Abstract

In this study, 11 novel NAM alleles were cloned from five species of Aegilops section sitopsis. These nucleotide sequences ranged from 1,540 to 1,555 bp with 3 exons and 2 introns. Their coding proteins contained both N-terminal nitrogen assimilation control (NAC) domain with 5 sub-domains and C-terminal transcriptional activation region (TAR). They have high identities and the closest homology with the NAM gene from Triticum dicoccoides Körn. and T. timopheevii Zhuk. indicating these NAM alleles of A. sect. sitopsisspecies probably having similar function to the NAM-B1 gene which control high grain protein content (GPC) inT. dicoccoides. Among these 11 alleles, there were 185 variation sites including 143 single nucleotide polymorphism sites (SNPs) and 42 insertion/deletion sites (InDels), despite high identity. Majority of SNPs occurred in coding domain with more non-synonymous mutations, resulting in 53 variation amino acids. These suggested NAM alleles in A. sect. sitopsis species having abundant polymorphism, which mainly existed in the TAR.

Key words: Aegilops section sitopsis, NAM gene, single nucleotide polymorphism, grain protein content.