Mung bean (Vigna radiata), an essential annual legume, holds substantial value in global agriculture due to its short growth cycle, low input requirements, and nutritional benefits. Despite extensive domestication, the genetic mechanisms underlying its morphological and physiological evolution remain incompletely understood. In this study, we present a gap-free, telomere-to-telomere genome assembly of the mung bean cultivar 'Weilv-9′, achieved through the integration of PacBio HiFi, Oxford Nanopore, and high-throughput chromosome conformation capture (Hi-C) sequencing technologies. The 500-Mb assembly, encompassing 11 chromosomes and containing 28 740 protein-coding genes, reveals that 49.17% of the genome comprises repetitive sequences. Within the genome, we found the recent amplification of transposable elements significantly impacts the expression of nearby genes. Furthermore, integrating structural variation and single-nucleotide polymorphism (SNP) data from resequencing, we identified that the fatty acid synthesis, suberin biosynthetic, and phenylpropanoid metabolic processes have undergone strong selection during domestication. These findings provide valuable insights into the genetic mechanisms driving domestication and offer a foundation for future genetic enhancement and breeding programs in mung beans and related species.

Pea (Pisum sativum L.) is an important legume crop. However, the yield of pea is adversely affected by heat stress in China. In this study, heat-tolerant germplasms were screened and evaluated in the field under multi-conditions. The results showed that heat stress could significantly affect pea yield. On the basis of grain weight per plant, 257 heat-tolerant and 175 heat-sensitive accessions were obtained from the first year’s screening, and 26 extremely heat-tolerant and 19 extremely heat-sensitive accessions were finally obtained in this study. Based on SNaPshot technology, two sets of SNP markers, including 46 neutral and 20 heat-tolerance-related markers, were used to evaluate the genetic diversity and population genetic structure of the 432 pea accessions obtained from the first year’s screening. Genetic diversity analysis showed that the average polymorphic information content was lower using heat-tolerance-related markers than neutral markers because of the selective pressure under heat stress. In addition, population genetic structure analysis showed that neutral markers divided the 432 pea accessions into two subpopulations associated with sowing date type and geographical origin, while the heat-tolerance-related markers divided these germplasms into two subpopulations associated with heat tolerance and sowing date type. Overall, we present a comprehensive resource of heat-tolerant and heat-sensitive pea accessions through heat-tolerance screenings in multi-conditions, which could help genetic improvements of pea in the future.

During the life cycle of a plant, seed germination is crucial. Upon ingestion of water, the dry seeds resumed energy metabolism and cellular repair. To dissect the complex mechanisms at the very beginning of seed germination, two approaches including transcriptome and small RNA sequencing were conducted during the water imbibition process of mung bean seeds compared with dry seed. The transcriptome sequencing analysis identified 10,108 differentially expressed genes (DEGs) between dry and imbibed mung bean seeds. KEGG enrichment analyses demonstrated numerous DEGs involved in hormone signaling pathways, carbohydrate, and energy metabolism. Out of the total DEGs, 129 genes were investigated to involve in abscisic acid, gibberellin, and ethylene pathways, with 56 genes involved in glycolysis and TCA cycle. Through the analysis of small RNA sequencing among different samples, there were 284 miRNAs found in the imbibed and dried seeds of mung bean containing 213 known and 71 novel miRNAs. From comparison between the two types of seeds, 51 miRNAs were differentially expressed. The integrated analyses of transcriptome and miRNAome data showed that 23 DEGs are the putative target genes of 8 miRNAs including miR156, miR171b-3p, miR166e-3p, miR169-1, etc. QRT-PCR was used to validate several DEGs and miRNAs. The data suggested that the seed imbibition process is regulated by a variety of DEGs and microRNAs. Meanwhile, we hope to gain a deeper insight into how mung bean seeds germinate in order to optimize seed growth.