INDIAN SCIENCE CONGRESS - India Environment Portal

166
Proc. 98th Indian Science Congress, Part II : Abstracts of Oral/Poster Presentation
depolymerizing agent, Latrunculin B (Lat B) also lead to substantial inhibition of
IAA-induced AR response and NO accumulation in the responding cells. Evidence
for changes in temporal and spatial expression of endogenous NO in the adventitious
root differentiating zone at various stages of development has been monitored
by fluorescence microscopy, using DAF-2DA as the probe in presence of various
pharmacological treatments. Quantitation of total NO level and NO content due to
putative NOS activity has been undertaken in hypocotyl explants subjected to AR
stimulatory and inhibitory treatments. Aminoguanidine (an inhibitor of inducible nitric
oxide synthase) brought about a reduction in total NO content, indicating a
significant contribution of the activity of putative NOS in endogenous NO accumulation.
Thus, evidence for a linkage between IAA and NO during AR formation has
been established.
208. Sodium Chloride Stress Induces Nitric Oxide Accumulation in Root
Tips and Oil Body surface Accompanying Slower Oleosin Degradation
in Sunflower Seedlings
Anisha David* and Satish C. Bhatla
Plant Physiology and Biochemistry Laboratory,
Department of Botany, University of Delhi,
North Campus, Delhi 110007
Keywords : Salt stress, nitric oxide, sunflower, putative nitric oxide synthase
activity, oleosin
Present work highlights the involvement of endogenous nitric oxide (NO) in
sodium chloride (NaCl)-induced inhibition of seedling growth in sunflower
(Helianthus annuus L. cv. Morden). The growth response is dependent on NaCl
concentration to which seedlings are exposed, they being tolerant to 40 mM NaCl
and showing a reduction in root extension growth and its proliferation at 120 mM
NaCl. NaCl sensitivity of sunflower seedlings accompanies a 4-fold increase in
Na + /K + ratio in roots (as compared to that in cotyledons) and a rapid transport
of Na + to the cotyledons, thereby enhancing Na + /K + ratio in the cotyledons, in
order to tolerate sodium toxicity by the growing seedling. A transient increase in
endogenous NO content, primarily contributed by putative NOS activity in roots