Author(s):

F. I. García-Maceira ◽

Antonio Di Pietro ◽

M. Isabel G. Roncero

Keyword(s):

Amino Acid ◽

Fusarium Oxysporum ◽

Vascular Tissue ◽

Single Copy ◽

Gene Replacement ◽

Amino Acid Sequences ◽

In Planta ◽

Calculated Molecular Mass ◽

Tomato Plants

Fusarium oxysporum f. sp. lycopersici, the causal agent of tomato vascular wilt, produces an array of pectinolytic enzymes, including at least two exo-α1,4-polygalac-turonases (exoPGs). A gene encoding an exoPG, pgx4, was isolated with degenerate polymerase chain reaction primers derived from amino acid sequences conserved in two fungal exoPGs. pgx4 encodes a 454 amino acid polypeptide with nine potential N-glycosylation sites and a putative 21 amino acid N-terminal signal peptide. The deduced mature protein has a calculated molecular mass of 47.9 kDa, a pI of 8.0, and 51 and 49% identity with the exoPGs of Cochliobolus carbonum and Aspergillus tubingensis, respectively. The gene is present in a single copy in different formae speciales of F. oxysporum. Expression of pgx4 was detected during in vitro growth on pectin, polygalacturonic acid, and tomato vascular tissue and in roots and stems of tomato plants infected by F. oxysporum f. sp. lycopersici. Two mutants of F. oxy-sporum f. sp. lycopersici with a copy of pgx4 inactivated by gene replacement were as virulent on tomato plants as the wild-type strain.

Download Full-text