Purpose: Gibberellins (GAs) are key phytohormones that regulate plant growth, development, and responses to environmental stress, and their metabolism is mediated by 2-oxoglutarate-dependent dioxygenases (2OGDs). Cotton (Gossypium spp.) is a polyploid crop with a complex genome; however, the evolutionary characteristics and stress-responsive regulation of GA-related 2OGDs remain poorly understood. This study aimed to systematically investigate the evolution, expression patterns, and stress-associated regulation of the cotton 2OGD multigene family, with particular emphasis on GA-related members. Methods: 2OGD genes were identified genome-wide in four Gossypium species and Arabidopsis thaliana. Phylogenetic relationships, gene structures, conserved motifs, cis-acting regulatory elements, and synteny were analyzed. Transcriptomic data from multiple tissues and developmental stages, together with time-course RNA-seq under salt stress, were examined. Transcriptome–metabolome association analysis, endogenous GA quantification, and predicted protein–protein interaction analysis were conducted. Results: A total of 583 2OGD genes were identified and classified into three major classes, including a Class C group comprising GA2ox, GA3ox, and GA20ox genes. Polyploidization-associated duplication contributed to the expansion of the 2OGD family, and most duplicated gene pairs exhibited signatures of purifying selection. GA-related 2OGDs displayed conserved motif compositions with variation in cis-acting elements. Promoter analysis identified abundant hormone-responsive, stress-responsive, and growth-related cis-elements, suggesting complex regulatory control of GA-related 2OGDs in cotton. Under salt stress, GhGA2OX1 and GhGA20OX2 were upregulated, whereas GhGA3OX1 was downregulated, accompanied by reduced endogenous GA levels. Conclusions: GA-related 2OGDs in cotton are transcriptionally responsive to salt stress and are associated with changes in GA metabolism, providing a basis for future functional studies.

Thesium chinense Turcz. (T. chinense), a perennial herb in the Santalaceae family, exhibits potent antibacterial and anti-inflammatory properties. Transcriptome sequencing was performed on one- and two-year-old T. chinense plants across seedling, flowering, and fruiting stages (all sampled from the same location) using the illumina NovaSeq 6000 platform. A total of 58,706 unigenes were identified, including 1656 transcription factors (TFs). Further analysis classified these TFs into seven functional categories, enabling the reconstruction of a representative TF regulatory network. Differential expression analysis revealed that the number of differentially expressed genes (DEGs) ranged from 2000 to 5000 during different developmental stages in first-year plants, while varying between 1000 and 2000 in second-year plants. Comparative analysis of DEGs between one- and two-year-old plants showed that they were primarily associated with sesquiterpene, triterpene, and terpene skeleton biosynthesis, as well as other metabolic pathways. Additionally, analysis of key genes involved in flavonoid biosynthesis—the major bioactive compounds in T. chinense—revealed their predominant accumulation during the first year of growth. This study provides valuable insights into the developmental biology of T. chinense and establishes a foundation for future research on flavonoid biosynthesis pathway genes and their therapeutic applications.