scholarly journals Number of Candidate Effector Genes in Accessory Genomes Differentiates Pathogenic From Endophytic Fusarium oxysporum Strains

2021 ◽  
Vol 12 ◽  
Author(s):  
Maria E. Constantin ◽  
Like Fokkens ◽  
Mara de Sain ◽  
Frank L. W. Takken ◽  
Martijn Rep
Keyword(s):  
Fusarium Oxysporum ◽  
Plant Species ◽  
Genetic Basis ◽  
Molecular Level ◽  
Similar Amount ◽  
Tomato Plants ◽  
Grass Roots ◽  
Effector Gene ◽  
Effector Genes ◽  
Potential Pathogen

The fungus Fusarium oxysporum (Fo) is widely known for causing wilt disease in over 100 different plant species. Endophytic interactions of Fo with plants are much more common, and strains pathogenic on one plant species can even be beneficial endophytes on another species. However, endophytic and beneficial interactions have been much less investigated at the molecular level, and the genetic basis that underlies endophytic versus pathogenic behavior is unknown. To investigate this, 44 Fo strains from non-cultivated Australian soils, grass roots from Spain, and tomato stems from United States were characterized genotypically by whole genome sequencing, and phenotypically by examining their ability to symptomlessly colonize tomato plants and to confer resistance against Fusarium Wilt. Comparison of the genomes of the validated endophytic Fo strains with those of 102 pathogenic strains revealed that both groups have similar genomes sizes, with similar amount of accessory DNA. However, although endophytic strains can harbor homologs of known effector genes, they have typically fewer effector gene candidates and associated non-autonomous transposons (mimps) than pathogenic strains. A pathogenic ‘lifestyle’ is associated with extended effector gene catalogs and a set of “host specific” effectors. No candidate effector genes unique to endophytic strains isolated from the same plant species were found, implying little or no host-specific adaptation. As plant-beneficial interactions were observed to be common for the tested Fo isolates, the propensity for endophytism and the ability to confer biocontrol appears to be a predominant feature of this organism. These findings allow prediction of the lifestyle of a Fo strain based on its genome sequence as a potential pathogen or as a harmless or even beneficial endophyte by determining its effectorome and mimp number.

scholarly journals Effector Gene Suites in Some Soil Isolates of Fusarium oxysporum Are Not Sufficient Predictors of Vascular Wilt in Tomato

2017 ◽  
Vol 107 (7) ◽  
pp. 842-851 ◽  
Author(s):  
Nicolas A. Jelinski ◽  
Karen Broz ◽  
Wilfried Jonkers ◽  
Li-Jun Ma ◽  
H. Corby Kistler
Keyword(s):  
Fusarium Oxysporum ◽  
Chromosomal Rearrangement ◽  
Vascular Wilt ◽  
Dynamic Nature ◽  
Free Living ◽  
Accurate Predictor ◽  
Effector Gene ◽  
Effector Genes ◽  
Complex Process ◽  
Tomato Wilt

Seventy-four Fusarium oxysporum soil isolates were assayed for known effector genes present in an F. oxysporum f. sp. lycopersici race 3 tomato wilt strain (FOL MN-25) obtained from the same fields in Manatee County, Florida. Based on the presence or absence of these genes, four haplotypes were defined, two of which represented 96% of the surveyed isolates. These two most common effector haplotypes contained either all or none of the assayed race 3 effector genes. We hypothesized that soil isolates with all surveyed effector genes, similar to FOL MN-25, would be pathogenic toward tomato, whereas isolates lacking all effectors would be nonpathogenic. However, inoculation experiments revealed that presence of the effector genes alone was not sufficient to ensure pathogenicity on tomato. Interestingly, a nonpathogenic isolate containing the full suite of unmutated effector genes (FOS 4-4) appears to have undergone a chromosomal rearrangement yet remains vegetatively compatible with FOL MN-25. These observations confirm the highly dynamic nature of the F. oxysporum genome and support the conclusion that pathogenesis among free-living populations of F. oxysporum is a complex process. Therefore, the presence of effector genes alone may not be an accurate predictor of pathogenicity among soil isolates of F. oxysporum.

scholarly journals Use of Comparative Genomics-Based Markers for Discrimination of Host Specificity in Fusarium oxysporum

2017 ◽  
Vol 84 (1) ◽  
Author(s):  
Peter van Dam ◽  
Mara de Sain ◽  
Anneliek ter Horst ◽  
Michelle van der Gragt ◽  
Martijn Rep
Keyword(s):  
Fusarium Oxysporum ◽  
Host Range ◽  
Host Specificity ◽  
Plant Species ◽  
Detection Methods ◽  
Taqman Assay ◽  
Content Type ◽  
Formae Speciales ◽  
Effector Genes ◽  
Forma Specialis

ABSTRACTThe polyphyletic nature of manyformae specialesofFusarium oxysporumprevents molecular identification of newly encountered strains based on conserved, vertically inherited genes. Alternative molecular detection methods that could replace labor- and time-intensive disease assays are therefore highly desired. Effectors are functional elements in the pathogen-host interaction and have been found to show very limited sequence diversity between strains of the sameforma specialis, which makes them potential markers for host-specific pathogenicity. We therefore compared candidate effector genes extracted from 60 existing and 22 newly generated genome assemblies, specifically targeting strains affecting cucurbit plant species. Based on these candidate effector genes, a total of 18 PCR primer pairs were designed to discriminate between each of the seven Cucurbitaceae-affectingformae speciales. When tested on a collection of strains encompassing different clonal lineages of theseformae speciales, nonpathogenic strains, and strains of otherformae speciales, they allowed clear recognition of the host range of each evaluated strain. WithinFusarium oxysporumf. sp.melonismore genetic variability exists than anticipated, resulting in threeF. oxysporumf. sp.melonismarker patterns that partially overlapped with the cucurbit-infectingFusarium oxysporumf. sp.cucumerinum,Fusarium oxysporumf. sp.niveum,Fusarium oxysporumf. sp.momordicae, and/orFusarium oxysporumf. sp.lagenariae. ForF. oxysporumf. sp.niveum, a multiplex TaqMan assay was evaluated and was shown to allow quantitative and specific detection of template DNA quantities as low as 2.5 pg. These results provide ready-to-use marker sequences for the mentionedF. oxysporumpathogens. Additionally, the method can be applied to find markers distinguishing other host-specific forms ofF. oxysporum.IMPORTANCEPathogenic strains ofFusarium oxysporumare differentiated intoformae specialesbased on their host range, which is normally restricted to only one or a few plant species. However, horizontal gene transfer between strains in the species complex has resulted in a polyphyletic origin of host specificity in many of theseformae speciales. This hinders accurate and rapid pathogen detection through molecular methods. In our research, we compared the genomes of 88 strains ofF. oxysporumwith each other, specifically targeting virulence-related genes that are typically highly similar within eachforma specialis. Using this approach, we identified marker sequences that allow the discrimination ofF. oxysporumstrains affecting various cucurbit plant species through different PCR-based methods.

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 A Molecular Vision of the Interaction of Tomato Plants and Fusarium oxysporum f. sp. lycopersic

2018 ◽  
Author(s):  
Ema Laura García-Enciso ◽  
Adalberto Benavides-Mendoza ◽  
María Liliana Flores-López ◽  
Armando Robledo-Olivo ◽  
Antonio Juárez-Maldonado ◽  
...  
Keyword(s):  
Fusarium Oxysporum ◽  
Tomato Plants

scholarly journals Fusarium oxysporum colonizes the stem of resistant tomato plants, the extent varying with the R-gene present

2018 ◽  
Vol 154 (1) ◽  
pp. 55-65 ◽  
Author(s):  
H. C. van der Does ◽  
M. E. Constantin ◽  
P. M. Houterman ◽  
F. L. W. Takken ◽  
B. J. C. Cornelissen ◽  
...  
Keyword(s):  
Fusarium Oxysporum ◽  
R Gene ◽  
Tomato Plants

scholarly journals Differential gene expression, induced by salicylic acid and Fusarium oxysporum f. sp. lycopersici infection, in tomato

2008 ◽  
Vol 43 (8) ◽  
pp. 1017-1023 ◽  
Author(s):  
Daniel Oliveira Jordão do Amaral ◽  
Marleide Magalhães de Andrade Lima ◽  
Luciane Vilela Resende ◽  
Márcia Vanusa da Silva
Keyword(s):  
Salicylic Acid ◽  
Fusarium Oxysporum ◽  
Foliar Application ◽  
Cost Effective ◽  
Subtractive Hybridization ◽  
Differentially Expressed ◽  
Transcript Profile ◽  
Tomato Plants ◽  
New Genes ◽  
Differential Gene

The objective of this work was to determine the transcript profile of tomato plants (Lycopersicon esculentum Mill.), during Fusarium oxysporum f. sp. lycopersici infection and after foliar application of salicylic acid. The suppression subtractive hybridization (SSH) technique was used to generate a cDNA library enriched for transcripts differentially expressed. A total of 307 clones was identified in two subtractive libraries, which allowed the isolation of several defense-related genes that play roles in different mechanisms of plant resistance to phytopathogens. Genes with unknown roles were also isolated from the two libraries, which indicates the possibility of identifying new genes not yet reported in studies of stress/defense response. The SSH technique is effective for identification of resistance genes activated by salicylic acid and F. oxysporum f. sp. lycopersici infection. Not only the application of this technique enables a cost effective isolation of differentially expressed sequences, but also it allows the identification of novel sequences in tomato from a relative small number of sequences.

scholarly journals Treatment with the Mycoparasite Pythium oligandrum Triggers Induction of Defense-Related Reactions in Tomato Roots When Challenged with Fusarium oxysporum f. sp. radicis-lycopersici

1997 ◽  
Vol 87 (1) ◽  
pp. 108-122 ◽  
Author(s):  
Nicole Benhamou ◽  
Patrice Rey ◽  
Mohamed Chérif ◽  
John Hockenhull ◽  
Yves Tirilly
Keyword(s):  
Plant Defense ◽  
Fusarium Oxysporum ◽  
Host Cell ◽  
Cell Walls ◽  
Pythium Oligandrum ◽  
Tomato Plants ◽  
Host Cytoplasm ◽  
Defense Reactions ◽  
Tomato Roots ◽  
Root Tissues

The influence exerted by the mycoparasite Pythium oligandrum in triggering plant defense reactions was investigated using an experimental system in which tomato plants were infected with the crown and root rot pathogen Fusarium oxysporum f. sp. radicis-lycopersici. To assess the antagonistic potential of P. oligandrum against F. oxysporum f. sp. radicis-lycopersici, the interaction between the two fungi was studied by scanning and transmission electron microscopy (SEM and TEM, respectively). SEM investigations of the interaction region between the fungi demonstrated that collapse and loss of turgor of F. oxysporum f. sp. radicis-lycopersici hyphae began soon after close contact was established with P. oligandrum. Ultrastructural observations confirmed that intimate contact between hyphae of P. oligandrum and cells of the pathogen resulted in a series of disturbances, including generalized disorganization of the host cytoplasm, retraction of the plasmalemma, and, finally, complete loss of the protoplasm. Cytochemical labeling of chitin with wheat germ agglutinin (WGA)/ovomucoid-gold complex showed that, except in the area of hyphal penetration, the chitin component of the host cell walls was structurally preserved at a time when the host cytoplasm had undergone complete disorganization. Interestingly, the same antagonistic process was observed in planta. The specific labeling patterns obtained with the exoglucanase-gold and WGA-ovomucoid-gold complexes confirmed that P. oligandrum successfully penetrated invading cells of the pathogen without causing substantial cell wall alterations, shown by the intense labeling of chitin. Cytological investigations of samples from P. oligandrum-inoculated tomato roots revealed that the fungus was able to colonize root tissues without inducing extensive cell damage. However, there was a novel finding concerning the structural alteration of the invading hyphae, evidenced by the frequent occurrence of empty fungal shells in root tissues. Pythium ingress in root tissues was associated with host metabolic changes, culminating in the elaboration of structural barriers at sites of potential fungal penetration. Striking differences in the extent of F. oxysporum f. sp. radicis-lycopersici colonization were observed between P. oligandrum-inoculated and control tomato plants. In control roots, the pathogen multiplied abundantly through much of the tissues, whereas in P. oligandrum-colonized roots pathogen growth was restricted to the outermost root tissues. This restricted pattern of pathogen colonization was accompanied by deposition of newly formed barriers beyond the infection sites. These host reactions appeared to be amplified compared to those seen in nonchallenged P. oligandrum-infected plants. Most hyphae of the pathogen that penetrated the epidermis exhibited considerable changes. Wall appositions contained large amounts of callose, in addition to be infiltrated with phenolic compounds. The labeling pattern obtained with gold-complexed laccase showed that phenolics were widely distributed in Fusarium-challenged P. oligandrum-inoculated tomato roots. Such compounds accumulated in the host cell walls and intercellular spaces. The wall-bound chitin component in Fusarium hyphae colonizing P. oligandrum-inoculated roots was preserved at a time when hyphae had undergone substantial degradation. These observations provide the first convincing evidence that P. oligandrum has the potential to induce plant defense reactions in addition to acting as a mycoparasite.

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