Project description:<p>Heterosis, or hybrid vigor, refers to the phenomenon where F1 hybrids outperform their parental inbred lines. Despite more than a century of intensive research across various species, the genetic basis and environmental regulation of heterosis, particularly belowground, remain poorly understood. Recent studies have suggested that the soil microbiome may influence the expression of heterosis. However, it remains unclear whether and to what extent the manifestation of heterosis shapes the associated microbiome under abiotic stress, and how these microbiomes, in turn, influence the heterotic phenotype in response to stress. In this study, we explored the potential role of rhizosheath formation in maize growth heterosis under nitrogen deprivation. Soil sterilization and inoculation experiments with bacteria of the genus Massilia demonstrated that several functional root traits contribute to the manifestation of rhizosheath-associated heterosis. Untargeted metabolomics profiling and validation with flavone-deficient mutants indicated that Massilia promote flavone secretion, which is linked to rhizosheath formation. In addition, the integration of rhizosheath transplantation experiments with soil metagenomic sequencing data confirmed that rhizosheath size determined plant growth performance under stress conditions. Taken together, these results suggest that the rhizosheath formation, which integrates root development, root exudates, and their associated microbiome, can be considered as an adaptive and heritable root trait with potential applications in modern crop breeding to combat global climate change.</p>
Project description:This research reports the analysis of sRNAs in 14 and 7 inbred lines from a breeding population. We analyzed the contribution of sRNAs to the formation of heterosis via integrative association analysis with field data of 98 hybrids generated from the set of inbred lines. Our results indicate a contribution of sRNAs to heterosis. We were able to identify different sets of sRNAs associated with heterosis with distinct length and genome distribution patterns.
Project description:Through a two-year field experiment, G70×GDH11 with strong heterosis and K326×GDH11 with weak heterosis were screened out. Transcriptome analyses revealed that 80.89% and 57.28% of the differentially expressed genes (DEGs) in the strong and weak heterosis combinations exhibited an overdominant expression pattern, respectively. The genes that up-regulated the overdominant expression in the strong heterosis hybrids were significantly enriched in the ion homeostasis. Genes involved in K+ transport (KAT1/2, GORK, AKT2 and KEA3), activity regulation complex (CBL-CIPK5/6), and vacuole (TPKs) genes were overdominant expressed in strong heterosis hybrids, which contributed to K+ homeostasis and heterosis in tobacco leaves.
