Background: During the germination of soybean seeds, many biochemical metabolic reactions become extremely active, resulting in a series of physiological and biochemical activities, and the seeds being rich in nutrients. Studying the network and key genes that regulate the nutritional content of bean sprouts is particularly important.
Methods: In this study, the nutrient contents of Dongnong 254 and Heze small beans were measured when the bean sprouts were 1 cm, 3 cm, 5 cm and 7 cm long, and transcriptome sequencing was performed.
Results: Clustering and principal component analysis (PCA) revealed that the samples could be divided into three groups. The differences between Dongnong 254 and Heze small bean samples with sprout lengths of 5 cm and 7 cm were greater than those between materials. Through differential expression analysis, 18,472 differentially expressed genes (DEGs) in the material included 1816 unique DEGs, and a total of six clusters with statistical significance were identified, which were enriched in pathways related to photosynthesis and sugar metabolism. The 6938 DEGs among the materials included 1044 unique DEGs, and a total of nine statistically significant clusters were identified, which were mainly annotated in pathways related to photosynthesis, hormones and flavonoids. Three specific modules that were significantly related to the nutritional content of bean sprouts were identified via WGCNA. The connectivity and functional annotation of genes within the modules were calculated, and nine candidate genes were found, nine of which encoded transcription factors (Glyma.16G071900 (WD40), Glyma.17G172400 (bHLH), Glyma.18G148000 (AP2) and Glyma.01G003000 (MYB)).
Conclusions: These research results provide a theoretical basis for an in-depth understanding of the molecular mechanisms of soybean sprout development and nutritional components and provide new genetic resources for the study of nutritional components in soybean sprouts.
Keywords: WGCNA; bean sprouts; candidate genes; soybean; transcriptome.