Auxin Response Factors (ARFs) mediate auxin signaling and govern diverse biological processes. However, a comprehensive analysis of the ARF gene family and identification of their key regulatory functions have not been conducted in Melastoma dodecandrum, leading to a weak understanding of further use and development for this functional shrub. In this study, we successfully identified a total of 27 members of the ARF gene family in M. dodecandrum and classified them into Class I–III. Class II–III showed more significant gene duplication than Class I, especially for MedARF16s. According to the prediction of cis-regulatory elements, the AP2/ERF, BHLH, and bZIP transcription factor families may serve as regulatory factors controlling the transcriptional pre-initiation expression of MedARF. Analysis of miRNA editing sites reveals that miR160 may play a regulatory role in the post-transcriptional expression of MeARF. Expression profiles revealed that more than half of the MedARFs exhibited high expression levels in the stem compared to other organs. While there are some specific genes expressed only in flowers, it is noteworthy that MedARF16s, MedARF7A, and MedARF9B, which are highly expressed in stems, also demonstrate high expressions in other organs of M. dodecandrum. Further hormone treatment experiments revealed that these MedARFs were sensitive to auxin changes, with MedARF6C and MedARF7A showing significant and rapid changes in expression upon increasing exogenous auxin. In brief, our findings suggest a crucial role in regulating plant growth and development in M. dodecandrum by responding to changes in auxin. These results can provide a theoretical basis for future molecular breeding in Myrtaceae.

Cymbidium ensifolium, a prominent orchid species, is both highly valued for its ornamental qualities and commercially cultivated. However, the species has a considerable challenge in its breeding efforts due to the lengthy period of 7–8 years required for it to transition from seed germination to flowering. BBXs are multifunctional proteins that modulate the actions of critical regulators including HY5 and COP1 in response to blue light, ultimately impacting photomorphogenic processes. In this study, BBX proteins, known for their essential roles in regulating developmental processes under various light conditions, were chosen as the main subject of investigation. The outcome reveals the presence of 19 BBX genes in their genome. The genes are classified into four separate clades and dispersed among 12 out of the 20 chromosomes. Located in the nuclear, physicochemical properties of proteins, analysis of the promoter region reveals the existence of almost 800 cis-acting elements, highlighting the complex regulatory mechanisms that control the expression of the CeBBXs in various organs, as well as their response to light and hormone inputs. Moreover, the examination of differential expression under blue light therapy reveals their involvement in photomorphogenic reactions. The expression of CeBBXs exhibits substantial alterations as the duration of exposure to blue light increases. These findings contribute to a deeper understanding of the roles that BBX genes serve in C. ensifolium, providing a basis for future studies on the functions and regulatory mechanisms of BBX members in the context of floral initiation and development within this species.

LBD transcription factors are critical regulators of plant growth and development. Recent studies highlighted their significant role in the transcriptional regulation of plant growth and metabolism. Thus, identifying the CeLBD gene in Cymbidium ensifolium, a species abundant in floral scent metabolites, could provide deeper insights into its functional significance. A total of 34 LBD genes were identified in C. ensifolium. These CeLBDs fell into two major groups: Class I and Class II. The Class I group contained 30 genes, while the Class II group included only 4 genes. Among the 30 Class I genes, several genes in the Ie branch exhibited structural variations or partial deletions (CeLBD20 and CeLBD21) in the coiled-coil motif (LX₆LX₃LX₆L). These changes may contribute to the difficulty in root hair formation in C. ensifolium. The variations may prevent normal transcription, leading to low or absent expression, which may explain the fleshy and corona-like root system of C. ensifolium without prominent lateral roots. The expansion for CeLBDs was largely due to special WGD events in orchids during evolution, or by segmental duplication and tandem duplication. CeLBDs in different branches exhibit similar functions and expression characteristics. Promoter analysis enriched environmental response elements, such as AP2/ERF, potentially mediating the specific expression of CeLBDs under different stresses. CeLBDs were predicted to interact with multiple transcription factors or ribosomal proteins, forming complex regulatory networks. CeLBD20 was localized in the cytoplasm, it may act as a signaling factor to activate other transcription factors. CeLBD6 in Class II was significantly up-regulated under cold, drought, and ABA treatments, suggesting its role in environmental responses. Furthermore, metabolic correlation analysis revealed that its expression was associated with the release of major aromatic compounds, such as MeJA. These findings offer valuable insights for further functional studies of CeLBD genes in C. ensifolium.

Plant mitochondrial genomes exist and function in a special way, this third-kind genetic material is essential for plant growth and development. However, i