Cloning and polymorphism analysis of the 2-methyl-6-phytyl-1,4-benzoquinol methyltransferase gene (VTE3) in Arachis hypogaea, A. duranensis, and A. ipaënsis.

One of the critical enzymes involved in vitamin E biosynthesis in plants is 2-methyl-6-phytyl-1,4-benzoquinol methyltransferase (MPBQ MT). The full-length VTE3 cDNA (designated rVTE3-1 and -2) encoding MPBQ MT and the full-length DNA of VTE3 (designated gVTE3-1 and -2) were isolated from cultivated peanuts (Arachis hypogaea). The full-length DNA of VTE3 (designated gVTE3-A and -B) was isolated from the wild groundnut species A. duranensis (A-genome) and A. ipaënsis (B-genome), and polymorphism analysis of VTE3 was performed. The results demonstrated that rVTE3-1 and -2 both have a DNA sequence that is 1059 bp long and encodes 351 amino acids; the homology of the 2 amino acid sequences was 98.6%. The gVTE3-1 of cultivated Fenghua 2 peanut samples was 2710 bp long, with 3 introns located at 44-163, 772-1295, and 1603-2437 bp, and the Fenghua 2 gVTE3-2 was 2706 bp long, with 3 introns located at 44-169, 778-1291, and 1599-2433 bp. The homology for gVTE3-1 and -2 across 13 cultivated peanut samples was 99.9 and 100%, respectively. gVTE3-1 and -2 were from A- and B-genome, respectively, with 96.6% homology between the 2 sequences. The present study demonstrated that abundant polymorphisms were present in the VTE3 genes from different genomes. Additionally, polymorphisms were observed in the gVTE3-1 alleles of the 13 cultivars and wild A. duranensis species but not in the gVTE3-2 alleles of the 13 cultivars and wild A. ipaënsis species.