scholarly journals Cloning and Characterization of an Esophageal-Gland-Specific Pectate Lyase from the Root-Knot Nematode Meloidogyne javanica

2002 ◽  
Vol 15 (6) ◽  
pp. 549-556 ◽  
Author(s):  
Elizabeth A. Doyle ◽  
Kris N. Lambert
Keyword(s):  
Plant Root ◽  
Middle Lamella ◽  
Pectate Lyase ◽  
Meloidogyne Javanica ◽  
Basal Cells ◽  
Class Iii ◽  
Root Knot Nematode ◽  
Ph Optimum ◽  
Pectate Lyases ◽  
Esophageal Gland

Root-knot nematodes (Meloidogyne javanica) are obligate sedentary endoparasites that must penetrate the host root to initiate their life cycle. Many enzymes are secreted by the nematode to facilitate host penetration; required enzymes may include pectate lyases and cellulases. Using differential screening, a class III pectate lyase, Mj-pel-1 (M. javanica pectate lyase 1), was cloned from a library enriched for esophageal gland genes. DNA gel blotting confirmed that the Mj-pel-1 gene was of nematode origin and a member of a small multigene family. In situ hybridization localized the expression of Mj-pel-1 to the basal cells of the esophageal glands, while immunolocalization detected the protein in the esophageal glands as well as on the exterior of the nematode, confirming that the protein is secreted. When MJ-PEL-1 was expressed in Pichia pastoris, the resulting protein was active. The pH optimum of MJ-PEL-1 was 10.0, and the enzyme was five times more active on pectate than on pectin. Like other class III pectate lyases, MJ-PEL-1 also displayed an absolute requirement for Ca2+. The root-knot nematode migrates through the middle lamella of the plant root; therefore, MJ-PEL-1 may be an important enzyme early in the infection process.

scholarly journals Periplasmic depolymerase provides insight into ABC transporter-dependent secretion of bacterial capsular polysaccharides

2018 ◽  
Vol 115 (21) ◽  
pp. E4870-E4879 ◽  
Author(s):  
Sean D. Liston ◽  
Stephen A. McMahon ◽  
Audrey Le Bas ◽  
Michael D. L. Suits ◽  
James H. Naismith ◽  
...  
Keyword(s):  
Cell Surface ◽  
Abc Transporter ◽  
Pectate Lyase ◽  
Capsular Polysaccharides ◽  
Ph Optimum ◽  
Pectate Lyases ◽  
Surface Assembly ◽  
Binding Groove ◽  
Biochemical Analyses ◽  
Vi Antigen

Capsules are surface layers of hydrated capsular polysaccharides (CPSs) produced by many bacteria. The human pathogenSalmonella entericaserovar Typhi produces “Vi antigen” CPS, which contributes to virulence. In a conserved strategy used by bacteria with diverse CPS structures, translocation of Vi antigen to the cell surface is driven by an ATP-binding cassette (ABC) transporter. These transporters are engaged in heterooligomeric complexes proposed to form an enclosed translocation conduit to the cell surface, allowing the transporter to power the entire process. We identified Vi antigen biosynthesis genetic loci in genera of theBurkholderiales, which are paradoxically distinguished fromS.Typhi by encoding VexL, a predicted pectate lyase homolog. Biochemical analyses demonstrated that VexL is an unusual metal-independent endolyase with an acidic pH optimum that is specific for O-acetylated Vi antigen. A 1.22-Å crystal structure of the VexL-Vi antigen complex revealed features which distinguish common secreted catabolic pectate lyases from periplasmic VexL, which participates in cell-surface assembly. VexL possesses a right-handed parallel β-superhelix, of which one face forms an electropositive glycan-binding groove with an extensive hydrogen bonding network that includes Vi antigen acetyl groups and confers substrate specificity. VexL provided a probe to interrogate conserved features of the ABC transporter-dependent export model. When introduced intoS. Typhi, VexL localized to the periplasm and degraded Vi antigen. In contrast, a cytosolic derivative had no effect unless export was disrupted. These data provide evidence that CPS assembled in ABC transporter-dependent systems is actually exposed to the periplasm during envelope translocation.

scholarly journals Cloning and Characterization of an Esophageal-Gland-Specific Chorismate Mutase from the Phytoparasitic Nematode Meloidogyne javanica

1999 ◽  
Vol 12 (4) ◽  
pp. 328-336 ◽  
Author(s):  
Kris N. Lambert ◽  
Keith D. Allen ◽  
Ian M. Sussex
Keyword(s):  
Cell Formation ◽  
Shikimate Pathway ◽  
Aromatic Amino Acids ◽  
Meloidogyne Javanica ◽  
Giant Cells ◽  
Chorismate Mutase ◽  
Root Knot Nematode ◽  
Esophageal Gland ◽  
Giant Cell Formation

Root-knot nematodes are obligate plant parasites that alter plant cell growth and development by inducing the formation of giant feeder cells. It is thought that nematodes inject secretions from their esophageal glands into plant cells while feeding, and that these secretions cause giant cell formation. To elucidate the mechanisms underlying the formation of giant cells, a strategy was developed to clone esophageal gland genes from the root-knot nematode Meloidogyne javanica. One clone, shown to be expressed in the nematode's esophageal gland, codes for a potentially secreted chorismate mutase (CM). CM is a key branch-point regulatory enzyme in the shikimate pathway and converts chorismate to prephenate, a precursor of phenylalanine and tyrosine. The shikimate pathway is not found in animals, but in plants, where it produces aromatic amino acids and derivative compounds that play critical roles in growth and defense. Therefore, we hypothesize that this CM is involved in allowing nematodes to parasitize plants.

scholarly journals Cloning and Characterization of Pectate Lyases Expressed in the Esophageal Gland of the Pine Wood Nematode Bursaphelenchus xylophilus

2006 ◽  
Vol 19 (3) ◽  
pp. 280-287 ◽  
Author(s):  
Taisei Kikuchi ◽  
Hajime Shibuya ◽  
Takuya Aikawa ◽  
John T. Jones
Keyword(s):  
Pectate Lyase ◽  
Bursaphelenchus Xylophilus ◽  
Amino Acid Sequences ◽  
Parasitic Nematodes ◽  
Pine Wood Nematode ◽  
Pine Wood ◽  
Polysaccharide Lyase ◽  
Pectate Lyases ◽  
Esophageal Gland ◽  
And Migration

Two pectate lyase genes (Bx-pel-1 and Bx-pel-2) were cloned from the pine wood nematode, Bursaphelenchus xy-lophilus. The deduced amino acid sequences of these pectate lyases are most similar to polysaccharide lyase family 3 proteins. Recombinant BxPEL1 showed highest activity on polygalacturonic acid and lower activity on more highly methylated pectin. Recombinant BxPEL1 demonstrated full dependency on Ca2+ for activity and optimal activity at 55°C and pH 8 to 10 like other pectate lyases of polysaccharide lyase family 3. The protein sequences have predicted signal peptides at their N-termini and the genes are expressed solely in the esophageal gland cells of the nematode, indicating that the pectate lyases could be secreted into plant tissues to help feeding and migration in the tree. This study suggests that pectate lyases are widely distributed in plant-parasitic nematodes and play an important role in plant-nematode interactions.

scholarly journals Mineral composition of beetroot treated with potential elicitors and inoculated with Meloidogyne javanica

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Paula Juliana Grotto Débia ◽  
Beatriz Cervejeira Bolanho ◽  
Claudia Regina Dias-Arieira
Keyword(s):  
Population Density ◽  
Mineral Composition ◽  
Integrated Management ◽  
Meloidogyne Javanica ◽  
Nematode Population ◽  
Root Knot Nematode ◽  
Cu Content ◽  
Manganese Zinc ◽  
Nematode Population Density ◽  
Elicitor Treatments

Abstract Background The root-knot nematode Meloidogyne javanica can infect beetroots, causing extensive damage to this food crop. As chemical and genetic control tactics have shown limited efficacy, new strategies are needed to improve the integrated management of this parasite. This study assessed the influence of potential defence elicitors and M. javanica infection on the mineral composition of beetroot. Plants were treated with acibenzolar-S-methyl (ASM), citrus biomass, or a mannanoligosaccharide-based product (MOS) and inoculated with 1000 eggs and second-stage juveniles of M. javanica. At 60 days after inoculation, beetroot plants were harvested and evaluated for nematode population density, vegetative growth, and mineral content. Results All potential elicitors reduced nematode population density in beetroots (p ≤ 0.10) and improved the vegetative parameters of inoculated plants (p ≤ 0.05), except shoot fresh weight. Some minerals were found to be negatively affected by treatments, particularly calcium, whose levels were consistently lower in treated plants. On the other hand, M. javanica inoculation increased magnesium, iron, manganese, zinc, and copper contents in beetroots. However, the latter mineral (Cu content) of inoculated plants was positively influenced by MOS and ASM. Conclusion Potential elicitor treatments did not improve the mineral composition of beetroot, but were effective in reducing nematode population density. Plants inoculated with M. javanica had higher mineral levels. However, gall formation decreases the commercial value of the crop and might render it unsuitable for commercialisation. M. javanica-infected beetroots may be used for nutrient extraction or sold to food processing industries.

scholarly journals Pectate lyase C from Bacillus subtilis: a novel endo-cleaving enzyme with activity on highly methylated pectin

Microbiology ◽  
2006 ◽  
Vol 152 (3) ◽  
pp. 617-625 ◽  
Author(s):  
Margarita Soriano ◽  
Pilar Diaz ◽  
Francisco I. Javier Pastor
Keyword(s):  
Bacillus Subtilis ◽  
Pectate Lyase ◽  
Maximum Activity ◽  
Methyl Esterification ◽  
Pectate Lyases ◽  
Action Analysis ◽  
Paenibacillus Barcinonensis ◽  
Esterification Degree ◽  
Micro Organisms ◽  
High Degree

The gene yvpA from Bacillus subtilis was cloned and expressed in Escherichia coli. It encoded a pectate lyase of 221 amino acids that was denominated PelC. The heterologously expressed enzyme was purified by His-tag affinity chromatography and characterized. PelC depolymerized polygalacturonate and pectins of methyl esterification degree from 22 % to 89 %, exhibiting maximum activity on 22 % esterified citrus pectin. It showed an absolute Ca2+ requirement and the optimum temperature and pH were 65 °C and pH 10, respectively. The deduced amino acid sequence of PelC showed 53 % identity to pectate lyase PelA from Paenibacillus barcinonensis, which was also characterized. Similarly to PelC, purified PelA showed activity on polygalacturonate and pectins with a high degree of methyl esterification. The two enzymes cleaved pectic polymers to a mixture of oligogalacturonates, indicating an endo mode of action. Analysis of activity on trigalacturonate showed that PelC cleaved it to galacturonic acid and unsaturated digalacturonate, whereas PelA did not show activity on this substrate. PelC and PelA showed high homology to a few recently identified pectate lyases of family 3 and form with them a cluster of small-sized pectate lyases from non-pathogenic micro-organisms.

The effect of organic compost of Caryocar brasiliense waste against Meloidogyne javanica in two vegetable crops

Nematology ◽  
2021 ◽  
pp. 1-8
Author(s):  
Fabíola de J. Silva ◽  
Regina C.F. Ribeiro ◽  
Adelica A. Xavier ◽  
Vanessa A. Gomes ◽  
Paulo V.M. Pacheco ◽  
...  
Keyword(s):  
Integrated Control ◽  
Meloidogyne Javanica ◽  
Control Measures ◽  
Vegetable Crops ◽  
Root Knot Nematode ◽  
Second Stage ◽  
Tomato Roots ◽  
Crop Development ◽  
Caryocar Brasiliense ◽  
Organic Compost

Summary Root-knot nematodes (Meloidogyne spp.) are responsible for various significant crop losses, which require taking integrated control measures. The present study aimed to identify a possible sustainable approach to the management of Meloidogyne javanica in vegetable crops using an organic compound based on pequi (Caryocar brasiliense) fruit residues. A pot experiment was conducted using cultivars of tomato and lettuce susceptible to M. javanica, with three amendments including inorganic fertiliser, cattle manure and five doses of organic compost with pequi residues. All treatments were inoculated with second-stage juveniles of M. javanica to simulate the root-knot nematode disease in field conditions. Increasing doses of organic compost with pequi residues from 5 kg m−3 to 30 kg m−3 promoted a significant decrease in the nematode population in both cultures evaluated. Organic compost (30 kg m−3) reduced the numbers of galls and eggs of M. javanica by 41.6 and 46.5% in tomato roots, and by 80.3 and 59.2% in lettuce roots, respectively, compared with non-treated control. Organic compost also increased crop development considerably. In general, there was a 43.0% increase in plant development compared to non-treated control. Hence, organic compost of pequi residues could be an alternative to toxic chemical nematicides and recommended as eco-friendly management of M. javanica in vegetable crops.

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