In this study, we assembled and characterized the complete chloroplast (cp) genome of Angelonia angustifolia Benth., 1846, a herbaceous and perennial plant, native to Latin America. It is an ornamental and medicinal plant that showed bright prospects for application. The cp genome of A. angustifolia has a typical conserved quadripartite structure of 154,316 bp in total length. The genome includes a large single-copy (LSC) region (84,110 bp), a small single-copy (SSC) region (15,950 bp), and a pair of inverted repeat (IR) regions (27,128 bp). The cp genome contains 130 genes comprising 85 protein-coding, 37 tRNA, and 8 rRNA genes. Phylogenetic analysis indicates that A. angustifolia is closely related to Bacopa monnieri, Scoparia dulcis, and Limnophila sessiliflora in the Plantaginaceae. Taken together, the complete cp genomes of A. angustifolia provided significant insights and important information for molecular biology, evolution, and taxonomy in the genus Angelonia.

Background: Penstemon, a core genus of the tribe Cheloneae in Plantaginaceae, possesses significant ecological and horticultural value. However, its interspecific phylogenetic relationships remain unclear due to morphological convergence, hybridization events, and limited genomic resources. This study aimed to characterize the complete chloroplast (cp) genome of Penstemon digitalis and explore its genomic features and phylogenetic position within Plantaginaceae. Methods: We sequenced the cp genome of P. digitalis using high-throughput sequencing, assembled and annotated the genome, and compared it with other Plantaginaceae species. Repetitive sequences and hypervariable regions were identified. Phylogenetic analyses were performed using maximum likelihood (ML) based on complete cp genomes from 46 taxa (36 Plantaginaceae, six Scrophulariaceae, and four outgroup species). Results: The cp genome is 152,993 bp with a typical quadripartite structure, containing 132 functional genes (87 protein-coding, 37 tRNA, and eight rRNA). Comparative analyses showed high gene content and structural conservation within the tribe Cheloneae. Several hypervariable regions and repeats were detected as potential markers. ML analysis strongly supported the monophyly of Penstemon among the sampled species (100% bootstrap) and placed P. digitalis in a well-supported clade within the genus; Penstemon was recovered as the sister group of Russelia equisetiformis. Conclusions: This study provides the first complete cp genome resource for P. digitalis, confirming its phylogenetic affinity and offering valuable genomic data for future studies on population genetics, species delimitation, and adaptive evolution in Penstemon. These findings will aid taxonomic revision and conservation efforts for this diverse genus.

Osteospermum ecklonis (DC.) Norl. 1838 is a herbaceous and perennial plant native to South Africa. It is an ornamental plant that shows great commercial potential. In the present study, the complete chloroplast (cp) genome was 151,295 bp in total length, and 127 genes were identified, including 85 protein-coding, 34 tRNA, and eight rRNA genes. The cp genome includes a large single-copy (LSC) region of 83,293 bp, a small single-copy (SSC) region of 18,012 bp, and a pair of inverted repeats (IRs) regions of 24,995 bp. The phylogenetic relationship of O. ecklonis revealed by cp genome provides a foundation for future studies of the phylogeny in the Asteraceae.

Gibberellins (GAs) are essential hormones that regulate plant growth and development, yet the downstream metabolic pathways through which they modulate phenotypic plasticity remain poorly understood. Here, we investigated the GA-mediated regulatory network in Agapanthus praecox subsp. orientalis by integrating phenotypic, transcriptomic, and targeted metabolomic analyses across three complementary perturbation strategies: gradient paclobutrazol (PAC) treatments, GA20ox RNA interference (RNAi) lines, and exogenous GA₄ rescue. PAC suppressed vegetative growth dose-dependently and completely arrested floral development at 200 mg·L⁻¹, while increasing soluble sugar and starch contents; plants treated with it in the first year displayed enhanced vegetative growth in the following season, suggesting a possible carbon legacy effect. GA20ox silencing caused dwarfism and flowering failure, which were largely rescued by GA₄. Exogenous GA₄ restored bioactive GA pools to above wild-type levels without recovering endogenous synthesis, indicating functional compensation. Transcriptomic and qRT-PCR analyses revealed that sugar metabolism-related genes and metabolites underwent the most pronounced changes among all tested categories; these changes were partially reversed by GA₄, though certain catabolic genes remained suppressed, revealing hierarchical regulatory logic. Collectively, these findings indicate that GA is closely associated with growth and carbohydrate allocation, and that the GA–sugar metabolic axis represents a major downstream component in developmental plasticity. This study provides species-specific insights into GA-mediated growth regulation and offers implications for ornamental crop management.