Soybean is an important crop worldwide that provides ~ 50% oil for humans. Salinity is a major abiotic stress that inhibits soybean growth and yield. Dissecting the genetic basis of salt tolerance is an effective way for soybean plants to combat salt-related yield losses. In this study, the variety salt tolerance index (STIv) of a natural population of 140 soybean germplasms was calculated in terms of plant height (PH), leaf area (LA), shoot fresh weight (SFW) and shoot dry weight (SDW), which were measured under normal condition and in a 1.50% NaCl solution. GWAS analysis was subsequently conducted on the basis of STIv and 150 K SNP markers of “Zhongdouxin-1”. The results revealed that 365 significant SNPs located on 19 chromosomes (excluding Gm03) were associated with STIv. Among them, 108 SNPs were associated with LA-STIv, 71 SNPs associated with PH-STIv, 95 SNPs associated with SDW-STIv and 91 SNPs associated with SFW-STIv. A total of 333 genes were identified according to the flanking region (150 kb) of the significant SNPs. 333 genes were identified. Based on gene functional annotations, SNP mutations, and RNA expressions, nine causal genes responsible for soybean salt tolerance were identified. Thus, the significantly associated SNPs and candidate genes detected in this study might provide novel insights into soybean salt tolerance in breeding programs.

Introduction: Soybean is an indispensable crop supplying protein and oil for humans and animals, and playing an essential role in global food security. Drought represses soybean seed germination, reducing biomass accumulation and even inhibiting yield. Methods: In order to dissect the genetic components underlying soybean drought tolerance during different development stage, a natural population containing 140 accessions was employed to evaluate seven drought tolerance-related traits under water-welled and drought stress conditions. Subsequently, genome-wide association study (GWAS) was conducted based on 150K single nucleotide polymorphism (SNP) markers of “Zhongdouxin-1”. And the drought tolerance coefficient of seven different traits were analyzed with seven GWAS models. Results: A total of 1807 significant SNPs were detected across 20 chromosome, including 569 SNPs for germination stage, and 1242 SNPs for seedling stage. Of 569 SNPs identified in germination stage, 354 SNPs on chromosomes 2, 7, 13, 14, and 17 accounting for 62.21%. Among 1242 SNPs found in seedling stage, 869 SNPs on chromosomes 11, 14, 15, 17 and 18 accounting for 69.97%. Moreover, among 1807 significant SNPs, 163 SNPs exhibited pleiotropic effects, of which 23 were located in exon, 21 in intron, 12 in 5’UTR or 3’UTR and 11 in upstream or downstream. Furthermore, 249 stable SNPs were detected by more than four GWAS models. According to these stable SNPs, RNA expression levels and gene annotations, four causal genes ( Glyma.02G080200 , Glyma.11G056200 , Glyma.12G188900 , and Glyma.18G110200 ) conferring soybean drought tolerance were detected, which participated in ethylene stimulus response, water deprivation response, and proteolysis. Discussion: Collectively, 249 stable SNPs, 163 pleiotropic SNPs and four candidate genes identified in present study provided promising molecular resources and reliable foundation for drought resistance improvement and marker-assisted selective breeding in soybean.

Background: Soybean is an important crop with multiple uses for oil, food, and feed, providing 50% of the vegetable protein and 20% of the edible oil in the world. The WD40 family genes play crucial regulatory roles in growth, development, secondary metabolism, and stress responses. However, the definition of WD40 family genes in soybean remained unclear, which limited their application potential in genetic improvement. Methods: To identify soybean WD40 family members and screen candidate genes for breeding improvement, this study performed genome-wide identification of the soybean WD40 gene family via bioinformatic approaches based on the latest Williams 82 reference genome (Wm82.a6.v1). Meanwhile, the function of the family gene GmWD40-257 regulating seed quality was analyzed. Results: The results showed that a total of 458 GmWD40 genes were identified, which were distributed on the 20 chromosomes. Subcellular localization showed that most members were mainly concentrated in the nucleus, chloroplast, and cytoplasm. Phylogenetic tree analysis divided the 458 GmWD40 genes into eight groups. Synteny analysis identified 160 syntenic genes between soybean and Arabidopsis thaliana. Conserved motif analysis identified ten core motifs. The promoter regions of GmWD40 contained 19 types of cis-acting elements. Functional analysis revealed that the nonsense mutation of GmWD40-257 significantly reduced the content of oil, palmitic acid, oleic acid, linoleic acid, α-linolenic acid and soluble sugar, while significantly increasing the contents of protein, γ-tocopherol and δ-tocopherol. Conclusions: A total of 458 members of the WD40 gene family were identified in soybean. Among these, GmWD40-257 was found to positively regulate the contents of soybean oil, palmitic acid, oleic acid, linoleic acid, α-linolenic acid and soluble sugar, while negatively regulating the contents of soybean protein, γ-tocopherol and δ-tocopherol.

In salt-affected soil, different agronomic practices can alter crop productivity and rhizosphere microbial dynamics, yet whether their short-term responses are consistent remains unclear. A single-site, one-season field experiment was conducted in 2025 in Zepu County, southern Xinjiang, China. Three tillage treatments, conventional tillage (CT), no-tillage (NT), and no-tillage with straw mulching (NT&SM), were compared for soybean yield, rhizosphere soil properties, and bacterial communities. The results showed that the soybean yield under CT was significantly higher than that under NT&SM. Contrary to the yield trend, the NT&SM treatment exhibited the highest mean values for the Chao1 and Shannon indices (the overall treatment effect was significant). PERMANOVA based on Bray–Curtis distance indicated that short-term tillage significantly altered the rhizosphere bacterial community structure, explaining 34.6% of the variation in composition. Tillage practices produced different rhizosphere bacterial community profiles. However, these short-term shifts in bacterial diversity and composition did not parallel the yield response. This suggests that both crop productivity and rhizosphere ecological responses should be considered simultaneously when evaluating conservation tillage practices. These findings represent short-term responses under the conditions of a single site and growing season and require validation through multi-year, multi-site experiments.