Soybean (Glycine max (L.) Merrill) is a key source of plant protein, with 7S and 11S globulins being the primary fractions. This study investigated the protein content, protein composition, and 11S/7S globulin ratios of 411 soybean samples, and then selected six varieties (S1, S2, S3, S4, S5, and S6) for the analysis of the protein structures and functional properties. The results revealed that varieties with low 11S/7S ratios (S1, S2, and S3) exhibited relatively high random coil contents (20.11–22.94%) and lower β-sheet contents (34.17–38.37%), suggesting the presence of more loosely structured proteins. S2 showed good solubility (73.21%) and water-holding capacity (WHC) (2.73 g/g), which can improve product quality and yield. In contrast, varieties with high 11S/7S ratios (S4, S5, and S6) demonstrated more compact protein structures, increased surface hydrophobicity, larger particle sizes, lower absolute zeta potential values, and greater oil-holding capacity (OHC) values (7.58–8.48 g/g). S4, in particular, demonstrated superior emulsification properties, with emulsion activity index (EAI) (4.71 m²/g) and emulsion stability index (ESI) (58.73 min), which are widely used in the food industry such as in cake, ice cream, and bread. This study provides valuable information for the selection of soybean varieties with optimal 11S/7S ratios for processing soybean products.

Hydrogen sulfide (H₂S) is an important signaling molecule that regulates diverse cellular signaling pathways through persulfidation. Our previous study revealed that H₂S is involved in the improvement of rice drought tolerance. However, the corresponding enzymatic sources of H₂S and its regulatory mechanism in response to drought stress are not clear. Here, we cloned and characterized a putative l-cysteine desulfhydrase (LCD) gene in rice, which encodes a protein possessing H₂S-producing activity and was named OsLCD1. Overexpression of OsLCD1 results in enhanced H₂S production, persulfidation of total soluble protein, and confers rice drought tolerance. Further, we found that nitrate reductase (NR) activity was decreased under drought stress, and the inhibition of NR activity was controlled by endogenous H₂S production. Persulfidation of NIA2, an NR isoform responsible for the main NR activity, led to a decrease in total NR activity in rice. Furthermore, drought stress-triggered inhibition of NR activity and persulfidation of NIA2 was intensified in the OsLCD1 overexpression line. Phenotypical and molecular analysis revealed that mutation of NIA2 enhanced rice drought tolerance by activating the expression of genes encoding antioxidant enzymes and ABA-responsive genes. Taken together, our results showed the role of OsLCD1 in modulating H₂S production and provided insight into H₂S-regulated persulfidation of NIA2 in the control of rice drought stress.

Hydrogen sulfide (H₂S) is an endogenous gaseous molecule that plays an important role in the plant life cycle. The multiple transcription factor ABSCISIC ACID INSENSITIVE 4 (ABI4) was precisely regulated to participate in the abscisic acid (ABA) mediated signaling cascade. However, the molecular mechanisms of how H₂S regulates ABI4 protein level to control seed germination and seedling growth have remained elusive. In this study, we demonstrated that ABI4 controls the expression of L-CYSTEINE DESULFHYDRASE1 (DES1), a critical endogenous H₂S-producing enzyme, and both ABI4 and DES1-produced H₂S have inhibitory effects on seed germination. Furthermore, the ABI4 level decreased during seed germination while H₂S triggered the enhancement of the persulfidation level of ABI4 and alleviated its degradation rate, which in turn inhibited seed germination and seedling establishment. Conversely, the mutation of ABI4 at Cys250 decreased ABI4 protein stability and facilitated seed germination. Moreover, ABI4 degradation is also regulated via the 26S proteasome pathway. Taken together, these findings suggest a molecular link between DES1 and ABI4 through the post-translational modifications of persulfidation during early seedling development.

The volatile flavor profiles and sensory properties of different vegetable soybean varieties popularized and cultivated in China for 20, 10, and 2 years (TW292, X3, and SX6, respectively) were investigated. Nutrient composition analysis revealed that TW292 had a high soluble protein and soluble sugar content but low fat content. The total free amino acid content (15.43 mg/g) and umami free amino acid content (6.08 mg/g) of SX6 were significantly higher (p < 0.05) than those of the other varieties. An electronic tongue effectively differentiated between the umami and sweetness characteristics of the vegetable soybeans. Differences in sensory evaluation results were mainly reflected in texture and taste. A total of 41 volatile compounds were identified through HS-SPME-GC-MS, and the main flavor compounds were 1-octen-3-ol, hexanal, (Z)-2-heptenal, 2-octene, nonanal, (Z)-2-decenal, and 3,5-octadien-2-one. However, the volatile composition of different vegetable soybean varieties exhibited large variability in type and relative contents. Considerable differences in nutritional, organoleptic, and aroma characteristics were found among different varieties. The results of this study will provide a good basis for the assessment and application of the major vegetable soybean varieties grown in China.

Although mungbean (Vigna radiata (L.) R. Wilczek) is an important legume crop, its seed yield is relatively low. To address this issue, here 196 accessions with 3,607,508 SNP markers were used to identify quantitative trait nucleotides (QTNs), QTN-by-environment interactions (QEIs), and their candidate genes for seed length (SL), seed width, and 100-seed weight (HSW) in two environments. As a result, 98 QTNs and 20 QEIs were identified using 3VmrMLM, while 95, >10,000, and 15 QTNs were identified using EMMAX, GEMMA, and CMLM, respectively. Among 809 genes around these QTNs, 12 were homologous to known seed-development genes in rice and Arabidopsis thaliana, in which 10, 2, 1, and 0 genes were found, respectively, by the above four methods to be associated with the three traits, such as VrEmp24/25 for SL and VrKIX8 for HSW. Eight of the 12 genes were significantly differentially expressed between two large-seed and two small-seed accessions, and VrKIX8, VrPAT14, VrEmp24/25, VrIAR1, VrBEE3, VrSUC4, and Vrflo2 were further verified by RT-qPCR. Among 65 genes around these QEIs, VrFATB, VrGSO1, VrLACS2, and VrPAT14 were homologous to known seed-development genes in A. thaliana, although new experiments are necessary to explore these novel GEI-trait associations. In addition, 54 genes were identified in comparative genomics analysis to be associated with seed development pathway, in which VrKIX8, VrABA2, VrABI5, VrSHB1, and VrIKU2 were also identified in genome-wide association studies. This result provided a reliable approach for identifying seed-size-related genes in mungbean and a solid foundation for further molecular biology research on seed-size-related genes.