The Biochemical Responses Of Rice And Soybean To Stress Of Chlorsulfuron And Ethametsulfuron

Chlorsulfuron (CSF) and ethametsulfuron (EMSF), which are the long residual sulfonylurea herbicides, own the traits of ultra-bioactivity. The growth of rice and soybean is extremely sensitive to CSF and EMSF. The bioactivities of these herbicides on the growth of rice and soybean in different developmental stages were assayed, and the effect of the herbicides on some biochemical indexes including activity of enzymes, the content of GSH and endogenous hormones was determined in this paper. The main results were showed as follows.1. Chlorsulfuron and ethametsulfuron were respectively applied at the germination, 2-lesf, 4-leaf, 7-leaf stage of rice or at the germination, 5-trifoliolate leaf stage of sobean. The bioactivity results indicated that the length of the bud and the radicle of rices, which incubated in CSF at concentration of 0.0005-0.05μg/L in Petri dish were more than those of control, but the growth of both rice bud and radicle was inhibited at 0.1μg/L of CSF. The same tendence of CSF treatment after sowing 15 days was observed in the soil experimentation. The height of rice treated with 0.001μg/kg of CSF (0.001μg active ingredient of CSF in per kilogram dry soil, as same as the below) was as much as that of control at both 2-leaf stage and 7-leaf stage. That of soybean treated at 5-trifoliolate leaf stage was more than that of control at the same concentration. The growth of both rice and sobean was inhibited at concentration of 0.1μg/Kg of CSF. The height of rice treated at 2-leaf, 7-leaf stage and sobean treated at 5-trifoliolate leaf stage respectively at concentration of 0.002~2μg/kg of EMSF was more than that of control, and the growth of both rice and sobean was inhibited at concentration of 20μg/kg of EMSF.2. The activities of peroxidase (POD), polyphenol oxidase (PPO), glutathione transferase (GST) and content of glutathione (GSH) were determined at the germination, 2-lesf, 4-leaf, 7-leaf stage of rice or at the germination, 5-trifoliolate leaf stage of sobean., which had been treated with CSF at concentration of 0.001, 0.1μg/kg and EMF at concentration of 2, 20μg/kg, respectively. The results showed that the activity levels of both POD and GST in leaf of rice or sobean were obviously more than those of control after treatment at concentration of 0.1μg/kg of CSF or at concentration of 20μg/kg of EMSF. However, the activity of PPO and GSH content were obviously less than those of control in the same test. In other treatments with CSF at concentration of 0.001μg/kg or EMSF at concentration of 2μg/kg, the activity of POD and GST were as much as those of control, but the activity of PPO and GSH content were obviously more than control.3. The contents of the endogenous hormone of rice or soybean treated by CSF and EMSF were detected with ELISA. The results showed that after treatment 15 days, the content of abscisic acid (ABA) in treatment of 0.1μg/kg of CSF or 20μg/kg of EMSF were obviously more than that of control, and the contents of gibberellins (GA), zeatin riboside (ZR) in the same treatment were obviously less than those of control in leaves of the crops, which had been treated at the germination, 2-leaf, 4-leaf and 7-leaf stage of rice or at the germination, 5-trifoliolate stage of soybean. However, the content of ABA obviously dropped and the content of GA, ZR obviously rose in the treatment of 0.001μg/kg of CSF or 2μg/kg of EMSF in all experiments.