Induction of Microbial Genes for Pathogenesis and Symbiosis by Chemicals from Root Border Cells

Zhu, Yanmin; Pierson, Leland S.; Hawes, Martha C.

doi:10.1104/pp.115.4.1691

Cited by 65 publications

(24 citation statements)

References 37 publications

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“…However, the primary source of exudates in most species is not the region of elongation but the root tip itself (Griffin et al 1976;McDougall and Rovira 1970;Schroth and Snyder 1961). In addition, the release of specific products-such as flavonoids, that influence infection by symbiotic bacteria and fungi-also predominates at the root tip rather than at the site of infection behind the root tip (Peters and Long 1988;Zhu et al 1997). If exudation patterns do play a role in localized root infection, then altering root exudation could be predicted to result in a change in infection patterns.…”

Section: Introductionmentioning

confidence: 96%

Altered susceptibility to infection by Sinorhizobium meliloti and Nectria haematococca in alfalfa roots with altered cell cycle

2004

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Most infections of plant roots are initiated in the region of elongation; the mechanism for this tissue-specific localization pattern is unknown. In alfalfa expressing PsUGT1 antisense mRNA under the control of the cauliflower mosaic virus (CaMV) 35S promoter, the cell cycle in roots is completed in 48 h instead of 24 h, and border cell number is decreased by more than 99%. These plants were found to exhibit increased root-tip infection by a fungal pathogen and reduced nodule formation by a bacterial symbiont. Thus, the frequency of infection in the region of elongation by Nectria haematocca was unaffected, but infection of the root tip was increased by more than 90%; early stages of Sinorhizobium meliloti infection and nodule morphology were normal, but the frequency of nodulation was fourfold lower than in wild-type roots.

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Section: Introductionmentioning

confidence: 96%

Altered susceptibility to infection by Sinorhizobium meliloti and Nectria haematococca in alfalfa roots with altered cell cycle

2004

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“…Border cells can act by forming a boundary that inhibits accumulation of certain bacteria or alternatively by attracting and providing nutrients to other bacteria species (Hawes et al, 1998). Furthermore, Zhu et al (1997) have demonstrated that chemicals released by root border cells can regulate the expression of bacterial genes required for the establishment of plant-microbe associations.…”

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confidence: 99%

Root Border-Like Cells of Arabidopsis. Microscopical Characterization and Role in the Interaction with Rhizobacteria

et al. 2005

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Plant roots of many species produce thousands of cells that are released daily into the rhizosphere. These cells are commonly termed border cells because of their major role in constituting a biotic boundary layer between the root surface and the soil. In this study, we investigated the occurrence and ultrastructure of such cells in Arabidopsis (Arabidopsis thaliana) using light and electron microscopy coupled to high-pressure freezing. The secretion of cell wall molecules including pectic polysaccharides and arabinogalactan-proteins (AGPs) was examined also using immunofluorescence microscopy and a set of anticarbohydrate antibodies. We show that root tips of Arabidopsis seedlings released cell layers in an organized pattern that differs from the rather randomly dispersed release observed in other plant species studied to date. Therefore, we termed such cells border-like cells (BLC). Electron microscopical results revealed that BLC are rich in mitochondria, Golgi stacks, and Golgi-derived vesicles, suggesting that these cells are actively engaged in secretion of materials to their cell walls. Immunocytochemical data demonstrated that pectins as well as AGPs are among secreted material as revealed by the high level of expression of AGPepitopes. In particular, the JIM13-AGP epitope was found exclusively associated with BLC and peripheral cells in the root cap region. In addition, we investigated the function of BLC and root cap cell AGPs in the interaction with rhizobacteria using AGP-disrupting agents and a strain of Rhizobium sp. expressing a green fluorescent protein. Our findings demonstrate that alteration of AGPs significantly inhibits the attachment of the bacteria to the surface of BLC and root tip.Many plants can produce large numbers of metabolically active root ''border'' cells that are programmed to separate from each other and to be released from the root tip periphery into the external environment (Brigham et al., 1995a;Hawes et al., 1998). Root border cells are defined as cells that are released into solution within seconds when root tips are placed into water (Hawes et al., 2000(Hawes et al., , 2003. In the absence of free water, these cells remain adherent to the root tips. The border cells of most species remain viable even after separation from the root tips (Hawes et al., 2000) and can survive independently from roots in vitro as well as in natural field conditions. Interestingly, border cells can undergo cell division in vitro and develop into callus tissue (Hawes and Lin, 1990).As to the role of the border cells, Brigham et al. (1995b) have proposed that these cells are differentiated tissue of the root system that modulates the environment of the plant root by producing specific substances to be released into the rhizosphere. Proteins synthesized in border cells exhibit profiles that are distinct, qualitatively and quantitatively, from those synthesized in the root tips (Brigham et al., 1995b). These important differences in protein expression profiles are correlated with similarly distinct...

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“…These cells, termed border cells for their ability to form a protective border around the root tip, are separate from the root, but appressed to it by a water-soluble polysaccharide matrix (Hawes et al, 2000). Border cells are much more than by-products of root cap growth and have been shown to attract and immobilize nematodes, produce defence structures in response to fungi, bind and repel bacteria, and increase mucilage production in response to aluminum (Zhu et al, 1997;Hawes et al, 2000;Miyasaka & Hawes, 2001;Woo et al, 2004;Humphris et al, 2005). Border cells appear within 48-72 hours after germination (Colour Plates 11.2a, b, c and d) and once a species-specific number of border cells are produced, root cap turnover ceases and border cells remain appressed to the root until exposed to water.…”

Section: Spatially Resolved Metabolomics Of Alfalfa (Medicago Sativa)mentioning

confidence: 99%

Spatially Resolved Plant Metabolomics

Sumner

Yang

Bench

et al. 2011

Annual Plant Reviews Volume 43

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Primary and secondary metabolism of plants are segregated amidst many differentiated and specialized plant organs, tissues, cells and organelles. The specialized physiology of anatomically distinct components contribute to highly sophisticated, autotrophic systems that are foundational to global energy, ecology, biology and nutrition. An established literature base exists for focused studies of metabolism in specific organs, tissue, cells, and this literature is briefly reviewed here. However, modern metabolic studies are moving towards more global metabolite analyses (i.e. metabolomics and systems biology) with high anatomical, spatial and temporal resolution to better understand the massive complexity of plant systems. Several current examples of such spatially resolved metabolomics experiments are provided here, and the current prospects of metabolite imaging reviewed. Although current metabolomics approaches have been quite informative, they are still constrained by multiple factors. The major challenges that still face plant metabolomics are metabolite annotation, depth-of-coverage or comprehensiveness, instrumental sensitivity and dynamic range. These plant metabolomics challenges are discussed in general and relative to temporally and spatially resolved metabolomics.

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Induction of Microbial Genes for Pathogenesis and Symbiosis by Chemicals from Root Border Cells

Cited by 65 publications

References 37 publications

Altered susceptibility to infection by Sinorhizobium meliloti and Nectria haematococca in alfalfa roots with altered cell cycle

Altered susceptibility to infection by Sinorhizobium meliloti and Nectria haematococca in alfalfa roots with altered cell cycle

Root Border-Like Cells of Arabidopsis. Microscopical Characterization and Role in the Interaction with Rhizobacteria

Spatially Resolved Plant Metabolomics

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