Expression of a Cs(+)-resistant guard cell K+ channel confers Cs(+)-resistant, light-induced stomatal opening in transgenic arabidopsis.

Journal Article (Journal Article)

Inward-rectifying K+ (K+in) channels in the guard cell plasma membrane have been suggested to function as a major pathway for K+ influx into guard cells during stomatal opening. When K+in channels were blocked with external Cs+ in wild-type Arabidopsis guard cells, light-induced stomatal opening was reduced. Transgenic Arabidopsis plants were generated that expressed a mutant of the guard cell K+in channel, KAT1, which shows enhanced resistance to the Cs+ block. Stomata in these transgenic lines opened in the presence of external Cs+. Patch-clamp experiments with transgenic guard cells showed that inward K+(in) currents were blocked less by Cs+ than were K+ currents in controls. These data provide direct evidence that KAT1 functions as a plasma membrane K+ channel in vivo and that K+in channels constitute an important mechanism for light-induced stomatal opening. In addition, biophysical properties of K+in channels in guard cells indicate that components in addition to KAT1 may contribute to the formation of K+in channels in vivo.

Full Text

Duke Authors

Cited Authors

  • Ichida, AM; Pei, ZM; Baizabal-Aguirre, VM; Turner, KJ; Schroeder, JI

Published Date

  • October 1997

Published In

Volume / Issue

  • 9 / 10

Start / End Page

  • 1843 - 1857

PubMed ID

  • 9368418

Pubmed Central ID

  • PMC157026

Electronic International Standard Serial Number (EISSN)

  • 1532-298X

International Standard Serial Number (ISSN)

  • 1040-4651

Digital Object Identifier (DOI)

  • 10.1105/tpc.9.10.1843


  • eng