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de Almeida Engler J.,French National Institute for Agricultural Research | Vieira P.,University of Evora | Rodiuc N.,Laboratorio Of Interacao Molecular Planta Praga | Grossi de Sa M.F.,Laboratorio Of Interacao Molecular Planta Praga | Engler G.,French National Institute for Agricultural Research
Advances in Botanical Research | Year: 2015

Plant-parasitic nematodes, like root-knot and cyst nematodes, usurp and modulate the plant cell cycle machinery in their favour. Both, the plant mitotic cycle and the endocycle, are essential targets for a successful susceptible interaction between the host plant and these pathogens. Key cell cycle genes, as well as their inhibitor genes, are important components to allow the induction and maintenance of the nematode feeding site (NFS) development. Giant cells undergo acytokinetic mitosis and DNA endoreduplication and are surrounded by rapidly dividing neighbouring cells. Nuclei in an initial syncytial cell do not divide and an increase in nuclei number results from cell fusion followed by endoreduplication. Cells neighbouring syncytia undergo active mitosis before their incorporation into the NFS. The increase of ploidy levels in nuclei of feeding cells most likely sustains their high metabolic activity needed for the nematode growth and reproduction. Functional analysis using adapted microscopy approaches allowed us to gain insight into the role of core cell cycle components in these intriguing feeding sites. In addition, we describe some imaging methods that were developed to investigate nuclear behaviour and how the cell cycle progress in the complex nematode feeding structures of plant host roots. © 2015 Elsevier Ltd. Source

Vieira P.,French National Institute for Agricultural Research | Vieira P.,University of Evora | De Clercq A.,Vlaams Institute for Biotechnology | De Clercq A.,Ghent University | And 27 more authors.
Plant Cell | Year: 2014

In Arabidopsis thaliana, seven cyclin-dependent kinase (CDK) inhibitors have been identified, designated interactors of CDKs or Kip-related proteins (KRPs). Here, the function of KRP6 was investigated during cell cycle progression in roots infected by plant-parasitic root-knot nematodes. Contrary to expectations, analysis of Meloidogyne incognita-induced galls of KRP6-overexpressing lines revealed a role for this particular KRP as an activator of the mitotic cell cycle. In accordance, KRP6-overexpressing suspension cultures displayed accelerated entry into mitosis, but delayed mitotic progression. Likewise, phenotypic analysis of cultured cells and nematode-induced giant cells revealed a failure in mitotic exit, with the appearance of multinucleated cells as a consequence. Strong KRP6 expression upon nematode infection and the phenotypic resemblance between KRP6 overexpression cell cultures and root-knot morphology point toward the involvement of KRP6 in the multinucleate and acytokinetic state of giant cells. Along these lines, the parasite might have evolved to manipulate plant KRP6 transcription to the benefit of gall establishment. © 2014 American Society of Plant Biologists. All rights reserved. Source

Rodiuc N.,Laboratorio Of Interacao Molecular Planta Praga | Vieira P.,University of Evora | Banora M.Y.,Ain Shams University | de Almeida Engler J.,Laboratorio Of Interacao Molecular Planta Praga | de Almeida Engler J.,French National Institute for Agricultural Research
Frontiers in Plant Science | Year: 2014

Transfer cells are ubiquitous plant cells that play an important role in plant development as well as in responses to biotic and abiotic stresses. They are highly specialized and differentiated cells playing a central role in the acquisition, distribution and exchange of nutrients. Their unique structural traits are characterized by augmented ingrowths of invaginated secondary wall material, unsheathed by an amplified area of plasma membrane enriched in a suite of solute transporters. Similar morphological features can be perceived in vascular root feeding cells induced by sedentary plant-parasitic nematodes, such as root-knot and cyst nematodes, in a wide range of plant hosts. Despite their close phylogenetic relationship, these obligatory biotrophic plant pathogens engage different approaches when reprogramming root cells into giant cells or syncytia, respectively. Both nematode feeding-cells types will serve as the main source of nutrients until the end of the nematode life cycle. In both cases, these nematodes are able to remarkably maneuver and reprogram plant host cells. In this review we will discuss the structure, function and formation of these specialized multinucleate cells that act as nutrient transfer cells accumulating and synthesizing components needed for survival and successful offspring of plant-parasitic nematodes. Plant cells with transfer-like functions are also a renowned subject of interest involving still poorly understood molecular and cellular transport processes. © 2014 Rodiuc, Vieira, Banora and de Almeida Engler. Source

Oliveira M.B.,Federal University of Goais | Junior M.L.,Embrapa Arroz e Feijao | Grossi-de-Sa M.F.,Laboratorio Of Interacao Molecular Planta Praga | Petrofeza S.,Federal University of Goais
Journal of Plant Physiology | Year: 2015

Sclerotinia sclerotiorum (Lib.) de Bary is a necrotrophic fungal pathogen that causes a disease known as white mold, which is a major problem for dry bean (Phaseolus vulgaris L.) and other crops in many growing areas in Brazil. To investigate the role of methyl jasmonate (MeJA) in defending dry bean plants against S. sclerotiorum, we used suppression subtractive hybridization (SSH) of cDNA and identified genes that are differentially expressed during plant-pathogen interactions after treatment. Exogenous MeJA application enhanced resistance to the pathogen, and SSH analyses led to the identification of 94 unigenes, presumably involved in a variety of functions, which were classified into several functional categories, including metabolism, signal transduction, protein biogenesis and degradation, and cell defense and rescue. Using RT-qPCR, some unigenes were found to be differentially expressed in a time-dependent manner in dry bean plants during the interaction with S. sclerotiorum after MeJA treatment, including the pathogenesis-related protein PR3 (chitinase), PvCallose (callose synthase), PvNBS-LRR (NBS-LRR resistance-like protein), PvF-box (F-box family protein-like), and a polygalacturonase inhibitor protein (PGIP). Based on these expression data, the putative roles of differentially expressed genes were discussed in relation to the disease and MeJA resistance induction. Changes in the activity of the pathogenesis-related proteins β-1,3-glucanase, chitinase, phenylalanine ammonia-lyase, and peroxidase in plants after MeJA treatment and following inoculation of the pathogen were also investigated as molecular markers of induced resistance. Foliar application of MeJA induced partial resistance against S. sclerotiorum in plants as well as a consistent increase in pathogenesis-related protein activities. Our findings provide new insights into the physiological and molecular mechanisms of resistance induced by MeJA in the P. vulgaris-. S. sclerotiorum pathosystem. © 2015 Elsevier GmbH. Source

Oliveira M.B.,Federal University of Goais | de Andrade R.V.,Catholic University of Brasilia | Grossi-de-Sa M.F.,Catholic University of Brasilia | Grossi-de-Sa M.F.,Laboratorio Of Interacao Molecular Planta Praga | Petrofeza S.,Federal University of Goais
Frontiers in Microbiology | Year: 2015

The fungus Sclerotinia sclerotiorum (Lib.) de Bary, one of the most important plant pathogens, causes white mold on a wide range of crops. Crop yield can be dramatically decreased due to this disease, depending on the plant cultivar and environmental conditions. In this study, a suppression subtractive hybridization cDNA library approach was used for the identification of pathogen and plant genes that were differentially expressed during infection of the susceptible cultivar BRS Pérola of Phaseolus vulgaris L. A total of 979 unigenes (430 contigs and 549 singletons) were obtained and classified according to their functional categories. The transcriptional profile of 11 fungal genes related to pathogenicity and virulence were evaluated by reverse transcription quantitative real-time polymerase chain reaction (RT-qPCR). Additionally, the temporal expression profile obtained by RT-qPCR was evaluated for the following categories of plant defense-related genes: pathogenesis-related genes (PvPR1, PvPR2, and PvPR3), phenylpropanoid pathway genes (PvIsof, PvFPS1, and 4CL), and genes involved in defense and stress-related categories (PvLox, PvHiprp, PvGST, PvPod, and PvDox). Data obtained in this study provide a starting point for achieving a better understanding of the pathosystem S. sclerotiorum-P. vulgaris. © 2015 Oliveira, de Andrade, Grossi-de-Sá and Petrofeza. Source

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