In-vivo Nitrate Reductase Activity Of Marine Angiosperm Halodule pinifolia (Miki) Hartog

IJEP 41(3): 298-302 : Vol. 41 Issue. 3 (March 2021)

Gunabalan Gunasekaran1, Saravanakumar Ayyappan1, Asaithambi Kalaiselvi2 and Jeyapragash Danaraj1,2*

1. Annamalai University, Centre of Advanced Study in Marine Biology, Annamalai – 608 002, Tamil Nadu, India
2. Karpagam Academy of Higher Education, Department of Biotechnology, Coimbatore – 641 021, Tamil Nadu, India


Halodule pinifolia, a marine angiosperm collected from the Gulf of Mannar were assayed for nitrate reductase activity in order to determine the nitrate as a sole nitrogen source. Roots, rhizomes and leaves of H. pinifolia were used in the present study and the activity observed was very low. Pre-treatment of plant parts with varying concentration of nitrate did not induce higher nitrate reductase activity. Roots at a concentration of 100 µM NaNO3 showed the maximum nitrate reductase activity (21.9 x 10-9 equiv. NO2/h.gfr.wt), followed by the leaf part at a concentration of 100 µM NaNO3 (19.65 x 10-9 equiv. NO2/h.gfr.wt). Nitrate reductase activity was not significantly influenced by varying the nitrate and propanol concentrations or pH of the assay medium. Present findings conclude that H. pinifolia does not use nitrate as a sole nitrogen source for their growth and might undergo other mechanisms, such as N2 fixation and/or ammonium uptake to reach their growth and productivity in the marine environment.


Halodule pinifolia, Enzyme, Nitrate reductase, Propanol, Pre-treatment


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