Studies On Genetic Transformation And Function Analysis Of CpSAMT Gene From Chimonanthus Praecox L.

Chimonanthus praecox L. is a special famous traditional flower that originates in China, which gives our strong and pleasing fragrance in winter and is a well-known winter-flowering deciduous shrub. At the same time, this plant can be taken as a new source of natural essential oil. SAMT gene is a key gene which synthesize methyl salicylate; Our lab has been cloned the gene from the petals of C. praecox. It is significant to study genetic transformation, expression and regulation mechanism for clarify function of the gene, investigate the metabolic pathways of aroma compositions and explore genetic improvement of floral plant. This paper presents the studies on genetic transformation of tobacco and petunia with CpSAMT gene mediated by Agrobacterium, and analysis of floral scent in transgenic plant with HS-SPME-GC-MS. The main results were as follows:1. The CpSAMT gene was cloned successfully, and then the plant binary expression vector PBI121-CpSAMT was constructed and transferred into Agrobacterium tumefaciens EHA105 by freeze-thaw method.2. The CpSAMT gene was transferred into tobacco and petunia through Agrobacterium mediated transformation method,70 tobacco and 40 petunia independent transgenic plants obtained from culture with antibiotics.3. PCR analysis of transgenic tobacco and petunia was conducted, the results showed that 15 resistant lines had the target strips in 16 transgenic tobacco and 9 resistant lines had the target strips in transgenic petunia. In the further detection of RT-PCR, we found that CpSAMT gene have expressed in transcription level in transgenic tobacco and petunia.4. The method of HS-SPME-GC-MS was applied to determine the volatile compounds in flowers of tobacco. We found that it has higher levels benzyl alcohol, benzaldehyde, caryophyllene and hexenol in tobacco which transgenic CpSAMT gene. In transgenic PBI121 vector tobacco it has higher levels cedrol and linalool. In wild tobacco we found that it has higher levels methyl benzoate, but can’t found in transgenic tobacco.5. The method of HS-SPME-GC-MS was applied to determine the volatile compounds in flowers of petunia. We found that benzaldehyde and phenylethanol was significantly increased and resulted in higher levels citronellol, citronellyl acetate and phenethyl acetate in petunia which transgenic CpSAMT gene. In transgenic PBI121 vector petunia we found that it has higher levels methyl benzoate and resulted in benzyl alcohol and benzyl acetate. In no transgenic petunia it has higher levels diisobutyl phthalate.The methyl salicylate has not obvious change in flowers of petunia which transgenic or no transgenic.