Cloning, subcellular localization, and expression analysis of NtGGPPS4 gene in Nicotiana tabacum

Geranylgeranyl pyrophosphate synthase (GGPPS) catalyzes the synthesis of geranylgeranyl pyrophosphate (GGPP). It is an important branching enzyme for the synthesis of terpenoids, which are the precursors of the main aroma components in tobacco and cigarette. A new cDNA sequence encoding GGPPS (named NtGGPPS4) was cloned from the tobacco (Nicotiana tabacum) by RACE (Rapid amplification of cDNA ends) method. NtGGPPS4 had a 1 119 bp ORF (Open reading frame) that encoded 372 amino acids. The deduced amino acid sequence shared a high similarity with other plant GGPPSs, and contained two Asp-rich motifs characteristic of the isoprenyl synthase family. RT-qPCR analysis showed that NtGGPPS4 was ubiquitously expressed in all organs at all growth stages and its expression increased significantly in stem after topping. Transient expression of GFP-NtGGPPS4 in tobacco protoplast indicated that NtGGPPS4 was localized in mitochondria.