AUTHOR=Wang Shasha , Yan Xuefang , Wang Yongyan , Liu Hongmei , Cui Dangqun , Chen Feng 

TITLE=Haplotypes of the TaGS5-A1 Gene Are Associated with Thousand-Kernel Weight in Chinese Bread Wheat

JOURNAL=Frontiers in Plant Science

VOLUME=7

YEAR=2016

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2016.00783

DOI=10.3389/fpls.2016.00783

ISSN=1664-462X

ABSTRACT=<p>In previous work, we cloned <italic>TaGS5</italic> gene and found the association of <italic>TaGS5-A1</italic> alleles with agronomic traits. In this study, the promoter sequence of the <italic>TaGS5-A1</italic> gene was isolated from bread wheat. Sequencing results revealed that a G insertion was found in position -1925 bp of the <italic>TaGS5-A1</italic> gene (Reference to ATG), which occurred in the <italic>Sp1</italic> domain of the promoter sequence. Combined with previous single nucleotide polymorphism (SNP) in the <italic>TaGS5-A1</italic> exon sequence, four genotypes were formed at the <italic>TaGS5-A1</italic> locus and were designated as <italic>TaGS5-A1a-a, TaGS5-A1a-b, TaGS5-A1b-a</italic>, and <italic>TaGS5-A1b-b</italic>, respectively. Analysis of the association of <italic>TaGS5-A1</italic> alleles with agronomic traits indicated that cultivars with the <italic>TaGS5-A1a-b</italic> allele possessed significantly higher thousand-kernel weight (TKW) and lower plant height than cultivars with the <italic>TaGS5-A1a-a</italic> allele, and cultivars with the <italic>TaGS5-A1b-b</italic> allele showed higher TKW than cultivars with the <italic>TaGS5-A1b-a</italic> allele. The differences of these traits between the <italic>TaGS5-A1a-a</italic> and <italic>TaGS5-A1a-b</italic> alleles were larger than those of the <italic>TaGS5-A1b-a</italic> and <italic>TaGS5-A1b-b</italic> alleles, suggesting that the -1925G insertion plays the more important role in <italic>TaGS5-A1a</italic> genotypes than in <italic>TaGS5-A1b</italic> genotypes. qRT-PCR indicated that <italic>TaGS5-A1b-b</italic> possessed the significantly highest expression level among four <italic>TaGS5-A1</italic> haplotypes in mature seeds and further showed a significantly higher expression level than <italic>TaGS5-A1b-a</italic> at five different developmental stages of the seeds, suggesting that high expression of <italic>TaGS5-A1</italic> was positively associated with high TKW in bread wheat. This study could provide a relatively superior genotype in view of TKW in wheat breeding programs and could also provide important information for dissection of the regulatory mechanism of the yield-related traits.</p>