51
|
Dorokhov YL, Shindyapina AV, Sheshukova EV, Komarova TV. Metabolic methanol: molecular pathways and physiological roles. Physiol Rev 2015; 95:603-44. [PMID: 25834233 DOI: 10.1152/physrev.00034.2014] [Citation(s) in RCA: 122] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Methanol has been historically considered an exogenous product that leads only to pathological changes in the human body when consumed. However, in normal, healthy individuals, methanol and its short-lived oxidized product, formaldehyde, are naturally occurring compounds whose functions and origins have received limited attention. There are several sources of human physiological methanol. Fruits, vegetables, and alcoholic beverages are likely the main sources of exogenous methanol in the healthy human body. Metabolic methanol may occur as a result of fermentation by gut bacteria and metabolic processes involving S-adenosyl methionine. Regardless of its source, low levels of methanol in the body are maintained by physiological and metabolic clearance mechanisms. Although human blood contains small amounts of methanol and formaldehyde, the content of these molecules increases sharply after receiving even methanol-free ethanol, indicating an endogenous source of the metabolic methanol present at low levels in the blood regulated by a cluster of genes. Recent studies of the pathogenesis of neurological disorders indicate metabolic formaldehyde as a putative causative agent. The detection of increased formaldehyde content in the blood of both neurological patients and the elderly indicates the important role of genetic and biochemical mechanisms of maintaining low levels of methanol and formaldehyde.
Collapse
Affiliation(s)
- Yuri L Dorokhov
- A. N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, Moscow, Russia; and N. I. Vavilov Institute of General Genetics, Russian Academy of Science, Moscow, Russia
| | - Anastasia V Shindyapina
- A. N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, Moscow, Russia; and N. I. Vavilov Institute of General Genetics, Russian Academy of Science, Moscow, Russia
| | - Ekaterina V Sheshukova
- A. N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, Moscow, Russia; and N. I. Vavilov Institute of General Genetics, Russian Academy of Science, Moscow, Russia
| | - Tatiana V Komarova
- A. N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, Moscow, Russia; and N. I. Vavilov Institute of General Genetics, Russian Academy of Science, Moscow, Russia
| |
Collapse
|
52
|
Lionetti V. PECTOPLATE: the simultaneous phenotyping of pectin methylesterases, pectinases, and oligogalacturonides in plants during biotic stresses. FRONTIERS IN PLANT SCIENCE 2015; 6:331. [PMID: 26029230 PMCID: PMC4429564 DOI: 10.3389/fpls.2015.00331] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Accepted: 04/27/2015] [Indexed: 05/18/2023]
Abstract
Degradation of pectin, a major component of plant cell wall, is important for fungal necrotrophs to achieve a successful infection. The activities of pectin methylesterases (PMEs) from both plants and pathogens and the degree and pattern of pectin methylesterification are critical for the outcome of plant-pathogen interaction. Partial degradation of pectin by pectin degrading enzymes releases oligogalacturonides (OGs), elicitors of plant defense responses. Few analytical techniques are available to monitor pectin methylesterification-modulating machineries and OGs produced during plant pathogen interaction. In the present study, ruthenium red is presented as useful dye to monitor both Botrytis cinerea mycelium growth and the induction of PME activity in plant tissue during fungal infection. Moreover a simple, inexpensive and sensitive method, named PECTOPLATE, is proposed that allows a simultaneous phenotyping of PME and pectinase activities expressed during pathogen infection and of pectinase potential in generating OGs. The results in the manuscript also indicate that PME inhibitors can be used in PECTOPLATE as a tool to discriminate the activities of plant PMEs from those of pathogen PMEs expressed during pathogenesis.
Collapse
Affiliation(s)
- Vincenzo Lionetti
- *Correspondence: Vincenzo Lionetti, Dipartimento di Biologia e Biotecnologie Charles Darwin, Sapienza Università di Roma, Piazzale Aldo Moro 5, 00185 Roma, Italy,
| |
Collapse
|
53
|
Knox JP, Benitez-Alfonso Y. Roles and regulation of plant cell walls surrounding plasmodesmata. CURRENT OPINION IN PLANT BIOLOGY 2014; 22:93-100. [PMID: 25286000 DOI: 10.1016/j.pbi.2014.09.009] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2014] [Revised: 09/16/2014] [Accepted: 09/20/2014] [Indexed: 05/28/2023]
Abstract
In plants, the intercellular transport of simple and complex molecules can occur symplastically through plasmodesmata. These are membranous channels embedded in cell walls that connect neighbouring cells. The properties of the cell walls surrounding plasmodesmata determine their transport capacity and permeability. These cell wall micro-domains are enriched in callose and have a characteristic pectin distribution. Cell wall modifications, leading to changes in plasmodesmata structure, have been reported to occur during development and in response to environmental signals. Cell wall remodelling enzymes target plasmodesmata to rapidly control intercellular communication in situ. Here we describe current knowledge on the composition of cell walls at plasmodesmata sites and on the proteins and signals that modify cell walls to regulate plasmodesmata aperture.
Collapse
Affiliation(s)
- J Paul Knox
- Centre for Plant Sciences, School of Biology, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - Yoselin Benitez-Alfonso
- Centre for Plant Sciences, School of Biology, University of Leeds, Leeds LS2 9JT, United Kingdom.
| |
Collapse
|
54
|
Sénéchal F, Wattier C, Rustérucci C, Pelloux J. Homogalacturonan-modifying enzymes: structure, expression, and roles in plants. JOURNAL OF EXPERIMENTAL BOTANY 2014; 65:5125-60. [PMID: 25056773 PMCID: PMC4400535 DOI: 10.1093/jxb/eru272] [Citation(s) in RCA: 155] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2014] [Revised: 05/20/2014] [Accepted: 05/22/2014] [Indexed: 05/18/2023]
Abstract
Understanding the changes affecting the plant cell wall is a key element in addressing its functional role in plant growth and in the response to stress. Pectins, which are the main constituents of the primary cell wall in dicot species, play a central role in the control of cellular adhesion and thereby of the rheological properties of the wall. This is likely to be a major determinant of plant growth. How the discrete changes in pectin structure are mediated is thus a key issue in our understanding of plant development and plant responses to changes in the environment. In particular, understanding the remodelling of homogalacturonan (HG), the most abundant pectic polymer, by specific enzymes is a current challenge in addressing its fundamental role. HG, a polymer that can be methylesterified or acetylated, can be modified by HGMEs (HG-modifying enzymes) which all belong to large multigenic families in all species sequenced to date. In particular, both the degrees of substitution (methylesterification and/or acetylation) and polymerization can be controlled by specific enzymes such as pectin methylesterases (PMEs), pectin acetylesterases (PAEs), polygalacturonases (PGs), or pectate lyases-like (PLLs). Major advances in the biochemical and functional characterization of these enzymes have been made over the last 10 years. This review aims to provide a comprehensive, up to date summary of the recent data concerning the structure, regulation, and function of these fascinating enzymes in plant development and in response to biotic stresses.
Collapse
Affiliation(s)
- Fabien Sénéchal
- EA3900 BIOPI Biologie des Plantes et Innovation, Université de Picardie Jules Verne, 33 Rue St Leu, F-80039 Amiens, France
| | - Christopher Wattier
- EA3900 BIOPI Biologie des Plantes et Innovation, Université de Picardie Jules Verne, 33 Rue St Leu, F-80039 Amiens, France
| | - Christine Rustérucci
- EA3900 BIOPI Biologie des Plantes et Innovation, Université de Picardie Jules Verne, 33 Rue St Leu, F-80039 Amiens, France
| | - Jérôme Pelloux
- EA3900 BIOPI Biologie des Plantes et Innovation, Université de Picardie Jules Verne, 33 Rue St Leu, F-80039 Amiens, France
| |
Collapse
|
55
|
Shindyapina AV, Petrunia IV, Komarova TV, Sheshukova EV, Kosorukov VS, Kiryanov GI, Dorokhov YL. Dietary methanol regulates human gene activity. PLoS One 2014; 9:e102837. [PMID: 25033451 PMCID: PMC4102594 DOI: 10.1371/journal.pone.0102837] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2014] [Accepted: 06/23/2014] [Indexed: 12/02/2022] Open
Abstract
Methanol (MeOH) is considered to be a poison in humans because of the alcohol dehydrogenase (ADH)-mediated conversion of MeOH to formaldehyde (FA), which is toxic. Our recent genome-wide analysis of the mouse brain demonstrated that an increase in endogenous MeOH after ADH inhibition led to a significant increase in the plasma MeOH concentration and a modification of mRNA synthesis. These findings suggest endogenous MeOH involvement in homeostasis regulation by controlling mRNA levels. Here, we demonstrate directly that study volunteers displayed increasing concentrations of MeOH and FA in their blood plasma when consuming citrus pectin, ethanol and red wine. A microarray analysis of white blood cells (WBC) from volunteers after pectin intake showed various responses for 30 significantly differentially regulated mRNAs, most of which were somehow involved in the pathogenesis of Alzheimer's disease (AD). There was also a decreased synthesis of hemoglobin mRNA, HBA and HBB, the presence of which in WBC RNA was not a result of red blood cells contamination because erythrocyte-specific marker genes were not significantly expressed. A qRT-PCR analysis of volunteer WBCs after pectin and red wine intake confirmed the complicated relationship between the plasma MeOH content and the mRNA accumulation of both genes that were previously identified, namely, GAPDH and SNX27, and genes revealed in this study, including MME, SORL1, DDIT4, HBA and HBB. We hypothesized that human plasma MeOH has an impact on the WBC mRNA levels of genes involved in cell signaling.
Collapse
Affiliation(s)
- Anastasia V. Shindyapina
- A. N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, Moscow, Russia
- N. I. Vavilov Institute of General Genetics, Russian Academy of Science, Moscow, Russia
| | - Igor V. Petrunia
- N. I. Vavilov Institute of General Genetics, Russian Academy of Science, Moscow, Russia
| | - Tatiana V. Komarova
- A. N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, Moscow, Russia
- N. I. Vavilov Institute of General Genetics, Russian Academy of Science, Moscow, Russia
| | | | | | - Gleb I. Kiryanov
- A. N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, Moscow, Russia
| | - Yuri L. Dorokhov
- A. N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, Moscow, Russia
- N. I. Vavilov Institute of General Genetics, Russian Academy of Science, Moscow, Russia
| |
Collapse
|
56
|
Cruz-Jaramillo JL, Ruiz-Medrano R, Rojas-Morales L, López-Buenfil JA, Morales-Galván O, Chavarín-Palacio C, Ramírez-Pool JA, Xoconostle-Cázares B. Characterization of a proposed dichorhavirus associated with the citrus leprosis disease and analysis of the host response. Viruses 2014; 6:2602-22. [PMID: 25004279 PMCID: PMC4113785 DOI: 10.3390/v6072602] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Revised: 05/22/2014] [Accepted: 05/28/2014] [Indexed: 12/23/2022] Open
Abstract
The causal agents of Citrus leprosis are viruses; however, extant diagnostic methods to identify them have failed to detect known viruses in orange, mandarin, lime and bitter orange trees with severe leprosis symptoms in Mexico, an important citrus producer. Using high throughput sequencing, a virus associated with citrus leprosis was identified, belonging to the proposed Dichorhavirus genus. The virus was termed Citrus Necrotic Spot Virus (CNSV) and contains two negative-strand RNA components; virions accumulate in the cytoplasm and are associated with plasmodesmata-channels interconnecting neighboring cells-suggesting a mode of spread within the plant. The present study provides insights into the nature of this pathogen and the corresponding plant response, which is likely similar to other pathogens that do not spread systemically in plants.
Collapse
Affiliation(s)
- José Luis Cruz-Jaramillo
- Departamento de Biotecnología y Bioingeniería, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional Av. IPN 2508, Zacatenco 07360, México D.F., Mexico.
| | - Roberto Ruiz-Medrano
- Departamento de Biotecnología y Bioingeniería, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional Av. IPN 2508, Zacatenco 07360, México D.F., Mexico.
| | - Lourdes Rojas-Morales
- LaNSE, Centro de Investigación y de Estudios Avanzados del IPN Av. IPN 2508, Zacatenco 07360, México D.F., Mexico.
| | - José Abel López-Buenfil
- Departamento de Biotecnología y Bioingeniería, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional Av. IPN 2508, Zacatenco 07360, México D.F., Mexico.
| | - Oscar Morales-Galván
- Servicio Nacional de Sanidad Inocuidad y Calidad Agroalimentaria, Guillermo Pérez Valenzuela 127, Coyoacán 04100, México D.F., Mexico.
| | - Claudio Chavarín-Palacio
- Servicio Nacional de Sanidad Inocuidad y Calidad Agroalimentaria, Guillermo Pérez Valenzuela 127, Coyoacán 04100, México D.F., Mexico.
| | - José Abrahán Ramírez-Pool
- Departamento de Biotecnología y Bioingeniería, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional Av. IPN 2508, Zacatenco 07360, México D.F., Mexico.
| | - Beatriz Xoconostle-Cázares
- Departamento de Biotecnología y Bioingeniería, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional Av. IPN 2508, Zacatenco 07360, México D.F., Mexico.
| |
Collapse
|
57
|
Lionetti V, Raiola A, Cervone F, Bellincampi D. Transgenic expression of pectin methylesterase inhibitors limits tobamovirus spread in tobacco and Arabidopsis. MOLECULAR PLANT PATHOLOGY 2014; 15:265-74. [PMID: 24127644 PMCID: PMC6638747 DOI: 10.1111/mpp.12090] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Plant infection by a virus is a complex process influenced by virus-encoded factors and host components which support replication and movement. Critical factors for a successful tobamovirus infection are the viral movement protein (MP) and the host pectin methylesterase (PME), an important plant counterpart that cooperates with MP to sustain viral spread. The activity of PME is modulated by endogenous protein inhibitors (pectin methylesterase inhibitors, PMEIs). PMEIs are targeted to the extracellular matrix and typically inhibit plant PMEs by forming a specific and stable stoichiometric 1:1 complex. PMEIs counteract the action of plant PMEs and therefore may affect plant susceptibility to virus. To test this hypothesis, we overexpressed genes encoding two well-characterized PMEIs in tobacco and Arabidopsis plants. Here, we report that, in tobacco plants constitutively expressing a PMEI from Actinidia chinensis (AcPMEI), systemic movement of Tobacco mosaic virus (TMV) is limited and viral symptoms are reduced. A delayed movement of Turnip vein clearing virus (TVCV) and a reduced susceptibility to the virus were also observed in Arabidopsis plants overexpressing AtPMEI-2. Our results provide evidence that PMEIs are able to limit tobamovirus movement and to reduce plant susceptibility to the virus.
Collapse
Affiliation(s)
- Vincenzo Lionetti
- Dipartimento di Biologia e Biotecnologie 'C. Darwin', 'Sapienza' Università di Roma, 00185, Roma, Italy
| | | | | | | |
Collapse
|
58
|
Komarova TV, Petrunia IV, Shindyapina AV, Silachev DN, Sheshukova EV, Kiryanov GI, Dorokhov YL. Endogenous methanol regulates mammalian gene activity. PLoS One 2014; 9:e90239. [PMID: 24587296 PMCID: PMC3937363 DOI: 10.1371/journal.pone.0090239] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2013] [Accepted: 01/28/2014] [Indexed: 11/18/2022] Open
Abstract
We recently showed that methanol emitted by wounded plants might function as a signaling molecule for plant-to-plant and plant-to-animal communications. In mammals, methanol is considered a poison because the enzyme alcohol dehydrogenase (ADH) converts methanol into toxic formaldehyde. However, the detection of methanol in the blood and exhaled air of healthy volunteers suggests that methanol may be a chemical with specific functions rather than a metabolic waste product. Using a genome-wide analysis of the mouse brain, we demonstrated that an increase in blood methanol concentration led to a change in the accumulation of mRNAs from genes primarily involved in detoxification processes and regulation of the alcohol/aldehyde dehydrogenases gene cluster. To test the role of ADH in the maintenance of low methanol concentration in the plasma, we used the specific ADH inhibitor 4-methylpyrazole (4-MP) and showed that intraperitoneal administration of 4-MP resulted in a significant increase in the plasma methanol, ethanol and formaldehyde concentrations. Removal of the intestine significantly decreased the rate of methanol addition to the plasma and suggested that the gut flora may be involved in the endogenous production of methanol. ADH in the liver was identified as the main enzyme for metabolizing methanol because an increase in the methanol and ethanol contents in the liver homogenate was observed after 4-MP administration into the portal vein. Liver mRNA quantification showed changes in the accumulation of mRNAs from genes involved in cell signalling and detoxification processes. We hypothesized that endogenous methanol acts as a regulator of homeostasis by controlling the mRNA synthesis.
Collapse
Affiliation(s)
- Tatiana V. Komarova
- A. N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, Moscow, Russia
- N. I. Vavilov Institute of General Genetics, Russian Academy of Science, Moscow, Russia
| | - Igor V. Petrunia
- N. I. Vavilov Institute of General Genetics, Russian Academy of Science, Moscow, Russia
| | | | - Denis N. Silachev
- A. N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, Moscow, Russia
| | | | - Gleb I. Kiryanov
- A. N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, Moscow, Russia
| | - Yuri L. Dorokhov
- A. N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, Moscow, Russia
- N. I. Vavilov Institute of General Genetics, Russian Academy of Science, Moscow, Russia
- * E-mail:
| |
Collapse
|
59
|
Komarova TV, Pozdyshev DV, Petrunia IV, Sheshukova EV, Dorokhov YL. Pectin methylesterase-generated methanol may be involved in tobacco leaf growth. BIOCHEMISTRY. BIOKHIMIIA 2014; 79:102-10. [PMID: 24794725 DOI: 10.1134/s0006297914020035] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Plant leaves undergo a sink-source modification of intercellular macromolecular transport during the transition from carbon import to carbon export. After assessing the role of metabolite signaling in gene regulation in Nicotiana tabacum sink and source leaves, we observed increased pectin methylesterase (PME)-mediated methanol generation in immature leaves. Using suppression subtractive hybridization (SSH), we identified a number of genes whose activity changes from sink to source leaves. The most abundant SSH-identified genes appeared to be sensitive to methanol. We hypothesize that tobacco leaf maturation and the sink-source transition are accompanied by a change in mRNA levels of genes that function in methanol-dependent cell signaling.
Collapse
Affiliation(s)
- T V Komarova
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119991, Russia.
| | | | | | | | | |
Collapse
|
60
|
Duran-Flores D, Heil M. Damaged-self recognition in common bean (Phaseolus vulgaris) shows taxonomic specificity and triggers signaling via reactive oxygen species (ROS). FRONTIERS IN PLANT SCIENCE 2014; 5:585. [PMID: 25400650 PMCID: PMC4215620 DOI: 10.3389/fpls.2014.00585] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2014] [Accepted: 10/09/2014] [Indexed: 05/20/2023]
Abstract
Plants require reliable mechanisms to detect injury. Danger signals or "damage-associated molecular patterns" (DAMPs) are released from stressed host cells and allow injury detection independently of enemy-derived molecules. We studied the response of common bean (Phaseolus vulgaris) to the application of leaf homogenate as a source of DAMPs and measured the production of reactive oxygen species (ROS) as an early response and the secretion of extrafloral nectar (EFN) as a jasmonic acid (JA)-dependent late response. We observed a strong taxonomic signal in the response to different leaf homogenates. ROS formation and EFN secretion were highly correlated and responded most strongly to leaf homogenates produced using the same cultivar or closely related accessions, less to a distantly related cultivar of common bean or each of the two congeneric species, P. lunatus and P. coccineus, and not at all to homogenates prepared from species in different genera, not even when using other Fabaceae. Interestingly, leaf homogenates also reduced the infection by the bacterial pathogen, Pseudomonas syringae, when they were applied directly before challenging, although the same homogenates exhibited no direct in vitro inhibitory effect in the bacterium. We conclude that ROS signaling is associated to the induction of EFN secretion and that the specific blend of DAMPs that are released from damaged cells allows the plant to distinguish the "damaged-self" from the damaged "non-self." The very early responses of plants to DAMPs can trigger resistance to both, herbivores and pathogens, which should be adaptive because injury facilitates infection, independently of its causal reason.
Collapse
Affiliation(s)
| | - Martin Heil
- *Correspondence: Martin Heil, Laboratory of Plant Ecology, Departamento de Ingeniería Genética, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional Unidad Irapuato, Km 9.6 Libramiento Norte, Carretera Irapuato-León, Irapuato, Guanajuato, Mexico e-mail:
| |
Collapse
|
61
|
Komarova TV, Sheshukova EV, Dorokhov YL. Cell wall methanol as a signal in plant immunity. FRONTIERS IN PLANT SCIENCE 2014; 5:101. [PMID: 24672536 PMCID: PMC3957485 DOI: 10.3389/fpls.2014.00101] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2014] [Accepted: 03/02/2014] [Indexed: 05/20/2023]
Abstract
Cell wall pectin forms a matrix around the cellulose-xyloglucan network that is composed of rhamnogalacturonan I, rhamnogalacturonan II, and homogalacturonan (HG), a major pectic polymer consisting of α-1,4-linked galacturonic acids. HG is secreted in a highly methyl-esterified form and selectively de-methyl-esterified by pectin methylesterases (PMEs) during cell growth and pathogen attack. The mechanical damage that often precedes the penetration of the leaf by a pathogen promotes the activation of PME, which in turn leads to the emission of methanol (MeOH), an abundant volatile organic compound, which is quickly perceived by the intact leaves of the damaged plant, and the neighboring plants. The exposure to MeOH may result in a "priming" effect on intact leaves, setting the stage for the within-plant, and neighboring plant immunity. The emission of MeOH by a wounded plant enhances the resistance of the non-wounded, neighboring "receiver" plants to bacterial pathogens and promotes cell-to-cell communication that facilitates the spread of viruses in neighboring plants.
Collapse
Affiliation(s)
- Tatiana V. Komarova
- A. N. Belozersky Institute of Physico-Chemical Biology, Moscow State UniversityMoscow, Russia
- N. I. Vavilov Institute of General Genetics, Russian Academy of ScienceMoscow, Russia
| | | | - Yuri L. Dorokhov
- A. N. Belozersky Institute of Physico-Chemical Biology, Moscow State UniversityMoscow, Russia
- N. I. Vavilov Institute of General Genetics, Russian Academy of ScienceMoscow, Russia
- *Correspondence: Yuri L. Dorokhov, A. N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, Moscow 119991, Russia e-mail:
| |
Collapse
|
62
|
Heil M, Land WG. Danger signals - damaged-self recognition across the tree of life. FRONTIERS IN PLANT SCIENCE 2014; 5:578. [PMID: 25400647 PMCID: PMC4215617 DOI: 10.3389/fpls.2014.00578] [Citation(s) in RCA: 138] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2014] [Accepted: 10/07/2014] [Indexed: 05/15/2023]
Abstract
Multicellular organisms suffer injury and serve as hosts for microorganisms. Therefore, they require mechanisms to detect injury and to distinguish the self from the non-self and the harmless non-self (microbial mutualists and commensals) from the detrimental non-self (pathogens). Danger signals are "damage-associated molecular patterns" (DAMPs) that are released from the disrupted host tissue or exposed on stressed cells. Seemingly ubiquitous DAMPs are extracellular ATP or extracellular DNA, fragmented cell walls or extracellular matrices, and many other types of delocalized molecules and fragments of macromolecules that are released when pre-existing precursors come into contact with enzymes from which they are separated in the intact cell. Any kind of these DAMPs enable damaged-self recognition, inform the host on tissue disruption, initiate processes aimed at restoring homeostasis, such as sealing the wound, and prepare the adjacent tissues for the perception of invaders. In mammals, antigen-processing and -presenting cells such as dendritic cells mature to immunostimulatory cells after the perception of DAMPs, prime naïve T-cells and elicit a specific adaptive T-/B-cell immune response. We discuss molecules that serve as DAMPs in multiple organisms and their perception by pattern recognition receptors (PRRs). Ca(2+)-fluxes, membrane depolarization, the liberation of reactive oxygen species and mitogen-activated protein kinase (MAPK) signaling cascades are the ubiquitous molecular mechanisms that act downstream of the PRRs in organisms across the tree of life. Damaged-self recognition contains both homologous and analogous elements and is likely to have evolved in all eukaryotic kingdoms, because all organisms found the same solutions for the same problem: damage must be recognized without depending on enemy-derived molecules and responses to the non-self must be directed specifically against detrimental invaders.
Collapse
Affiliation(s)
- Martin Heil
- Departamento de Ingeniería Genética, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional-IrapuatoIrapuato, México
- *Correspondence: Martin Heil, Departamento de Ingeniería Genética, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional-Irapuato, Km 9.6 Libramiento Norte, Carretera Irapuato- León, Irapuato, Guanajuato, Mexico e-mail:
| | - Walter G. Land
- Molecular ImmunoRheumatology, INSERM UMR S1109, Laboratory of Excellence Transplantex, Faculty of Medicine, University of StrasbourgStrasbourg, France
| |
Collapse
|
63
|
Bellincampi D, Cervone F, Lionetti V. Plant cell wall dynamics and wall-related susceptibility in plant-pathogen interactions. FRONTIERS IN PLANT SCIENCE 2014. [PMID: 24904623 DOI: 10.3389/fpls.2017.0228] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
The cell wall is a dynamic structure that often determines the outcome of the interactions between plants and pathogens. It is a barrier that pathogens need to breach to colonize the plant tissue. While fungal necrotrophs extensively destroy the integrity of the cell wall through the combined action of degrading enzymes, biotrophic fungi require a more localized and controlled degradation of the cell wall in order to keep the host cells alive and utilize their feeding structures. Also bacteria and nematodes need to degrade the plant cell wall at a certain stage of their infection process, to obtain nutrients for their growth. Plants have developed a system for sensing pathogens and monitoring the cell wall integrity, upon which they activate defense responses that lead to a dynamic cell wall remodeling required to prevent the disease. Pathogens, on the other hand, may exploit the host cell wall metabolism to support the infection. We review here the strategies utilized by both plants and pathogens to prevail in the cell wall battleground.
Collapse
Affiliation(s)
- Daniela Bellincampi
- Dipartimento di Biologia e Biotecnologie "Charles Darwin", Sapienza Università di Roma Rome, Italy
| | - Felice Cervone
- Dipartimento di Biologia e Biotecnologie "Charles Darwin", Sapienza Università di Roma Rome, Italy
| | - Vincenzo Lionetti
- Dipartimento di Biologia e Biotecnologie "Charles Darwin", Sapienza Università di Roma Rome, Italy
| |
Collapse
|
64
|
Hann CT, Bequette CJ, Dombrowski JE, Stratmann JW. Methanol and ethanol modulate responses to danger- and microbe-associated molecular patterns. FRONTIERS IN PLANT SCIENCE 2014; 5:550. [PMID: 25360141 PMCID: PMC4197774 DOI: 10.3389/fpls.2014.00550] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2014] [Accepted: 09/25/2014] [Indexed: 05/15/2023]
Abstract
Methanol is a byproduct of cell wall modification, released through the action of pectin methylesterases (PMEs), which demethylesterify cell wall pectins. Plant PMEs play not only a role in developmental processes but also in responses to herbivory and infection by fungal or bacterial pathogens. Molecular mechanisms that explain how methanol affects plant defenses are poorly understood. Here we show that exogenously supplied methanol alone has weak effects on defense signaling in three dicot species, however, it profoundly alters signaling responses to danger- and microbe-associated molecular patterns (DAMPs, MAMPs) such as the alarm hormone systemin, the bacterial flagellum-derived flg22 peptide, and the fungal cell wall-derived oligosaccharide chitosan. In the presence of methanol the kinetics and amplitudes of DAMP/MAMP-induced MAP kinase (MAPK) activity and oxidative burst are altered in tobacco and tomato suspension-cultured cells, in Arabidopsis seedlings and tomato leaf tissue. As a possible consequence of altered DAMP/MAMP signaling, methanol suppressed the expression of the defense genes PR-1 and PI-1 in tomato. In cell cultures of the grass tall fescue (Festuca arundinacea, Poaceae, Monocots), methanol alone activates MAPKs and increases chitosan-induced MAPK activity, and in the darnel grass Lolium temulentum (Poaceae), it alters wound-induced MAPK signaling. We propose that methanol can be recognized by plants as a sign of the damaged self. In dicots, methanol functions as a DAMP-like alarm signal with little elicitor activity on its own, whereas it appears to function as an elicitor-active DAMP in monocot grasses. Ethanol had been implicated in plant stress responses, although the source of ethanol in plants is not well established. We found that it has a similar effect as methanol on responses to MAMPs and DAMPs.
Collapse
Affiliation(s)
- Claire T. Hann
- Department of Biological Sciences, University of South CarolinaColumbia, SC, USA
| | - Carlton J. Bequette
- Department of Biological Sciences, University of South CarolinaColumbia, SC, USA
| | - James E. Dombrowski
- National Forage Seed Production Research Center, United States Department of Agriculture – Agricultural Research ServiceCorvallis, OR, USA
| | - Johannes W. Stratmann
- Department of Biological Sciences, University of South CarolinaColumbia, SC, USA
- *Correspondence: Johannes W. Stratmann, Department of Biological Sciences, University of South Carolina, 715 Sumter Street, Columbia, SC 29208, USA e-mail:
| |
Collapse
|
65
|
Bellincampi D, Cervone F, Lionetti V. Plant cell wall dynamics and wall-related susceptibility in plant-pathogen interactions. FRONTIERS IN PLANT SCIENCE 2014; 5:228. [PMID: 24904623 PMCID: PMC4036129 DOI: 10.3389/fpls.2014.00228] [Citation(s) in RCA: 225] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2014] [Accepted: 05/06/2014] [Indexed: 05/20/2023]
Abstract
The cell wall is a dynamic structure that often determines the outcome of the interactions between plants and pathogens. It is a barrier that pathogens need to breach to colonize the plant tissue. While fungal necrotrophs extensively destroy the integrity of the cell wall through the combined action of degrading enzymes, biotrophic fungi require a more localized and controlled degradation of the cell wall in order to keep the host cells alive and utilize their feeding structures. Also bacteria and nematodes need to degrade the plant cell wall at a certain stage of their infection process, to obtain nutrients for their growth. Plants have developed a system for sensing pathogens and monitoring the cell wall integrity, upon which they activate defense responses that lead to a dynamic cell wall remodeling required to prevent the disease. Pathogens, on the other hand, may exploit the host cell wall metabolism to support the infection. We review here the strategies utilized by both plants and pathogens to prevail in the cell wall battleground.
Collapse
Affiliation(s)
| | | | - Vincenzo Lionetti
- *Correspondence: Vincenzo Lionetti, Dipartimento di Biologia e Biotecnologie “Charles Darwin”, Sapienza Università di Roma, Rome 00185, Italy e-mail:
| |
Collapse
|
66
|
Lionetti V, Raiola A, Cervone F, Bellincampi D. How do pectin methylesterases and their inhibitors affect the spreading of tobamovirus? PLANT SIGNALING & BEHAVIOR 2014; 9:e972863. [PMID: 25482766 PMCID: PMC4623000 DOI: 10.4161/15592316.2014.972863] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2014] [Revised: 07/23/2014] [Accepted: 07/23/2014] [Indexed: 05/24/2023]
Abstract
After replication in the cytoplasm, viruses spread from the infected cell into the neighboring cells through plasmodesmata, membranous channels embedded by the cell wall. As obligate parasites, viruses have acquired the ability to utilize host factors that unwillingly cooperate for the viral infection process. For example, the viral movement proteins (MP) interacts with the host pectin methylesterase (PME) and both proteins cooperate to sustain the viral spread. However, how and where PMEs interact with MPs and how the PME/MP complexes favor the viral translocation is not well understood. Recently, we demonstrated that the overexpression of PME inhibitors (PMEIs) in tobacco and Arabidopsis plants limits the movement of Tobacco mosaic virus and Turnip vein clearing virus and reduces plant susceptibility to these viruses. Here we discuss how overexpression of PMEI may reduce tobamovirus spreading.
Collapse
Key Words
- CP, coat protein.
- CW, cell wall
- ER, Endoplasmic Reticulum
- MP, movement protein
- MeOH, methanol
- PD, plasmodesmata
- PM, Plasma membrane
- PME, pectin methylesterase
- PMEI, pectin methylesterase inhibitor
- TMV, Tobacco mosaic virus
- cell wall
- methanol
- pectin methylesterase
- pectin methylesterase inhibitors
- pectin methylesterification
- plasmodesmata
- virus spreading
Collapse
Affiliation(s)
- Vincenzo Lionetti
- Dipartimento di Biologia e Biotecnologie ‘C. Darwin'; ‘Sapienza' Università di Roma; Roma, Italy
| | - Alessandro Raiola
- Dipartimento Territorio e Sistemi Agroforestali; Università di Padova; Legnaro (PD), Italy
| | - Felice Cervone
- Dipartimento di Biologia e Biotecnologie ‘C. Darwin'; ‘Sapienza' Università di Roma; Roma, Italy
| | - Daniela Bellincampi
- Dipartimento di Biologia e Biotecnologie ‘C. Darwin'; ‘Sapienza' Università di Roma; Roma, Italy
| |
Collapse
|
67
|
Dixit S, Upadhyay SK, Singh H, Sidhu OP, Verma PC, K C. Enhanced methanol production in plants provides broad spectrum insect resistance. PLoS One 2013; 8:e79664. [PMID: 24223989 PMCID: PMC3818224 DOI: 10.1371/journal.pone.0079664] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2013] [Accepted: 09/23/2013] [Indexed: 01/22/2023] Open
Abstract
Plants naturally emit methanol as volatile organic compound. Methanol is toxic to insect pests; but the quantity produced by most of the plants is not enough to protect them against invading insect pests. In the present study, we demonstrated that the over-expression of pectin methylesterase, derived from Arabidopsis thaliana and Aspergillus niger, in transgenic tobacco plants enhances methanol production and resistance to polyphagous insect pests. Methanol content in the leaves of transgenic plants was measured using proton nuclear spectroscopy (1H NMR) and spectra showed up to 16 fold higher methanol as compared to control wild type (WT) plants. A maximum of 100 and 85% mortality in chewing insects Helicoverpa armigera and Spodoptera litura larvae was observed, respectively when fed on transgenic plants leaves. The surviving larvae showed less feeding, severe growth retardation and could not develop into pupae. In-planta bioassay on transgenic lines showed up to 99 and 75% reduction in the population multiplication of plant sap sucking pests Myzus persicae (aphid) and Bemisia tabaci (whitefly), respectively. Most of the phenotypic characters of transgenic plants were similar to WT plants. Confocal microscopy showed no deformities in cellular integrity, structure and density of stomata and trichomes of transgenic plants compared to WT. Pollen germination and tube formation was also not affected in transgenic plants. Cell wall enzyme transcript levels were comparable with WT. This study demonstrated for the first time that methanol emission can be utilized for imparting broad range insect resistance in plants.
Collapse
Affiliation(s)
- Sameer Dixit
- CSIR-National Botanical Research Institute, Council of Scientific and Industrial Research, Lucknow, Uttar Pradesh, India
- Academy of Scientific and Innovative Research (AcSIR), Anusandhan Bhawan, 2-Rafi Marg, New Delhi, India
| | - Santosh Kumar Upadhyay
- CSIR-National Botanical Research Institute, Council of Scientific and Industrial Research, Lucknow, Uttar Pradesh, India
- Department of Biotechnology, National Agri-Food Biotechnology Institute, Ministry of Science and Technology, Mohali, Punjab, India
| | - Harpal Singh
- CSIR-National Botanical Research Institute, Council of Scientific and Industrial Research, Lucknow, Uttar Pradesh, India
| | - Om Prakash Sidhu
- CSIR-National Botanical Research Institute, Council of Scientific and Industrial Research, Lucknow, Uttar Pradesh, India
| | - Praveen Chandra Verma
- CSIR-National Botanical Research Institute, Council of Scientific and Industrial Research, Lucknow, Uttar Pradesh, India
- Academy of Scientific and Innovative Research (AcSIR), Anusandhan Bhawan, 2-Rafi Marg, New Delhi, India
| | - Chandrashekar K
- CSIR-National Botanical Research Institute, Council of Scientific and Industrial Research, Lucknow, Uttar Pradesh, India
- Indian Agricultural Research Institute, Shivaji Nagar, Pune, Maharashtra, India
| |
Collapse
|
68
|
Action of jasmonates in plant stress responses and development--applied aspects. Biotechnol Adv 2013; 32:31-9. [PMID: 24095665 DOI: 10.1016/j.biotechadv.2013.09.009] [Citation(s) in RCA: 148] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2013] [Revised: 09/18/2013] [Accepted: 09/24/2013] [Indexed: 11/22/2022]
Abstract
Jasmonates (JAs) are lipid-derived compounds acting as key signaling compounds in plant stress responses and development. The JA co-receptor complex and several enzymes of JA biosynthesis have been crystallized, and various JA signal transduction pathways including cross-talk to most of the plant hormones have been intensively studied. Defense to herbivores and necrotrophic pathogens are mediated by JA. Other environmental cues mediated by JA are light, seasonal and circadian rhythms, cold stress, desiccation stress, salt stress and UV stress. During development growth inhibition of roots, shoots and leaves occur by JA, whereas seed germination and flower development are partially affected by its precursor 12-oxo-phytodienoic acid (OPDA). Based on these numerous JA mediated signal transduction pathways active in plant stress responses and development, there is an increasing interest in horticultural and biotechnological applications. Intercropping, the mixed growth of two or more crops, mycorrhization of plants, establishment of induced resistance, priming of plants for enhanced insect resistance as well as pre- and post-harvest application of JA are few examples. Additional sources for horticultural improvement, where JAs might be involved, are defense against nematodes, biocontrol by plant growth promoting rhizobacteria, altered composition of rhizosphere bacterial community, sustained balance between growth and defense, and improved plant immunity in intercropping systems. Finally, biotechnological application for JA-induced production of pharmaceuticals and application of JAs as anti-cancer agents were intensively studied.
Collapse
|
69
|
Dixit S, Upadhyay SK, Singh H, Pandey B, Chandrashekar K, Verma PC. Pectin methylesterase of Datura species, purification, and characterization from Datura stramonium and its application. PLANT SIGNALING & BEHAVIOR 2013; 8:doi: 10.4161/psb.25681. [PMID: 23887498 PMCID: PMC4091111 DOI: 10.4161/psb.25681] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2013] [Revised: 07/08/2013] [Accepted: 07/09/2013] [Indexed: 05/29/2023]
Abstract
Pectin methylesterases (PME; EC 3.1.1.11) involved in de-esterification of pectin and have applicability in food, textiles, wines, pulp, and paper industries. In the present study, we compared PME activity of different parts of 3 Datura species and found that fruit coat showed maximum PME activity followed by leaf and seed. PME from leaves of D. stramonium (DsPME) was purified and characterized. DsPME showed optimum activity at 60 °C and pH 9 in the presence of 0.3 M NaCl. DsPME was stable at 70 °C and retained more than 40% activity after 60 min of incubation. However, enzyme activity completely abolished at 80 after 5 min of incubation. It follows Michaelis-Menten enzyme kinetics. Km and Vmax with citrus pectin were 0.008 mg/ml and 16.96 µmol/min, respectively. DsPME in combination with polygalactourenase (PGA) increased the clarity of orange, apple, pomegranate and pineapple juices by 2.9, 2.6, 2.3, and 3.6 fold, respectively in comparison to PGA alone. Due to very high de-esterification activity, easy denaturation and significant efficacy in incrementing clarification of fruit juice makes DsPME useful for industrial application.
Collapse
Affiliation(s)
- Sameer Dixit
- CSIR-National Botanical Research Institute; Council of Scientific and Industrial Research; Rana Pratap Marg; Lucknow, UP India
| | - Santosh Kumar Upadhyay
- Department of Biotechnology; National Agri - Food Biotechnology Institute; Ministry of Science and Technology; Mohali, Punjab, India
| | - Harpal Singh
- CSIR-National Botanical Research Institute; Council of Scientific and Industrial Research; Rana Pratap Marg; Lucknow, UP India
| | - Bindu Pandey
- CSIR-National Botanical Research Institute; Council of Scientific and Industrial Research; Rana Pratap Marg; Lucknow, UP India
| | - Krishnappa Chandrashekar
- CSIR-National Botanical Research Institute; Council of Scientific and Industrial Research; Rana Pratap Marg; Lucknow, UP India
| | - Praveen Chandra Verma
- CSIR-National Botanical Research Institute; Council of Scientific and Industrial Research; Rana Pratap Marg; Lucknow, UP India
| |
Collapse
|
70
|
Wang SP, Hu XX, Meng QW, Muhammad SA, Chen RR, Li F, Li GQ. The involvement of several enzymes in methanol detoxification in Drosophila melanogaster adults. Comp Biochem Physiol B Biochem Mol Biol 2013; 166:7-14. [DOI: 10.1016/j.cbpb.2013.05.008] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2013] [Revised: 05/30/2013] [Accepted: 05/31/2013] [Indexed: 12/15/2022]
|
71
|
Zavaliev R, Levy A, Gera A, Epel BL. Subcellular dynamics and role of Arabidopsis β-1,3-glucanases in cell-to-cell movement of tobamoviruses. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2013; 26:1016-30. [PMID: 23656331 DOI: 10.1094/mpmi-03-13-0062-r] [Citation(s) in RCA: 85] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
β-1,3-Glucanases (BG) have been implicated in enhancing virus spread by degrading callose at plasmodesmata (Pd). Here, we investigate the role of Arabidopsis BG in tobamovirus spread. During Turnip vein clearing virus infection, the transcription of two pathogenesis-related (PR)-BG AtBG2 and AtBG3 increased but that of Pd-associated BG AtBG_pap did not change. In transgenic plants, AtBG2 was retained in the endoplasmic reticulum (ER) network and was not secreted. As a stress response mediated by salicylic acid, AtBG2 was secreted and appeared as a free extracellular protein localized in the entire apoplast but did not accumulate at Pd sites. At the leading edge of Tobacco mosaic virus spread, AtBG2 co-localized with the viral movement protein in the ER-derived bodies, similarly to other ER proteins, but was not secreted to the cell wall. In atbg2 mutants, callose levels at Pd and virus spread were unaffected. Likewise, AtBG2 overexpression had no effect on virus spread. However, in atbg_pap mutants, callose at Pd was increased and virus spread was reduced. Our results demonstrate that the constitutive Pd-associated BG but not the stress-regulated extracellular PR-BG are directly involved in regulation of callose at Pd and cell-to-cell transport in Arabidopsis, including the spread of viruses.
Collapse
Affiliation(s)
- Raul Zavaliev
- Department of Molecular Biology and Ecology of Plants, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
| | | | | | | |
Collapse
|
72
|
Gutiérrez S, Michalakis Y, Munster M, Blanc S. Plant feeding by insect vectors can affect life cycle, population genetics and evolution of plant viruses. Funct Ecol 2013. [DOI: 10.1111/1365-2435.12070] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Serafín Gutiérrez
- UMR BGPI, INRA‐CIRAD‐SupAgro, TA‐A54K Campus International de Baillarguet 34398 Montpellier Cedex 05 France
- UMR MIVEGEC 5290 CNRS‐IRD‐UM1‐UM2, IRD 911 Avenue Agropolis B.P. 64501 34394 Montpellier Cedex 05 France
| | - Yannis Michalakis
- UMR MIVEGEC 5290 CNRS‐IRD‐UM1‐UM2, IRD 911 Avenue Agropolis B.P. 64501 34394 Montpellier Cedex 05 France
| | - Manuella Munster
- UMR BGPI, INRA‐CIRAD‐SupAgro, TA‐A54K Campus International de Baillarguet 34398 Montpellier Cedex 05 France
| | - Stéphane Blanc
- UMR BGPI, INRA‐CIRAD‐SupAgro, TA‐A54K Campus International de Baillarguet 34398 Montpellier Cedex 05 France
| |
Collapse
|
73
|
Abstract
Recently, we demonstrated that leaf wounding results in the synthesis of pectin methylesterase (PME), which causes the plant to release methanol into the air. Methanol emitted by a wounded plant increases the accumulation of methanol-inducible gene mRNA and enhances antibacterial resistance as well as cell-to-cell communication, which facilitates virus spreading in neighboring plants. We concluded that methanol is a signaling molecule involved in within-plant and plant-to-plant communication. Methanol is considered to be a poison in humans because of the alcohol dehydrogenase (ADH)-mediated conversion of methanol into toxic formaldehyde. However, recent data showed that methanol is a natural compound in normal, healthy humans. These data call into question whether human methanol is a metabolic waste product or whether methanol has specific function in humans. Here, to reveal human methanol-responsive genes (MRGs), we used suppression subtractive hybridization cDNA libraries of HeLa cells lacking ADH and exposed to methanol. This design allowed us to exclude genes involved in formaldehyde and formic acid detoxification from our analysis. We identified MRGs and revealed a correlation between increases in methanol content in the plasma and changes in human leukocyte MRG mRNA levels after fresh salad consumption by volunteers. Subsequently, we showed that the methanol generated by the pectin/PME complex in the gastrointestinal tract of mice induces the up- and downregulation of brain MRG mRNA. We used an adapted Y-maze to measure the locomotor behavior of the mice while breathing wounded plant vapors in two-choice assays. We showed that mice prefer the odor of methanol to other plant volatiles and that methanol changed MRG mRNA accumulation in the mouse brain. We hypothesize that the methanol emitted by wounded plants may have a role in plant-animal signaling. The known positive effect of plant food intake on human health suggests a role for physiological methanol in human gene regulation.
Collapse
|