Chin J Plant Ecol ›› 2007, Vol. 31 ›› Issue (5): 804-813.DOI: 10.17521/cjpe.2007.0102

• Research Articles • Previous Articles     Next Articles

PHYSIOLOGICAL AND ECOLOGICAL MECHANISMS OF LONG-DISTANCE WATER TRANSPORT IN PLANTS: A REVIEW OF RECENT ISSUES

WAN Xian-Chong1(), Meng Ping2   

  1. 1Institute of New Forest Technology, Chinese Academy of Forestry, Beijing 100091, China
    2Institute of Forestry, Chinese Academy of Forestry, Beijing 100091, China
  • Received:2006-10-20 Accepted:2007-01-11 Online:2007-10-20 Published:2007-09-30

Abstract:

Long-distance water transport in plants is an important issue in plant physiology and eco-physiology. The recent development of the Xylem Pressure Probe for direct measurement of pressure in individual xylem elements of intact, transpiring plants elicited challenges to the long-standing, widely accepted Cohesion-Tension (C-T) Theory. These challenges instigated debate in the field of plant physiology over mechanisms of long-distance water transport. The challengers and proponents of the C-T theory mutually criticized the Pressure Bomb and the Xylem Pressure Probe technology, and they debated over all three elements of C-T theory (high tension in xylem units; pressure gradients over tree height; the continuous water column in xylem vessels) by reviewing literature and providing physical bases. The debate has cooled down. As a result, the C-T theory has not been discredited while the raised questions in the debate remain mainly unanswered and call for future researches.

Key words: cohesion-tension theory, xylem pressure probe, pressure bomb, long-distance water transport, xylem cavitation