Abscisic acid activation of plasma membrane Ca(2+) channels in guard cells requires cytosolic NAD(P)H and is differentially disrupted upstream and downstream of reactive oxygen species production in abi1-1 and abi2-1 protein phosphatase 2C mutants.

Published

Journal Article

The hormone abscisic acid (ABA) regulates stress responses and developmental processes in plants. Calcium-permeable channels activated by reactive oxygen species (ROS) have been shown recently to function in the ABA signaling network in Arabidopsis guard cells. Here, we report that ABA activation of these I(Ca) Ca(2)+ channels requires the presence of NAD(P)H in the cytosol. The protein phosphatase 2C (PP2C) mutant abi1-1 disrupted ABA activation of I(Ca) channels. Moreover, in abi1-1, ABA did not induce ROS production. Consistent with these findings, in abi1-1, H(2)O(2) activation of I(Ca) channels and H(2)O(2)-induced stomatal closing were not disrupted, suggesting that abi1-1 impairs ABA signaling between ABA reception and ROS production. The abi2-1 mutation, which lies in a distinct PP2C gene, also disrupted ABA activation of I(Ca). However, in contrast to abi1-1, abi2-1 impaired both H(2)O(2) activation of I(Ca) and H(2)O(2)-induced stomatal closing. Furthermore, ABA elicited ROS production in abi2-1. These data suggest a model with the following sequence of events in early ABA signal transduction: ABA, abi1-1, NAD(P)H-dependent ROS production, abi2-1, I(Ca) Ca(2)+ channel activation followed by stomatal closing.

Full Text

Duke Authors

Cited Authors

  • Murata, Y; Pei, ZM; Mori, IC; Schroeder, J

Published Date

  • November 2001

Published In

Volume / Issue

  • 13 / 11

Start / End Page

  • 2513 - 2523

PubMed ID

  • 11701885

Pubmed Central ID

  • 11701885

Electronic International Standard Serial Number (EISSN)

  • 1532-298X

International Standard Serial Number (ISSN)

  • 1040-4651

Digital Object Identifier (DOI)

  • 10.1105/tpc.010210

Language

  • eng