Bosen Weng, Xiangyu Xie, Jinjin Yang, Jingchun Liu,

Haoliang Lu, Chongling Yan.Marine Pollution Bulletin.76 (2013)

227-240

The present study investigated nitrogen

process in rhizosphere of Kandelia obovata under nitrogen input.Results showed

that nitrogen additions significantly increased 4 kinds of enzyme activities (Urease, Nitrate

reductase, Nitrite reductase and hydroxylamine reductase). The pH value

increased to 7.1 underammonium addition, but decreased to 6.9 under nitrate

addition. Potential Nitrification Intensity (PNI) increased 200–1500% compared with control

under ammonium addition, and Potential Denitrification Intensity (PDI) increased more than 200% under nitrate

addition. Ten types of organic acids were detectedfrom root exudates, which

mainly included oxalic acid, tartaric acid, formic acid, acetic acid, and

citricacid. The abundance of 5 kinds of microbial functional groups (nifH, AOA,

AOB, nirS, nirK) responded differently. Total nitrogen in organs of K. obovata

increased more than 200%. This indicated that nitrogenadditions accelerated the

transformation of nitrogen directly and stimulated the exudation of root

exudates and 5 kinds of genes indirectly.

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