NAM is an important domestication gene and valuable to enhance grain protein contents (GPCs) of modern wheat cultivars.
Bihua Wu and his teammates cloned 12 NAM-G1 genes in Triticum timopheevii Zhuk. (AAGG, 2n = 4x = 28). These genes had the same length of 1546 bp including two introns and three exons, and encoded a polypeptide of 407 amino acid residues which contained a N-terminal NAC domain with five sub-domains, and a C-terminal transcriptional activation region (TAR). They were highly similar to the previously published functional NAM-B1 gene DQ871219 from T. turgidum ssp. dicoccoides Körn. (AABB, 2n = 4x = 28) in both the nucleotide and protein sequences, with a very high identity of 99.5%. The differences among the 12 NAM-G1 genes resulted from 17 SNPs including 14 transitions and 3 transversions. They had outstandingly different expression levels in qRT-PCR. And, their relative expression quantities were significantly positively correlated with GPC of the accessions. In addition, the difference in amino acid sequences of the NAM-G1 genes may also affect the GPC variation.
Fig. Expression pattern of NAM-G1 gene in qRT-PCR and GPC from twelve T. timopheevii accessions.
A and B are the amplicons of actin and NAM-G1 genes, respectively,and Lane M is the DNA ladder;
C is the expression pattern of NAM-G1 gene; D is the representation of GPC,
and the horizontals lines represent the first high GPC (18.0%) and medium-high GPC (15.0%).
Additional Information:
1 Author Information:Xigui Hu, Bihua Wu, Dengcai Liu, Yuming Wei, Shibin Gao, Youliang Zheng
Correspondence: wubihua2001@yahoo.com.cn.
2 Published:
Journal of Plant Physiology 170 (2013) 330-337