الفهرس 
Nitric oxideOnly 14 pages are availabe for public view
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Abstract
Botany Department, Faculty of Science, Ain
Shams University.
The experiments conducted in this research were carried
out to investigate the possible defensive role of nitric oxide
(NO) against abiotic stress induced by salinity and heavy metal
in lupine plant.
A preliminary study was made on Lupinus termis L.
plant, to throw the light on the effect of different
concentrations of sodium nitroprusside (SNP) (0.2,0.4,0.6 and
0.8mM) (as a NO donor) on percentage of germination and
survival, growth characteristics, photosynthetic pigments and
nitric oxide contents, . from the obtained results, the most
effective concentrations of SNP (0.4 and 0.6mM) were chosen
for conducting the main experiment.
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The main experiment was conducted where Lupinus
termis L. plants were sprayed with two concentrations (0.4 and
0.6 mM) of sodium nitroprusside (SNP; as a NO donor) and
subjected to two levels of sodium chloride (75 and 150mM)
and nickel sulphate (100 and 150 mM), in order to determine
the different strategies taken by the plant and to improve its
ability to resist these kinds of abiotic stress using nitric oxide
as a protective agent.
The toxic effects of salinity and Ni on Lupinus termis
plants was evaluated by detecting the growth characteristics,
photosynthetic pigments, nitric oxide, proline, endogenous
soluble sugars, polysaccharides and total carbohydrates
content. Total phenols and flavonoids were also measured,
oxidative stress markers (lipid peroxidation, H2O2 and
electrolyte leakage);phytohormones (indole acetic acid (IAA),
giberellic acid(GA3), abscisic Acid (ABA) and jasmonic
acid(JA), enzyme activities (superoxide dismutase (SOD),
peroxidase (POD), ascorbate peroxidase (APX) , catalase
(CAT) and glutathione transferase (GST) and mineral ions
Na+, Ca2+,K+ and Mg2+ beside Ni2+ accumulation, in presence
or absence of NO.
Salinity and Ni stress resulted in significantly elevated
levels of lipid peroxidation, H2O2, electrolyte leakage, abscisic
i
acid(ABA), jasmonic acid(JA) and proline contents associated
with significant reduction in growth parameters,
photosynthetic pigments, carbohydrates, indole acetic acid
(IAA), giberellic acid (GA3) contents compared to control
plants. Treatment with SNP was found to alleviate the toxic
effect of salinity and Ni on Lupinus termis L. plants in addition
to increasing the amounts of proline, soluble sugars and
polysaccharides of shoots and roots of Lupinus termis L. as a
possible defensive mechanism against salinity and heavy metal
toxicity compared to untreated lupine plant subjected to the
same stress conditions. The effect of SNP treatment was much
more pronounced in plant received 0.4 mM than those treated
with 0.6 mM.
Yield characteristics of Lupinus termis showed an
increase in most parameters when treated with 0.4 mM SNP
and 0.6 mM SNP, when compared with salinity and Ni
treatments.
Key words:-
Sodium nitroprusside (SNP), nitric oxide (NO),Lupinus
termis, salinity stress, heavy metal stress, nickel, growth
characteristics, metabolic activities, phytohormones,
antioxidative enzymes and yield characteristics.