ABSTRACT
Objective: To study the biosynthesis mechanism and transshipment law of limonin compounds in Citri Reticulatae Semen, traditional medicinal variety Citrus reticulata "Dahongpao". Methods: In the process of seed growth and development, the contents of limonin, nomilin, and obacunone in stem, vane, peel, and seeds were determined by UPLC tangerine; Using grey relational analysis method, the correlation analysis between the contents and the cloning of squalene synthase gene (ss), squalene epoxidase gene (se), and glucose transferase (lgt) expression was performed. Results: Limonin compounds in different organs had the largest accumulation in seeds; The accumulation of limonin compounds in different organs was significantly correlated with ss, se, and lgt gene expression, but in the seeds the accumulation of limonin has the most closely correlation with ss, se, and lgt gene expression; The ss gene expression had the largest contribution on the accumulation of limonin, nomilin, and obacunone. Conclusion: The study provides reliable and scientific envidendce for the synthesis mechanism and transshipment law of limonin compounds.
ABSTRACT
【Objective】 To clone the squalene synthase gene of Artemisia annua L. for improving the quality and production of Artemisia annua L. by genetic engineering. 【Methods】 PCR amplification, RT-PCR amplification, ligation of the target fragment with a T-vector and sequence analysis of the interested gene were performed. 【Results】 An expected 3590 bp fragment was amplified by PCR and an expected 1257 bp fragment was amplified by RT-PCR. The two cloned fragments were identified by PCR and restriction enzyme digestion respectively. The preliminary sequence data indicated that the results obtained were similar to that from GenBank, and the difference was only found in several base pairs. 【Conclusion】 The squalene synthase gene and cDNA of Artemisia annua L. were successfully cloned and sequenced.
ABSTRACT
Objective To lay the foundation for studying the synthesis of artemisinin in microorganism,squalene synthase(SS) gene,a key enzyme gene from Saccharomyces cerevisiae,was cloned and a yeast expression vector was constructed.Methods After amplification of SS gene by polymerase chain reaction(PCR),ligation to T-vector and analysis of the cloned sequence,enzyme digestion and reconfirmation of the target gene,the antisense yeast expression vector was constructed by inverted insertion of the target gene into a yeast expression vector,pGAPZ?A,and digested with two restriction enzymes for vertifying the recombinant.Results The length of SS gene was 1335bp.The preliminary sequence data indicated that SS gene obtained from the experiment had a high sequence homology with that from GenBank,except for a few base pairs.The antisense yeast expression vector has been constructed and vertified by digesting with two enzymes.Conclusion SS gene from Saccharomyces cerevisiae has been successfully cloned and sequenced.An antisense yeast expression vector has been also constructed.
