scholarly journals Secreted in Xylem Genes: Drivers of Host Adaptation in Fusarium oxysporum

2021 ◽  
Vol 12 ◽  
Author(s):  
Pooja Jangir ◽  
Namita Mehra ◽  
Karuna Sharma ◽  
Neeraja Singh ◽  
Mamta Rani ◽  
...  
Keyword(s):  
Fusarium Oxysporum ◽  
Current Knowledge ◽  
Economic Status ◽  
Protein Profile ◽  
Effector Proteins ◽  
Significant Implication ◽  
Vascular Wilt ◽  
Vegetative Compatibility Groups ◽  
Formae Speciales ◽  
Molecular Framework

Fusarium oxysporum (Fo) is a notorious pathogen that significantly contributes to yield losses in crops of high economic status. It is responsible for vascular wilt characterized by the browning of conductive tissue, wilting, and plant death. Individual strains of Fo are host specific (formae speciales), and approximately, 150 forms have been documented so far. The pathogen secretes small effector proteins in the xylem, termed as Secreted in Xylem (Six), that contribute to its virulence. Most of these proteins contain cysteine residues in even numbers. These proteins are encoded by SIX genes that reside on mobile pathogenicity chromosomes. So far, 14 proteins have been reported. However, formae speciales vary in SIX protein profile and their respective gene sequence. Thus, SIX genes have been employed as ideal markers for pathogen identification. Acquisition of SIX-encoding mobile pathogenicity chromosomes by non-pathogenic lines, through horizontal transfer, results in the evolution of new virulent lines. Recently, some SIX genes present on these pathogenicity chromosomes have been shown to be involved in defining variation in host specificity among formae speciales. Along these lines, the review entails the variability (formae speciales, races, and vegetative compatibility groups) and evolutionary relationships among members of F. oxysporum species complex (FOSC). It provides updated information on the diversity, structure, regulation, and (a)virulence functions of SIX genes. The improved understanding of roles of SIX in variability and virulence of Fo has significant implication in establishment of molecular framework and techniques for disease management. Finally, the review identifies the gaps in current knowledge and provides insights into potential research landscapes that can be explored to strengthen the understanding of functions of SIX genes.

scholarly journals Evolutionary Relationships among the Fusarium oxysporum f. sp. cubense Vegetative Compatibility Groups

2009 ◽  
Vol 75 (14) ◽  
pp. 4770-4781 ◽  
Author(s):  
Gerda Fourie ◽  
E. T. Steenkamp ◽  
T. R. Gordon ◽  
A. Viljoen
Keyword(s):  
Fusarium Oxysporum ◽  
Evolutionary History ◽  
Genetic Relatedness ◽  
Vegetative Compatibility ◽  
Vascular Wilt ◽  
Vegetative Compatibility Groups ◽  
Formae Speciales ◽  
History Of ◽  
Fusarium Wilt Of Banana ◽  
Banana Cultivar

ABSTRACT 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.

scholarly journals Gene Genealogies and AFLP Analyses in the Fusarium oxysporum Complex Identify Monophyletic and Nonmonophyletic Formae Speciales Causing Wilt and Rot Disease

2000 ◽  
Vol 90 (8) ◽  
pp. 891-900 ◽  
Author(s):  
Robert P. Baayen ◽  
Kerry O'Donnell ◽  
Peter J. M. Bonants ◽  
Elizabeth Cigelnik ◽  
Laurens P. N. M. Kroon ◽  
...  
Keyword(s):  
Fusarium Oxysporum ◽  
Dna Sequences ◽  
Mitochondrial Gene ◽  
Elongation Factor ◽  
Small Subunit ◽  
Vegetative Compatibility Groups ◽  
Formae Speciales ◽  
Evolutionary Origins ◽  
Bulb Rot ◽  
Rot Disease

The monophyletic origin of host-specific taxa in the plant-pathogenic Fusarium oxysporum complex was tested by constructing nuclear and mitochondrial gene genealogies and amplified fragment length polymorphism (AFLP)-based phylogenies for 89 strains representing the known genetic and pathogenic diversity in 8 formae speciales associated with wilt diseases and root and bulb rot. We included strains from clonal lineages of F. oxysporum f. spp. asparagi, dianthi, gladioli, lilii, lini, opuntiarum, spinaciae, and tulipae. Putatively nonpathogenic strains from carnation and lily were included and a reference strain from each of the three main clades identified previously in the F. oxysporum complex; sequences from related species were used as outgroups. DNA sequences from the nuclear translation elongation factor 1α and the mitochondrial small subunit (mtSSU) ribosomal RNA genes were combined for phylogenetic analysis. Strains in vegetative compatibility groups (VCGs) shared identical sequences and AFLP profiles, supporting the monophyly of the two single-VCG formae speciales, lilii and tulipae. Identical genotypes were also found for the three VCGs in F. oxysporum f. sp. spinaciae. In contrast, multiple evolutionary origins were apparent for F. oxysporum f. spp. asparagi, dianthi, gladioli, lini, and opuntiarum, although different VCGs within each of these formae speciales often clustered close together or shared identical EF-1α and mtSSU rDNA haplotypes. Kishino-Hasegawa analyses of constraints forcing the monophyly of these formae speciales supported the exclusive origin of F. oxysporum f. sp. opuntiarum but not the monophyly of F. oxysporum f. spp. asparagi, dianthi, gladioli, and lini. Most of the putatively nonpathogenic strains from carnation and lily, representing unique VCGs, were unrelated to F. oxysporum f. spp. dianthi and lilii, respectively. Putatively nonpathogenic or rot-inducing strains did not form exclusive groups within the molecular phylogeny. Parsimony analyses of AFLP fingerprint data supported the gene genealogy-based phylogram; however, AFLP-based phylogenies were considerably more homoplasious than the gene genealogies. The predictive value of the forma specialis naming system within the F. oxysporum complex is questioned.

An evaluation of Fusarium oxysporum from crucifers based on pathogenicity, isozyme polymorphism, vegetative compatibility, and geographic origin

1987 ◽  
Vol 65 (10) ◽  
pp. 2067-2073 ◽  
Author(s):  
Paul W. Bosland ◽  
Paul H. Williams
Keyword(s):  
Fusarium Oxysporum ◽  
Fusarium Species ◽  
Geographic Origin ◽  
Vegetative Compatibility ◽  
Host Specialization ◽  
Complementation Test ◽  
Vegetative Compatibility Groups ◽  
Formae Speciales ◽  
Isozyme Polymorphism ◽  
Host Families

A global collection of 123 putative isolates of Fusarium oxysporum from crucifers was examined for pathogenicity, isozyme polymorphism, and vegetative compatibility. Of these isolates, 103 were found to be pathogenic on one or more of six differential crucifer cultivars. Three patterns of isozyme polymorphism (electrophoretic types) were found and by means of a nitrate reductase complementation test, three major vegetative compatibility groups were identified that could differentiate among the F. oxysporum pathotypes. Complete correspondence was found among pathotype, electrophoretic type, and vegetative compatibility. It seems appropriate to classify isolates from the Cruciferae into the subspecific taxa, F. oxysporum f.sp. conglutinans, F. oxysporum f.sp. raphani, and F. oxysporum f.sp. matthioli, based on their naturally infected host species, Brassica oleracea, Raphanus sativus, and Matthiola incana, and on estimates of genetic identity. Within formae speciales, races can be identified based on intraspecific host specialization. Geographic origin was not found to be associated with the vegetative compatibility, isozyme phenotype, or pathotype. Isozyme polymorphisms also differentiated among four F. oxysporum formae speciales from other host families and among various Fusarium species.

Potential for Dispersal of Fusarium oxysporum f. sp. erythroxyli by Infested Seed

Plant Disease ◽  
1999 ◽  
Vol 83 (5) ◽  
pp. 451-455 ◽  
Author(s):  
J. A. Gracia-Garza ◽  
D. R. Fravel ◽  
A. J. Nelson ◽  
K. S. Elias ◽  
B. A. Bailey ◽  
...  
Keyword(s):  
Fusarium Oxysporum ◽  
Seed Coat ◽  
Dna Analysis ◽  
Random Amplified Polymorphic Dna ◽  
Vegetative Compatibility ◽  
Vascular Wilt ◽  
Field Site ◽  
Vegetative Compatibility Groups ◽  
Experimental Field ◽  
Fruit Part

Fusarium oxysporum f. sp. erythroxyli causes a vascular wilt of the narcotic plant coca (Erythroxylum coca var. coca). To determine whether this pathogen can be transmitted by infested seed, fruit from symptomatic and asymptomatic plants was collected from different coca-growing areas in Peru and from an experimental field site in Hawaii. A total of 202 fruit from Peru and 69 fruit from Hawaii were surface-disinfested and separated into five parts: pedicel, pericarp, seed coat, endosperm, and cotyledons. After the pedicel and pericarp were removed from the seed coat, the seed was surface disinfested again. Each fruit part was plated separately. Both F. oxysporum and F. moniliforme were recovered from fruit collected in Peru. Both species were isolated from all parts of some fruit. F. oxysporum was isolated from 33% of the fruit plated and most (35%) of these isolates were obtained from the seed coat. Slightly greater numbers of isolates (57%) were recovered from asymptomatic plants than from symptomatic plants (43%). Only F. oxysporum was isolated from fruit collected in Hawaii. Most of these isolates (59%) were from the pedicels of fruit collected from symptomatic plants. Out of 91 isolates of F. oxysporum, 21 were pathogenic to coca seedlings in a bioassay. Six of these pathogenic isolates were originally from the pedicel of the fruit, eight from the pericarp, four from the seed coat, and three from the endosperm. No isolates from the cotyledons were pathogenic. Most of the pathogenic isolates (76%) were from symptomatic plants. The pathogenic isolates were characterized using random amplified polymorphic DNA analysis and vegetative compatibility groups. Based on these analyses, two different subpopulations of the forma specialis erythroxyli were found in Peru, whereas only one was present in Hawaii. These data indicate that infested seed may contribute significantly to dissemination of this pathogen because seed is collected by growers and planted fresh or fermented briefly before planting.

scholarly journals SIX6 Shows High Divergence in Fusarium oxysporum f. sp. cubense TR4

2021 ◽  
Vol 25 (06) ◽  
pp. 1331-1338
Author(s):  
Nadya Farah
Keyword(s):  
Positive Selection ◽  
Fusarium Oxysporum ◽  
Purifying Selection ◽  
Synonymous Substitution ◽  
Effector Proteins ◽  
Pr Genes ◽  
Ratio Distribution ◽  
Formae Speciales ◽  
Pathogenesis Related ◽  
Synonymous Substitution Rates

Secreted fungal effector proteins and their host targets are good examples to understand the mechanism of host-pathogen co-evolution with genes involved in the interaction undergoing positive selection. SIX genes (secreted in xylem) are obtained via horizontal transfer and can be found within the formae speciales of Fusarium oxysporum. SIX6 and SIX9 of F. oxysporum f. spp. cubense (Foc) are predicted to play a role as effectors. However, their involvement in the pathogenicity of Foc in banana plants has not been determined yet. In the susceptible banana cultivar, we found that the SIX6 and SIX9 genes of Foc TR4 were highly expressed in roots, but not in corms or leaves. The host, however, expressed the pathogenesis-related (PR) genes, PR-1 and PR-3, in corms earlier than in the roots. Phylogenetic analysis on SIX6 and SIX9 genes of F. oxysporum has revealed the separation of SIX6 and SIX9 of Foc from other formae speciales. This leads to detecting genes under positive selection using the ratio nonsynonymous to synonymous substitution rates (Ka/Ks). SIX6 of Foc showed an increase in diversity, but insufficient to drive positive selection. Conversely, SIX9 of Foc showed no divergence in the dN/dS ratio distribution, indicating purifying selection. © 2021 Friends Science Publishers

scholarly journals Endopolygalacturonase PG1 in Different Formae Speciales of Fusarium oxysporum

1998 ◽  
Vol 64 (5) ◽  
pp. 1967-1971 ◽  
Author(s):  
Antonio Di Pietro ◽  
Fe I. Garc�a-Maceira ◽  
M. Dolores Huertas-Gonz�lez ◽  
M. Carmen Ru�z-Roldan ◽  
Zaira Caracuel ◽  
...  
Keyword(s):  
Fusarium Oxysporum ◽  
Gel Electrophoresis ◽  
Genomic Dna ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Vascular Wilt ◽  
Specific Primers ◽  
Formae Speciales ◽  
Encoding Gene

ABSTRACT PG1, the major endopolygalacturonase of the vascular wilt pathogenFusarium oxysporum, was secreted during growth on pectin by 10 of 12 isolates belonging to seven formae speciales, as determined with isoelectric focusing zymograms and sodium dodecyl sulfate-polyacrylamide gel electrophoresis gels. A Southern analysis of genomic DNA and PCR performed with gene-specific primers revealed that the pg1 locus was highly conserved structurally in most isolates. Two PG1-deficient isolates were identified; one lacked the encoding gene, and the other carried a pg1 allele disrupted by a 3.2-kb insertion with sequence homology to hATtransposases. The virulence for muskmelon of different F. oxysporum f. sp. melonis isolates was not correlated with PG1 production in vitro. We concluded that PG1 is widely distributed in F. oxysporum and that it is not essential for pathogenicity.

scholarly journals Rho GTPases as Key Molecular Players within Intestinal Mucosa and GI Diseases

Cells ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 66
Author(s):  
Rashmita Pradhan ◽  
Phuong A. Ngo ◽  
Luz d. C. Martínez-Sánchez ◽  
Markus F. Neurath ◽  
Rocío López-Posadas
Keyword(s):  
Intestinal Mucosa ◽  
Rho Gtpases ◽  
Current Knowledge ◽  
Cell Types ◽  
Effector Proteins ◽  
Special Focus ◽  
Specific Cell ◽  
Rho Proteins

Rho proteins operate as key regulators of the cytoskeleton, cell morphology and trafficking. Acting as molecular switches, the function of Rho GTPases is determined by guanosine triphosphate (GTP)/guanosine diphosphate (GDP) exchange and their lipidation via prenylation, allowing their binding to cellular membranes and the interaction with downstream effector proteins in close proximity to the membrane. A plethora of in vitro studies demonstrate the indispensable function of Rho proteins for cytoskeleton dynamics within different cell types. However, only in the last decades we have got access to genetically modified mouse models to decipher the intricate regulation between members of the Rho family within specific cell types in the complex in vivo situation. Translationally, alterations of the expression and/or function of Rho GTPases have been associated with several pathological conditions, such as inflammation and cancer. In the context of the GI tract, the continuous crosstalk between the host and the intestinal microbiota requires a tight regulation of the complex interaction between cellular components within the intestinal tissue. Recent studies demonstrate that Rho GTPases play important roles for the maintenance of tissue homeostasis in the gut. We will summarize the current knowledge on Rho protein function within individual cell types in the intestinal mucosa in vivo, with special focus on intestinal epithelial cells and T cells.

scholarly journals Vegetative Compatibility Groups of Fusarium oxysporum f. sp. lactucae from Lettuce

Plant Disease ◽  
2005 ◽  
Vol 89 (3) ◽  
pp. 237-240 ◽  
Author(s):  
Matias Pasquali ◽  
Flavia Dematheis ◽  
Giovanna Gilardi ◽  
Maria Lodovica Gullino ◽  
Angelo Garibaldi
Keyword(s):  
Fusarium Oxysporum ◽  
Genetic Relatedness ◽  
The United States ◽  
Vegetative Compatibility ◽  
Vegetative Compatibility Group ◽  
Vegetative Compatibility Groups ◽  
Compatibility Group ◽  
Race 1

Fusarium oxysporum f. sp. lactucae, the causal agent of Fusarium wilt of lettuce, has been reported in three continents in the last 10 years. Forty-seven isolates obtained from infected plants and seed in Italy, the United States, Japan, and Taiwan were evaluated for pathogenicity and vegetative compatibility. Chlorate-resistant, nitrate-nonutilizing mutants were used to determine genetic relatedness among isolates from different locations. Using the vegetative compatibility group (VCG) approach, all Italian and American isolates, type 2 Taiwanese isolates, and a Japanese race 1 were assigned to the major VCG 0300. Taiwanese isolates type 1 were assigned to VCG 0301. The hypothesis that propagules of Fusarium oxysporum f. sp. lactucae that caused epidemics on lettuce in 2001-02 in Italian fields might have spread via import and use of contaminated seeds is discussed.

Molecular aspects of tomato (Solanum lycopersicum) vascular wilt by Fusarium oxysporum f. sp. lycopersici and antagonism by Trichoderma spp.

2021 ◽  
Vol 40 (1) ◽  
Author(s):  
Paula Andrea Castillo-Sanmiguel ◽  
Laura Rocío Cortés-Sánchez ◽  
Jovanna Acero-Godoy
Keyword(s):  
Fusarium Oxysporum ◽  
Solanum Lycopersicum ◽  
Negative Impact ◽  
Vascular Wilt ◽  
Trichoderma Spp ◽  
Genetic Characteristics ◽  
Synthetic Chemicals ◽  
Efficient Alternative ◽  
Molecular Aspects ◽  
The One

<p>Tomato plants (<em>Solanum lycopersicum</em>) are susceptible to the infection by diverse pathogens that cause devastating diseases such as vascular wilt, which causes great losses at the production level. The fungus <em>Fusarium oxysporum</em> f. sp. <em>lycopersici</em> (<em>Fol</em>) is one of the etiologic agents of this disease and its control lies in the use of synthetic chemicals which generate a negative impact in both health and the environment; thus, it is necessary to implement biological control as a healthier and more efficient alternative. The fungus <em>Trichoderma</em> spp. is a favorable option to be employed as a biocontroller against this pathogen thanks to its antagonist mechanisms, determined by metabolic and genetic characteristics. On the one hand, for <em>Fol</em> it is indispensable the activation of signaling routes such as MAPK Fmk1, MAPK Mpk1 y HOG, while <em>Trichoderma</em> spp. uses effectors involved in the interaction with the plant such as proteins, enzymes and secondary metabolites that also strengthen its immune response against infection, determined by both Pathogen Associated Molecular Patterns (PAMP) and effectors. Therefore, this article makes a review about the mentioned characteristics and suggests a greater application of tools and molecular markers for the management of this disease.</p>

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