Record ID No. |
4230 |
Author(s) |
Huilan Zeng, Fengxiao Tan, Yanyan Zhang, Yuanjiao Feng, Yinghua Shu, Jianwu Wang , 2014 |
Affiliation |
Research Center for Resources, Environment and Food Safety, College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China, *Email: fenggu@cau.edu.cn |
Title |
Hyphosphere interactions between an arbuscular mycorrhizal fungus and a phosphate solubilizing bacterium promote phytate mineralization in soil |
Source. Vol.(no):Page |
Soil Biology and Biochemistry 74(July): 177-183p. |
Categories |
Arbuscular Mycorrhiza |
Subjects |
Biological Interaction |
Sub-subjects |
Phosphorus solubilizers |
Host |
Medicago sativa |
Organism |
Rhizophagus irregularis, Pseudomonas alcaligenes |
Country |
China, East Asia |
Abstracts |
Both arbuscular mycorrhizal (AM) fungi and phosphate solubilizing bacteria (PSB) are involved in phosphorus (P) mobilization and turnover but the influence of their interaction on organic P mineralization in the root free soil (hyphosphere) have been little studied. We investigated the interactive effects of an AM fungus (Rhizophagus irregularis, RI) and/or PSB (Pseudomonas alcaligenes, PA) on phytate mineralization and subsequent transfer to the host plant (Medicago sativa) using a two-compartment microcosm with a central 30 μm nylon mesh barrier. The root growth compartment containing 5 mg inorganic P (Pi, KH2PO4) kg−1 soil was inoculated with RI or uninoculated and the AM fungal hyphal soil containing 75 mg organic P (Po, Na-phytate) plus 0 or 5 mg Pi kg−1 soil was inoculated with PA or uninoculated. Sole inoculation with RI increased shoot P content compared with the uninoculated treatment and dual inoculation with both RI and PA did not increase shoot P compared with sole RI inoculation. Sole PA inoculation significantly increased microbial biomass P (MBP). Compared with sole PA inoculation soil MBP increased under zero-Pi addition but decreased under 5 mg Pi kg−1 soil addition in the dual inoculation RI/PA treatment. The uninoculated microcosms had the lowest acid phosphatase activity and the highest phytate-P remaining in the soil. Inoculation with PA led to higher acid phosphatase activity and lower phytate-P than did RI. Dual RI/PA inoculation had the highest acid phosphatase activity and the lowest phytate-P remaining in the soil. Addition of 5 mg Pi kg−1 soil to the hyphal compartment decreased phytate-P remaining in the RI and/or PA treatments. The phytate-P remaining in the soil was negatively correlated with soil acid phosphatase activity or MBP in the presence of RI but there was no correlation between shoot P and soil phytate-P. In conclusion, our results indicate that the mineralization of soil phytate was promoted by the interaction between the AM fungus and its hyphosphere PSB. |