Leymus chinensis is a grass species in the family Triticeae that is found in the Eurasian grassland region and is known for its outstanding ecological advantages and economic value. However, the increasing adoption of photovoltaic agriculture has modified the light environment for the grass, markedly inhibiting its photosynthesis, growth, and yield. This study used physiological and transcriptomic analyses to investigate the complex response mechanisms of two L. chinensis genotypes (Zhongke No. 3 [Lc3] and Zhongke No. 5 [Lc5]) under shading stress. Growth phenotype analysis revealed the superior growth performance of Lc3 under shading stress, evidenced by enhanced plant height and photosynthetic parameters. Additionally, differentially expressed genes (DEGs) were predominantly enriched in starch and sucrose metabolism and glycolysis/gluconeogenesis pathways, which were the most consistently enriched in both L. chinensis genotypes. However, the flavonoid biosynthesis and galactose metabolism pathways were more enriched in Lc3. Weighted gene co-expression network analysis identified the LcGolS2 gene, which encodes galactinol synthase, as a potential hub gene for resistance to shade stress in comparisons across different cultivars and shading treatments. The use of qRT-PCR analysis further validated the genes involved in these pathways, suggesting that they may play critical roles in regulating the growth and development of L. chinensis under shading conditions. These findings provide new insights into the molecular mechanisms underlying the growth and development of L. chinensis under different shading stress conditions.

Vicia villosa Roth var. glabrescens (smooth vetch) is an economically important legume cover crop valued for its nitrogen-fixing capacity, high biomass yield, and adaptability across diverse agroecosystems. Here, we present a chromosome-scale, high-quality genome assembly of V. villosa var. glabrescens, constructed using PacBio HiFi sequencing combined with Hi-C scaffolding. The assembly spans 3.70 Gb with a scaffold N50 of 4.69 Mb and exhibits lower heterozygosity (0.9%) compared to V. villosa Roth (3.1%). Genome analysis revealed significant expansion of long terminal repeat retrotransposons (LTR-RTs), as well as lineage-specific proliferation of miniature inverted-repeat transposable elements (MITEs) in V. villosa var. glabrescens. Comparative genomics with V. villosa Roth highlighted gene family expansions associated with trichome development, providing insights into the genetic basis of morphological and adaptive differences within the Vicia species. This reference genome provides a foundational resource for accelerating the breeding of V. villosa varieties with enhanced agronomic traits and contributes to a broader understanding of legume genomics and plant genome evolution.