Cloning of betaine aldehyde dehydrogenase gene (CaBADH) from Chenopodium album L. and expression analysis of salt stress and construction of plant expression vector.

[Objective]To provide candidate genes for plant genetic engineering in improving salt tolerance,[Method] in present study,Chenopodium album L.,a salt-tolerant species distributed in Xinjiang was used as material,BADH gene was cloned through homology cloning technique,and a preliminary analysis was performed for expression of BADH under different salt stresses by RT-PCR,then a plant expression vector pCN2300-CaBADH was constructed.[Result]Results showed that:(1) After being sequenced and multiple alignment with other several Chenopodiaceae species,it indicated that CaBADH was successfully cloned,and its nucleotide sequence was 1 503 bp,500 amino acid deduced by code;(2) RT-PCR analysis with primers of BADH gene core sequence under salt stress showed that CaBADH exhibit relatively high basal level in Chenopodium album,and there was no significant increase of transcript level after 2,5,12,24 h stress under 100 mmol/L 1 NaCl;However,a higher expression level was observed under 60 d stress of 50 mmol/L NaCl or KCl treatment,rather than that of 100 mmol/L NaCl or KCl compared with the control.(3) By double digestion verifying,CaBADH gene was correctly inserted into the plant expression vector pCN2300,and recombinant plasmid of pCN2300-CaBADH was obtained.[Conclusion]The present study will provide evidence for further exploring salt tolerant mechanisms of C.album in physiological and molecular levels,and also help scientists in developing new salt-tolerant varieties through transgenic technology.