Abstract:An aerenchyma-related gene named SmLSD1 (GenBank accession number OL690334) was cloned from Saussurea medusa Maxim using RT-PCR and RACE methods, the expression of the gene and the structure of its encoded protein under different stresses were determined and analyzed. The results showed that: 1) the length of SmLSD1 was 965 bp, contained 537 bp open reading frame and encoded 178 amino acids. 2) homology amino acid sequences comparison showed that SmLSD1 protein had more high similarity with LSD1 in Arctium lappa (98.31%); subcellular localization assays showed that SmLSD1 protein mainly expressed in the nucleus and cell membrane; prokaryotic expression results showed that the molecular weight of the amino acid encoded by the SmLSD1 gene was about 18kD. 3) qRT-PCR showed that: (1) SmLSD1 gene was expressed in roots, stems and leaves, and the highest expression emerged in the leaves; (2) the expression of SmLSD1 gene was down-regulated under low temperature stress, low oxygen stress, and UV stress. It is speculated that the SmLSD1 gene played an important role in the formation of aerenchyma and in response to adverse environmental stress.