Surviving a Dry Future: Abscisic Acid (ABA)-Mediated Plant Mechanisms for Conserving Water under Low Humidity

• Main Authors: Frances C. Sussmilch, Scott A. M. McAdam
• Format: Article
• Language: English
• Published: MDPI AG 2017-11-01
• Series: Plants
• Subjects: stomata; humidity; vapor pressure deficit (VPD); abscisic acid (ABA); 9-cis-epoxycarotenoid dioxygenase (NCED); water deficit stress; evolution; sensing water status
• Online Access: https://www.mdpi.com/2223-7747/6/4/54

Angiosperms are able to respond rapidly to the first sign of dry conditions, a decrease in air humidity, more accurately described as an increase in the vapor pressure deficit between the leaf and the atmosphere (VPD), by abscisic acid (ABA)-mediated stomatal closure. The genes underlying this response offer valuable candidates for targeted selection of crop varieties with improved drought tolerance, a critical goal for current plant breeding programs, to maximize crop production in drier and increasingly marginalized environments, and meet the demands of a growing population in the face of a changing climate. Here, we review current understanding of the genetic mechanisms underpinning ABA-mediated stomatal closure, a key means for conserving water under dry conditions, examine how these mechanisms evolved, and discuss what remains to be investigated.