Membrane potentials (V(m)) and intracellular calcium variations were studied in Lima bean (Phaseolus lunatus) leaves when the Mediterranean climbing cutworm (Spodoptera littoralis) was attacking the plants. In addition to the effect of the feeding insect the impact of several N-acyl Glns (volicitin, N-palmitoyl-Gln, N-linolenoyl-Gln) from the larval oral secretion was studied. The results showed that the early events upon herbivore attack were: a) a strong V(m) depolarization at the bite zone and an isotropic wave of V(m) depolarization spreading throughout the entire attacked leaf; b) a V(m) depolarization observed for the regurgitant but not with volicitin [N-(17-hydroxy-linolenoyl)-Gln] alone; c) an enhanced influx of Ca(2+) at the very edge of the bite, which is halved, if the Ca(2+) channel blocker Verapamil is used. Furthermore, the dose-dependence effects of N-acyl Gln conjugates-triggered influx of Ca(2+) studied in transgenic aequorin-expressing soybean (Glycine max) cells, showed: a) a concentration-dependent influx of Ca(2+); b) a configuration-independent effect concerning the stereochemistry of the amino acid moiety; c) a slightly reduced influx of Ca(2+) after modification of the fatty acid backbone by functionalization with oxygen and; d) a comparable effect with the detergent SDS. Finally, the herbivore wounding causes a response in the plant cells that cannot be mimicked by mechanical wounding. The involvement of Ca(2+) in signaling after herbivore wounding is discussed.

Effects of feeding Spodoptera littoralis on Lima bean leaves. I. Membrane potentials, intracellular calcium variations, oral secretions, and regurgitate components

MAFFEI, Massimo Emilio;BOSSI, Simone;
2004-01-01

Abstract

Membrane potentials (V(m)) and intracellular calcium variations were studied in Lima bean (Phaseolus lunatus) leaves when the Mediterranean climbing cutworm (Spodoptera littoralis) was attacking the plants. In addition to the effect of the feeding insect the impact of several N-acyl Glns (volicitin, N-palmitoyl-Gln, N-linolenoyl-Gln) from the larval oral secretion was studied. The results showed that the early events upon herbivore attack were: a) a strong V(m) depolarization at the bite zone and an isotropic wave of V(m) depolarization spreading throughout the entire attacked leaf; b) a V(m) depolarization observed for the regurgitant but not with volicitin [N-(17-hydroxy-linolenoyl)-Gln] alone; c) an enhanced influx of Ca(2+) at the very edge of the bite, which is halved, if the Ca(2+) channel blocker Verapamil is used. Furthermore, the dose-dependence effects of N-acyl Gln conjugates-triggered influx of Ca(2+) studied in transgenic aequorin-expressing soybean (Glycine max) cells, showed: a) a concentration-dependent influx of Ca(2+); b) a configuration-independent effect concerning the stereochemistry of the amino acid moiety; c) a slightly reduced influx of Ca(2+) after modification of the fatty acid backbone by functionalization with oxygen and; d) a comparable effect with the detergent SDS. Finally, the herbivore wounding causes a response in the plant cells that cannot be mimicked by mechanical wounding. The involvement of Ca(2+) in signaling after herbivore wounding is discussed.
2004
134(4)
1752
1762
http://dx.doi.org/10.1104/pp.103.034165
M. Maffei; S. Bossi; D. Spiteller; A. Mithöfer; W. Boland
File in questo prodotto:
File Dimensione Formato  
2004 Maffei et al Plant Phys I.pdf

Accesso riservato

Tipo di file: POSTPRINT (VERSIONE FINALE DELL’AUTORE)
Dimensione 504.76 kB
Formato Adobe PDF
504.76 kB Adobe PDF   Visualizza/Apri   Richiedi una copia

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/2318/100800
Citazioni
  • ???jsp.display-item.citation.pmc??? 60
  • Scopus 172
  • ???jsp.display-item.citation.isi??? 151
social impact