scholarly journals Nematode-Induced Changes of Transporter Gene Expression in Arabidopsis Roots

2005 ◽  
Vol 18 (12) ◽  
pp. 1247-1257 ◽  
Author(s):  
Ulrich Z. Hammes ◽  
Daniel P. Schachtman ◽  
R. Howard Berg ◽  
Erik Nielsen ◽  
Wolfgang Koch ◽  
...  
Keyword(s):  
Gene Families ◽  
Transcript Abundance ◽  
Giant Cells ◽  
Transport Processes ◽  
Transfer Cells ◽  
Parasitic Nematodes ◽  
Feeding Site ◽  
Feeding Sites ◽  
The Many ◽  
And Function

Root-knot plant-parasitic nematodes (Meloidogyne spp.) account for much of the damage inflicted to plants by nematodes. The feeding sites of these nematodes consist of “giant” cells, which have characteristics of transfer cells found in other parts of plants. Increased transport activity across the plasma membrane is a hallmark of transfer cells, and giant cells provide nutrition for nematodes; therefore, we initiated a study to identify the transport processes that contribute to the development and function of nematode-induced feeding sites. The study was conducted over a 4-week period, during which time the large changes in the development of giant cells were documented. The Arabidopsis ATH1 GeneChip was used to identify the many transporter genes that were regulated by nematode infestation. Expression of 50 transporter genes from 18 different gene families was significantly changed upon nematode infestation. Sixteen transporter genes were studied in more detail using real-time reverse-transcriptase polymerase chain reaction to determine transcript abundance in nematode-induced galls that contain giant cells and uninfested regions of the root. Certain genes were expressed primarily in galls whereas others were expressed primarily in the uninfested regions of the root, and a third group was expressed evenly throughout the root. Multiple transport processes are regulated and these may play important roles in nematode feeding-site establishment and maintenance.

scholarly journals Differences in Feeding Sites Induced by Root-Knot Nematodes, Meloidogyne spp., in Chickpea

2005 ◽  
Vol 95 (4) ◽  
pp. 368-375 ◽  
Author(s):  
Nicola Vovlas ◽  
Hava F. Rapoport ◽  
Rafael M. Jiménez Díaz ◽  
Pablo Castillo
Keyword(s):  
Giant Cell ◽  
Faba Bean ◽  
Nematode Species ◽  
Giant Cells ◽  
The Other ◽  
Root Knot Nematodes ◽  
Feeding Site ◽  
Feeding Sites ◽  
Meloidogyne Spp ◽  
Meloidogyne Species

Root-knot nematodes (Meloidogyne spp.) are sedentary, obligate endoparasites in plants, where they induce specialized feeding sites. The feeding sites act as strong metabolic sinks to which photosynthates are mobilized. The histopathological modifications in the nematode-induced feeding sites of artificially inoculated chickpea cv. UC 27 were qualitatively and quantitatively compared using five isolates of M. artiellia and one isolate each of M. arenaria, M. incognita, and M. javanica. All Meloidogyne isolates infected chickpea plants, but root gall thickening was significantly less for M. artiellia isolates than for the other Meloidogyne species. Nevertheless, neither the number of giant cells in the feeding site (averaging four to six) nor the area of individual giant cells was influenced by nematode species or isolate. However, the number of nuclei per giant cell was significantly smaller, and the maximum diameters of nuclei and nucleoli were significantly greater, in giant cells induced by M. artiellia isolates than in those induced by M. arenaria, M. incognita, or M. javanica. In a second experiment, M. artiellia-induced giant cells in faba bean and rapeseed also contained a small number of large nuclei.

scholarly journals Effectors of Root-Knot Nematodes: An Arsenal for Successful Parasitism

2021 ◽  
Vol 12 ◽  
Author(s):  
Shounak Jagdale ◽  
Uma Rao ◽  
Ashok P. Giri
Keyword(s):  
Plant Immunity ◽  
Plant Defence ◽  
Giant Cells ◽  
Parasitic Nematodes ◽  
Plant Parasitic Nematodes ◽  
Root Knot Nematodes ◽  
Feeding Sites ◽  
The Past ◽  
Complex Functions ◽  
Insight Into

Root-knot nematodes (RKNs) are notorious plant-parasitic nematodes first recorded in 1855 in cucumber plants. They are microscopic, obligate endoparasites that cause severe losses in agriculture and horticulture. They evade plant immunity, hijack the plant cell cycle, and metabolism to modify healthy cells into giant cells (GCs) – RKN feeding sites. RKNs secrete various effector molecules which suppress the plant defence and tamper with plant cellular and molecular biology. These effectors originate mainly from sub-ventral and dorsal oesophageal glands. Recently, a few non-oesophageal gland secreted effectors have been discovered. Effectors are essential for the entry of RKNs in plants, subsequently formation and maintenance of the GCs during the parasitism. In the past two decades, advanced genomic and post-genomic techniques identified many effectors, out of which only a few are well characterized. In this review, we provide molecular and functional details of RKN effectors secreted during parasitism. We list the known effectors and pinpoint their molecular functions. Moreover, we attempt to provide a comprehensive insight into RKN effectors concerning their implications on overall plant and nematode biology. Since effectors are the primary and prime molecular weapons of RKNs to invade the plant, it is imperative to understand their intriguing and complex functions to design counter-strategies against RKN infection.

scholarly journals A Distinct Role of Pectate Lyases in the Formation of Feeding Structures Induced by Cyst and Root-Knot Nematodes

2014 ◽  
Vol 27 (9) ◽  
pp. 901-912 ◽  
Author(s):  
K. Wieczorek ◽  
A. Elashry ◽  
M. Quentin ◽  
F. M. W. Grundler ◽  
B. Favery ◽  
...  
Keyword(s):  
Cell Wall ◽  
Plant Cell Wall ◽  
Middle Lamella ◽  
Giant Cells ◽  
Heterodera Schachtii ◽  
Parasitic Nematodes ◽  
Rt Pcr ◽  
Cell Wall Degrading Enzymes ◽  
Feeding Sites

Pectin in the primary plant cell wall is thought to be responsible for its porosity, charge density, and microfibril spacing and is the main component of the middle lamella. Plant-parasitic nematodes secrete cell wall–degrading enzymes that macerate the plant tissue, facilitating the penetration and migration within the roots. In sedentary endoparasitic nematodes, these enzymes are released only during the migration of infective juveniles through the root. Later, nematodes manipulate the expression of host plant genes, including various cell wall enzymes, in order to induce specific feeding sites. In this study, we investigated expression of two Arabidopsis pectate lyase-like genes (PLL), PLL18 (At3g27400) and PLL19 (At4g24780), together with pectic epitopes with different degrees of methylesterification in both syncytia induced by the cyst nematode Heterodera schachtii and giant cells induced by the root-knot nematode Meloidogyne incognita. We confirmed upregulation of PLL18 and PLL19 in both types of feeding sites with quantitative reverse-transcriptase polymerase chain reaction (RT-PCR) and in situ RT-PCR. Furthermore, the functional analysis of mutants demonstrated the important role of both PLL genes in the development and maintenance of syncytia but not giant cells. Our results show that both enzymes play distinct roles in different infected root tissues as well as during parasitism of different nematodes.

scholarly journals Multiple Nodulation Genes Are Up-Regulated During Establishment of Reniform Nematode Feeding Sites in Soybean

2018 ◽  
Vol 108 (2) ◽  
pp. 275-291 ◽  
Author(s):  
Nathan W. Redding ◽  
Paula Agudelo ◽  
Christina E. Wells
Keyword(s):  
Syncytium Formation ◽  
Parasitic Nematodes ◽  
Nodule Formation ◽  
Cell Cycle Regulators ◽  
Reniform Nematode ◽  
Feeding Site ◽  
Sugar Transporters ◽  
Feeding Sites ◽  
Growth System ◽  
And Control

The semi-endoparastic reniform nematode (Rotylenchulus reniformis) infects over 300 plant species. Females penetrate host roots and induce formation of complex, multinucleate feeding sites called syncytia. While anatomical changes associated with reniform nematode infection are well documented, little is known about their molecular basis. We grew soybean (Glycine max) in a split-root growth system, inoculated half of each root system with R. reniformis, and quantified gene expression in infected and control root tissue at four dates after inoculation. Over 6,000 genes were differentially expressed between inoculated and control roots on at least one date (false discovery rate [FDR] = 0.01, |log2FC| ≥ 1), and 507 gene sets were significantly enriched or depleted in inoculated roots (FDR = 0.05). Numerous genes up-regulated during syncytium formation had previously been associated with rhizobia nodulation. These included the nodule-initiating transcription factors CYCLOPS, NSP1, NSP2, and NIN, as well as multiple nodulins associated with the plant-derived peribacteroid membrane. Nodulation-related NIP aquaporins and SWEET sugar transporters were induced, as were plant CLAVATA3/ESR-related (CLE) signaling proteins and cell cycle regulators such as CCS52A and E2F. Nodulins and nodule-associated genes may have ancestral functions in normal root development and mycorrhization that have been co-opted by both parasitic nematodes and rhizobial bacteria to promote feeding site and nodule formation.

scholarly journals Spanning the gap: unraveling RSC dynamics in vivo

2021 ◽  
Author(s):  
Heinz Neumann ◽  
Bryan J. Wilkins
Keyword(s):  
Cell Cycle ◽  
Posttranslational Modifications ◽  
Transcriptional Activation ◽  
Binding Mode ◽  
Binding Modes ◽  
Binding Domains ◽  
Binding Interface ◽  
The Many ◽  
And Function

AbstractMultiple reports over the past 2 years have provided the first complete structural analyses for the essential yeast chromatin remodeler, RSC, providing elaborate molecular details for its engagement with the nucleosome. However, there still remain gaps in resolution, particularly within the many RSC subunits that harbor histone binding domains.Solving contacts at these interfaces is crucial because they are regulated by posttranslational modifications that control remodeler binding modes and function. Modifications are dynamic in nature often corresponding to transcriptional activation states and cell cycle stage, highlighting not only a need for enriched spatial resolution but also temporal understanding of remodeler engagement with the nucleosome. Our recent work sheds light on some of those gaps by exploring the binding interface between the RSC catalytic motor protein, Sth1, and the nucleosome, in the living nucleus. Using genetically encoded photo-activatable amino acids incorporated into histones of living yeast we are able to monitor the nucleosomal binding of RSC, emphasizing the regulatory roles of histone modifications in a spatiotemporal manner. We observe that RSC prefers to bind H2B SUMOylated nucleosomes in vivo and interacts with neighboring nucleosomes via H3K14ac. Additionally, we establish that RSC is constitutively bound to the nucleosome and is not ejected during mitotic chromatin compaction but alters its binding mode as it progresses through the cell cycle. Our data offer a renewed perspective on RSC mechanics under true physiological conditions.

How do nematodes get their sweets? Solute supply to sedentary plant-parasitic nematodes

Nematology ◽  
2007 ◽  
Vol 9 (4) ◽  
pp. 451-458 ◽  
Author(s):  
Julia Hofmann ◽  
Florian Grundler
Keyword(s):  
Nutrient Supply ◽  
Heterodera Schachtii ◽  
Transport Systems ◽  
Parasitic Nematodes ◽  
Plant Parasitic Nematodes ◽  
Cyst Nematodes ◽  
Root Knot Nematodes ◽  
Feeding Sites ◽  
Inorganic Solutes ◽  
Nematode Development

AbstractSedentary cyst and root-knot nematodes withdraw large amounts of solutes from feeding structures induced in host roots. The feeding structures are specialised cells with a high metabolic activity and a tremendous capacity in translocation of nutrients. The required nutrients are provided by the plant transport systems – water and inorganic solutes from the xylem, assimilates such as sugars and amino acids from the phloem. Here we discuss the available data on the mechanisms by which nutrients are translocated into the nematode feeding sites. The interaction between Heterodera schachtii and Arabidopsis thaliana serves as a model system for cyst nematodes. In this case sufficient data are available to propose a conclusive concept for the mechanisms of nutrient flow: basically, in the early stages of nematode development syncytia are symplasmically isolated, so that transport proteins are responsible for the nutrient supply. Later, connections to the phloem via plasmodesmata are established, so that developing females are well supplied with assimilates. The interactions of root-knot nematodes with their hosts share a number of similarities but the data currently available are not sufficient to draw similar conclusions. As nutrient supply and functionality of feeding structures are the basis of biotrophic parasitism of sedentary nematodes, it is tempting to unravel the mechanisms by which both plant and nematodes influence each other via nutrient fluxes.

scholarly journals Molecular and Biochemical Analysis of Periplastidial Starch Metabolism in the Cryptophyte Guillardia theta

2006 ◽  
Vol 5 (6) ◽  
pp. 964-971 ◽  
Author(s):  
Ilka Haferkamp ◽  
Philippe Deschamps ◽  
Michelle Ast ◽  
Wolfgang Jeblick ◽  
Uwe Maier ◽  
...  
Keyword(s):  
Continuous Light ◽  
Subcellular Location ◽  
Transcript Abundance ◽  
Transport Processes ◽  
Phosphate Transporter ◽  
Light Phase ◽  
Abundance Pattern ◽  
Total Enzyme Activity ◽  
Triose Phosphate ◽  
Guillardia Theta

ABSTRACT Starch in synchronously grown Guillardia theta cells accumulates throughout the light phase, followed by a linear degradation during the night. In contrast to the case for other unicellular algae such as Chlamydomonas reinhardtii, no starch turnover occurred in this organism under continuous light. The gene encoding granule-bound starch synthase (GBSS1), the enzyme responsible for amylose synthesis, displays a diurnal expression cycle. The pattern consisted of a maximal transcript abundance around the middle of the light phase and a very low level during the night. This diurnal regulation of GBSS1 transcript abundance was demonstrated to be independent of the circadian clock but tightly light regulated. A similar yet opposite type of regulation pattern was found for two α-amylase isoforms and for one of the two plastidic triose phosphate transporter genes investigated. In these cases, however, the transcript abundance peaked in the night phase. The second plastidic triose phosphate transporter gene had the GBSS1 mRNA abundance pattern. Quantification of the GBSS1 activity revealed that not only gene expression but also total enzyme activity exhibited a maximum in the middle of the light phase. To gain a first insight into the transport processes involved in starch biosynthesis in cryptophytes, we demonstrated the presence of both plastidic triose phosphate transporter and plastidic ATP/ADP transporter activities in proteoliposomes harboring either total membranes or plastid envelope membranes from G. theta. These molecular and biochemical data are discussed with respect to the environmental conditions experienced by G. theta and with respect to the unique subcellular location of starch in cryptophytes.

scholarly journals A Role for AtWRKY23 in Feeding Site Establishment of Plant-Parasitic Nematodes

2008 ◽  
Vol 148 (1) ◽  
pp. 358-368 ◽  
Author(s):  
Wim Grunewald ◽  
Mansour Karimi ◽  
Krzysztof Wieczorek ◽  
Elke Van de Cappelle ◽  
Elisabeth Wischnitzki ◽  
...  
Keyword(s):  
Parasitic Nematodes ◽  
Plant Parasitic Nematodes ◽  
Feeding Site ◽  
Plant Parasitic

THE CRITICALLY ILL CHILD: SICKLE CELL DISEASE CRISES AND THEIR MANAGEMENT

PEDIATRICS ◽  
1971 ◽  
Vol 48 (4) ◽  
pp. 629-635
Author(s):  
Howard A. Pearson ◽  
Louis K. Diamond
Keyword(s):  
Sickle Cell Disease ◽  
Sickle Cell ◽  
Mutant Gene ◽  
Point Of View ◽  
Clinical Aspects ◽  
Cell Disease ◽  
Form And Function ◽  
Heterozygous Form ◽  
The Many ◽  
And Function

This brief review, being limited in scope to the recognition and management of the life-threatening and painful crises in infants and children with sickle-cell disease, has not even touched on the intriguing mystery of the molecular basis for the sickling phenomenon–how one amino-acid substitution (gene controlled) in the beta chain sequence of 146 amino acids can cause such serious disruption in form and function; or how this mutation occurred in the first place and why it has persisted in contrast to the rapid disappearance of many other deleterious mutants. Nor has there been even mention of the many milder symptoms, signs, and complications due to the presence of Hb. S., either in the homozygous (disease-producing) state or heterozygous form when found in combination with other hereditary hemoglobin defects. The accumulated knowledge about this mutant gene, its biochemical effects, and geographic distribution is enormous. From a fundamental scientific standpoint, sickle cell disease is one of the best understood of human afflictions. However, from a practical point of view treatment of the patient himself is often only symptomatic and palliative. Nevertheless, prompt and effective therapy of the myriad manifestations of sickle cell disease can effectively reduce morbidity and mortality. The pediatrician who cares for black children in his practice should be familiar with the cardinal diagnostic and clinical aspects of sickle cell disease and its crises.

scholarly journals Serotonin Regulates the Feeding and Reproductive Behaviors of Pratylenchus penetrans

2017 ◽  
Vol 107 (7) ◽  
pp. 872-877 ◽  
Author(s):  
Ziduan Han ◽  
Stephanie Boas ◽  
Nathan E. Schroeder
Keyword(s):  
Parasitic Nematodes ◽  
Male Mating ◽  
Pratylenchus Penetrans ◽  
Root Knot Nematodes ◽  
Reproductive Behaviors ◽  
Diverse Range ◽  
Lesion Nematodes ◽  
And Function ◽  
Plant Parasitic

The success of all plant-parasitic nematodes is dependent on the completion of several complex behaviors. The lesion nematode Pratylenchus penetrans is an economically important parasite of a diverse range of plant hosts. Unlike the cyst and root-knot nematodes, P. penetrans moves both within and outside of the host roots and can feed from both locations. Adult females of P. penetrans require insemination by actively moving males for reproduction and can lay eggs both within and outside of the host roots. We do not have a complete understanding of the molecular basis for these behaviors. One candidate modulator of these behaviors is the neurotransmitter serotonin. Previous research demonstrated an effect of exogenously applied serotonin on the feeding and male mating behaviors of cyst and root-knot nematodes. However, there are no data on the role of exogenous serotonin on lesion nematodes. Similarly, there are no data on the presence and function of endogenous serotonin in any plant-parasitic nematode. Here, we establish that exogenous serotonin applied to P. penetrans regulates both feeding and sex-specific behaviors. Furthermore, using immunohistochemistry and pharmacological assays, our data suggest that P. penetrans utilizes endogenous serotonin to regulate both feeding and sex-specific behaviors.

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