scholarly journals Role of the White Collar 1 Photoreceptor in Carotenogenesis, UV Resistance, Hydrophobicity, and Virulence of Fusarium oxysporum

2008 ◽  
Vol 7 (7) ◽  
pp. 1227-1230 ◽  
Author(s):  
M. Carmen Ruiz-Roldán ◽  
Victoriano Garre ◽  
Josep Guarro ◽  
Marçal Mariné ◽  
M. Isabel G. Roncero
Keyword(s):  
Fusarium Oxysporum ◽  
White Collar ◽  
Surface Hydrophobicity ◽  
Uv Resistance ◽  
Uv Treatment ◽  
Tomato Plants ◽  
Knockout Mutants ◽  
Aerial Hyphae ◽  
Infection Experiments

ABSTRACT Knockout mutants of Fusarium oxysporum lacking the putative photoreceptor Wc1 were impaired in aerial hyphae, surface hydrophobicity, light-induced carotenogenesis, photoreactivation after UV treatment, and upregulation of photolyase gene transcription. Infection experiments with tomato plants and immunodepressed mice revealed that Wc1 is dispensable for pathogenicity on plants but required for full virulence on mammals.

Role of methyl jasmonate in the expression of mycorrhizal induced resistance against Fusarium oxysporum in tomato plants

2015 ◽  
Vol 92 ◽  
pp. 139-145 ◽  
Author(s):  
Aswathy Nair ◽  
Swati P. Kolet ◽  
Hirekodathakallu V. Thulasiram ◽  
Sujata Bhargava
Keyword(s):  
Methyl Jasmonate ◽  
Fusarium Oxysporum ◽  
Induced Resistance ◽  
Tomato Plants

scholarly journals Repellents have functionally replaced hydrophobins in mediating attachment to a hydrophobic surface and in formation of hydrophobic aerial hyphae in Ustilago maydis

Microbiology ◽  
2006 ◽  
Vol 152 (12) ◽  
pp. 3607-3612 ◽  
Author(s):  
Wieke R. Teertstra ◽  
Heine J. Deelstra ◽  
Miroslav Vranes ◽  
Ralph Bohlmann ◽  
Regine Kahmann ◽  
...  
Keyword(s):  
Hydrophobic Surface ◽  
Ustilago Maydis ◽  
Surface Hydrophobicity ◽  
Class I ◽  
Wild Type ◽  
Repeat Sequences ◽  
Recognition Sites ◽  
Aerial Hyphae ◽  
Type Strains

Ustilago maydis contains one repellent and two class I hydrophobin genes in its genome. The repellent gene rep1 has been described previously. It encodes 11 secreted repellent peptides that result from the cleavage of a precursor protein at KEX2 recognition sites. The hydrophobin gene hum2 encodes a typical class I hydrophobin of 117 aa, while hum3 encodes a hydrophobin that is preceded by 17 repeat sequences. These repeats are separated, like the repellent peptides, by KEX2 recognition sites. Gene hum2, but not hum3, was shown to be expressed in a cross of two compatible wild-type strains, suggesting a role of the former hydrophobin gene in aerial hyphae formation. Indeed, aerial hyphae formation was reduced in a Δhum2 cross. However, the reduction in aerial hyphae formation was much more dramatic in the Δrep1 cross. Moreover, colonies of the Δrep1 cross were completely wettable, while surface hydrophobicity was unaffected and only slightly reduced in the Δhum2 and the Δhum2Δhum3 cross, respectively. It was also shown that the repellents and not the hydrophobins are involved in attachment of hyphae to hydrophobic Teflon. Deleting either or both hydrophobin genes in the Δrep1 strains did not further affect aerial hyphae formation, surface hydrophobicity and attachment. From these data it is concluded that hydrophobins of U. maydis have been functionally replaced, at least partially, by repellents.

scholarly journals Disease Development Following Infection of Tomato and Basil Foliage by Airborne Conidia of the Soilborne Pathogens Fusarium oxysporum f. sp. radicis-lycopersici and F. oxysporum f. sp. basilici

2000 ◽  
Vol 90 (12) ◽  
pp. 1322-1329 ◽  
Author(s):  
Y. Rekah ◽  
D. Shtienberg ◽  
J. Katan
Keyword(s):  
Fusarium Oxysporum ◽  
Disease Incidence ◽  
Selective Medium ◽  
Management Program ◽  
Causal Agent ◽  
Soilborne Pathogens ◽  
Tomato Plants ◽  
Pathogen Invasion ◽  
Crown And Root Rot

Fusarium oxysporum f. sp. radicis-lycopersici, the causal agent of Fusarium crown and root rot of tomato, and F. oxysporum f. sp. basilici, the causal agent of Fusarium wilt in basil, are soilborne pathogens capable of producing conspicuous masses of macroconidia along the stem. The role of the airborne propagules in the epidemics of the disease in tomato plants was studied. In the field, airborne propagules of F. oxysporum f. sp. radicis-lycopersici were trapped with a selective medium and their prevalence was determined. Plants grown in both covered and uncovered pots, detached from the field soil, and exposed to natural aerial inoculum developed typical symptoms (82 to 87% diseased plants). The distribution of inoculum in the growth medium in the pots also indicated the occurrence of foliage infection. In greenhouse, foliage and root inoculations were carried out with both tomato and basil and their respective pathogens. Temperature and duration of high relative humidity affected rate of colonization of tomato, but not of basil, by the respective pathogens. Disease incidence in foliage-inoculated plants reached 75 to 100%. In these plants, downward movement of the pathogens from the foliage to the crown and roots was observed. Wounding enhanced pathogen invasion and establishment in the foliage-inoculated plants. The sporulation of the two pathogens on stems, aerial dissemination, and foliage infection raise the need for foliage protection in addition to soil disinfestation, in the framework of an integrated disease management program.

scholarly journals Role of the Transcriptional Activator XlnR of Fusarium oxysporum in Regulation of Xylanase Genes and Virulence

2007 ◽  
Vol 20 (8) ◽  
pp. 977-985 ◽  
Author(s):  
Fernando Calero-Nieto ◽  
Antonio Di Pietro ◽  
M. Isabel G. Roncero ◽  
Concepcion Hera
Keyword(s):  
Fusarium Oxysporum ◽  
Transcriptional Activation ◽  
Carbon Sources ◽  
Xylanase Activity ◽  
Transcriptional Activator ◽  
Vascular Wilt ◽  
Lytic Enzymes ◽  
Tomato Plants ◽  
Host Cell Wall

Fungal infection of plants involves degradation of the host cell wall through the action of lytic enzymes secreted by the pathogen. The role of these enzymes in virulence is difficult to determine due to their functional redundancy and, therefore, remains controversial. Here, we have studied XlnR, a zinc-finger transcription factor from the vascular wilt pathogen Fusarium oxysporum that is orthologous to the major transcriptional activator of xylanase genes in Aspergillus spp. Transcription of the xlnR gene was activated by inducing carbon sources such as oat spelt xylan (OSX) and repressed by glucose. Targeted knockout of xlnR in F. oxysporum resulted in lack of transcriptional activation of structural xylanase genes, both in culture and during infection of tomato plants, as well as in dramatically reduced extracellular xylanase activity. By contrast, overexpression of xlnR under the control of the Aspergillus nidulans gpdA promoter did not significantly increase xylanase activity, suggesting that XlnR is regulated not only at the transcriptional but also at the post-translational level. The ΔxlnR mutants were still fully virulent on tomato plants. Thus, XlnR, the major transcriptional activator of xylanase genes, is not an essential virulence determinant in F. oxysporum.

Race identification of Fusarium oxysporum f. sp. lycopersici isolates obtained from tomato plants in Nova Friburgo, Brazil

2021 ◽  
Author(s):  
Cristiana Maia de Oliveira ◽  
Margarida Gorete Ferreira do Carmo ◽  
Leandro Martins Ferreira ◽  
Monica Höfte ◽  
Nelson Moura Brasil do Amaral Sobrinho
Keyword(s):  
Fusarium Oxysporum ◽  
Tomato Plants ◽  
Race Identification

scholarly journals Signaling in the Tomato Immunity against Fusarium oxysporum

Molecules ◽  
2021 ◽  
Vol 26 (7) ◽  
pp. 1818
Author(s):  
Francisco Hernández-Aparicio ◽  
Purificación Lisón ◽  
Ismael Rodrigo ◽  
José María Bellés ◽  
M. Pilar López-Gresa
Keyword(s):  
Fusarium Oxysporum ◽  
Environmental Sustainability ◽  
Control Strategies ◽  
Marker Gene ◽  
Crop Protection ◽  
Incompatible Interaction ◽  
Tomato Plants ◽  
Fatty Acid Derivatives ◽  
Resistance Inducers ◽  
Plant Pathogen Interactions

New strategies of control need to be developed with the aim of economic and environmental sustainability in plant and crop protection. Metabolomics is an excellent platform for both understanding the complex plant–pathogen interactions and unraveling new chemical control strategies. GC-MS-based metabolomics, along with a phytohormone analysis of a compatible and incompatible interaction between tomato plants and Fusarium oxysporum f. sp. lycopersici, revealed the specific volatile chemical composition and the plant signals associated with them. The susceptible tomato plants were characterized by the over-emission of methyl- and ethyl-salicylate as well as some fatty acid derivatives, along with an activation of salicylic acid and abscisic acid signaling. In contrast, terpenoids, benzenoids, and 2-ethylhexanoic acid were differentially emitted by plants undergoing an incompatible interaction, together with the activation of the jasmonic acid (JA) pathway. In accordance with this response, a higher expression of several genes participating in the biosynthesis of these volatiles, such as MTS1, TomloxC,TomloxD, and AOS, as well as JAZ7, a JA marker gene, was found to be induced by the fungus in these resistant plants. The characterized metabolome of the immune tomato plants could lead to the development of new resistance inducers against Fusarium wilt treatment.

scholarly journals Ralstonia solanacearum Needs Motility for Invasive Virulence on Tomato

2001 ◽  
Vol 183 (12) ◽  
pp. 3597-3605 ◽  
Author(s):  
Julie Tans-Kersten ◽  
Huayu Huang ◽  
Caitilyn Allen
Keyword(s):  
Bacterial Wilt ◽  
Ralstonia Solanacearum ◽  
Soft Agar ◽  
Cell Protein ◽  
In Planta ◽  
Tomato Plants ◽  
Bacterial Wilt Disease ◽  
Virulence Assay ◽  
Flagellar Filament

ABSTRACT Ralstonia solanacearum, a widely distributed and economically important plant pathogen, invades the roots of diverse plant hosts from the soil and aggressively colonizes the xylem vessels, causing a lethal wilting known as bacterial wilt disease. By examining bacteria from the xylem vessels of infected plants, we found thatR. solanacearum is essentially nonmotile in planta, although it can be highly motile in culture. To determine the role of pathogen motility in this disease, we cloned, characterized, and mutated two genes in the R. solanacearum flagellar biosynthetic pathway. The genes for flagellin, the subunit of the flagellar filament (fliC), and for the flagellar motor switch protein (fliM) were isolated based on their resemblance to these proteins in other bacteria. As is typical for flagellins, the predicted FliC protein had well-conserved N- and C-terminal regions, separated by a divergent central domain. The predicted R. solanacearum FliM closely resembled motor switch proteins from other proteobacteria. Chromosomal mutants lackingfliC or fliM were created by replacing the genes with marked interrupted constructs. Since fliM is embedded in the fliLMNOPQR operon, the aphAcassette was used to make a nonpolar fliM mutation. Both mutants were completely nonmotile on soft agar plates, in minimal broth, and in tomato plants. The fliC mutant lacked flagella altogether; moreover, sheared-cell protein preparations from the fliC mutant lacked a 30-kDa band corresponding to flagellin. The fliM mutant was usually aflagellate, but about 10% of cells had abnormal truncated flagella. In a biologically representative soil-soak inoculation virulence assay, both nonmotile mutants were significantly reduced in the ability to cause disease on tomato plants. However, the fliC mutant had wild-type virulence when it was inoculated directly onto cut tomato petioles, an inoculation method that did not require bacteria to enter the intact host from the soil. These results suggest that swimming motility makes its most important contribution to bacterial wilt virulence in the early stages of host plant invasion and colonization.

Bacteria Transport and Deposition under Unsaturated Flow Conditions: The Role of Water Content and Bacteria Surface Hydrophobicity

2008 ◽  
Vol 7 (2) ◽  
pp. 406-419 ◽  
Author(s):  
G. Gargiulo ◽  
S. A. Bradford ◽  
J. Simunek ◽  
P. Ustohal ◽  
H. Vereecken ◽  
...  
Keyword(s):  
Water Content ◽  
Unsaturated Flow ◽  
Surface Hydrophobicity ◽  
Flow Conditions ◽  
Bacteria Transport

scholarly journals Role of ethylene and light in chitosan-induced local and systemic defence responses of tomato plants

2021 ◽  
pp. 153461
Author(s):  
Zalán Czékus ◽  
Nadeem Iqbal ◽  
Boglárka Pollák ◽  
Atina Martics ◽  
Attila Ördög ◽  
...  
Keyword(s):  
Tomato Plants ◽  
Defence Responses
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