NOx UPTAKE BY MANGROVE PLANTS AND ITS EFFECT ON MANGROVE DNA BASE HETEROGENEITY

AOGS-AGU (WPGM) JOINT ASSEMBLY,2012

INTERNATIONAL CONFERENCE, SINGAPORE 13-17TH AUGUST,2012

NOx Uptake by Mangrove Plants and Its Effect on Mangrove DNA Base Heterogeneity
Natasha MAJUMDER^1#+, Tapan Kumar JANA^1
1University of Calcutta, India
^#Corresponding author: natasha.majumder@gmail.com ⁺Presenter

Mangroves can use atmospheric NO_x as a source of nitrogen under soil nitrogen source constrain. In the atmosphere over Sundarban mangrove, progressive decrease of NOx was observed from a maximum of 4.34 ± 1.49 ppbv in January to a minimum of 1.57 ± 0.19 ppbv at 10 m in the month of September. During the period of September to February, the biosphere atmosphere NOx exchange rates of -0.84 to -1.63 ng N m^-2 s^-1 in the day and -0.36 to 5.19 ng N m^-2 s^-1 in the night were observed. However, during the period of March to August, the ecosystem showed NOx emission without any uptake and ranged from 0.34 to 2.13 ng N m^-2 s^-1 in the day and from 0.88 to 3.26 ng N m^-2 s^-1 in the night. The mean DNA concentrations in mangrove plant leaves were found to be 32.57 ± 6.12 mg g ^-1with 0.22 - 0.25 µg µg^-1DNA nitrogen in leaf DNA. in January during the max uptake of NOx, while 0.16 - 0.20 µg µg^-1DNA nitrogen in September when mangrove exhibited  minimum uptake of NO x from the atmosphere. The percentage of G-C base pairs in leaves (58.42-64.38%) was found greater than the percentage of A-T-base pairs (35.58-41.57%) which indicate the presence of N rich nucleotides. Statistical analysis revealed significant correlation between leaf protein and independent variables (TIN, NOx flux) tested (R = 0.92, p = 0.016) with 85.2% explained variability. Which supports the hypothesis that the leaf stomata can contribute to the atmospheric NOx uptake and its can shape the DNA base composition of the mangrove leaves.