Foxtail millet has attracted substantial attention in recent years because of its excellent properties as a cereal crop with high nutritional value. Although the cultivation area of foxtail millet keeps growing, the fundamental research into the nutritional and eating qualities of foxtail millet germplasm collections is limited. In this study, we performed a survey of protein content, amino acid composition and eating quality among a germplasm collection of foxtail millet accessions grown in different environments. Our results revealed 21 accessions with stable protein content under different environments. The correlation analysis further revealed that the protein content of the grains was affected by environmental and genotypic interactions. The further amino acid composition analyses suggested that higher protein content accessions have a better essential amino acid index, providing more nutritional value for human beings and animal feedstock. Moreover, the flavor-related amino acid content and other eating-quality trait analyses were also performed. The subordinative analysis suggested that B331 could be the best accession with high protein content and superior eating quality. Taken together, this study provides essential nutritional and eating-quality data on our germplasm collection of foxtail millets, and provides a core genetic resource from which to breed elite foxtail millet varieties in the future.

Panicle traits are important factors affecting yield, and their improvement has long been a critical goal in foxtail millet breeding. In order to understand the genetic basis of panicle formation, a large-scale genome-wide association study (GWAS) was performed in this study for six panicle-related traits based on 706,646 high-polymorphism SNP loci in 407 accessions. As a result, 87 quantitative trait loci (QTL) regions with a physical distance of less than 100 kb were detected to be associated with these traits in three environments. Among them, 27 core regions were stably detected in at least two environments. Based on rice–foxtail millet homologous comparison, expression, and haplotype analysis, 27 high-confidence candidate genes in the QTL regions, such as Si3g11200 (OsDER1), Si1g27910 (OsMADS6), Si7g27560 (GS5), etc., affected panicle-related traits by involving multiple plant growth regulator pathways, a photoperiod response, as well as panicle and grain development. Most of these genes showed multiple effects on different panicle-related traits, such as Si3g11200 affecting all six traits. In summary, this study clarified a strategy based on the integration of GWAS, a homologous comparison, and haplotype analysis to discover the genomic regions and candidate genes for important traits in foxtail millet. The detected QTL regions and candidate genes could be further used for gene clone and marker-assisted selection in foxtail millet breeding.

Wheat plays a crucial role in global food security. However, drought stress severely restricts its growth and development, and drought during the seedling stage significantly affects its organogenesis, thereby affecting yield. To study wheat drought tolerance mechanisms at the seedling stage and to explore drought tolerance gene resources, this study focused on the drought-tolerant wheat variety Bainong 207 and performed RNA-Seq and metabolome sequencing on leaves collected at the three-leaf stage under drought stress conditions. Drought stress significantly altered the expression of 12,930 genes and 2544 metabolites in wheat seedlings. Through bioinformatics methods such as O2PLS-DA, a gene–metabolite correlation network was constructed, and key regulatory genes within this network were subsequently identified. The results identified the important gene module MEbrown and metabolite module Meta6 and finally screened 20 transcription factors that are closely related to drought response. These transcription factors were predicted to be able to combine and regulate the expression of six key genes, which together help the variety to improve drought tolerance under drought stress conditions by regulating reactive oxygen species metabolism, maintaining intracellular redox homeostasis, promoting wax biosynthesis, enhancing the osmotic stress response, and regulating abscisic acid response.