Soil Nutrients Drive Function and Composition of phoC-Harboring Bacterial Community in Acidic Soils of Southern China.

Man Man Zheng,Ren Fang Shen,Wen Xing Li,Chao Wang,Wen Feng Song

doi:10.3389/fmicb.2019.02654

Abstract

Phosphorus (P) deficiency is an important factor that limits the agricultural production potential in acidic soils. The bacterial phoC gene encodes non-specific acid phosphatase (ACP), which participates in the mineralization of soil organic P and is therefore important for the improvement of soil P availability. However, the function and community population of phoC-harboring bacteria and their driving factors in acidic soil remain largely unknown. For this study, 51 soil samples and 207 plant samples were collected from four locations in the acidic soil region of southern China. Quantitative PCR and high-throughput sequencing were employed to analyze abundance and community composition of phoC-harboring bacteria. The results showed that soil P availability was the important nutrient element limiting the growth of both plants and soil bacteria. Soil ACP activity was clearly higher than alkaline phosphatase, indicating the important effect of phoC-harboring bacteria in acidic soils. ACP activity and phoC gene abundance showed a significant positive correlation, and both were closely related to soil available P, total carbon, and total nitrogen. The dominant genera of phoC-harboring bacteria involved Cupriavidus, Stenotrophomonas, and Xanthomonas. Compared to land-use pattern, sampling location, and soil parent material, soil property played a more important role in affecting phoC-harboring bacterial community structure, where N-related variables including soil NO -N, NH -N, and C/N ratio appeared to be the main factors. These findings suggest that phoC-harboring bacteria should provide an important contribution to soil P availability in acidic soil, and its function and community composition were strongly associated with soil nutrients.

Highlights

Acidic soil accounts for more than 50% of the potential arable land globally (Kochian et al, 2004)
The contents of N, P, and K in plant leaves were positively (p < 0.05 or p < 0.01) correlated with soil total carbon (TC), total N (TN), total P (TP), Available P (AP), NO−3 -N, and Available K (AK), 2http://www.drive5.com/usearch/ 3http://blast.ncbi.nlm.nih.gov/Blast.cgi in which soil AP showed the highest correlation with plant P content
Similar to a previous study (Fraser et al, 2017), we found that acid phosphatase (ACP) activity correlated positively with phoC gene abundance (Figure 3B), and both were clearly related to soil nutrients, especially TN, TC, and AP (Figure 1)

Summary

Introduction

In China, acidic soils cover an area of 2.18 million km, distributed widely in the tropical and subtropical regions of southern China (Zhao, 2002) These regions are rich in water and heat resources, the potential crop production is severely restricted by low pH-induced toxicity of aluminum (Al) and manganese (Mn) and nutrient deficiency of phosphorus (P), phoC-Harboring Bacterial Community in Acidic Soils calcium (Ca), and magnesium (Mg) (von Uexküll and Mutert, 1995). Their limitations are intensified due to the accelerated rate of soil acidification (Guo et al, 2010). Exploiting soil-fixed P resources is an alternative approach to alleviate soil P deficiency, which improves plant P utilization efficiency and reduces the requirement for chemical P fertilization (Khan et al, 2007)

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Conclusion