Identification of sorghum grain mold resistance loci through genome wide association mapping. (January 2019)

• Record Type: Journal Article
• Authors: Nida, Habte; Girma, Gezahegn; Mekonen, Moges; Lee, Sanghun; Seyoum, Amare; Dessalegn, Kebede; Tadesse, Taye; Ayana, Getachew; Senbetay, Tsegau; Tesso, Tesfaye; Ejeta, Gebisa; Mengiste, Tesfaye
• Is Part Of: Journal of cereal science. Volume 85(2019)
• Page Start: 295
• Page End: 304
• Publication Date: 2019-01
• Subjects: Grain mold -- YELLOW SEED1 -- YELLOW SEED3 -- 3-Deoxyanthocyanidins; bHLH basic helix–loop–helix -- CMLM Compressed mixed linear model -- FDR False discovery rate -- FHB fusarium head blight -- GAPIT Genome association and prediction integrated tool -- GBS Genotyping by sequencing -- GWAS Genome wide association study -- HCAAs Hydroxycinnamic acid amides -- IGV Integrative genomics viewer -- MAF Minor allele frequency -- MYB Myeloblastosis -- MBW MYB–bHLH–WDR -- Q-Q Quantile-quantile plot -- TBT Tags by taxa -- TOPM Tags on physical map; Grain -- Periodicals; Cereal products -- Periodicals; Céréales -- Périodiques; Produits céréaliers -- Périodiques; Cereal products; Grain; Periodicals; 664.705
• DOI: 10.1016/j.jcs.2018.12.016
• Languages: English
• ISSNs: 0733-5210

Abstract

Abstract: Grain mold, caused by a consortium of pathogenic fungal species, is the most important disease of sorghum [ Sorghum bicolor (L.) Moench]. Genome wide association study on 1425 diverse Ethiopian sorghum landraces identified a major grain mold resistance locus containing tightly linked and sequence related MYB transcription factor genes. The locus contains YELLOW SEED1 ( Y1 ), a likely non-functional pseudo gene ( Y2 ), and YELLOW SEED3 ( Y3 ). SNPs and other sequence polymorphisms that alter the Y1 and Y3 genes correlated with susceptibility to grain mold and provided a strong genetic evidence. Accordingly, the expression of both Y1 and Y3 genes in the developing grain and glumes of a widely known susceptible sorghum line, RTx430, were severely reduced but significantly increased in the resistant line, RTx2911. In addition, the expression of flavonoid biosynthesis genes such as DIHYDROFLAVONOL 4-REDUCTASE 3 ( DFR3 ) was significantly induced in the resistant line in response to inoculation by a mixture of spores from different molding fungi while the susceptible line displayed reduced expression. The data suggest that the MYB genes and their grain and glume specific expressions may determine the differential regulation of the flavonoid biosynthesis pathway genes, the synthesis of 3-Deoxyanthocynidins and ultimately responses to molding fungi. The study also suggested that resistance to grain mold may be negatively associated with grain functionality traits such as ' injera ' making quality of sorghum. Highlights: Grain mold resistance locus containing MYB transcription factor genes identified. The locus regulates responses to molding fungi in the developing sorghum grain. The locus contains a MYB gene, YELLOW SEED3 previously not described. YELLOW SEED3 may be involved in synthesis of 3-Deoxyanthocyanins phytoalexins. Grain mold resistance may be negatively associated with grain functionality traits.