Study On The Effect Of Mushroom Residue On The Hormone And Antioxidant Enzyme System Of Paulownia

The preliminary study found that Paulownia is a good woody plant resistant to lead and zinc heavy metals,and through the continuous screening of the matrix improvors,mushroom slag is an affordable and easy-to-obtain matrix improver.However,the response mechanism of the hormone and antioxidant enzyme system of mushroom slag improver to the Paulownia has yet to be studied.In this study,Paulownia was used as plant material.At the first year’s experiment,we were set three different soils as Paulownia’s growing environment,which namely red soil,improved lead-zinc slag soil and lead-zinc slag soil,and the accumulation of lead and zinc,the change of hormone and antioxidant enzyme in Paulownia were studied as well.In the next year’s experiment,we set five different concentrations of IAA,GA3,ZT and ABA as exogenous hormones,and studied the addition of five different concentrations of mixed hormones,the biomass change of Paulownia in lead-zinc slag and improved lead-zinc slag and the change of lead and zinc content in different parts.It provides the theoretical basis and application basis for the application of Paulownia to mine ecological restoration.The main results are:(1)On the biomass of Paulownia in three soils:There were significant differences in total Pb,Zn and aboveground biomass of Paulownia Plants under three soil conditions.The cumulative concentration of Pb and Zn was as follows:slag soil>improved slag soil>laterite,and the aboveground biomass was as follows:improved slag soil>slag soil>laterite;Mushroom residue effectively increased the content of organic matter,CEC,water content and porosity of slag soil,promoted the growth of Paulownia Plants,and greatly increased the biomass of Paulownia.(2)The concentrations of ZT and IAA in Paulownia Leaves of slag soil were lower than that of improved slag soil and lateritic soil when the growth time was 60 and 90 days,while GA3 and ABA were higher than the other two soils.Under the stress of slag and improved slag,GA3 and ABA were the main response hormones.With the increase of stress time,the synthesis rate of two hormones in improved slag soil was significantly lower than that of slag soil;The improvement of mushroom residue effectively restored the dynamic balance of endogenous hormones in Paulownia and improved its growth.(3)In the aspect of antioxidant system response:In the slag soil environment,the activities of cat and SOD were significantly higher than the other two soil treatments,while in the mushroom slag improved slag soil environment,with the growth time increasing,the Paulownia biomass was increased,the concentration of heavy metals in Paulownia Plants was significantly reduced,the degree of membrane lipid peroxidation of Paulownia leaves was significantly improved,and the toxicity of hydrogen peroxide and ROS was also effectively alleviated The balance of toxicant metabolism and antioxidant system was restored,Paulownia Plants grew normally,and the stress resistance was significantly improved.(4)There were significant differences in the biomass of Paulownia under the treatment of five hormones between the slag soil and the improved slag soil.In the slag soil,the aboveground biomass of Paulownia increased first and then decreased with the increase of hormone concentration,and reached the maximum value of 2.81(g/strain)under the fourth concentration of hormone,while the aboveground biomass increased with the increase of hormone concentration,with the maximum value of 15.61(g/strain).In the mushroom slag modified slag soil,the aboveground and underground biomass of Paulownia increased first and then decreased.The maximum value of aboveground biomass was 33.51(g/strain)when the fourth concentration of hormone was added.Different from the slag soil,the maximum value of underground biomass of Paulownia in the modified slag soil was 32.31(g/strain)when the third concentration of hormone was added.In the slag soil,the content of lead and zinc in the ground and underground of Paulownia decreased first and then increased with the addition of five different concentrations of hormones;In the improved slag soil,the content of lead and zinc in the five different treatments of Paulownia was lower than that of Paulownia in the slag soil,and the concentration of heavy metals in the ground and underground of Paulownia was added in the fourth concentration of hormones.The lowest value is 9.60mg/kg(lead-aboveground part),218.96mg/kg(lead-underground part),208.18mg/kg(zinc-aboveground part),607.83mg/kg(zinc-underground part).