Comparative transcriptomics of transgenic tobacco plants overexpressing Miscanthus sinensis BTF3.

Background: Plant basic transcription factor3 (BTF3) plays an important role in photosynthesis rate and plant growth and development. In addition, it is involved in resistance mechanisms related to abiotic and biotic stress and has a significant impact on plant growth phenotype. This study was conducted to expand our understanding on plant transcriptome changes as there are no reports on plant transcriptome changes in normal environments due to the overexpression of Miscanthus sinensis BTF3 gene.

Results: The amino acid sequence length of the BTF3 gene isolated from M. sinensis was 158 aa, and it showed the highest homology (97.47 %) with that of Paniocum virgatum (PvBTF3). Nicotiana benthamiana (Nb) transgenic plant was produced by transforming a binary vector into which the MsBTF3 gene was inserted into Agrobacterium. Up- and down-regulatory factors were classified through transcriptome analysis using transgenic plants overexpressing MsBTF3. Gene ontology (GO) analysis of up-regulated transcripts showed that the most expressed transcripts were involved in biological processes. Analysis of down-regulated differentially expressed genes (DEGs) showed that they were involved in metabolic processes that corresponded to biological processes. Blast analysis revealed that Nb03180T (chloroplast photosystem II 22 kDa component), Nb04871T (basic transcription factor 3-like), Nb13433T (expansin-B15- like), Nb15392T (receptor-like serine/threonine-protein kinase SD1-8 isoform X3), Nb17216T (3-bata-glucan endohydrolase), and Nb20214T (probable rhamnogalacturonate lyase B) were among the DEGs whose transcript expression was up-regulated more than 2-fold compared to the wild type. In particular, the reference gene, that is the NbBTF3 gene, showed the highest expression owing to the overexpression of MsBTF3.

Conclusions: Transcriptome changes in tobacco plants through MsBTF3 overexpression revealed that MsBTF3 caused broad-spectrum changes in the biological processes of plants. MsBTF3 showed that various metabolic and defense responses could be activated by regulating the level of specific gene expression in plants. These data obtained through this process will greatly contribute to elucidating the mechanism by which MsBTF3 helps strong physiological responses in plants.