Membrane Depolarization Induced by N-Acetylchitooligosaccharide Elicitor in Suspension-Cultured Rice Cells

元データ 日本植物生理学会


N-acetylchitooligosaccharides (fragments of chitin) elicit defense responses, including phytoalexin production, in suspension-cultured rice cells. They induced rapid and transient membrane depolarization accompanied by a transient increase in net Cl^<-1> -effiux. The membrane depolarization was not affected by anaerobiosis or azide, suggesting that the major part of the depolarization was mediated by ion channels, not by energy-dependent ion pumps. Depolarization was partly inhibited in the presence of Ca^<2+> or Cl^<-1> channel blockers and highly inhibited by depletion of Ca^<2+> in the extracellular medium. A calcium ionophore, A23187, caused a transient depolarization but not an increase in Cl^<-1> efflux, while it did not inhibit the elicitor-induced transient depolarization and Cl^<-1> efflux. These suggest that the influx of Ca^<2+> from the extracellular space to the cytoplasm is necessary as an initial trigger but not sufficient for membrane depolarization, Cl^<-1> efflux, and the following signaling processes.


SHIBUYA Naoto Department Biochemistry, National Institute of Agrobiological Science
Kikuyama Munehiro Biological Laboratory, The University of the Air
Kuchitsu Kazuyuki Department of Cell Biology, National Institute of Agrobiological Resources
Kikuyama M Niigata Univ. Niigata Jpn
Kuchitsu Kazuyuki Dept. Biotech. Natl. Inst. Agrobiol. Resources
Kuchitsu Kazuyuki Department Of Applied Biological Science Tokyo University Of Science
Shibuya N Dep. Of Life Sciences Fac. Of Agriculture Meiji Univ.
Kikuyama Munehiro Biological Laboratory The University Of The Air.
Kikuyama Munehiro Biological Laboratory The University Of The Air