Role Of Tyrosine Aminotransferase AccTATN In Response To Pesticide Stress In Apis Cerana Cerana

Apis cerana cerana is a unique bee species in our country.It can bring huge economic benefits to society,and play an important function in protecting ecological environment stability in our country.In recent decades,in order to increase agricultural output,pesticides have been widely used,which has caused serious environmental pollution and seriously threatened the survival of Apis cerana cerana.Bees will suffer oxidative damage when exposed to pesticides.Therefore,it is important to explore the mechanism of coping with pesticide stress in Apis cerana cerana to promote the healthy development of apiary industry system.Tyrosine is involved in various metabolic cycles and plays an important role in maintaining normal metabolism.However,the accumulation of tyrosine due to abnormal metabolism will produce toxic reactions to the body.Tyrosine aminotransferase（TATN）is the first enzyme involved in the metabolic degradation of tyrosine and degrades tyrosine through a series of catalytic reactions,and plays a crucial role in metabolizing excess tyrosine and reducing the accumulation of M-tyrosine,as well as helping the body to resist oxidative damage.In this study,AccTATN was isolated from Apis cerana cerana,and the bioinformatics,expression characteristics and protein function analysis were analyzed to elucidate the molecular mechanisms in response to pesticide stress.The main results are as follows:（1）AccTATN was isolated from Apis cerana cerana,and its sequence analysis showed that the open reading frame（ORF）of AccTATN was 1284 bp,encoding a protein composed of 427amino acids with a molecular weight of about 44.12 k Da and the isoelectric point of 5.17.（2）Multiple sequence alignment of amino acids showed that AccTATN had the highest homology with Ad TATN.The amino acid sequence of AccTATN contains a lysine site that is highly conserved in almost all species.In addition,phylogenetic tree analysis showed that AccTATN was closely related to Ad TATN.（3）The spatial and temporal expression characteristics of AccTATN were explored by RT-q PCR.The results showed that the expression level of AccTATN was the highest in 30-day-adult stage of Apis cerana cerana.In different tissue parts of Apis cerana cerana,AccTATN was highly expressed in the epidermis,leg,head and chest,with the highest expression in the epidermis.（4）The expression patterns of AccTATN under different stress were investigated by RT-q PCR.The results showed that after paraquat,glyphosate,bifenthrin,haloxyfop-P-methyl,beta-cypermethrin,avermectins and H₂O₂ treatments,the expression level of AccTATN was significantly increased.After Cd Cl₂ and Hg Cl₂ treatments,AccTATN expression levels were significantly induced.These results indicate that AccTATN may play an important role in resisting pesticide,heavy metal stress and alleviating oxidative stress damage.（5）The function of AccTATN recombinant protein was studied by heterologous expression.The results showed that overexpression of AccTATN recombinant protein significantly enhanced the resistance of Escherichia coli to H₂O₂,Hg Cl₂ and cumene hydroperoxide treatments.In addition,the growth curve showed that the survival ability of Escherichia coli overexpressing AccTATN in liquid medium containing H₂O₂,Hg Cl₂ and cumene hydroperoxide was higher than that of the control group,which further indicated that the overexpression of AccTATN recombinant protein could play an important role in helping cells resist oxidative stress damage.（6）After silencing AccTATN,explore the role of AccTATN in response to pesticide stress in Apis cerana cerana.The results showed that silencing AccTATN decreased the resistance of Apis cerana cerana to glyphosate and avermectin,and the expression levels of antioxidation-related genes and the activity of antioxidant enzymes in Apis cerana cerana were significantly decreased In conclusion,AccTATN could respond to pesticide stress by regulating the antioxidant capacity of Apis cerana cerana.