Cloning And Analysis Of MfNAC3 From Medicago Falcatea And Construction Of The Over-expression Vector

The NAC transcription factors(TFs)have been confirmed to contribute to the growth and development of plant,and also respond to stress-related regulations.In this study,we cloned a NAC TFs,which contained an NAM domain,and been named MfNAC3,from wild type Medicago falcatea.The MfNAC3 ORF contains 990 bp and its genomic DNA has 2 introns.It encoded a protein of 329 amino acid residues with a predicted molecular mass of 36.9 kDa and an isoelectric point of 6.981.The MfNAC3 protein sequence was compared with known MfNAC3(AMB51752.1),and showed 99%similarity.The bioinformatics analysis showed that MfNAC3 protein may locate to the nucleus.It may be a kind of hydrophilic protein and has no transmembrane domains and signal peptides.The secondary structure analysis showed that the predicted structure mainly be comprised of random-coil..The relative expression of MfNAC3 in leaves was the highest,with the lowest of roots.The expression of MfVAC3 was up-regulated in roots,stems and leaves of Medicago falcate in response to salt,drought and ABA stress.Meanwhile,the over-expression vector pPZP221(35S-MfNAC3-NOS),which contains the MfNAC3 ORF regulated by the 35S promoter from the binary vector pPZP221(35S-NOS),was constructed successfully.,was constructed successfully.It would be a foundation for obtaining the alfalfa with the enhanced stresses resistance.