Cloning and sequence analysis of ADC gene fragments in Brassica napus L.

[Objective]The present experiment was conducted to isolate the cDNA fragment of arginine decarboxylase(ADC) gene from Brassica napus L.in order to provide information for obtaining its full length gene and understanding its biological functions.[Method]The cDNA fragments of ADC were isolated from floral buds of Brassica napus L.variety Zhongshuang 6 using degenerated primers and homologous cloning method.[Result]Eight different sequences of ADC gene which were divided into three groups,viz.,1011,999 and 981 bp were obtained successfully.These 8 DNA sequences shared 81-99% homology in nucleotides and 86-99% homology in deduced amino acid sequences.All of the 8 sequences were named as S1-S3 of 1011 bp,S4-S5 of 999 bp,S6-S8 of 981 bp with 9,3 and 14 SNP sites in three groups,respectively.Compared with S1-S3,there were 2 sections base deletion in S4 and S5,and 4 sections base deletion in S6-S8,and the nucleotide sequence in sites 632-634 and 642-650 were absent in both S4-S5 and S6-S8.Furthermore,a nonsense mutation located in the nucleotide sequence in site 67 of S8 was identified.Amino acids homology and evolutionary analysis results indicated that the 8 sequences had high homology with those of other reported plants including Brassica juncea L.,Arabidopsis thaliana L.,Thellungiella halophila L.and so on.[Conclusion]The studies clearly demonstrated that these 8 sequences were derived from ADC gene of Brassica napus L.variety Zhongshuang 6.