Genetic variation of HvXYN1 associated with endoxylanase activity and TAX content in barley (Hordeum vulgare L.)

Abstract

Background: Endo-β-1,4-xylanase1 (EA), the key endoxylanase in plants, is involved in the degradation of arabinoxylan during grain germination. In barley (Hordeum vulgare L.), one gene (HvXYN-1) that encode a endo-beta-1,4-xylanase, has been cloned. However, the single nucleotide polymorphisms (SNPs) that affect the endoxylanase activity and total arabinoxylan (TAX) content have yet to be characterized. The investigation of genetic variation in HvXYN1 may facilitate a better understanding of the relationship between TAX content and EA activity in barley. Results: In the current study, 56 polymorphisms were detected in HvXYN1 among 210 barley accessions collected from 34 countries, with 10 distinct haplotypes identified. The SNPs at positions 110, 305, 1045, 1417, 1504, 1597, 1880 bp in the genomic region of HvXYN1 were significantly associated with EA activity (P < 0.0001), and the sites 110, 305, and 1045 were highly significantly associated with TAX content. The amount of phenotypic variation in a given trait explained by each associated polymorphism ranged from 6.96 to 9.85%. Most notably, we found two variants at positions 1504 bp and 1880 bp in the second exon that significantly (P < 0.0001) affected EA activity; this result could be used in breeding programs to improve beer quality. In addition, African accessions had the highest EA activity and TAX content, and the richest germplasm resources were from Asia, indicating the high potential value of Asian barley. Conclusion: This study provided insight into understanding the relationship, EA activity, TAX content with the SNPs of HvXYN1 in barley. These SNPs can be applied as DNA markers in breeding programs to improve the quality of barley for beer brewing after further validation.

Identification, Characterization, and Expression Profile Analysis of the mTERF Gene Family and Its Role in the Response to Abiotic Stress in Barley (Hordeum vulgare L.)

“…In this study, 481 SNPs were identified from 60 HvmTERF genes across 220 wild and landrace barley accessions. The SNPs were distributed unevenly along the genomic sequence, including a total of 292 exon and 44 intron variations, which was consistent with a previous study showing higher polymorphism of SNPs in exon regions than in intron regions (Lu et al, 2019) but opposite to observations in other studies (Uçarli et al, 2016;Xia et al, 2017). The PCA, admixture, and phylogenetic analyses clearly divided all the accessions into landraces and wild barley accessions and further distinguished them geographically.…”

Effects of Growth Conditions and Cultivar on the Content and Physiochemical Properties of Arabinoxylan in Barley

“…This can be explained considering that the total AX content may be greatly affected by environmental factors; for example, water deficiency could increase AX content. 3 Nevertheless, the factorial analysis demonstrated that the influence of year on the total AX content was not statistically significant.…”

“…Recently the gene HvXYN-1 that encode a endobeta-1,4-xylanase (EA) in barley was studied to understand the relationship between AX content and EA. These authors found two variants that significantly ( P < 0.0001) affected EA activity and that could be applied as DNA markers in breeding programs to improve barley quality . Approximately 50% of the AX in barley is found in the husk and pericarp .…”

“…The content of AX in barley depends on genetic and environmental factors. − Some authors reported that variability in AX contents is statistically highly significantly affected by the variety, location, year, growing technology, and their mutual interactions. The highest effect on AX content was found for the genotypes, growing technology, and multiple interactions .…”

“…These authors found two variants that significantly (P < 0.0001) affected EA activity and that could be applied as DNA markers in breeding programs to improve barley quality. 3 Approximately 50% of the AX in barley is found in the husk and pericarp. 4 When barley is dehulled, AX accounts for 20− 25% of the remaining nonstarch polysaccharides and is distributed mainly in the cell walls of the aleurone and in the endosperm.…”