Influence Of Sulfamethazine And Cadmium In Combination On Growth And Ultra-structural Features Of Lachica Sativa L.

Antibiotics have been widely used as medicine for the treatment of diseases and in livestock fodder applied to enhance production recently.Sulfamethazine（SM2）is one of the most widely used antibiotics in recent years.There exists a phenomenon that antibiotics and heavy metal generally coexist in the environment,while cadmium（Cd）has attracted widely attention due to its high toxicity and harmfulness.When SM2 and Cd coexist together,their interaction may influence plant growth and physiological variationand even has effects on the concentration of pollutants in plants,resulting in food safety risks.However,the current research mainly focuses on the influence of SM2 or Cd in plants alone few researches are seldom reported about the influence of SM2 associated with Cd in plants,especially in physiological characteristics.Therefore,studing the physiological characteristics of growth crop caused by the compound pollution of SM2 and Cd is necessary for assessing the ecological and environmental risks and food safety in combination pollution.In this study,Lachica sativa L.was used as the research object to investigate the growth of plants,the accumulation of pollutants in plants and the variation of ultrastructure of plants under different concentrations group of SM2 and Cd compound pollution.The results are as below:1.Since the toxicity was enhanced under the compound pollution of SM2 and Cd,the growth of Lachica sativa L.was inhibited.Compared with the single pollution,the compound pollution synergistically inhibited germination index,root length and biomass of Lachica sativa L..The inhibition extent was correlated with the concentration,owing to the higher toxicity in the complex product produced by the action of SM2 and Cd,while Lachica sativa L.enhanced environmental adaptability by adjusting root surface area and root-shoot ratio.2.The accumulation of Cd/SM2 in Lachica sativa L increased with the increased addition of Cd/SM2 under the single pollution of Cd or SM2.Under low concentration of Cd treatment(1 mg·L^-1),the content of Cd in roots and shoots of Lachica sativa L.was significantly decreased by adding SM2.While the accumulation of Cd in roots and shoots was increased by adding SM2 with high concentration of Cd(5 mg L^-1).Cd-SM2 composition can inhibit the accumulation of Cd in Lachica sativa L.,but promoted when the concentration of Cd was 5 mg·L^-1.Under low concentration of SM2(0.5 and 2 mg·L^-1),the accumulation of SM2 in the roots were significantly promoted by Cd addition,whereas under high concentration of SM2(10 mg·L^-1),the accumulation of SM2 in the roots were significantly reduced by Cd addition.Meanwhile,there was no significant difference in the accumulation of SM2 in aerial portion between single SM2 and compound pollution.The accumulation of Cd in Lachica sativa L.under combined pollution showed synergistic effect at higher Cd concentration with SM2 combined pollution,while the accumulation of SM2 Lachica sativa L.under combined pollution showed synergistic effect at lower SM2 concentration with Cd combined pollution.This may be related to the formation of complexes in the presence of Cd and SM2,and the toxic effect of complexes on Lachica sativa L..3.Compared with single pollution,the root morphological variation was promoted when Cd and SM2 in complexation and the damage of root physiological structure was more serious,mainly in structure and number of organelle,which may be related to the accumulation of Cd in the root of Lachica sativa L..At the same time,the damage of physiological structure was alleviated,mainly in the membrane structure and number of organelles.The inhibition rate of leaf SPAD was significantly related to the degree of chloroplast destruction and increased with the culture time.It was suggested that stress would accumulate with culture time,which might be due to the decrease of Cd-TF and Cd transport in the aboveground part of the organism under compound pollution.The effects of antibiotics and heavy metals in combination on growth of Lachica sativa L.were studied using hydroponics experiments.It was found that the interaction between antibiotics and heavy metals could affect the growth and physiological characteristics of vegetables,and also affect the accumulation of pollutants in vegetables.This result has a certain reference for safety production of vegetables in future.