Cloning and Expression Analysis of Ribulose-1，5-bisphosphate carboxylase/oxygenase Small Subunit Gene BcrbcS in Pakchoi
LIU Dong-rang 1，2，HOU Xi-lin1，XIAO Dong 1，2，3*
1 State Key Laboratory of Crop Genetics and Germplasm Enhancement，Nanjing Agricultural University，Nanjing
210095，Jiangsu，China；2 Key Laboratory of Biology and Germplasm Enhancement of Horticultural Crops，Ministry of
Agriculture and Rural Affairs，Institute of Vegetables and Flowers，Chinese Academy of Agricultural Sciences，Beijing
100081，China；3 Jiangsu Engineering and Technology Center for Modern Horticulture，Nanjing 210095，Jiangsu，China
The full-length cDNA sequence of ribulose-1，5-bisphosphate carboxylase/oxygenase small subunit
（BcrbcS）gene was cloned from the leaves of pakchoi cultivar‘Suzhouqing’with resistance to downy mildew by
RACE technique．This paper analyzed the expression pattern of this gene under different tissues by qRT-PCR and
also prokaryotic expression characteristics of this gene by SDS-PAGE technology．Results of sequence analysis
showed that the full-length cDNA of BcrbcS gene was 733 bp，among which the length of open reading frame
was 543 bp．The total encodings were 181 amino acids．The molecular mass was 20.3×103 Da，and theoretical
isoelectric point was 8.23．The phylogenetic analysis of amino acid homology showed that the pakchoi BcrbcS gene
had similar evolutionary relationship with the other plants in the same family．Results of quantitative real-time
analysis showed that the expression of BcrbcS gene was the strongest in pakchoi leaves．The expression of BcrbcS
gene in pakchoi peaked at 24 hours after infection with SA and NaCl．Prokaryotic expression vector was induced by
IPTG to express a fusion protein with a molecular weight of about 20×103 Da．
