scholarly journals Meloidogyne javanica Chorismate Mutase 1 Alters Plant Cell Development

2003 ◽  
Vol 16 (2) ◽  
pp. 123-131 ◽  
Author(s):  
Elizabeth A. Doyle ◽  
Kris N. Lambert
Keyword(s):  
Plant Cell ◽  
Hairy Roots ◽  
Vascular Tissue ◽  
Lateral Roots ◽  
Cell Formation ◽  
Meloidogyne Javanica ◽  
Giant Cells ◽  
Cell Development ◽  
Chorismate Mutase ◽  
Root Knot Nematodes

Root-knot nematodes are obligate plant parasites that alter plant cell growth and development by inducing the formation of giant cells for feeding. Nematodes inject secretions from their esophageal glands through their stylet and into plant cells to induce giant cell formation. Meloidogyne javanica chorismate mutase 1 (MjCM-1) is one such esophageal gland protein likely to be secreted from the nematode as giant cells form. MjCM-1 has two domains, an N-terminal chorismate mutase (CM) domain and a C-terminal region of unknown function. It is the N-terminal CM domain of the protein that is the predominant form produced in root-knot nematodes. Transgenic expression of MjCM-1 in soybean hairy roots results in a phenotype of reduced and aborted lateral roots. Histological studies demonstrate the absence of vascular tissue in hairy roots expressing MjCM-1. The phenotype of MjCM-1 expressed at low levels can be rescued by the addition of indole-3-acetic acid (IAA), indicating MjCM-1 overexpression reduces IAA biosynthesis. We propose MjCM-1 lowers IAA by causing a competition for chorismate, resulting in an alteration of chorismate-derived metabolites and, ultimately, in plant cell development. Therefore, we hypothesize that MjCM-1 is involved in allowing nematodes to establish a parasitic relationship with the host plant.

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.

Comparative cellular responses in susceptible and resistant soybean cultivars infected by Meloidogyne incognita

Nematology ◽  
2013 ◽  
Vol 15 (6) ◽  
pp. 695-708 ◽  
Author(s):  
Hendrika Fourie ◽  
Hendrika Fourie ◽  
Alexander H. Mc Donald ◽  
Hendrika Fourie ◽  
Alexander H. Mc Donald ◽  
...  
Keyword(s):  
Meloidogyne Incognita ◽  
Vascular Tissue ◽  
Cell Formation ◽  
Giant Cells ◽  
Hypersensitive Reaction ◽  
Resistant Cultivar ◽  
Egg Mass ◽  
Soybean Cultivars ◽  
Nematode Penetration ◽  
Sampling Times

Meloidogyne incognita, a predominant nematode parasite of soybean in South Africa, increasingly threatens production of the crop as it is expanding to maize-producing areas infected by this nematode. The parasitic relationship between M. incognita and soybean were compared on a susceptible and a resistant cultivar in terms of nematode penetration, development, reproduction and fecundity as well as histopathology studies. Second-stage juveniles (J2) of M. incognita were inoculated on roots of a resistant (LS5995) and a susceptible (Prima2000) cultivar in three concurrent but separate glasshouse trials. For pre-infectional studies, root systems of plants were harvested 2, 4, 10, 16 and 20 DAI. Sampling times for the post-infectional experiment were 4, 10, 20 and 30 DAI, whilst those for the histopathology experiment were 2, 4, 10, 20 and 30 DAI. J2 penetrated roots of both cultivars in comparable numbers 2 DAI but vermiform J2 numbers were significantly lower in roots of LS5995 at 4, 16 and 20 DAI. Final (Pf) J2 population density (vermiform plus swollen individuals) in roots of Prima2000 was significantly higher at all sampling times than those in roots of LS5995. Development of M. incognita J2 to third- (J3) and fourth-stage juveniles (J4) was significantly affected by cultivar susceptibility and time, being slower in LS5995. Development of J2 to J3 and J4 or into mature females was also consistently slower in LS5995 for the duration of this experiment. Adult females in roots of Prima2000 produced significantly more (98%) eggs per egg mass and also maintained significantly more egg and J2 numbers (98.5%) per root system 30 DAI than those in roots of LS5995. Histopathological observations showed that J2 penetrated roots of both soybean cultivars and migrated intercellularly to undifferentiated provascular tissue 2 and 4 DAI, with pronounced cellular changes taking place. A hypersensitive reaction was observed 2 DAI in roots of the resistant cultivar. From 10 to 30 DAI giant cell formation in the differentiated vascular tissue in the roots of LS5995 differed substantially from those in roots of Prima2000. Giant cells that developed in roots of the LS5995 were smaller and fewer compared to those in Prima2000. Giant cells in roots of LS5995 also contained empty as well as sub-optimal giant cells with thicker cell walls than those reported for resistant soybean cultivars in earlier studies. The induction, development and maintenance of giant cells in LS5995 proved to be typically retarded.

scholarly journals Silencing SmD1 in Solanaceae alters susceptibility to root-knot nematodes

2020 ◽  
Author(s):  
Joffrey Mejias ◽  
Yongpan Chen ◽  
Nhat-My Truong ◽  
Karine Mulet ◽  
Stéphanie Jaubert-Possamai ◽  
...  
Keyword(s):  
Giant Cell ◽  
Susceptibility Gene ◽  
Cell Formation ◽  
Giant Cells ◽  
R Genes ◽  
Virus Induced Gene Silencing ◽  
Root Cells ◽  
Root Knot Nematodes ◽  
Specific Effector ◽  
Cell Transcriptome

SummaryRoot-knot nematodes (RKNs) are among the most damaging pests of agricultural crops. Indeed, Meloidogyne is an extremely polyphagous genus of nematodes that can infect thousands of plant species. A few genes for resistance (R-genes) to RKNs suitable for use in crop breeding have been identified, and new virulent strains and species of nematode emerge rendering these R-genes ineffective. Effective parasitism is dependent on the secretion, by the RKN, of effectors targeting plant functions, which mediate the reprogramming of root cells into specialised feeding cells. These cells, the giant cells, are essential for RKN development and reproduction. The EFFECTOR 18 protein (EFF18) from M. incognita interacts with the spliceosomal protein SmD1 in Arabidopsis, disrupting its function in alternative splicing regulation and modulating the giant cell transcriptome. We show here that EFF18 is a conserved RKN-specific effector. We also show here that EFF18 effectors also target SmD1 in Nicotiana benthamiana and Solanum lycopersicum. The alteration of SmD1 expression by virus-induced gene silencing (VIGS) in Solanaceae affects giant cell formation and nematode development. Thus, SmD1 is a susceptibility gene and a promising target for the development of broad resistance, especially in Solanaceae, for the control of Meloidogyne spp.

Plant cell development and aging may accelerate in microgravity

2019 ◽  
Vol 157 ◽  
pp. 157-161 ◽  
Author(s):  
Elizabeth Kordyum ◽  
David Chapman ◽  
Vasyl Brykov
Keyword(s):  
Plant Cell ◽  
Cell Development ◽  
Development And Aging

The mechanism of mouse egg-cylinder morphogenesis in vitro

Development ◽  
1981 ◽  
Vol 61 (1) ◽  
pp. 277-287
Author(s):  
A. J. Copp
Keyword(s):  
Giant Cell ◽  
Cell Formation ◽  
Cell Movement ◽  
Giant Cells ◽  
Cell Number ◽  
Dependent Change ◽  
Morphogenesis In Vitro ◽  
Trophoblast Giant Cells

The number of trophoblast giant cells in outgrowths of mouse blastocysts was determined before, during and after egg-cylinder formation in vitro. Giant-cell numbers rose initially but reached a plateau 12 h before the egg cylinder appeared. A secondary increase began 24 h after egg-cylinder formation. Blastocysts whose mural trophectoderm cells were removed before or shortly after attachment in vitro formed egg cylinders at the same time as intact blastocysts but their trophoblast outgrowths contained fewer giant cells at this time. The results support the idea that egg-cylinder formation in vitro is accompanied by a redirection of the polar to mural trophectoderm cell movement which characterizes blastocysts before implantation. The resumption of giant-cell number increase in trophoblast outgrowths after egg-cylinder formation may correspond to secondary giant-cell formation in vivo. It is suggested that a time-dependent change in the strength of trophoblast cell adhesion to the substratum occurs after blastocyst attachment in vitro which restricts the further entry of polar cells into the outgrowth and therefore results in egg-cylinder formation.

PATHOLOGY IN LEUKEMIA COMPLICATED BY FATAL MEASLES

PEDIATRICS ◽  
1958 ◽  
Vol 21 (3) ◽  
pp. 436-442
Author(s):  
C. Lenore Simpson ◽  
Donald Pinkel
Keyword(s):  
Lymph Nodes ◽  
Giant Cell ◽  
Inclusion Bodies ◽  
Fatal Case ◽  
Cell Formation ◽  
Giant Cells ◽  
Giant Cell Formation

A fatal case of measles complicating leukemia in an infant is reported. Giant-cell pneumonia and a few giant cells in lymph nodes were seen as in previously reported cases. In addition, necroses in liver, lymph nodes, thymus, pancreas and kidney associated with giant-cell formation and inclusion bodies were observed.

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