- 期刊
- OpenAccess
Molecular Characterization of TcNMD3 in Taiwania cryptomerioides Hayata
台灣杉TcNMD3之分子特性解析
摘要
無義介導之mRNA降解蛋白(nonsense-mediated mRNA decay protein 3, NMD3)為一細胞核質間的穿梭蛋白，將60S核糖體從細胞核運送至細胞質，再回到細胞核。為了解NMD3在演化及臺灣杉中所具之生理現象，我們從臺灣杉苗木選殖出的假定NMD3基因命名為TcNMD3。TcNMD3的轉譯區共有1,548個核苷酸，此在臺灣杉的基因體中屬多套數的基因。NMD3蛋白質主要特徵為在其胺基酸N端序列中四個Cys-X2-Cys結構，且在其C端中發現NLS和NES序列。經由組織專一性的表現分析結果顯示TcNMD3基因在70年生臺灣杉的樹皮和頂端分生組織較其雄花與雌花中為多；而在四年生的臺灣杉苗木中，則是在葉和莖中較其在根中為多。除此之外，TcNMD3的RNA表現量在吲乙酸，茉莉酸，離層酸，水楊酸等濃度梯度處理下比起控制組為多，這個結果顯示TcNMD3和植物的生長發育、防禦機制與植物賀爾蒙所牽涉的訊息傳導有著直接或間接的關連性。
並列摘要
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.