Abstract: With the expanded application of heavy metal cadmium,the soil cadmium pollution is increasingly serious. Saliz matsudana,which has potential of phytoremediation,was selected as research object,and the changes of gene expression and metabolic pathway were investigated after 1 d,7 d and 30 d under 2.5 mg/L and 50 mg/L concentrations of cadmium stress. The result of transcriptome sequencing showed that 102 595 Unigenes were obtained,and there were 26 623 and 32 154 differential expressed genes（DEGs）in the same concentration while at different stress time,and 8 550,3 444 and 11 428 DEGs in different concentrations while at the same stress time. Total 25 genes closely related to cadmium stress responses were screened from them. The changes of genes expression（such as metallothionein,ABC transporter,zinc and manganese transporter）depended on both concentration of cadmium stress and stress time. The expressions of several genes were obviously up-regulated after cadmium stress,for example,3,6-deoxyinosinone ketolase（ROT3）in brassinolide synthesis pathway,as well as flavonoid synthase（FLS）and flavanone-3-hydroxylase（F3H）in the synthesis pathway of flavonoids. In addition,GO analysis showed that GO entries were mainly enriched in metabolic processes,cellular processes,membranes,cell organelles,cells,cellular fractions,catalytic activation and binding proteins in response to cadmium stress,and the number of DGEs involved in these GO entries increased along with cadmium concentration and stress time. The analyzed response mechanisms of S. matsudana after cadmium stress in this study by transcriptome sequencing provide theoretical guidance for the remediation of cadmium pollution in soil by S. matsudana.

Key words: Saliz matsudana, cadmium, transcriptome, differential gene