TY - JOUR

T1 - Age and sex-related changes in cytokinins, auxins and abscisic acid in a centenarian relict herbaceous perennial

AU - Onate Gutierrez, Marta

AU - Garcia, Maria B.

AU - Munne-Bosch, Sergi

PY - 2012/2

Y1 - 2012/2

N2 - 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.

AB - 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.

KW - Ageing

KW - Cytokinins

KW - Dioecy

KW - Perennial herb

KW - Hormones

KW - Senescence

KW - PHENOTYPIC PLASTICITY

KW - MEDITERRANEAN SHRUB

KW - BIOMASS ALLOCATION

KW - LEAF SENESCENCE

KW - FEMALE PLANTS

KW - PINUS-RADIATA

KW - CISTUS-CLUSII

KW - LIFE-HISTORY

KW - EVOLUTION

KW - ANIMALS

U2 - 10.1007/s00425-011-1513-x

DO - 10.1007/s00425-011-1513-x

M3 - Journal article

VL - 235

SP - 349

EP - 358

JO - Planta

JF - Planta

SN - 0032-0935

IS - 2

ER -