Comparative Study Of DMTU On Mitigation Of Cadmium Stress In Two Varieties Of Tall Fescue

When plants are stressed by heavy metals,the balance of ROS and hormones plays a major role in plant growth.In this study,two cultivars of tall fescue with different tolerances,’Commander’ and ’Crossfire Ⅲ’,were used as research materials,research object is root tip.Hydroponic method,and the three treatment groups are the control group,the high cadmium treatment group,and the DMTU(hydrogen peroxide scavenger)treatment group was applied under the cadmium stress.The purpose is to investigate the changes in root growth,active oxygen and endogenous hormone levels,and the expression levels of related genes in plants.The aim is to explore the best way to alleviate cadmium toxicity for tall fescue,and compare the mitigation effect of two different varietiesThe results showed that the main roots of the two cultivars of Tall Fescue were inhibited by cadmium stress,the Commander’s main root growth decreased from 5.90mm/day to 2.14mm/day,and Crossfire Ⅲ decreased from 6.00mn/day to 1.62mm/day.which was alleviated after DMTU treatment and the effect of Crossfire Ⅲ was better;In the cadmium treatment group,the content of hydrogen peroxide increased sequentially with the increase of time.In the DMTU treatment group,Commander’s H2O2 content rise significantly during 1h to 2h;The auxin content of two varieties of Tall Fescue decreased significantly under cadmium stress,while after DMTU treatment,it increased significantly The change trend of AUX gene expression is opposite to that of IAA;The content of ZR and the expression of ipt gene in the three treatment group decreased in turn.In conclusion,compared with the control group,cadmium treatment group and DMTU treatment group induces changes in hormone levels by affecting two varieties of tall fescue gene expression levels,then affect the phenotype and physiological condition of the plant.Among them,the impact of Crossfire Ⅲ was more obvious than that of Commanders.