Fig. 2-A showed that calcium phytate could be utilized by
T. asperellum Q1 and the activities of acid phosphatase and
phytase were detected in culture filltrayes.However,the level
of available phosphorus released from calcium phytate after
inoculated with strain Q1 was not significantly higher than
those of DCP and TCP. This may be due to the absorption of available phosphorus from calcium phytate by the strain Q1
and the inhibition of synthesis of phytase and phosphatases
by those available phosphorus in growth medium. In order
to exclude the influence of cell absorption,water culture
experiments were conducted to study the effects of phosphate
solubillzation of culture filltrate from strain Q1 on cucumber
seedlings growth under salt stress. The cucumber seedlings
with different treatments showed a visible distinction in their
growth conditions,especially in the size of the first euphylla
(Fig. 3-A). Under 60 mmol L–1 NaCl stress, the largest size
of the first euphylla was observed when cucumber seedlings
were exposed to insoluble phosphates and cuiture filtrates
(CF) treatment and the smallest size was from the contro plants (without phosphate and CF).
Meanwhile, the sizes of the first treated with phosphates were larger than those treated only with CF;however,
there was no significant difference between organic and inorganic phosphates.In addition,
the shoot length of the seedlings increased by 61.5%/57.7% and 37.6%/33.8% after treated with CF+TCP/
CF+Phytin and TCP/Phytin, and the root length increased
by 70.2%/65.8% and 37.1%/37.9%, whereas the size was barely increased by the treatment of CF, as compared with
those of the control plants (non-CF–P) (Fig. 3-B). Based on these data, it can be concluded that phosphate solubilization
might be one of the factors to ameliorate plant growth under
salt stress conditions by supplying phosphorus nutrition for
the plants.