Arbuscular mycorrhizal fungal hyphae mediating acidification can promote phytate mineralization in the hyphosphere of maize (Zea mays L.)

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• 作者：Fei Wang ; Rongfeng Jiang ; Michael A. Kertesz ; Fusuo Zhang ; Gu Feng
• 关键词：Ammonium ; Mycelium ; Phosphatases ; Organic phosphate ; Hydrolysis ; Phytin
• 刊名：Soil Biology & Biochemistry
• 出版年：2013
• 出版时间：October, 2013
• 年：2013
• 卷：65
• 期：Complete
• 页码：69-74
• 全文大小：516 K

文摘

Mycorrhizal and non-mycorrhizal maize (Zea mays L.) plants were grown in two-compartment rhizoboxes, in order to study the effect of mycorrhizal hyphae-mediated acidification on organic P mineralization in the hyphosphere. The soil in the two compartments was supplemented with either KNO₃ or (NH₄)₂SO₄, and phytin (0 or 75?mg P?kg^?1) was added to the hyphal compartment. P content in the shoots was significantly higher for the NH₄⁺ treatment than for the NO₃^? treatment, but only in the combined presence of phytin and AM fungal mycelium (Rhizophagus intraradices). NH₄⁺ treatment under these conditions also led to a decrease in hyphosphere pH, enhanced phosphatase activity in the hyphosphere and accelerated mineralization of phytin compared to the NO₃^? treatment. The results show that hyphosphere acidification induced by absorption of NH₄⁺ by the AM fungal mycelium leads to an increase in phosphatase activity, and consequently enhances mineralization of phytin and improves maize uptake of P from phytin-P.