nstantaneous and historical temperature effects on a-pinene
Growth,
photosynthetic activity and oxidative stress in wheat
(Triticumaestivum)
after exposure of lead to soil
Author Details
GurpreetKaur
Department
of Environment Studies, PanjabUniversity, Chandigarh - 160 014, India
Harminder Pal Singh
Department
of Environment Studies, PanjabUniversity, Chandigarh - 160 014, India
e-mail:
hpsingh_01@yahoo.com
DaizyR.Batish
Department
of Botany, PanjabUniversity, Chandigarh - 160 014, India
RavinderKumarKohli??????????????????
Department
of Botany, PanjabUniversity, Chandigarh - 160 014, India?
Publication Data
Paper received:
25
October 2010
Revised
received:
25
February 2011
Accepted:
07 March 2011
Abstract
The present study was
conducted to assess quantitative information about lead (Pb)
contamination in soil on the growth and physiology of wheat. Solutions with
three different concentrations of Pb as [Pb(NO3)2
at 500, 1000 and 2500 ?M] were incorporated into the soil to achieve Pb-stressed conditions in comparison to unstressed, water
treated, control variant. Wheat growth measured in terms of root length,
shoot length and dry weight exhibited a significant decline with increasing Pb concentrations in the soil. Root and shoot length and
seedling weight declined in the range of ~23?51, ~17?44, and ~21?44% in
response to 500 to 2500 ?M Pb. In addition, there
was a significant reduction in the levels of photosynthetic
pigments-chlorophyll a (16-66%) and b (10-24%) and total
chlorophyll content (by 14-39%) in plants growing in Pb-contaminated
soil. It indicated a negative effect on photosynthetic activity in wheat and
was confirmed by reduced photochemical efficiency of PSII (Fv/Fm) in the
range of ~ 3-37% in response to 500 to 2500 ?M Pb.
The reduction in wheat growth in Pb-contaminated
soil was accompanied by induction of oxidative stress as indicated by
enhanced lipid peroxidation in terms of malondialdehyde (MDA) content (by 18-40%) and hydrogen
peroxide (H2O2) content (by 34-123%) and alterations in
the activity of enzymes, superoxidedismutases (SOD) and guaiacolperoxidases (GPX) in wheat roots. The study concludes
that Pb in soil inhibits growth and phototsynthetic activity in wheat through induction of
oxidative stress.
Key
words
Lead toxicity, Seedling
growth, Photosynthetic pigments, Photochemical efficiency, Membrane peroxidation?
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