Drought until death do us part: a case study of the desiccation-tolerance of a tropical moist forest seedling-tree, Licania platypus (Hemsl.) Fritsch

J Exp Bot. 2002 Nov;53(378):2239-47. doi: 10.1093/jxb/erf078.

Abstract

Studies of the desiccation tolerance of 15-month-old Licania platypus (Hemsl.) Fritsch seedlings were performed on potted plants. Pots were watered to field capacity and then dehydrated for 23-46 d to reach various visible wilting stages from slightly-wilted to dead. Root hydraulic conductance, k(r), was measured with a high-pressure flow meter and whole-stem hydraulic conductance, k(ws), was measured by a vacuum chamber method. Leaf punches were harvested for measurement of leaf water potential by a thermocouple psychrometer and for measurement of fresh- and dry-weight. L. platypus was surprisingly desiccation-tolerant, suggesting that most species of central Panama may be well adapted to the seasonality of rainfall in the region. The slightly-wilted stage corresponded to leaf water potentials and relative water contents of -2.7 MPa and 0.85, respectively, but plants did not die until these values fell to -7.5 MPa and 0.14, respectively. As desiccation proceeded k(r) and k(ws) declined relative to irrigated controls, but k(ws) was more sensitive to desiccation than k(r). Values of k(ws) declined by 70-85% in slightly-wilted to dead plants, respectively. By comparison, k(r) showed no significant change in slightly-wilted plants and fell by about 50% in plants having severely-wilted to dead shoots.

MeSH terms

  • Adaptation, Physiological / drug effects
  • Adaptation, Physiological / physiology*
  • Apoptosis / drug effects
  • Apoptosis / physiology*
  • Desiccation
  • Disasters
  • Panama
  • Plant Leaves / drug effects
  • Plant Leaves / physiology
  • Plant Roots / drug effects
  • Plant Roots / physiology
  • Plant Stems / drug effects
  • Plant Stems / physiology
  • Plant Transpiration / drug effects
  • Plant Transpiration / physiology
  • Rosales / drug effects
  • Rosales / physiology*
  • Temperature
  • Tropical Climate
  • Water / pharmacology*
  • Water / physiology

Substances

  • Water