Molecular survey of Tamyb10-1 genes and their association with grain colour and germinability in Chinese wheat and Aegilops tauschii

Abstract

To investigate allelic variation of Myb10-1 genes in Chinese wheat and to examine its association with germination level in wheat, a total of 582 Chinese bread wheat cultivars and 110 Aegilops tauschii accessions were used to identify allelic variations of three Myb10-1 genes. Identification results indicated that there is a novel Tamyb10-B1 allele, designated Tamyb10-B1c, in the five Chinese landraces. The Tamyb10-B1c possibly has a large deletion including Tamyb10-B1 gene. There are three novel Tamyb10-D1 alleles (Aetmyb10-D1c, Aetmyb10-D1d and Aetmyb10-D1e) that were discovered in Aegilops tauschii. Of them, Aetmyb10-D1c allele possessed a 104-bp deletion and this resulted in a frame shift in the open reading frame of the Aetmyb10-D1 gene. AETMYB10-D1d and AETMYB10-D1e proteins possessed three and two different amino acids when compared with TAMYB10-D1b protein, respectively. Association of Tamyb10-1 allelic variation with grain germination level indicated that all five allelic combinations with red grains showed a significantly higher GP (germination percentage) and GI (germination index) values than those of white-grained Tamyb10-A1a/Tamyb10-B1a/Tamyb10-D1a genotype after storing it for one year. Moreover, the Tamyb10-A1b/Tamyb10-B1c/Tamyb10-D1b genotype possesses the significantly highest GP and GI among the six different Tamyb10-1 combinations. This study could provide useful information for wheat breeding programme in terms of grain colour and germination level.

Genome-Wide Association Study for Pre-harvest Sprouting Resistance in a Large Germplasm Collection of Chinese Wheat Landraces

“…QTL1 was positioned close to the Tamyb10 gene located at 174.1 Mb on Chr 3A which is significantly associated with grain color and germination (Himi et al, 2011; Dong et al, 2015; Lin et al, 2015). SNP maker AX-111578083 linked to QTL1 was positioned only 0.3 Mb away from Tamyb10 ( Figure 3B ).…”

“…So far, seven genes associated with PHS have also been cloned in wheat, including: TaVp1 (Nakamura and Toyama, 2001; Chang et al, 2010, 2011; Wang et al, 2011), TaMFT (Nakamura et al, 2011), TaPHS1 (Liu S. et al, 2013; Liu et al, 2015), TaSdr (Zhang et al, 2014, 2017), TaPm19 (Barrero et al, 2015), Tamyb10 (Dong et al, 2015; Wang et al, 2016), and TaMKK3 (Torada et al, 2016). Some of them (i.e., TaVp1 , TaMFT , TaPHS1 , and TaSdr ) have been used to test PHS in Chinese cultivars by developing KASP markers (Rasheed et al, 2016).…”

“…In this study, highly significant main QTL were positioned on the group 3 chromosomes. Positioned in close proximity to the strong signals detected on Chr 3A (QTL1) and Chr 3D (QTL2), is the grain color transcription factor Tamyb10 , known to be associated with PHS resistance (Groos et al, 2002; Dong et al, 2015). Tamyb10 is located at the distal region of the long arm of Chr 3A, 3B, and 3D, as reported by Himi and Noda (2005) and Himi et al (2011).…”

“…Although Tamyb10-D1 has not been mapped on the ‘Chinese Spring’ survey sequence, it is likely that the strong signal of R-loci on Chr 3D in the current study is Tamyb10-D1 . Recently, a molecular investigation of allelic variation in Tamyb10 provided information on grain color and GR in Chinese wheat (Wang et al, 2016) and Aegilops tauschii (Dong et al, 2015). In this study, two genes associated with grain color ( Tamyb10-A1 and Tamyb10-D1 ) were positioned in close proximity to PHS-resistant QTL ( Figure 3A ).…”

CRISPR/Cas9‐mediated restoration of Tamyb10 to create pre‐harvest sprouting‐resistant red wheat

“…In most white wheat varieties, the Tamyb10 ‐ A1a , Tamyb10 ‐ B1a , and Tamyb10 ‐ D1a genes have large insertions or deletions, which disrupt the IRTKAL/IRC motif and regulatory function (Himi et al ., 2011). Among the Tamyb10 genes, the Tamyb10‐B1a allele has a 19‐bp deletion in nearly 88.6% of bread wheat lines; this deletion causes a frameshift in the open‐reading frame and disrupts the resulting protein (Dong et al ., 2015; Himi et al ., 2011). Given that CRISPR/Cas9‐induced mutations are typically +1/−1‐bp indels at the specific target sites (Zhang et al ., 2014, 2016), we can revert the frameshift mutations within the Tamyb10‐B1a allele (caused by a 19‐bp deletion) to in‐frame mutations (18‐bp or other multiples of three bases).…”