Planta

, Volume 225, Issue 4, pp 1039–1049

Age-related changes in oxidative stress markers and abscisic acid levels in a drought-tolerant shrub, Cistus clusii grown under Mediterranean field conditions

Original Article

DOI: 10.1007/s00425-006-0412-z

Cite this article as:
Munné-Bosch, S. & Lalueza, P. Planta (2007) 225: 1039. doi:10.1007/s00425-006-0412-z

Abstract

Compared with our knowledge of senescence in annuals and biennials, little is known about age-related changes in perennials. To get new insights into the mechanisms underlying aging in perennials, we measured oxidative stress markers in leaves and organelles, together with abscisic acid levels in leaves of 2- and 7-year-old Cistus clusii dunal plants grown under Mediterranean field conditions. Recently emerged leaves, which either appeared during autumn or spring, were compared to evaluate the effects of environmental constraints on oxidative stress and abscisic acid accumulation as plants aged. Plant aging led to an enhanced oxidation of α-tocopherol and ascorbate, increased lipid peroxidation and reduced PSII efficiency in leaves during the more stressful conditions of spring and summer, but not during autumn. Analyses of lipid peroxidation in organelles isolated from the same leaves revealed that oxidative stress occurred both in chloroplasts and mitochondria. Although both plant groups showed similar leaf water and nitrogen contents throughout the study, abscisic acid levels were markedly higher (up to 75%) in 7-year-old plants compared to 2-year-old plants throughout the study. It is concluded that (a) meristematic tissues of C. clusii maintain the capacity to make new leaves with no symptoms of oxidative stress for several years, unless these leaves are exposed to environmental constraints, (b) leaves of oldest plants show higher oxidative stress than those of young plants when exposed to adverse climatic conditions, thus supporting the idea that the oxidative stress associated with aging is due at least partly to extrinsic factors, (c) at the subcellular level, age-induced oxidative stress occurs both in chloroplasts and mitochondria, and (d) even in the absence of environmental stress, newly emerged leaves accumulate higher amounts of ABA as plants age.

Keywords

Abscisic acid Aging Antioxidants Oxidative stress Perennials Senescence 

Abbreviations

ABA

Abscisic acid

DW

Dry weight

Fv/Fm

Maximum efficiency of PSII

FW

Fresh weight

MDA

Malondialdehyde

PPFD

Photosynthetically-active photon flux density

PSII

Photosystem II

ROS

Reactive oxygen species

RWC

Relative water content

Copyright information

© Springer-Verlag 2006

Authors and Affiliations

  1. 1.Departament de Biologia Vegetal, Facultat de BiologiaUniversitat de BarcelonaBarcelonaSpain