Evidence that differences in phosphate metabolism in mycorrhizas formed by species of Glomus and Gigaspora might be related to their life-cycle strategies
Evidence that differences in phosphate metabolism in mycorrhizas formed by species of Glomus and Gigaspora might be related to their life-cycle strategies
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DOI：
10.1046/j.1469-8137.1999.00422.x
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发表时间：
1999-06-01
期刊：
影响因子：
9.4
通讯作者：
Dodd, JC
中科院分区：
文献类型：
--
作者：
Boddington, CL;Dodd, JC
通过温室试验，研究了3种不同磷源浓度下，卵叶山蚂蝗（Desmodium ovalifolium）上丛枝菌根真菌（AMF）Gigaspora和Glomus的生长发育和磷代谢。磷酸盐（0-100 mg P kg ~（-1））对Gigaspora rosea（BEG 111）根内菌丝体的碱性磷酸酶活性没有影响，但在10周内，磷酸盐降低了Glomus manihotis（BEG 112）根内菌丝体的碱性磷酸酶活性。在10周内，两种AMF的根外菌丝体的碱性磷酸酶活性不受增加磷酸盐添加量（0-100 mg P kg（-1））的影响。Gi.的根外菌丝体。rosea（BEG 111）积累聚磷酸盐，而G.木薯属（BEG 112）。这项工作表明，不同属的AMF菌丝体在热带宿主上的磷代谢机制存在差异。这可能是由这些真菌的生活史策略，特别是辅助细胞的形成在巨孢。Gi胞外菌丝体中碱性磷酸酶与多磷酸酶之间存在负反馈机制的可能性。rosea（BEG 111）的共生关系以及多聚磷酸盐在共生过程中的作用。
A glasshouse experiment was done to assess the development and phosphate metabolism of mycorrhizas formed by species of arbuscular mycorrhizal fungi (AMF) from two different genera, Gigaspora and Glomus on Desmodium ovalifolium plants at three concentrations of a phosphate source. The addition of phosphate (0-100 mg P kg(-1))had no effect on the alkaline phosphatase activity, stained histochemically, in the intra-radical mycelium of Gigaspora rosea (BEG111), but decreased that of Glomus manihotis (BEG112) over a 10-wk period. The alkaline phosphatase activity of the extra-radical mycelium was unaffected by increasing phosphate addition (0-100 mg P kg(-1)) in both species of AMF ol er a IO-wk period. The extra-radical mycelium of Gi. rosea (BEG111) accumulated polyphosphate, determined by staining with 4',6-diamidino-2-phenylindole, whereas polyphosphate was not detected in the extra-radical mycelium of G. manihotis (BEG112). This work indicates differences in the mechanisms of phosphate metabolism in the mycelium of AMF from different genera on a tropical host. This might be determined by the life-cycle strategies of these fungi, in particular the formation of auxiliary cells in Gigaspora. The possibility of a negative-feedback mechanism between alkaline phosphatase and polyphosphate in the extra-radical mycelium of Gi. rosea (BEG111) and the role of polyphosphate in the symbiosis are discussed.