Identification and Analysis of the GASR Gene Family in Common Wheat (Triticum aestivum L.) and Characterization of TaGASR34, a Gene Associated With Seed Dormancy and Germination

Abstract

Seed dormancy and germination are important agronomic traits in wheat (Triticum aestivum L.) because they determine pre-harvest sprouting (PHS) resistance and thus affect grain production. These processes are regulated by Gibberellic Acid-Stimulated Regulator (GASR) genes. In this study, we identified 37 GASR genes in common wheat, which were designated TaGASR1-37. Moreover, we identified 40 pairs of paralogous genes, of which only one had a Ka/Ks value greater than 1, indicating that most TaGASR genes have undergone negative selection. Chromosomal location and duplication analysis revealed 25 pairs of segmentally duplicated genes and seven pairs of tandemly duplicated genes, suggesting that large-scale duplication events may have contributed to the expansion of TaGASR gene family. Microarray analysis of the expression of 18 TaGASR genes indicated that these genes play diverse roles in different biological processes. Using wheat varieties with contrasting seed dormancy phenotypes, we investigated the expression patterns of TaGASR genes and the corresponding seed germination index phenotypes in response to water imbibition, exogenous ABA and GA treatment, and low- and high-temperature treatment. Based on these data, we identified the TaGASR34 gene as potentially associated with seed dormancy and germination. Further, we used a SNP mutation of the TaGASR34 promoter (-16) to develop the CAPS marker GS34-7B, which was then used to validate the association of TaGASR34 with seed dormancy and germination by evaluating two natural populations across environments. Notably, the frequency of the high-dormancy GS34-7Bb allele was significantly lower than that of the low-dormancy GS34-7Ba allele, implying that the favorable GS34-7Bb allele has not previously been used in wheat breeding. These results provide valuable information for further functional analysis of TaGASR genes and present a useful gene and marker combination for future improvement of PHS resistance in wheat.

Identification of the Wheat VQ Protein Family and Expression Analysis of Candidate Genes Associated with Seed Dormancy and Germination

“…ZM895, ZY9507, YXM and SNTT are provided by Xianchun Xia from Chinese Academy of Agricultural Sciences.). The germination index was determined according to previous studies [46].…”

“…Seed germination and dormancy are important traits in wheat production. They determine PHS resistance, thus affecting the yield and quality of wheat [46]. Identi cation of candidate genes that control seed dormancy and germination may help to minimize yield and quality losses caused by PHS.…”

“…To determine the number of VQ genes in common wheat, we used sequences obtained from the Ensembl database (http://plants.ensembl.org/index.html) to build a local wheat database [46]. The VQ domain hidden Markov model (PF05678) was used to identify candidate genes by BLAST in the established local wheat database.…”

“…The VQ domain hidden Markov model (PF05678) was used to identify candidate genes by BLAST in the established local wheat database. To ensure the accuracy of the results, all candidate genes were inspected, repetitive sequences were removed, and Pfam, SMART, and NCBI online tools were used to verify the existence of the VQ conserved domain in all candidate genes [46,48].…”

Identification and characterization of the Pvul-GASA gene family in the Phaseolus vulgaris and expression patterns under salt stress

“…in Arabidopsis thaliana by Herzog et al (1995) and then Roxrud et al (2007) have identified six new GASA genes, bringing the total number of GASA gene family members to 14 in A. thaliana (Herzog et al 1995;Roxrud et al 2007). Followingly, GASA genes have been studied on several plant species including Solanum tuberosum (Nahirñak et al 2016), Malus domestica (Fan et al 2017), Phyllostachys edulis (Hou et al 2018), Glycine max (Ahmad et al 2019), Oryza sativa (Muhammad et al 2019), Triticum aestivum L. (Cheng et al 2019), Vitis vinifera L. (Ahmad et al 2020), Sorghum bicolor (Filiz and Kurt 2020), Theobroma cacao (Faraji et al 2021) and cotton (Kaikai et al 2021) up to date. However, there is limited knowledge regarding the GASA genes in P. vulgaris genome.…”