Transcriptome Analysis Of The Caudal Fin Cell Line Of Silver Crucian Carp (Carassius Auratus Gibelio)(GiCF) Affected By Phoxim And The Interaction Between Phoxim And Photosynthetic Bacteria

The use of pesticides in agricultural production is undoubtedly a great progress,but due to the toxicity of pesticides and pesticide residues and other problems,agricultural production and the environment has a great negative impact.Phoxim is a kind of high efficiency,low toxicity and low residue broad-spectrum organophosphorus pesticide,which also has good control effect on aquatic animal parasites,so it is widely used in aquaculture.However,there is still a lack of research on the effects of phoxim on physiological and genetic levels of aquatic animals.Photosynthetic bacteria are widely distributed probiotics which can photosynthesize in anaerobic environment by using light energy.It plays a very important role in treating wastewater and purify water quality.In this study,the potential safety of phoxim in practical applications was evaluated at the gene level,and the interaction between Phoxim and photosynthetic Bacteria was explored on the basis of isolating a photosynthetic bacterium.1.Transcriptome analysis of the caudal fin cell line of silver crucian carp?Carassius auratus gibelio??Gi CF?affected by PhoximThe caudal fin cell line of silver crucian carp?Carassius auratus gibelio??Gi CF?samples,which were treated with 0.5 mg/L phoxim?dissolved in DMSO?,were analyzed through RNA-sequencing platform Illumina Hi Seq TM²⁵⁰⁰.The results showed that cell activity assay?CCK?indicateed that 0.5 mg/L phoxim had no significant effect on cell activity.Compared with 0.25%DMSO,a total of 972 differentially expressed genes were obtained,of which 550 were up-regulated and 422 were down-regulated.According to the classification of GO functions,differentially expressed genes can be divided into 55 branches of three major categories:biological processes,cellular components,and molecular functions.KEGG Pathway Significant enrichment analysis of differentially expressed genes involved a total of 260 pathways,including lysine degradation,glutathione metabolism,PI3K/AKT and other pathways.Especially,drug-metabolism-related pathways were significantly altered,which include Drug metabolism-cytochrome P450,Drug metabolism-other enzymes and EGFR tyrosine kinase inhibitor resistance EGFR.We pick out nine differentially expressed genes to confirm the accuracy of RNA-seq results by Real time RT-PCR,and the results demonstrated that the results from transciptome analysis were in consistence with the RT-PCR assay.In summary,0.5mg/L of phoxim had little effect on Gi CF,and Gi CF cells could be used as cytotoxicity research materials for pesticides;0.5 mg/L of phoxim did systematically interfere the gene expression profiles of Gi CF cells.Our results pave the way for further research on gene regulation of phoxim and should enhance the understanding of the effect of the commercial phoxim on Gi CF cells,which provides a theoretical basis for rational utilization of pesticide phoxim in aquaculture.2.The enrichment,separation and preservation of Photosynthetic BacteriaA photosynthetic bacterium was enriched and isolated from minghu lake.Based on the traditional method of strain identification,the strain was preliminarily identified as Rhodopseudomonas palustris according to the identification results of strain morphology,color,16Sr DNA and phylogenetic tree,and named it PSB-Z.The number of live bacteria and growth characteristic curve were obtained by routine counting and growth quantity measurement.The amount of live bacteria is about 10¹⁰CFU/m L,and the optimal inoculation amount is 10%,which can be used as the material for further research.Aluminum sulfate with a concentration of 0.7%was added as flocculant,trehalose as bacterial protectant,and diatomite as fixative to stabilize the bacterial solution.This method is a way for the preparation of wettable powder of strain PSB-Z,and can also be used as a method for the preservation of strain.3.Interaction between phoxim and Photosynthetic BacteriaThe interaction between photosynthetic bacteria PSB-Z and pesticide phoxim was investigated by using photosynthetic bacteria PSB-Z as research material.Compare PSB-Z in the solution of low concentration and high concentration of phoxim in different growth situation,when not add phoxim,PSB-Z is in a state of normal growth.After the addition of phoxim solution,each OD value within 6h is obvious downtrend.After 6 hours,the OD value began to rise,and the increment was significantly greater than that of the blank group without addition of phoxim solution.This indicated that phoxim had a certain inhibitory effect on the growth of photosynthetic bacteria in a short time.But its effect on photosynthetic bacteria varied according to the added concentration of phoxim.When the addition concentration of phoxim was less than 10mg/L,the growth of photosynthetic bacteria was promoted,and was slightly better than that of the blank group.When the concentration was above100mg/L,the phoxim showed an obvious inhibitory effect on the growth of photosynthetic bacteria,and the growth potential of photosynthetic bacteria was significantly worse than that of the blank group.The effect of PSB-Z on phoxim was shown in that the liquid phase detection concentration of phoxim decreased significantly after the addition of PSB-Z compared with the control group,indicating that the addition of photosynthetic bacteria had a certain degradation and elimination effect on phoxim.In 96h,the degradation rate of phoxim by photosynthetic bacteria was up to about 50%.In the control group,the detection concentration of phoxim decreased with the change of time,which was speculated to be related to the physical and chemical properties,temperature,light,p H and other conditions of phoxim.Through the detection of the standard recovery rate,it is found that the recovery rate of phoxim is relatively high within 72 hours,while the recovery rate of 96h is about 32%.On the basis of the recovery rate,the detection concentration of phoxim was still reduced after the addition of photosynthetic bacteria,which further indicated that the addition of photosynthetic bacteria had a degradation effect on phoxim.