Cloning and expression analysis of a tyrosine decarboxylase gene from Rehmannia glutinosa / 中国中药杂志

Tyrosine decarboxylase (TyrDC) is an important enzyme in the secondary metabolism of several plant species, and was hypothesized to play a key role in the biosynthesis of phenylethanoid glycosides. Based on the transcriptome data, we cloned the full-length cDNA (GenBank accession NO. KU640395) of RgTyDC gene from Rehmannia glutinosa, and then performed bioinformatic analysis of the sequence. Further, we detected the expression pattern in different organs and hair roots treated with four elicitors by qRT-PCR. The results showed that the full length of RgTyDC cDNA was 1 530 bp encoding 509 amino acids. The molecular weight of the putative RgTyDC protein was about 56.6 kDa and the theoretical isoelectric point was 6.25. The RgTyDC indicated the highest homology with Sesamum indicum SiTyDC and Erythranthe guttata EgTyDC, both of them were reached 88%. RgTyDC highly expressed in R. glutinosa leaf, especially in senescing leaf, and rarely expressed in tuberous root. After the treatment of SA and MeJA, the relative expression level of RgTyDC mRNA was substantially increased. The results provide a foundation for exploring the molecular function of RgTyDC involved in phenylethanoid glycosides biosynthesis.

Cloning, Sequencing and Homologous Analysis of Tyrosine Decarboxylase Gene from Aristolochia contorta Bge / 广州中医药大学学报

[Objective] To obtain the tyrosine decarboxylase gene (tyrDC) from Aristolochia contorta Bge.and to assay its cDNA sequence and homologous analysis, thus to remove its nephrotoxieity. [Methods] The primers designed by referring to the conservative amino acid sequences of known plant tyrDC were used to amplify a fragment of cDNA from Aristolochia contorta Bge.by reverse transcription-polymerase chain reaction (RT-PCR). The amplified cDNA sequence was cloned and sequenced to design a pair of specific primers and to amplify a full-length tyrDC cDNA from Aristolochia contorta Bge.by rapid amplification of cDNA ends (RACE). [Results] The length of cloned tyrDC cDNA is 1678 base pairs (bp), which comprises an open reading frame ( ORF) of 1551 bp encoding 516 amino acids and a downstream untranslated region (3'UTR) of 127 bp. The results of sequence comparison indicated that the amino acid sequence deduced from the nucleotide sequence of tyrDC from Aristolochia contorta Bge.shares 76% homology with issued tyrosine decarboxylase of Papaver somniferum L. and 79% homology with tyrosine /DOPA decarboxylase from Thalictrum flavum subsp. glaucum. [Conclusion] The full-length tyrDC cDNA has been amplified from Aristolochia contorta Bge. and the homologous retrieve of tyrosine decarboxylase reveals an extensive sequence similarity among tyrosine decarboxylases of different plants. This will provide evidence for the romoval of nephrotoxicity of Aristolochia contorta Bge. .