Yujiao Liu

Aphis craccivora is a major piercing–sucking insect pest in faba bean (Vicia faba L.) production and severely restricts yield and quality. To identify aphid-resistant genetic resources and clarify the key physiological and biochemical mechanisms underlying resistance and susceptibility, 937 faba bean germplasm accessions were evaluated using a stepwise strategy comprising natural field screening, precise net-house re-screening, laboratory validation based on aphid life-table parameters, and physiological and biochemical characterization of representative resistant and susceptible accessions. After final laboratory validation, three resistant and three susceptible accessions were selected and subjected to aphid feeding for 0 h (CK), 36 h, and 72 h. Eleven physiological and biochemical traits were dynamically analyzed, including the activities of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and phenylalanine ammonia-lyase (PAL), as well as the contents of soluble protein, soluble sugar, free amino acids, tannins, total phenolics, flavonoids, and lignin. Three stable aphid-resistant accessions were ultimately identified. Laboratory life-table analysis showed that the net reproductive rate of aphids on resistant accessions was significantly lower than that on susceptible accessions, with R₀ decreasing from 53.63 to 25.08, representing a reduction of 53.2%. The intrinsic rate of increase decreased by 26.7%, whereas the mean generation time increased by 10.7%, confirming the reliability of the screening results. Physiological and biochemical analyses showed that aphid feeding induced significant and time-dependent increases in SOD, POD, CAT, and PAL activities and in tannin, total phenolic, flavonoid, and lignin contents in resistant accessions, whereas these defense responses were weak in susceptible accessions. In contrast, susceptible accessions showed abnormal accumulation of soluble sugars and free amino acids, whereas resistant accessions maintained these nutrients at low levels. Lignin exhibited both constitutive and inducible defense characteristics in resistant accessions and emerged as a prominent candidate indicator for aphid resistance in faba bean. This study establishes an effective technical pipeline for screening aphid-resistant faba bean germplasm and reveals a coordinated defense network involving antioxidant enzymes, phenylpropanoid metabolism, secondary metabolites, and physical barriers. These findings provide elite parental germplasm and theoretical support for aphid-resistance breeding in faba bean.

The MADS-box gene family is important in florescence development and flower organ formation. Members can directly or indirectly influence leguminous crops growth habits. However, this gene family in faba bean (Vicia faba L.) and its role in the development of various growth habits have not been systematically reported. We identify 82 VfMADS genes in faba bean. Phylogenetic relationships, gene structure, conserved motifs, and expression patterns in varieties with different growth habits are investigated. Of them, 41 VfMADS proteins are classified as Type II and are attributed to 11 subfamilies. We report 12 pairs of tandem duplication events in VfMADS genes that involve 26 genes. Cis-acting elements in promoter regions suggest that these genes are involved mainly with hormone and stress responses. A new type of semi-determinate growth habit is reported for faba bean and transcriptome sequencing reveals 56 MADS-box genes to be differentially expressed in accessions with 3 types of growth habits. Significant differences are reported for expression levels of 10 VfMADS genes in different growth habits and tissues, indicating that VfMADS genes are closely related to floral transition, especially the floral termination at the shoot apex. We systematically identify MADS-box genes in faba bean and investigate their physicochemical properties, phylogenetic relationships, chromosomal distribution, conserved motifs, cis-acting elements and expression patterns in faba bean with different growth habits. By doing so, we improve understanding of the regulatory network of growth habits and provide a theoretical basis for future studies on the functional characteristics of VfMADS genes in faba bean.

Faba bean (Vicia faba L.) is a crucial cool-season legume crop, which is highly valued for its high protein content and key role in crop rotation systems. Considering the increasing threat of soil salinity and alkalinity globally, it is critical to screen germplasm resources with saline-alkali tolerance in faba bean and to identify the underlying genes. In this study, 12 morphological and physiological traits under compound saline-alkali stress conditions were measured to evaluate saline-alkali tolerance of 240 accessions based on principal component analysis. The results showed that biomass-related traits such as fresh weight of shoot and leaf number had relatively high weights in the evaluation of saline-alkali tolerance at the seedling stage, and 38 highly saline-alkali tolerant accessions were identified. A total of 242 SNPs affecting seedling saline-alkali tolerance were identified in a genome-wide association study of 240 faba bean accessions, with 57 SNPs significantly associated with 7 traits and identified by GLM and MLM models. It was found that 10 genes (such as L-GalLDH, ZAT4, NAC82) overlapped with the reported genes related to saline-alkali tolerance or stress resistance by functional annotation of candidate genes, and their elevated expression in tolerant accessions was validated by RT-qPCR. RT-qPCR indicated tissue-specific differential expression between tolerant and sensitive accessions, with most genes showing higher expression in the tolerant line. These findings enhance our understanding of the genetic mechanisms governing salt-alkali tolerance in faba bean seedlings and supplies valuable high-tolerance accessions alongside candidate gene resources for breeding programs, thereby laying a solid foundation for subsequent functional validation of these genes.

Grass–legume mixtures are increasingly recognized for their potential to enhance soil health and forage productivity through belowground biotic interactions. In this study, we evaluated the effects of Vicia faba L. (faba bean 4060)–Avena sativa L. (oat ‘Baylor II’) mixtures on biomass, soil properties, and bacterial community dynamics. Results showed that mixtures significantly reduced the fresh weight of faba bean (6.2 kg/m²) compared to monoculture (8.8 kg/m², p < 0.001), while oat biomass increased under mixtures (3.2 kg m⁻² vs. 2.8 kg m⁻², p < 0.01). Available phosphorus (AP) and available potassium (AK) significantly decreased in the rhizosphere of both mixtures, whereas alkali-hydrolyzable nitrogen (AN) significantly increased, particularly in oat. Mixtures significantly enhanced bacterial richness, evenness, and Shannon diversity in faba bean (p < 0.01) but had no significant effect on oat diversity metrics. NMDS indicated distinct shifts in bacterial community structures under mixtures. Acidobacteriota and Vicinamibacteraceae were enriched in faba bean mixtures, whereas Actinobacteriota decreased in both forages under mixtures. Source Tracker analysis suggested substantial microbial exchange between species, with over 40% of the bacterial community in mixed roots originating from the partner monoculture. Although microbial community stability tended to decline under mixtures, differences were not significant. Niche breadth was significantly expanded in faba bean mixtures. Community assembly processes remained predominantly stochastic; however, mixtures slightly shifted the balance toward deterministic processes. Structural equation model revealed that soil physicochemical properties had a significant negative effect on diversity (β = −0.371, p = 0.007), and diversity had a significant negative effect on freshweight (β = −0.770, p < 0.001), suggesting that bacterial diversity may play a mediating role in the relationship between soil properties and plant fresh weight (β = 0.285, p = 0.011). These findings demonstrate that mixture-induced changes in soil nutrient status and microbial community characteristics collaboratively mediate plant performance through altered community assembly and diversity–function relationships.

Broad beans, natural sources of L-DOPA and bioactive phenolics show promise for Parkinson’s disease intervention. This study investigated broad bean extracts’ protective mechanisms against PD pathogenesis. Among screened varieties, QC25 extract exhibited optimal protection in MPP⁺-injured PC12 cells, improving viability, reducing LDH release, and mitigating cell cycle arrest. QC25 extract rescued mitochondrial dysfunction by suppressing ROS, restoring membrane potential, normalizing Ca²⁺ homeostasis, and recovering ATP synthesis. Metabolomics identified glycerophospholipid metabolism as the core protective pathway, mediating mitochondrial membrane stabilization. QC25 extract further activated PINK1/Parkin-mediated mitophagy, upregulating PINK1 and Parkin expression. Crucially, 6-gingerol—uniquely detected in QC25 extract—synergized with L-DOPA, enhancing cell viability and amplifying mitophagy through complementary mitochondrial repair mechanisms. These findings demonstrate QC25 broad bean variety exerts’ protective effects on PD model cells by regulating mitochondrial function and mitophagy, and its unique component 6-gingerol synergizes with L-DOPA to strengthen these effects. This study provides a theoretical basis for the development of QC25 as a functional food ingredient for neurological health maintenance.