Age and sex-related changes in cytokinins, auxins and abscisic acid in a centenarian relict herbaceous perennial

Planta. 2012 Feb;235(2):349-58. doi: 10.1007/s00425-011-1513-x. Epub 2011 Sep 10.

Abstract

It is still an unsolved question of fundamental biology if, and how, perennial plants senesce. Here, age- and sex-related changes in phytohormones were tested in Borderea pyrenaica, a small dioecious geophyte relict of the Tertiary with one of the longest lifespan ever recorded for any non-clonal herb (more than 300 years). Biomass allocation, together with levels of cytokinins, auxins and absicisic acid, and other indicators of leaf physiology (chlorophylls, lipid peroxidation and F (v)/F (m) ratio) were measured in juvenile and mature plants, including both males and females of three age classes (up to 50 years, 50-100 years, and over 100 years). Plants maintained intact capacity of their vegetative growth and reproductive potential. Cytokinin levels decreased with age, but only in females. Such sex-related differences, however, were not associated with symptoms of physiological deterioration in leaves, but with an increased reproductive effort in females. It is concluded that B. pyrenaica does not show clear signs of senescence at the organism level. Altered cytokinin levels in females were associated with their reproductive effort, rather than to a degenerative process. The alternate use of five meristematic points in the tuber could explain the extraordinary longevity of this species.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Abscisic Acid / metabolism*
  • Chlorophyll / metabolism
  • Cytokinins / metabolism*
  • Dioscoreaceae / metabolism*
  • Dioscoreaceae / physiology
  • Fluorescence
  • Fruit / physiology
  • Indoleacetic Acids / metabolism*
  • Lipid Peroxidation
  • Photochemistry
  • Plant Growth Regulators / metabolism
  • Plant Leaves / metabolism
  • Plant Leaves / physiology
  • Plant Stems / metabolism
  • Plant Stems / physiology
  • Plant Tubers / metabolism
  • Plant Tubers / physiology
  • Reproduction / physiology
  • Species Specificity
  • Time Factors

Substances

  • Cytokinins
  • Indoleacetic Acids
  • Plant Growth Regulators
  • Chlorophyll
  • Abscisic Acid