Polyploid plants frequently exhibit altered vegetative growth, yet the molecular mechanisms remain unclear. This study reveals that hexaploidisation of triploid insect‐resistant poplar 741‐line Pb29 significantly reduces growth rate, leaf area, photosynthetic capacity and organic matter accumulation. Meanwhile, the degradation of auxin and gibberellic acid accelerated, the abscisic acid content increased, and insect resistance was diminished with the increase in ploidy. Comprehensive multiomics analysis elucidated the molecular mechanisms underlying the slow vegetative growth of hexaploids. Transcriptome analysis demonstrated reshaping of vegetative growth‐associated networks, manifested as reduced photosynthetic capacity and increased energy consumption, which ultimately reduced the energy available for vegetative growth. Differential expression of miR319, novel‐m0126‐5p and ptc‐miR6427‐3p altered the transcription levels of vegetative growth‐related genes. The genome of hexaploids exhibited significantly elevated DNA methylation levels, and significant changes in DNA methylation levels in vegetative growth‐related specific regions can affect the growth and development of hexaploids. Notably, we identified an ethylene response factor gene, ERF016‐like, in the vegetative growth regulatory network, and further experiments demonstrated that ERF016‐like negatively regulates plant vegetative growth by altering the accumulation of sugars produced through photosynthesis, the production of ATP, and the response to auxin. In summary, the slow vegetative growth of the hexaploids is a comprehensive manifestation of interactions in multilevel molecular regulatory networks. This phenomenon is related to adjustment of the gene expression network and changes in post‐transcriptional miRNA regulation as well as epigenetic modifications. These complex regulatory mechanisms work together to cause the slow vegetative growth and development characteristics of hexaploids.

Sambucus nigra L. (European elderberry) is distinguished among medicinal and edible plants by its exceptionally high cyanidin-3-O-glucoside (C3G) content, which markedly exceeds that of common berries. This unique phytochemical profile establishes C3G as the principal bioactive constituent underlying the antitumor activity of S. nigra. While numerous reviews on elderberry have been published, none has systematically integrated C3G biosynthesis, transcriptional regulation, in vivo metabolism, and anti-tumor mechanisms specifically in S. nigra—a critical research gap that this review fills for the first time. Herein, we systematically examine the chemical structure and content distribution of C3G in S. nigra, elucidate the phenylpropanoid–flavonoid biosynthetic pathway and the regulatory patterns of the MYB-bHLH-WD40 (MBW) transcriptional complex, and highlight the current research gap regarding the cloning and functional characterization of core MBW factors in this species. We further reveal the absorption and distribution characteristics of C3G in the human body, the gut microbiota-mediated biotransformation process, and the synergistic antitumor effects of its primary metabolite, protocatechuic acid. The molecular mechanisms through which C3G exerts antitumor activity, including the induction of tumor cell apoptosis, cell cycle arrest, inhibition of epithelial–mesenchymal transition, and modulation of key signaling pathways, such as NF-κB, PI3K/AKT/mTOR, and JNK, are systematically elaborated. This is the first review to construct a comprehensive “biosynthetic regulation–in vivo metabolism–antitumor function” framework for C3G in S. nigra, thereby addressing critical research gaps and providing a theoretical foundation for the germplasm breeding of high-C3G cultivars, functional product development, and clinical adjuvant cancer therapy.

The red-leaved poplar cultivars ‘Quanhong’ and ‘Xuanhong’ are bud mutations of Populus deltoides cv. ‘Zhonglin 2025’. These cultivars are valued for their beautiful shape, lack of flying catkins, and ornamental leaf colors. However, the understanding of the molecular mechanism of anthocyanin accumulation in the leaves of red-leaved poplars is still unclear. Here, we profiled the changes of pigment content, transcriptome and proteome expression in the leaves of three poplar cultivars and the results showed that the ratios of anthocyanin to total chlorophyll in both red-leaved poplars were higher than that in ‘Zhonglin 2025’, indicating that the anthocyanin was highly accumulated in the leaves of red-leaved poplars. Based on the results of integrated transcriptome and proteome analysis, 15 and 11 differentially expressed genes/proteins involved in anthocyanin synthesis were screened in ‘Quanhong’ and ‘Xuanhong’, respectively, including the CHS, F3H, and DFR genes. Among the 120 transcription factors, 3 (HY5, HYH, and TTG2), may be directly involved in the regulation of anthocyanin synthesis in both red-leaved poplars. This study screens the candidate genes involved in anthocyanin accumulation in the leaves of red-leaved poplars and lays a foundation for further exploring the molecular mechanism of leaf red coloration in red-leaved poplars.

BackgroundThe red-leaved poplar cultivars ‘Quanhong’ and ‘Xuanhong’ are bud mutations of Populus deltoides cv. ‘Zhonglin 2025’. These cultivars are valued for their beautiful shape, lack of flying catkins, and ornamental leaf colors. The molecular mechanism that leads to different leaf colors between these red-leaved poplars and ‘Zhonglin 2025’ remains unclear.ResultsIn this study, we analyzed growth and physiological indicators in the ‘Quanhong’, ‘Xuanhong’, and ‘Zhonglin 2025’ poplar cultivars, and performed transcriptome and proteome analysis of their leaves. The results showed that plant height and ground diameter were significantly lower in both red-leaved poplars than in ‘Zhonglin 2025’, indicating that their growth and development were markedly inhibited. The ratio of anthocyanin to total chlorophyll and photosynthetic capacity of the leaves were higher and lower, respectively, in the red-leaved cultivars than in ‘Zhonglin 2025’. At the transcript and protein levels, 6,792 differentially expressed genes (DEGs) and 2,786 differentially expressed proteins (DEPs) were screened in the ‘Quanhong’ cultivar, respectively, and 4,398 DEGs and 2,333 DEPs were screened in the ‘Xuanhong’ cultivar, respectively. We screened 769 DEGs/DEPs in ‘Quanhong’ and 399 DEGs/DEPs in ‘Xuanhong’ in an integrated transcriptomics/proteomics analysis. Based on the results of this integrated analysis, 15 and 11 genes/proteins involved in anthocyanin synthesis were further identified in ‘Quanhong’ and ‘Xuanhong’, respectively, including the CHS , F3H , and DFR genes. Among the 120 transcription factors, 3 (HY5, HYH, and TTG2), may be directly involved in the regulation of anthocyanin synthesis in both red-leaved poplars.ConclusionsBy comparing the proteomes and transcriptomes of red-leaved poplar cultivars and ‘Zhonglin 2025’, we identified the key genes and proteins related to red leaf coloration. The findings of this study provided insights that may aid further studies of the molecular mechanism of leaf red coloration in red-leaved poplars.

BackgroundWith the rapid development of transgenic technology, transgenic plants have been planted all over the world, and transgenic forest trees have also been commercialized. At the same time, the potential threat of transgenic plants to human health and the natural environment has aroused widespread concern. Therefore, safety assessments before field release and commercial planting of transgenic plants are necessary. By determining the copy number and integration sites of T-DNA in transgenic plants, the safety of transgenic plants at the genomic level can be assessed.ResultsIn this study, we performed genome resequencing of Pb29, a transgenic high-resistance poplar 741 line that has been commercialized, using next-generation and Nanopore sequencing. The results revealed that there are two T-DNA insertion sites, located at 9,283,905–9,283,937 bp on chromosome 3 (Chr03) and 10,868,777–10,868,803 bp on Chr10. The accuracy of the T-DNA insertion locations and directions was verified using polymerase chain reaction amplification. Through sequence alignment, different degrees of base deletions were detected on the T-DNA left and right border sequences, and in the flanking sequences of the insertion sites. An unknown fragment was inserted between the Chr03 insertion site and the right flanking sequence, but the Pb29 genome did not undergo chromosomal rearrangement. It is worth noting that we did not detect the API gene in the Pb29 genome, indicating that Pb29 is a transgenic line containing only the BtCry1AC gene. On Chr03, the insertion of T-DNA disrupted a gene encoding TAF12 protein, but the transcriptional abundance of this gene did not change significantly in the leaves of Pb29. Additionally, except for the gene located closest to the T-DNA integration site, the expression levels of four other neighboring genes did not change significantly in the leaves of Pb29. ConclusionsThis study provides important molecular information for safety assessments and management of transgenic poplar 741. Our findings also provide a theoretical basis for safety assessments of other transgenic poplar.