Molecular Characterization of TcNMD3 in Taiwania cryptomerioides Hayata
摘要
The nonsense-mediated mRNA decay protein 3 (NMD3) is a shuttling protein which moves between the nucleus and cytoplasm. It helps export the 60S ribosomal subunit from the nucleus to the cytoplasm and later is recycled back to the nucleus. A putative NMD3 gene cloned from Taiwania (Taiwania cryptomerioides Hayata) seedlings in this research was named TcNMD3 to elucidate the evolutionary role and physiological phenomenon in Taiwania. There are 1548 nucleotides in the coding region of TcNMD3, which has multiple copies in the Taiwania genome. Themain characteristic of NMD3 is the 4 Cys-X2-Cys zinc-binding motifs in its N terminal region plus the nuclear localization signal (NLS) and nuclear export signal (NES) that are also found in the C terminus of TcNMD3. By tissue-specific expression analysis, it was found that the TcNMD3 transcripts were more abundant in bark and the apical meristem than in male and female flowers in mature trees. In seedlings, TcNMD3 transcripts were more abundant in leaves and stems than in roots. In addition, the TcNMD3 transcripts were upregulated by gradient concentrations of indole-3-acetic acid, methyl jasmonate, abscisic acid, and salicylic acid treatments. Results showed that TcNMD3 has either direct or indirect connections with growth development, defense response, and signal transduction.