Soybean (Glycine max) seeds are rich in amino acids, offering key nutritional and physiological benefits. In this study, 290 soybean accessions from the USDA Germplasm Collection based in Urbana, IL Information Network (GRIN) were analyzed. Four Genome-Wide Association Study (GWAS) models—Bayesian-information and Linkage-disequilibrium Iteratively Nested Keyway (BLINK), Mixed Linear Model (MLM), Fixed and Random Model Circulating Probability Unification (FarmCPU), and Multi-Locus Mixed Model (MLMM)—identified two significant Single Nucleotide Polymorphisms (SNPs) associated with arginine content: Gm06_19014194_ss715593808 (LOD = 9.91, 3.91% variation) at 19,014,194 bp on chromosome 6 and Gm11_2054710_ss715609614 (LOD = 9.05, 19% variation) at 2,054,710 bp on chromosome 11. Two candidate genes, Glyma.06g203200 and Glyma.11G028600, were found in the two SNP marker regions, respectively. Genomic Prediction (GP) was performed for arginine content using several models: Bayes A (BA), Bayes B (BB), Bayesian LASSO (BL), Bayesian Ridge Regression (BRR), Ridge Regression Best Linear Unbiased Prediction (rrBLUP), Random Forest (RF), and Support Vector Machine (SVM). A high GP accuracy was observed in both across- and cross-populations, supporting Genomic Selection (GS) for breeding high-arginine soybean cultivars. This study holds significant commercial potential by providing valuable genetic resources and molecular tools for improving the nutritional quality and market value of soybean cultivars. Through the identification of SNP markers associated with high arginine content and the demonstration of high prediction accuracy using genomic selection, this research supports the development of soybean accessions with enhanced protein profiles. These advancements can better meet the demands of health-conscious consumers and serve high-value food and feed markets.

Chloroplasts play a crucial role in essential processes such as photosynthesis and the synthesis of primary and diverse secondary metabolites. Recent studies have also highlighted their significance linked to phytohormone production in plant immunity, especially SA and JA. Ubiquitination, a key post-translational modification, usually leads to target protein degradation, which acts as a signal for remodeling the proteome via the induction of protein endocytosis or targeting to other membrane associated systems. Previously, the potato E3 ligase StRFP1 was shown to enhance resistance against Phytophthora infestans, but its mechanism remained unclear. Here, we demonstrate that StRFP1 interacted with the dually localized plastid glucose 6-phosphate transporter StGPT1 on the endoplasmic reticulum (ER). Transient expressed StGPT1-GFP located on the chloroplast and ER in plant cells. Overexpression of StGPT1 enhances late blight resistance in potato and Nicotiana benthamiana, activates immune responses including ROS bursts and up-regulation of PTI marker genes. The resistance function of StGPT1 seems to be related to its dual localization. Remarkably, StRFP1 ubiquitinates StGPT1 at the ER, possibly due to its merely transient function in peroxisomes, leading to apparent accumulation in chloroplasts. Our findings point to a novel mechanism by which a plant E3 ligase contributes to immunity via interacting with dually-targeted GPT1 at the ER of plant cells.

Soybean mosaic virus (SMV), a pathogen responsible for inducing leaf mosaic or necrosis symptoms, significantly compromises soybean seed yield and quality. According to the classification system in the United States, SMV is categorized into seven distinct strains (G1 to G7). In this study, we performed a genome-wide association study (GWAS) in GAPIT3 using four analytical models (MLM, MLMM, FarmCPU, and BLINK) on 218 soybean accessions. We identified 22 SNPs significantly associated with G1 resistance across chromosomes 1, 2, 3, 12, 13, 17, and 18. Notably, a major quantitative trait locus (QTL) spanning 873 kb (29.85–30.73 Mb) on chromosome 13 exhibited strong association with SMV G1 resistance, including the four key SNP markers: Gm13_29459954_ss715614803, Gm13_29751552_ss715614847, Gm13_30293949_ss715614951, and Gm13_30724301_ss715615024. Within this QTL, four candidate genes were identified: Glyma.13G194100, Glyma.13G184800, Glyma.13G184900, and Glyma.13G190800 (3Gg2). The genomic prediction (GP) accuracies ranged from 0.60 to 0.83 across three GWAS-derived SNP sets using five models, demonstrating the feasibility of GP for SMV-G1 resistance. These findings could provide a useful reference in soybean breeding targeting SMV-G1 resistance.

Nucleoskeleton proteins modulate nuclear structure and play important roles in diverse cellular processes. Yet, their functions in immune responses are poorly understood. Here, we report that a nucleoskeleton protein, potato lamin-like protein StKAKU4, is targeted and stabilized by the oomycete RxLR effector Pi22798 to suppress immunity. StKAKU4 predominantly localizes to the nuclear envelope (NE) and is frequently trafficked between the NE and endosomal organelles. Enhanced expression of KAKU4 in Nicotiana benthamiana significantly increases Phytophthora infestans infection, whereas silencing of KAKU4 in potato and N. benthamiana enhances resistance, suggesting that it acts as a susceptibility (S) factor. GFP-StKAKU4 accumulates at the extrahaustorial membrane (EHM) during P. infestans infection. Moreover, Pi22798 interacts with StKAKU4 at the NE and accelerates endomembrane trafficking of StKAKU4 to the cytoplasm. An endomembrane enrichment assay indicates that StKAKU4 is involved in intracellular transport. In the immunopurified GFP-StKAKU4-associated endomembrane proteome, both host immunity-associated proteins and several P. infestans RxLR effectors are enriched, whereas apoplastic effectors such as PiSCR74, which do not enter host cells, are not. Our findings reveal a mechanism by which the potato NE protein StKAKU4 is involved in vesicle trafficking and is exploited by P. infestans to facilitate infection and colonization, offering valuable insights into S factors and potential strategies for improving disease resistance.

Soybean (Glycine max) seeds are rich in amino acids, offering key nutritional and physiological benefits. In this study, 290 soybean accessions from the USDA-ARS Germplasm Resources Information Network (GRIN) were analyzed. Four genome-wide association study (GWAS) models—Bayesian-information and Linkage-disequilibrium Iteratively Nested Keyway (BLINK), Mixed Linear Model (MLM), Fixed and Random Model Circulating Probability Unification (FarmCPU), and Multi-Locus Mixed Model (MLMM)—identified two significant single nucleotide polymorphisms (SNPs) associated with arginine content: Gm06_19014194_ss715593808 (LOD = 9.91, 3.91% variation) at 19,014,194 bp on chromosome 6 and Gm11_2054710_ ss715609614 (LOD = 9.05, 19% variation) at 2,054,710 bp on chromosome 11. Two candidate genes Glyma.06g203200 and Glyma.11G028600 were founded in the two SNP marker regions, respectively. Genomic prediction was performed for arginine content using several models: Bayes A (BA), Bayes B (BB), Bayesian LASSO (BL), Bayesian Ridge Regression (BRR), Ridge Regression Best Linear Unbiased Prediction (rrBLUP), Random Forest (RF), and Support Vector Machine (SVM). High genomic prediction accuracy were observed in both across- and cross-populations, supporting genomic selection (GS) for breeding high-arginine soybean cultivars.