Research

March 12, 2013

Variation and their relationship of NAM-G1 gene and grain protein content in Triticum timopheevii Zhuk.

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

Variation and their relationship of NAM-G1 gene and grain protein content in Triticum timopheevii Zhuk..pdf