Plasticity of antioxidant defence responses to abiotic stress in natural populations of Iris pumila
2013
Тип документа:
Конференцијски прилог (Објављена верзија)
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© 2013 by the European Society for Evolutionary Biology
Метаподаци
Приказ свих података о документуАпстракт:
For plants, sunlight is not only the major source of energy for photosynthesis, but also a powerful
evolutionary force that shapes the evolutionary trajectories of many traits. The aim of this study was to
examine seasonal- and habitat-dependent variations in the specific activities of different antioxidants in
the leaves of Iris pumila clones expressed under contrasting light conditions in the wild. Two
populations were selected in the Deliblato Sands: one experiencing full sunlight and one from a
woodland understory. Leaf samples were collected in spring, summer and autumn from the same clones
in each population. The specific activities of the antioxidative enzymes, SOD, APX, CAT, GR and
POD, and the contents of non-enzymatic antioxidants, anthocyanins and phenolics, were determined.
All of the examined antioxidants were observed to be upregulated in summer-harvested leaves when
compared to their spring or autumn counterparts. This suggests that reinforcement of the antioxidants
might be the key mechanism for acclimatization of I. pumila leaves to seasonal variations in light
intensity. In both populations, the antioxidative enzymes SOD, GR and POD expressed a greater mean
seasonal plasticity than the other antioxidants. However, the between-population difference was
significant only for POD. To elucidate whether variations in antioxidants reflect adaptations to local
environments, a reciprocal transplant experiment was conducted in the wild. The higher activities of
antioxidative enzymes were accompanied by increased contents of non-enzymatic antioxidants in both
populations in the open habitat in comparison to clones in the shaded habitat. This could be a reflection
of adaptive plasticity to the synergistic effect of strong light and high temperature. In contrast to
seasonal plasticity, habitat-dependent plasticity peaked for APX and CAT in both populations. Apart
from the phenolic content, a significant between-population difference was not observed.
У:
- Oral presentation abstracts and list of posters: 14th Congress of the European Society for Evolutionary Biology; 2013 Aug 19-24; Lisbon, Portugal. European Society for Evolutionary Biology; 2013. p. 266.