19 / 20
Page 53
conferenceseries
.com
Volume 9
Journal of Earth Science & Climatic Change
Natural Hazards Congress 2018
July 26-27, 2018
July 26-27, 2018 Melbourne, Australia
2
nd
International Conference on
Natural Hazards and Disaster Management
Coordinated effects of lead toxicity and nutrient deprivation on growth, oxidative status and elemental
composition of primed and non-primed rice seedlings
Saddam Hussain
University of Agriculture, Pakistan
A
factorial growth chamber experiment was carried out to unravel the coordinated effects of Pb stress (1 mM PbCl
2
) and
different nutrient management regimes (Sufficient nutrient supply, nitrogen (N) deprivation, phosphorus (P) deprivation
and potassium (K) deprivation) on morphological growth, Reactive Oxygen Species (ROS), antioxidants and nutrient status
in primed and non-primed rice seedlings. Seeding was primed with distilled water (hydropriming; HP), 60 µM selenium
(chemical priming; Se) or 100 mg L-1 salicylic acid (hormonal priming; SA). Results indicated that Pb toxicity did not affect the
root growth, but severely reduced the shoot growth (length and biomass) of rice in N- or P-deprived seedlings. Rice seedlings
grown with sufficient supply of nutrients (All Nut) or K-deprivation showed no growth reduction under Pb toxicity. Exposure
of Pb stress triggered the production of ROS (H
2
O
2
, O
2
•-, OH−) and lipid peroxidation rate under all the nutrient management
regimes particularly under N- or P-deprivation. Moreover, the shoot accumulations of macronutrients (particularly P) were
also restricted under Pb toxicity. Seed priming treatments (particularly Se and SA) were found to be significant in alleviating
the undesirable effects of Pb stress on rice growth. The primed rice seedlings showed minimal oxidative damage caused by
excessive generation of ROS under Pb stress and/or nutrient deprivation. Seed priming strengthened the anti-oxidative defense
system of rice seedlings by regulating the activities/levels of superoxide dismutase, catalase, peroxidase and glutathione in
rice leaves. Moreover, better accumulation of essential nutrients in primed rice seedlings prevented the excess uptake and
translocation of Pb, as evident by the lowered shoot accumulation of Pb. In short, these results suggested the protective role of
seed priming against the adversities caused by Pb toxicity and nutrient deprivation in rice seedlings.
sadamhussainuaf@gmail.comJ Earth Sci Clim Change 2018, Volume 9
DOI: 10.4172/2157-7617-C2-043