Biotechnology Bulletin ›› 2022, Vol. 38 ›› Issue (11): 202-209.doi: 10.13560/j.cnki.biotech.bull.1985.2021-1604

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Effects of Nitrogen Addition on the Abundance of Bacterial Phosphatase Encoding Genes in the Soil of Pinus sylvestris var. mongolica Plantation

WU Lin-hui(), GENG Bi-miao, WANG Yan-jie, ZHOU Guo-wei, SUN Qing-ye, ZHAO Qiong()   

  1. College of Resources and Environmental Engineering,Anhui University,Hefei 230601
  • Received:2021-12-28 Online:2022-11-26 Published:2022-12-01
  • Contact: ZHAO Qiong E-mail:2429728482@qq.com;zhaoqiong2019@ahu.edu.cn

Abstract:

In order to reveal the microbial processes regulating the responses of soil organic phosphorus(P)mineralization to nitrogen(N)addition, abundances of 3 soil bacterial phosphatase-encoding genes(phoC, phoD and appA)and corresponding acid phosphomonoesterase, alkaline phosphomonoesterase and phytase activities, as well as related soil physiochemical properties were measured in a Pinus sylvestris var. mongolica plantation that has subjected to 10 years of field N addition(100 kg N ha-2year-1). The results show that N addition reduced acidic and alkaline phosphomonoesterase activities in the soil of Pinus sylvestris var. mongolica plantation by 18.09% and 55.29%, and the phytase activity decreased by 41.88%. Nitrogen addition reduced the copy number of each gene by 40.97%(16S-rRNA), 78.38%(phoD), 67.92%(phoC), and 74.37%(appA), respectively. The proportion of the copy number of functional gene in the total bacterial gene 16S-rRNA decreased significantly by 61%(phoD), 44%(phoC), and 55%(appA). The contents of soil microbial biomass carbon and microbial biomass phosphorus were significantly positively correlated with the activities of acid phosphomonolipase, alkaline phosphomonoesterase, phytase and gene abundances of 16S rRNA, phoD, phoC and appA. Soil ammonium nitrogen content was significantly negatively correlated with the activities of acid phosphomonoesterase and alkaline phosphomonoesterase, as well as the abundance of 16S rRNA, phoC and appA genes. The activity of acid phosphomonoesterase was significantly positively correlated with its gene abundance, and the other two enzyme activities had no significant correlation with its gene abundance.The above results indicate that the N addition not only reduced abundance of soil phosphate-dissolving bacteria, but also reduced the proportion of phosphate-dissolving bacteria in the total bacteria, thereby greatly reduced phosphatase activities and depressed organic phosphorus mineralization.

Key words: nitrogen addition, phosphomonoesterase, phytase, gene abundance