In plants, root traits are governed by complex genetic networks whose natural variation critically shapes root system architecture. Because soybean breeding efforts aim to develop varieties with robust root systems to enhance water and nutrient use efficiency, researchers sought to elucidate the genetic basis of root development by identifying homologs of the rice Soil Surface Rooting 1 gene, known as OsSOR1, in the soybean genome. Through a comprehensive genome-wide analysis, the investigation identified and characterized seventeen GmSOR1-like genes, detailing their gene structures, conserved motifs, protein properties, cis-regulatory elements, phylogenetic relationships, and tissue-specific expression patterns.

To connect these genetic components with physical root performance, the team evaluated soybean germplasm accessions under both hydroponic and soil culture systems. Phenotyping across both growth environments focused on five key root metrics: primary root length, total root length, surface area of roots, root diameter, and root volume.

The phenotyping trials revealed marked differences in total root length across the tested accessions. Specifically, the soybean genotypes NRC2396, EC528623, HAL, and HARDEE consistently demonstrated high total root length across repeated experiments in both hydroponic and soil systems.

These contrasting accessions also displayed distinctive root orientation characteristics. The researchers observed inverse root angle patterns between the groups, where low-rooting lines generally displayed wider angles and high-rooting lines presented narrower angles, with the single exception of genotype NRC2396.

Building on these phenotypic classifications, the authors performed differential gene expression analysis comparing four high-rooting, low root angle genotypes against four low-rooting, high root angle genotypes. This transcriptomic profiling focused specifically on lateral root tissues collected at four distinct time points under hydroponic culture conditions, allowing the researchers to track transcriptional changes throughout developmental stages.

The transcriptional profiling highlighted significant differences in the expression of specific family members between contrasting groups. Notably, six genes—designated as Glyma01g097900, Glyma09g203400, Glyma10g210051, Glyma12g077333, Glyma14g185600, and Glyma20g180551—showed elevated expression in the lateral roots of low-rooting, high root angle genotypes at both the two-week and four-week stages, distinguishing them from the high-rooting cohort.

The researchers concluded that these six GmSOR1-like genes may play key regulatory roles in determining soybean root architecture.

Subject of Research: Genome-wide identification, characterization, and expression profiling of GmSOR1-like genes in soybean root architecture

Article Title: Genome wide identification, characterization and differential expression profiling of Soil Surface Rooting1-like gene family in soybean (Glycine max (L.) Merr.)

Article References: Agrawal, N., Kumawat, G., Choudhary, A., Verma, S., Patidar, K., Choyal, P., Ratnaparkhe, M. B., Satpute, G. K., Nataraj, V., Rajesh, V., Gupta, S., & Singh, K. H. (2026). Genome wide identification, characterization and differential expression profiling of Soil Surface Rooting1-like gene family in soybean (Glycine max (L.) Merr.). Molecular Biology Reports, 53(1), Article 1946. https://doi.org/10.1007/s11033-026-13069-y

Image Credits: AI Generated

DOI: 10.1007/s11033-026-13069-y

Keywords: soybean, Glycine max, root system architecture, OsSOR1, GmSOR1, gene family, hydroponic culture, soil culture, total root length, lateral roots, differential gene expression, cis-regulatory elements, primary root length, root diameter, root volume, plant genetics