Function Analysis Of BpTCP7 Gene In Betula Platyphylla

TCP genes encode plant-specific transcription factors with a bHLH motif which allows DNA binding and protein-protein interactions. TCP transcription factors participate in many biological process in plant, such as growth, cell division, formation of organs, and so on; TCP transcription factors also participated in biosynthetic pathways and response of some hormone, such as, cytokinin, methy jasmonate, auxin, brassinosteroids, and so on. This study is composed of the following aspects:(1) Fifteen BpTCP genes were obtained base on the 45 transcriptomes datas of birch, and named BpTCP1-BpTCP15. among of them, fourteen genes contained complete ORF, except BpTCP5. Expression patterns of BpTCP genes were analyzed using Real-time PCR, the result showed that these fifteen genes were expressed in all tissues, expression patterns existed difference and similarity among fifteen genes, the level of expression in apical bud, leaf and staminate flower were higher than those in other tissues, and expressive levels in leaf in mid-august was the highest.(2) Based on genome information of B. Platyphylla, a 1791 bp flanking sequence upstream of BpTCP? gene was cloned, and constructed into plant expression vector, and was transferred into Arabidopsis, then investigated the expression pattern via histechemical GUS staining. Cis-regulatory elements was analyzed, some response elements of hormone, stress, and tissue expression were contained in the promoter. Histechemical GUS staining showed that the BpTCP7 expressed in during both vegetative and reproductive phases, ensiform leaves with obvious GUS expression were found in transgenetic Arabidopsises.(3) Using Gateway technology, the plant overexpression and repression vector containing BpTCP7 gene were constructed and transformed into B.platyphylla by Agrobacterium through leaf disc and zygotic embryo transformation respectively, four overexpression transgenic lines and three repression transgenic lines were obtained. The overexpression transgenic plants were identified by PCR and Real-time PCR, the results showed that BpTCP1 gene was successfully integrated into the plant genome and expressed steadily. The RNA level of BpTCP7 in transgenic lines was far higher than the non-transgenic lines.(4) Overexpression transgenic and non-transgenic lines were implemented 0.8% NaCl and 20% PEG stress treatment. The injury index, the activity of SOD and the content of H2O2 and MDA were measured, transgenic lines showed higher stress resistance than non-transgenic lines under abiotic stress conditions.(5) BpTCP7 gene was subcloned to pGBKT7 vector to construct BD-TCP7 recombinant plasmid, and then the BD-TCP7 plasmid was used as a bait to screen the yeast two hybrid cDNA library of B.platyphylla. After screening and rotary experiment, one protein was detected to interact with BpTCP7. The conserved domain of this protein was analyzed and the protein (TCP 10) belongs to TCP superfamliy.