Effect of Exogenous γ-aminobutyric Acid on Cadmium Accumulation in Camptotheca acuminata
To reduce the cadmium(Cd)accumulation in Camptotheca acuminate,a pot experiment was conducted to study the effects of exogenous γ-aminobutyric acid(GABA)on the Cd accumulation in C.acuminate.The results showed that the concentration of 1 mg·L-1Cd treatment decreased the biomass of C.acuminate,and produced the stress to C.acuminate.Under Cd stress,the concentrations of 0.1 mmol·L-1 and 0.5 mmol·L-1 GABA increased the biomass of C.acuminate and increased the root-shoot ratio.For the Cd accumulation,the different concentrations 0.1,0.5,1.0 and 2.0 mmol·L-1 of GABA decreased the Cd contents,Cd accumulation amounts and bioconcentration factors in both roots and shoots of C.acuminate.The concentration of 0.1mmol·L-1 GABA had the best reduction effect of Cd,which decreased the Cd contents in roots and shoots of C.acuminate by 31.77%and 62.82%,respectively,compared with the control.In addition,different concentrations of GABA reduced the translocation factor of C.acuminate to a certain extent.There-fore,exogenous GABA can promote the growth of C.acuminate under Cd stress and reduce the Cd accumulation in C.a-cuminate to a certain extent,among which.the concentration of 0.1 mmol·L-1 of GABA has the best effect on Cd re-duction.