Synergism Of New Herbicide ZJ0273 And 5-aminolevulinic Acid In Relation To Seedling Growth And Its Regulation Mechanism In Brassica Napus And Malachium Aquaticum

Complex combinations of 5-aminolevulinic acid (ALA) and new post-emergence herbicide propyl 4-(2-(4,6-dimethoxypyrimidin-2-yloxy)benzylamino)benzoate (ZJ0273) were used to investigate their combined effects in relation to seed gemination and growth of oilseed rape (Brassica napus cv. ZS 758). Brassica seeds were treated with different concentrations of ZJ0273 [viz., 100 (normal dose for rape), 200, 500 and 1 000 mg/L] and ALA (viz., 0.1, 1.0, 10.0 and 50.0 mg/L). ALA was applied as pre- and post-treatment alone and in combination with ZJ0273. We found that ZJ0273 stress imposed negative effects on rape seed germination and growth. Shoot fresh weight, shoot length and root fresh weight was inhibited significantly under ZJ0273 stress and the rate of decline was consistently increased with the increase in ZJ0273 concentration. Root oxidizability was also inhibited significantly under ZJ0273 stress conditions and the higher concentration of the herbicide ZJ0273, the lower the oxidizability. Herbicide ZJ0273 treatment produced a gradual decrease in antioxidant enzymes (peroxidase (POD), superoxide dismutase (SOD) and ascorbate peroxidase (APX) activities) and increase in peroxidation substance (malondialdehyde (MDA) accumulation). The increase and decrease were consistent with the ZJ0273 dosages. Our results indicated that pre- and post-treatments with lower dosage of ALA (1.0 mg/L) improved the rape seedling growth and root oxidizability parameters while the higher concentration of ALA (50.0 mg/L) depressed the growth. We also found that the plant treated by 1.0 mg/L ALA produced the highest shoot fresh weight, shoot length, root fresh weight and root oxidizability when the seeds were treated with different concentrations of ZJ0273. Lower dosages of ALA improved the activities of antioxidant enzymes whereas the highest dosage of ALA increased the accumulation of peroxidation substance. These results indicate that ALA has promotive effects in the germination and growth of rape seeds under herbicide ZJ0273 toxicity stress.In order to find the optimum treatment time, complex combinations of ZJ0273 and ALA were used to investigate their combined effects in relation to seed germination and growth of oilseed rape (B. napus). Brassica seeds were treated with different concentrations of ZJ0273 [viz., 100 (normal dose for rape), 200, 500 and 1 000 mg/L] and ALA (viz., 1mg/L). ALA was applied as pre- and post-treatment alone and in combination with ZJ0273. Treatment time included 48h and 72 h. We found that ZJ0273 stress imposed negative effects on rape seed germination and growth and the rate of decline was consistently increased with the increase in ZJ0273 concentration and treatment time. These results indicate that 1 mg/L ALA has promotive effects in the recovery of seed germination and growth of rape seedlings under herbicide ZJ0273 toxicity stress, but the longer treatment time, the less efficiency.Complex combinations of ALA and ZJ0273 were used to investigate their combined effects in relation to seedling growth and development of oilseed rape (B. napus). We found that ZJ0273 stress imposed negative effects on rape seedling growth. Net photosynthetic rates (Pn) were inhibited significantly under ZJ0273 stress and the rate of decline was consistently increased with the increase in ZJ0273 concentration. Chlorophyll contents were also inhibited significantly under ZJ0273 stress conditions and the higher concentration of the herbicide ZJ0273, the lower the chlorophyll content. Herbicide ZJ0273 treatment produced a gradual decrease in activities of antioxidant enzymes POD, SOD and APX and increase in accumulation of peroxidation substance MDA. The increase and decrease were consistent with the ZJ0273 dosages. Our results indicated that pre- and post-treatments with lower dosage of ALA (10-100 mg/L) improved the rape seedling growth and net Pn rates while the higher concentration of ALA (500 mg/L) depressed the growth. It was also found that the plant treated by 100 mg/L ALA produced the highest net Pn rates and chlorophyll contents when the plants were treated with different concentrations of ZJ0273. Lower dosages of ALA improved the activities of antioxidant enzymes whereas the highest dosage of ALA increased the accumulation of MDA. These results indicate that ALA improves rape seedling tolerance under herbicide stress.Crickweed seedlings were treated with various concentrations of ZJ0273 (100, 200, 500 and 1 000 mg/L) and ALA (1, 10 and 100 mg/L). ALA was applied as pre- and post-treatment alone and in combination with ZJ0273. We found that ZJ0273 stress imposed negative effects on crickweed seedling growth. Net photosynthetic rates were inhibited significantly under ZJ0273 stress and the rate of decline was consistently increased with the increase in ZJ0273 concentration. SPAD values were also inhibited significantly under ZJ0273 stress conditions and the higher concentration of the ZJ0273 herbicide, the lower the SPAD values. Herbicide ZJ0273 treatment produced a gradual decrease in activities of antioxidant enzymes POD, SOD and APX and increase in accumulation of peroxidation substance MDA. The increase and decrease were consistent with the ZJ0273 dosages. Our results indicated that pre- and post-treatments with lower dosage of ALA (1-10 mg/L) improved the crickweed seedling growth but higher concentration of ALA (100 mg/L) depressed the growth. It was also found that the plant treated by 100 mg/L ALA produced the lowest net Pn rates and antioxidant system when the plants were treated with different concentrations of ZJ0273. These results indicate that the combined treatment of ALA and ZJ0273 synergizes the toxicity which are different from its independent effects on Malachium aquaticum (L.) Fries and thus could improve weed control efficacy.For M. aquaticum, chloroplasts of control plants exhibited normalities at the ultrastructural level. The grana number decreased in the ZJ0273 and ALA treated plants. It was observed that the aggregation and enlargement of plastoglobuli in the chloroplasts when plants were treated with ALA in combination with ZJ0273. Mitochondria of the control plants were normal and mitochondrial cristae were well developed. Mitochondria of the plants treated by ALA were swollen and mitochondrial cristae were poorly developed in comparison to the control plants. Vesicles could be observed in the mitochondria of plants treated by ZJ0273. Some mitochondria membranes began to degrade in plants treated by ALA in combination of ZJ0273. The nucleus shape of the control plants was normal. While the nucleus shape of plants treated by ALA showed no significant change in comparison to the control. Irregular nucleus shape was observed in the plants treated by ZJ0273 and plants treated by ALA in combination of ZJ0273. For B. napus, chloroplasts of control plants exhibited normalities at the ultrastructural level. It was observed that the aggregation and enlargement of plastoglobuli in the chloroplasts when plants were treated with ZJ0273, while the chloroplasts treated by ALA and ZJ0273 were normal as the control, chloroplasts treated by ALA were better than that of control plants. Mitochondria of the control plants were normal and mitochondrial cristae were well developed. Mitochondria of the plants treated by ALA were greatly developed in comparison to the control plants. Mitochondria of the plants treated by ALA and ZJ0273 were developed as well as the control plants. Vesicles could be observed in the mitochondria of plants treated by ZJ0273. The nucleus shape of the control plants and the plants treated by ALA was normal. While the nucleus shape of plants treated by ALA and ZJ0273 showed no significant change in comparison to the control. Irregular nucleus membrane was observed in the plants treated by ZJ0273 treated by ZJ0273. Present findings suggest that the combined treatment of ALA and ZJ0273 synergizes the toxicity inducing drastic ultrastructural alterations which are different from its independent effects on M. aquaticum and thus could improve weed control efficacy. We can also find that ALA has promotive effects in the ultrastructure of rape seedlings under herbicide ZJ0273 toxicity stress.M. aquaticum and B. napus, leaves were treated with herbicide ZJ0273 and ALA separately and in combination at the concentration of 500 mg/L for ZJ0273 and 100 mg/L for ALA for 24 h. Seven days later, protein content, SDS-PAGE and two-dimensional gel electrophoresis (2-DE) of protein in leaves were examined. Our study of plants revealed significant differences in the protein of leaves. For B. napus, when plants were treated with ZJ0273, the soluble protein content was significantly increased because of the herbicide stress. But when plants were treated by ZJ0273 in combination with ALA, the soluble protein content was decreased as similar as control plant. For M. aquaticum, when plants were treated with ZJ0273, the soluble protein content was significantly decreased. When plants were treated with ZJ0273 in combination with ALA, the soluble protein content was just the similar to the former, and both of them were less than the control plant. The changes were mainly at MW 20 kD. 2-DE results showed that proteins in different spots were classified into two types for B. napus and three types for M. aquaticum. We predict that these changes to be related to the reactive oxygen scavenging system or systemic acquired resistance, ZJ0273 and ALA mechanism.