Organic forms of phosphorus (P) tend to accumulate in soils with long-term fertilization, however they are generally not easily available to crops. Many crop plants are obligately arbuscular mycorrhizal (AM) and AM fungi are known for not being able to produce phosphatases, the enzyme involved in the mineralization of organic P. AM fungi are able to recruit bacteria in the hyphosphere which can produce phosphatases and access organic P. It is thought that fructose produced by AM fungi acts as a signal to select these bacteria. We designed a system to test whether fructose could stimulate phosphatase activity in the maize hyphosphere. The concentration of fructose produced by AM fungi and the large concentration of fructose equivalent to the entire concentration of hyphal exudate carbon, were added. Small concentrations of fructose did not stimulate phosphatase activity in soil, cause shifts in bacterial community structure or select phosphatase producing species. However, at large concentrations of fructose, phosphatase activity was increased and this was associated with a larger bacterial population and a shift in bacterial community structure towards species which specialized in using fructose and glucose for energy metabolism, such as Saccharibacteria. Nevertheless, there was no specific shift towards species which harbored alkaline phosphatase genes and it is suggested that the change in phosphatase activity was due to subtle shifts in the properties of the phosphatases being produced. These results suggest that fructose was unable to act as a signal to select phosphatase producing bacteria in soil, but could act as an energy source to stimulate phosphatase activity by shifting soil bacterial community structure.

长期施肥后，有机磷（P）往往会积聚在土壤中，但通常不容易从农作物中获取。许多农作物专心致密于丛枝菌根（AM），而AM真菌因无法产生磷酸酶而闻名，该酶参与有机P的矿化。AM真菌能够在菌丝中吸收细菌，从而产生磷酸酶并进入有机体。 P.认为AM真菌产生的果糖可作为选择这些细菌的信号。我们设计了一个系统来测试果糖是否可以刺激玉米叶片中的磷酸酶活性。加入由AM真菌产生的果糖浓度和相当于菌丝渗出碳总浓度的高浓度果糖。低浓度的果糖不会刺激土壤中的磷酸酶活性，不会引起细菌群落结构的改变或选择产生磷酸酶的物种。然而，在高浓度的果糖中，磷酸酶活性增加，这与更大的细菌种群和细菌群落结构向专门利用果糖和葡萄糖进行能量代谢的物种（如糖菌）的转变有关。然而，对于具有碱性磷酸酶基因的物种并没有特定的变化，这表明磷酸酶活性的变化是由于所产生的磷酸酶的性质发生了细微的变化。这些结果表明，果糖不能作为选择土壤中产生磷酸酶的细菌的信号，