Identification Of The Functional Substances From Rice Straw Obtained By Pyrolysis And Enzymolysis And Its Application To Achieve The Biological Effect

Rice straw is one of the main agricultural solid wastes in China.How to improve the reuse efficiency of rice straw is the current research focus.Due to the large amount of difficult-to-degrade compounds including lignin and cellulose in the straw structure,the effective utilization of traditional straw reusing technology in practical application is generally low.Using rice straw as raw material to produce plant growth promoter is an effective way for the utilization of agricultural waste,and also has great significance for reducing the amount of chemical fertilizer in agricultural production and improving the ecological environment.Based on this background,this study prepared high temperature extract and enzymatic hydrolysate from rice straw by high temperature water and Trichoderma guizhouense NJAU 4742 enzymes,respectively,and its growth-promoting effects on plants were also evaluated.The rice straw high temperature extract and enzymatic hydrolysate were identified and compared by LCMS.Finally,we studied the growth-promoting effects of rice straw high temperature extract and enzymatic hydrolysate combined with Trichoderma guizhouense NJAU 4742 on plant growth.The main research results are as follows:1.The high temperature extract and the enzymatic hydrolysis solution of rice straw can significantly promote the development of lateral roots of Arabidopsis seedlings when the content is 0.8%(v/v).The high temperature extract of rice straw owned the best growth promotion effect when it was diluted for 50 times,in which the dry weight of overground part,the underground part and the plant height of cucumber plants increased by 44.16%,63.38% and 55.56% respectively,and the number of plant root tips increased by 64.44%,by compared with CK.The enzymatic hydrolysate of rice straw showed significant growth promoting effect on cucumber when diluted for 100 times,and the dry weight of overground part,underground part and plant height of cucumber plants treated with 100 times dilution increased by52.64%,55.05% and 21.43% respectively,and the number of plant root tips increased by 31.95%,by compared with the CK.2.The LCMS results showed that: 714 different substances were identified in the high temperature extract of rice straw and 638 different substances were identified in the enzymatic hydrolysis solution;Further analysis based on the qualitative results of the secondary mass spectrometry revealed that acetylcholine,L-carnitine,myo-inositol and pantothenic acid may be functional substances related to growth.3.The standard products of these four substances were added to the cucumber root system,and the results showed that they all had considerable promotion effect on cucumber growth.Exogenous acetylcholine at the concentration of 1 μM,10 μM,and100 μM can promote the growth of cucumber seedlings.Exogenous L-carnitine is beneficial to the growth of cucumber seedlings with the concentrations of 0.1 m M and1 m M.Exogenous myo-inositol with the concentration of 0.05 m M and 0.1 m M can promote the growth of cucumber seedlings.Eexogenous pantothenic acid at 0.1 m M concentration can promote the growth of cucumber seedlings.4.The high temperature extract and enzymatic hydrolysate of rice straw with different dilution can significantly promote the growth of Trichoderma guizhouense NJAU 4742 on MS solid medium(no carbon source),and the treatment of 10 times dilution had the best promotion effect.On MS+1% glucose solid medium,the high temperature extract and enzymatic hydrolysate of rice straw with 10 times dilution could also promote the growth of Trichoderma guizhouense NJAU 4742.5.Adding rice straw high temperature extract/enzymatic hydrolysate can better promote the development of Arabidopsis lateral roots and the growth of cucumber shoot when combined with Trichoderma guizhouense NJAU 4742.Simultaneous application of rice straw high temperature extract/enzymatic hydrolysate and Trichoderma guizhouense NJAU 4742 can also increase the urease activity and invertase activity of the cucumber potting soil,and increase the number of Trichoderma guizhouense NJAU 4742 in the soil.In summary,there are various functional substances in rice straw which can promote plant growth.These substances can be released into the solution through high temperature extraction and enzymatic hydrolysis.Four small molecules including acetylcholine,L-carnitine,myo-inositol and pantothenic acid with typical growth-promoting effects were qualitatively identified and screened in the high temperature extraction products and enzymatic hydrolysis products of rice straw by LCMS and MS/MS.Rice straw high temperature extract and enzymatic hydrolysate also contain substances that are beneficial to the growth of Trichoderma guizhouense NJAU 4742.The addition of rice straw high temperature extract and enzymatic hydrolysate can enhance the effect of the growth promotion process of Trichoderma guizhouense NJAU 4742 which own a good application prospect.