Rice bean is an underutilized legume crop cultivated in Asia, and it is a good source of protein, minerals, and essential fatty acids for human consumption. Moreover, the leaves left over after harvesting rice bean seeds contain various biological constituents beneficial to humans and animals. In our study, we performed a de-novo transcriptome assembly of rice bean, characterized the WRKY transcription factors, and studied their response to aluminum stress. A total of 46.6 million clean reads, with a GC value of 43%, were generated via transcriptome sequencing. De novo assembly of the clean reads resulted in 90,933 transcripts and 74,926 unigenes, with minimum and maximum lengths of 301 bp and 24,052 bp, and N50 values of 1801 bp and 1710 bp, respectively. A total of 27,095 and 28,378 unigenes were annotated and subjected to GO and KEGG analyses. Among the unigenes, 15,593, 20,770, and 15,385 unigenes were identified in the domains of biological process, molecular function, and cellular component, respectively. A total of 16,132 unigenes were assigned to 188 pathways, including metabolic pathways (5500) and secondary metabolite biosynthesis (2858). Transcription factor analysis revealed 4860 unigenes from 98 different transcription factor families. For WRKY, a total of 95 unigenes were identified. Further analysis revealed the diverse response of WRKY transcription factors to aluminum stress. Collectively, the results of this study boost genomic resources and provide a baseline for further research on the role of WRKY transcription factors in aluminum tolerance in rice bean.

Mungbean is an important legume crop native to India. In this study, 500 indigenous mungbean accessions collected from diverse eco-geographical regions of India were evaluated for agronomic trait genetic variability and core collection development. The accessions were grown in an augmented design during 2019 and 2020, and data were recorded for seven quantitative and 13 qualitative traits. Analysis of variance (ANOVA), frequency distribution, and box-plot analyses revealed substantial phenotypic variation among the accessions. Traits including plant height (PHT), number of pods per plant (NPP), hundred-seed weight (HSW), and single-plant yield (SPY) exhibited high heritability coupled with high genetic advance, indicating the predominance of additive genetic effects. Principal component analysis showed that the first three principal components explained 70% of the total phenotypic variation. The Shannon–Weaver diversity index further indicated high levels of genetic diversity within the population. Based on quantitative traits, the accessions were grouped into six major clusters and 42 sub-clusters, with SPY, NPP, HSW, PHT, and days to 50% flowering (DFF) contributing substantially to genetic divergence. Correlation analysis suggested that direct selection for SPY and indirect selection through associated traits, including NPP, HSW, PHT, NSP, and pod length (POL), may enhance yield improvement. The germplasm collection also possessed desirable traits such as high yield potential, contrasting maturity groups, and plant types suitable for mechanical harvesting and bold-seeded type. A representative core set comprising 50 accessions was developed using the PowerCore program, providing valuable genetic resources for mungbean breeding and genetic improvement programs.

The basic helix–loop–helix (bHLH) gene family, a major class of transcription factors in plants, plays critical role in growth, development, and responses to environmental stresses. Despite its importance, knowledge of bHLH gene functions in cowpea remains limited. Here, we conducted a comprehensive genome-wide in silico analysis of the cowpea bHLH family. A total of 60 VubHLH genes were identified and found to be non-uniformly distributed across the 11 chromosomes. Phylogenetic analysis grouped 60 VubHLH and 127 AtbHLH genes into six distinct subgroups. Gene structural characteristics were conserved within subgroups but diversed among subgroups. Synteny analysis indicated that segmental duplication, rather than tandem duplication, was the primary driver of VubHLH family expansion. Promoter analysis revealed diverse cis-acting elements associated with plant growth, developmental processes, phytohormone regulation, and stress responses. Tissue-specific expression suggested functional diversification of VubHLH genes during evolution. qRT-PCR analysis showed that VubHLH1.1 and VubHLH11.1 genes were significantly upregulated under ABA, MeJA, and salt treatments, whereas VubHLH3.7, VubHLH5.1, and VubHLH6.3 were downregulated. Collectively, these results provide valuable insights into the evolutionary relationships and functional characteristics of the bHLH gene family and lay a foundation for future studies of bHLH gene function and improving the cowpea salt tolerance.