JXB Advance Access originally published online on June 26, 2007
Journal of Experimental Botany 2008 59(1):37-43; doi:10.1093/jxb/erm127
SPECIAL ISSUE REVIEW PAPER |
Long-distance signalling of abscisic acid (ABA): the factors regulating the intensity of the ABA signal
1College of Life Science, BeiJing Normal University, Xin Jie Kou Wai Da Jie 19, 100875 BeiJing, China
2Lehrstuhl Botanik I der Universität Würzburg, Julius von Sachs Platz 2, D 97082 Würzburg, Germany
* To whom correspondence should be addressed. E-mail: hartung{at}botanik.uni-wuerzburg.de
Abscisic acid (ABA) is a stress signal, which moves in the xylem from the roots to the aerial parts of the plant, where it regulates stomatal movement and the activity of shoot meristems. Root growth-promoting microorganisms in the rhizosphere, lateral ABA flows in the root cortex across apoplastic barriers, ABA redistribution in the stem, leaf apoplastic pH values, and the action of β-glucosidases, both in the apoplast and the cytosol of the mesophyll, play an important role in the regulation of signal intensity. The significance of abscisic acid glucose ester as a long-distance stress signal is discussed.
Key words: Abscisic acid glucose ester, apoplast, β-glucosidases, pH, rhizosphere, xylem
Received 14 March 2007; Revised 15 May 2007 Accepted 15 May 2007