Characteristics and expression analysis of MaTPS3 from Musa acuminal L. AAA group cv. Brazilian

A full－length MaTPS3 of 2 874 bp from banana roots cDNA library was obtained. It contained a complete open reading frame of 1 971 bp length，encoding 656 amino acids. Biological information analysis indicated that MaTPS3 protein belonged to the unstable protein，with isoelectric point of 6.26 and two domains TPS and TPP. Sequence prediction analysis indicated MaTPS3 protein was a hydrophobic transmembrane protein without signal peptide and located in cytoplasm. MaTPS3 protein sequence had 67.31% homology with other known plant TPS. Phylogenetic analysis indicated that MaTPS3 protein was closer with Oryza sativa Indica Group and Medicago truncatula，their homology respectively was 55.13%，54.71%. Organ－specific analysis showed that MaTPS3 was expressed in banana roots，corms，pseudo stems，leaves，flowers and fruits， but higher in leaves and flowers. qPCR analysis showed that the expression of MaTPS3 increased under salt stress，reached the highest at 24 h. The expression of MaTPS3 was significantly lower than the amount at 0 h under cold stress. The expression of MaTPS3 was four times at 24 h than that of 0 h，when the plantlets were under ACC treatment. When the banana plantlets were treated with FocTR4，The expression of MaTPS3 in roots significantly decreased lower than that at 0 h. ThereforeMaTPS3 may be involved in regulating the mechanism of banana salt stress resistance to improve the salt tolerance of banana，and participated in regulating plant hormone biosynthesis.