Furthermore, it is believed that tryptophan is naturally se out by means of phosphatase enzymes. In fact, the major source of phosphatase activity in soil is considered to be of microbial origin (Rodriguez and Fraga 1999); and these phosphatases could catalyze the hydrolysis of P from organic forms (Wang and Pant 2010). While phytase is a special type of phosphatase that is able to hydrolyze phosphate from phytic acid as well as from other phosphorylated
substrates (Gibson and Ullah 1990), it could be presumed that various phytases and phosphatases secreted by soil microorganisms were important for plants to enhance Pavailability, which might increase plant salt stress tolerance. Some Trichoderma spp. are well known to be active phytase and acid phosphatase producers (Nasi et al. 1999; Kapri and Tewari 2010), but there are few reports on the activity
of phytase which may determine the P mobilization in soil and increase P acquisition by plant. In our study, phytate was found to support better fungal strain Q1 growth, with little organic acids production in phytate medium and the activity of acid phosphatase was much higher than that of alkaline phosphatase, which is distinguishable from the report by Kapri and Tewari (2010).In the water culture experiment, we found that there was a particularly close connection between P content and the growth rate of plant by comparing the size of cucumber leaves, shoots and roots length under different conditions.
This is because both inorganic and organic insoluble phosphates could be transformed into available P by T. asperellum___________________!_______________________ _____by cucumber seedlings along with an increase in their own salt stress tolerance.