Biochemical plasticity and environmental stress: Iris pumila as a case study
2013
Tip dokumenta:
Konferencijski prilog (Objavljena verzija)
,
© 2013 by the European Society for Evolutionary Biology
Metapodaci
Prikaz svih podataka o dokumentuApstrakt:
Irradiance is the one of the most variable abiotic factors experienced by higher plants. Adaptive plastic
responses to fluctuating light conditions have been documented to affect all aspects of plant phenotype
– morphology, physiology and biochemistry. In order to examine the influence of light intensity on the
plasticity of biochemical traits, a random sample of ten Iris pumila clones inhabiting an exposed site in
the Deliblato Sands were partially covered with a neutral screen that transmitted 50% of daylight so
that half of the ramets of a single clone experienced reduced and the other half full exposure to
sunlight. In summer, leaf samples were collected and analyzed for the following biochemical traits: the
relative levels of heat stress proteins (Hsp70 and two isoforms of Hsp90 – inducible Hsp90a and
constitutive Hsp90b); the specific activities of antioxidant enzymes (SOD, CAT, POD, APX, GR); the
contents of non-enzymatic antioxidants (carotenoids), and the extent of lipid peroxidation (MDA
content). The relative levels of all three Hsps (in particular Hsp70 and Hsp90a) were elevated in the
unshaded ramets when compared to their shaded counterparts. In addition, the oxidative stress index
(OSI), expressed in terms of the ratio of MDA to the sum of the geometric means of all examined
antioxidants, was shown to be about 30% greater in ramets from the exposed clone parts than in ramets
from the shaded ones. Of all of the traits analyzed, Hsp70, Hsp90a and OSI exhibited higher values for
the plasticity indices (PIv: 0.44, 0.53 and 0.37, respectively), pointing to their substantial role in coping
with high light intensity. Conversely, Hsp90b appeared to be the least plastic trait (PIv: 0.21), which is
in agreement with its constitutive function. Our results provide evidence that I. pumila displays a
biochemical plastic response that enables overcoming fitness reduction under environmental stress that
commonly occurs in their natural habitats.
Finansiranje / projekti:
- Evolucija u laboratoriji i adaptacije u prirodi (RS-MESTD-Basic Research (BR or ON)-173007)
U:
- Abstract Book: 14th Congress of the European Society for Evolutionary Biology; 2013 Aug 19-24; Lisbon, Portugal. Basel: European Society for Evolutionary Biology; 2013. p. 272.