Exploring differentially expressed genes and associated biological processes across embryos with different seed dormancy in barley (Hordeum vulgare)

Abstract

Barley (Hordeum vulgare) has a wide range of seed dormancy. Seed dormancy is a crucial trait for plant survival and crop production. To explore genes and functions associated with the difference in barley seed dormancy, we performed differentially expressed gene and gene ontology (GO) enrichment analyses on seed embryos from a wild barley accession H602 with strong dormancy, a cultivated malting barley accession Kanto Nakate Gold (KNG) with weak dormancy, and reciprocal crosses between the two H602 × KNG and KNG × H602. RNA was extracted from embryos in seeds harvested at physiological maturity and dried for 1 week. We also assessed expression levels of known quantitative trait locus genes linked to seed dormancy. In H602 and H602 × KNG, 417 genes showed significantly higher expression than KNG and KNG × H602, with 14 GO terms enriched, including stress response and sugar metabolism. Genes involved in DNA repair were also enriched for highly expressed genes in H602 than KNG. In KNG and KNG × H602, 198 genes showed significantly higher expression than H602 and H602 × KNG, with 60 GO terms enriched, including development and auxin transport. Genes involved in translation were also enriched for highly expressed genes in KNG × H602 than H602 × KNG. Our findings indicated that genes involved in abiotic stress response, sugar metabolism, and DNA repair would be associated with strong seed dormancy, whereas genes involved in development and translation would be associated with weak dormancy in barley.