Effects of Erwinia amylovora harpin on tobacco leaf cell membranes are related to leaf necrosis and electrolyte leakage and distinct from perturbations caused by inoculated E. amylovora

S. M. Pike, A. Ádám, X. A. Pu, M. E. Hoyos, R. Laby, S. V. Beer, A. Novacky

Research output: Article

43 Citations (Scopus)

Abstract

We have characterized the membrane potential response of cells in tobacco leaves to externally applied or injected harpin from Erwinia amylovora (Ea321) and linked it to subsequent electrolyte leakage and eventual necrosis. We similarly examined depolarization in response to injected Ea321 cells, and mutant bacteria that are defective in harpin production. Injected and applied harpin depolarize only the H+-ATPase-dependent component of membrane potential, in contrast to injected wild-type Ea321, which greatly depolarizes both pump and diffusion potentials. The functional capacity of the H+-ATPase component is also much less impaired in harpin- than Ea321-injected leaves. Furthermore, harpin production dose not account for the entire set of differences in response to injected wild-type and mutant bacteria. Membrane depolarization in response to applied harpin and necrosis induced by injected harpin are similarly concentration-dependent and directly related. Parallel inhibition of harpin-caused membrane depolarization, electrolyte leakage and necrosis by the Ca2+ channel blocker, La3+, or the protein kinase inhibitor, K252a, links these events and suggests that prolonged Ca2+ entry and phosphorylation underlie them. Although harpin similarly depolarizes leaf and suspension cell potentials, there is a substantial difference: leaf cell membranes are less sensitive and repolarize. Increased repolarization upon harpin removal points to probable reversible association with the plant cell. Dependence of repolarization upon order of harpin/fusicoccin addition suggests separate modes or sites of action.

Original languageEnglish
Pages (from-to)39-60
Number of pages22
JournalPhysiological and Molecular Plant Pathology
Volume53
Issue number1
DOIs
Publication statusPublished - júl. 1998

Fingerprint

Erwinia amylovora
Electrolytes
electrolytes
Tobacco
cell membranes
necrosis
tobacco
Proton-Translocating ATPases
Necrosis
Cell Membrane
Membrane Potentials
H-transporting ATP synthase
membrane potential
Bacteria
leaves
Membranes
Plant Cells
Protein Kinase Inhibitors
calcium
fusicoccin

ASJC Scopus subject areas

  • Plant Science

Cite this

@article{8749868c69544a91a1c0ae7a37eba9e7,
title = "Effects of Erwinia amylovora harpin on tobacco leaf cell membranes are related to leaf necrosis and electrolyte leakage and distinct from perturbations caused by inoculated E. amylovora",
abstract = "We have characterized the membrane potential response of cells in tobacco leaves to externally applied or injected harpin from Erwinia amylovora (Ea321) and linked it to subsequent electrolyte leakage and eventual necrosis. We similarly examined depolarization in response to injected Ea321 cells, and mutant bacteria that are defective in harpin production. Injected and applied harpin depolarize only the H+-ATPase-dependent component of membrane potential, in contrast to injected wild-type Ea321, which greatly depolarizes both pump and diffusion potentials. The functional capacity of the H+-ATPase component is also much less impaired in harpin- than Ea321-injected leaves. Furthermore, harpin production dose not account for the entire set of differences in response to injected wild-type and mutant bacteria. Membrane depolarization in response to applied harpin and necrosis induced by injected harpin are similarly concentration-dependent and directly related. Parallel inhibition of harpin-caused membrane depolarization, electrolyte leakage and necrosis by the Ca2+ channel blocker, La3+, or the protein kinase inhibitor, K252a, links these events and suggests that prolonged Ca2+ entry and phosphorylation underlie them. Although harpin similarly depolarizes leaf and suspension cell potentials, there is a substantial difference: leaf cell membranes are less sensitive and repolarize. Increased repolarization upon harpin removal points to probable reversible association with the plant cell. Dependence of repolarization upon order of harpin/fusicoccin addition suggests separate modes or sites of action.",
author = "Pike, {S. M.} and A. {\'A}d{\'a}m and Pu, {X. A.} and Hoyos, {M. E.} and R. Laby and Beer, {S. V.} and A. Novacky",
year = "1998",
month = "7",
doi = "10.1006/pmpp.1998.0167",
language = "English",
volume = "53",
pages = "39--60",
journal = "Physiological and Molecular Plant Pathology",
issn = "0885-5765",
publisher = "Academic Press Inc.",
number = "1",

}

TY - JOUR

T1 - Effects of Erwinia amylovora harpin on tobacco leaf cell membranes are related to leaf necrosis and electrolyte leakage and distinct from perturbations caused by inoculated E. amylovora

AU - Pike, S. M.

AU - Ádám, A.

AU - Pu, X. A.

AU - Hoyos, M. E.

AU - Laby, R.

AU - Beer, S. V.

AU - Novacky, A.

PY - 1998/7

Y1 - 1998/7

N2 - We have characterized the membrane potential response of cells in tobacco leaves to externally applied or injected harpin from Erwinia amylovora (Ea321) and linked it to subsequent electrolyte leakage and eventual necrosis. We similarly examined depolarization in response to injected Ea321 cells, and mutant bacteria that are defective in harpin production. Injected and applied harpin depolarize only the H+-ATPase-dependent component of membrane potential, in contrast to injected wild-type Ea321, which greatly depolarizes both pump and diffusion potentials. The functional capacity of the H+-ATPase component is also much less impaired in harpin- than Ea321-injected leaves. Furthermore, harpin production dose not account for the entire set of differences in response to injected wild-type and mutant bacteria. Membrane depolarization in response to applied harpin and necrosis induced by injected harpin are similarly concentration-dependent and directly related. Parallel inhibition of harpin-caused membrane depolarization, electrolyte leakage and necrosis by the Ca2+ channel blocker, La3+, or the protein kinase inhibitor, K252a, links these events and suggests that prolonged Ca2+ entry and phosphorylation underlie them. Although harpin similarly depolarizes leaf and suspension cell potentials, there is a substantial difference: leaf cell membranes are less sensitive and repolarize. Increased repolarization upon harpin removal points to probable reversible association with the plant cell. Dependence of repolarization upon order of harpin/fusicoccin addition suggests separate modes or sites of action.

AB - We have characterized the membrane potential response of cells in tobacco leaves to externally applied or injected harpin from Erwinia amylovora (Ea321) and linked it to subsequent electrolyte leakage and eventual necrosis. We similarly examined depolarization in response to injected Ea321 cells, and mutant bacteria that are defective in harpin production. Injected and applied harpin depolarize only the H+-ATPase-dependent component of membrane potential, in contrast to injected wild-type Ea321, which greatly depolarizes both pump and diffusion potentials. The functional capacity of the H+-ATPase component is also much less impaired in harpin- than Ea321-injected leaves. Furthermore, harpin production dose not account for the entire set of differences in response to injected wild-type and mutant bacteria. Membrane depolarization in response to applied harpin and necrosis induced by injected harpin are similarly concentration-dependent and directly related. Parallel inhibition of harpin-caused membrane depolarization, electrolyte leakage and necrosis by the Ca2+ channel blocker, La3+, or the protein kinase inhibitor, K252a, links these events and suggests that prolonged Ca2+ entry and phosphorylation underlie them. Although harpin similarly depolarizes leaf and suspension cell potentials, there is a substantial difference: leaf cell membranes are less sensitive and repolarize. Increased repolarization upon harpin removal points to probable reversible association with the plant cell. Dependence of repolarization upon order of harpin/fusicoccin addition suggests separate modes or sites of action.

UR - http://www.scopus.com/inward/record.url?scp=0345698760&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0345698760&partnerID=8YFLogxK

U2 - 10.1006/pmpp.1998.0167

DO - 10.1006/pmpp.1998.0167

M3 - Article

VL - 53

SP - 39

EP - 60

JO - Physiological and Molecular Plant Pathology

JF - Physiological and Molecular Plant Pathology

SN - 0885-5765

IS - 1

ER -