Studies on Elicitor Recognition and Signal Transduction in Host and Non-Host Plant/Fungus Pathogenic Interactions

Scheel, Dierk; Colling, Christiane; Keller, Harald; Parker, Jane E.

doi:10.1007/978-3-642-74158-6_25

Cited by 15 publications

(6 citation statements)

References 16 publications

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“…Omission of Ca 2+ from the culture medium blocked defence-related gene activation and/or phytoalexin formation in soybean (StaÈ b and Ebel 1987), carrot (Kurosaki et al 1987), parsley (Scheel et al 1989;NuÈ rnberger et al 1994a), and tobacco cells (Tavernier et al 1995). Furthermore, the elicitor-induced defence responses and Ca 2+ in¯ux were inhibited by certain anion-channel blockers (Ebel et al 1995;Levine et al 1996;Jabs et al 1997 and own unpublished results) and by La 3+ (Ebel et al 1995;Tavernier et al 1995) in several systems.…”

Section: Signal Transductionmentioning

confidence: 87%

Early events in the elicitation of plant defence

Ebel

Mithöfer

1998

Planta

216

127

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Plants successfully use inducible defence mechanisms to combat potential pathogens. Elicitors are signaling compounds that stimulate any of such defence responses. Recent progress in the isolation of pure elicitors has made possible investigations on elicitor-binding proteins which might function as receptors in signal transduction pathways that ultimately activate the defences. The elicitor-binding sites studied so far show a high degree of ligand specificity, as do the candidate binding proteins identified for some of the ligands. Following elicitor perception, a number of rapid reactions are detectable in plant cells, including enhanced ion fluxes across the plasma membrane, formation of reactive oxygen intermediates, changes in protein phosphorylation, and lipid oxidation. Intriguing questions arising from these observations are whether the elicitor-binding proteins constitute receptors in plant defence signaling and whether any of the rapid events participate in signal transduction during defence activation

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Section: Signal Transductionmentioning

confidence: 87%

Early events in the elicitation of plant defence

Ebel

Mithöfer

1998

Planta

216

127

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“…An alternative, nonexclusive hypothesis is also conceivable, in which R-type anion channels contribute to regulation of other processes during stomatal movements, which require transient depolarization. Anion channels as found in guard cells may initiate signal transduction in other types of higher plant cells that show either transient or sustained depolarization patterns and anion efflux in response to physiological stimuli (9)(10)(11)(12)(13)(14)(15)(16). For example, a chloride conductance has been shown to contribute to depolarization during action potentials in algae (for review, see ref.…”

Section: Discussionmentioning

confidence: 99%

“…As an early event in signal transduction, many physiological stimuli including light signals, plant hormones, elicitors, and pathogens induce membrane depolarization (9)(10)(11)(12)(13)(14)(15)(16) from the normal range of resting potentials found in higher plant cells (approximately -120 to -160 mV). These depolarizations occur transiently, lasting for durations of several tens of seconds, or are sustained and have been shown to be accompanied by anion efflux in several cases (1,2,9,(14)(15)(16). The transmembrane gradient of free anions in plant cells produces anion efflux through anion channels, thereby providing a central mechanism for membrane depolarization to potentials more positive than the potassium equilibrium potential (3,14).…”

Section: Introductionmentioning

confidence: 99%

Two types of anion channel currents in guard cells with distinct voltage regulation.

Schroeder

Keller

1992

Proc. Natl. Acad. Sci. U.S.A.

254

232

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Transpirational water loss by plants is reduced by closing of stomatal pores in the leaf epidermis. Anion channels in the plasma membrane of guard cells may provide a key molecular mechanism for control of stomatal closing in leaves. However, central questions regarding the regulation, diversity, and function of anion channels in guard cells and other higher plant cells remain unanswered. We show here that two highly distinct types of depolarization-activated anion currents operate in the plasma membrane of Viciafaba guard cells. One described type of anion channel was activated rapidly within 50 ms by depolarization, inactivated during prolonged stimulation, and deactivated rapidly at hyperpolarized potentials (R-type anion current). The other depolarizationactivated anion current showed extremely slow voltagedependent activation and deactivation (S-type anion current) and lacked inactivation. The distinct voltage and time dependencies of R-type and S-type anion channels suggest that they may play a role during depolarization-associated signal transduction in higher plant cells and that these anion channels may contribute to different processes in the regulation of stomatal movements. In particular, the slow and sustained nature of S-type anion channel activation revealed here leads us to hypothesize that S-type anion channels may provide a central molecular mechanism for control of stomatal closing, which is accompanied by long-term anion efflux and depolarization.Stomatal pores in the epidermis of leaves control diffusion of CO2 into leaves for carbon fixation and transpiration of H20 to the atmosphere. In darkness or in response to environmental stress factors such as drought, stomata close to minimize water loss of plants. Closing of stomata is induced by long-term anion and K+ efflux from guard cell pairs, which surround stomatal pores (1-3). Recent studies suggest that stomatal closing may be mediated by simultaneous opening of Ca2+-and nucleotide-regulated anion channels (4-6) and depolarization-activated K+ channels (7,8).Anion channels in guard cells may provide a central control mechanism for regulation of stomatal closing, as anion channel activation causes depolarization (4, 5), which in turn drives K+ efflux through K+ channels (7,8) in the plasma membrane of guard cells. Anion channels in guard cells are permeable to the major anionic nutrients nitrate and malate (5), which are transported across plant membranes.In addition to stomatal regulation, anion channels may play a central role in initiation of many signal transduction processes in higher plant cells. As an early event in signal transduction, many physiological stimuli including light signals, plant hormones, elicitors, and pathogens induce membrane depolarization (9-16) from the normal range of resting potentials found in higher plant cells (approximately -120 to -160 mV). These depolarizations occur transiently, lasting for durations of several tens of seconds, or are sustained and have been shown to be accompanied by anion efflu...

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“…However, in the case of the glycoprotein isolated from P. megasperma f. sp. glycinea the polypeptide moiety has been shown clearly to be responsible for elicitor activity (Scheel et al, 1989;Scheel & Parker, 1990;Parker et al, 1991;Renelt et al, 1993;Sacks et al, 1993;Xurnberger et al, 1994n, b). The glycoprotein {M4 2 k), elicits accumulation of coumarin phytoalexins in parsley (Petroselinum crispum) tissues and contains ohgosaccharide residues of the high-mannose type.…”

Section: {B) Proteins and Glycoproteinsmentioning

confidence: 99%

Tansley Review No. 86 Accumulation of phytoalexins: defence mechanism and stimulus response system

Smith

1996

New Phytologist

214

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SUMMARY Phytoalexin synthesis is a defence‐response‐ that is characterized by a requirement for a number of distinct elements, all of which must be present for the response to be expressed fully. These same elements: a signal, a cellular receptor, a signal transduction system and a responsive metabolic system, are also used to describe a stimulus‐response system. A number of molecular species can function as signal molecules or elicitors of phytoalexin synthesis, including poly‐ and oligosaccharides, proteins and polypeptides, and fatty acids. Few receptors for elicitors have been identified but those that have been are proteins located on the plasma membrane of the plant. Induction of phytoalexin synthesis involves selective and co‐ordinated activation of specific defence response genes, including those encoding the enzymes of phytoalexin synthesis, and these genes constitute the responsive metabolic system. The separate, and distant, locations of the receptor and the responsive genes means that the event in which the signal is perceived by the receptor must be relayed to the genes by means of a second messenger system. Several second messengers are candidates for such a coupling‐ or signal transduction‐system, including udenosine‐3′,5′‐cyclic monophosphate, Ca2+, diacylglycerol and inositol 1,4,5‐trisphosphate, active oxygen species and jasmonic acid. Each has been examined as a possible component of the signal transduction system mediating between the elicitor receptor interaction and the phytoalexin synthesis it induces. Analysis of the signalling events is made complex by the simultaneous solicitation by the invading micro‐organism of several defence responses, each of which might involve elements of a different signal system. The same complexity is evident which the role of phytoalexin accumulation in resistance is analysed. Evaluation of the contribution made by phytoalexin accumulation towards resistance has been attempted by the use of various inhibitors and enhancers of the process. Transgenic and mutant plants with specific alterations in one or more ot those elements necessary for the plant to respond to the signals for phytoalexin synthesis and other defence responses, are beginning to aid resolution of the complex pattern ot signalling events and the respective roles of the inducible defence mechanisms in resistance.

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Studies on Elicitor Recognition and Signal Transduction in Host and Non-Host Plant/Fungus Pathogenic Interactions

Cited by 15 publications

References 16 publications

Early events in the elicitation of plant defence

Early events in the elicitation of plant defence

Two types of anion channel currents in guard cells with distinct voltage regulation.

Tansley Review No. 86 Accumulation of phytoalexins: defence mechanism and stimulus response system

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