Phyllostachys nigra has green young culms (S1) and purple black mature culms (S4). Anthocyanins are the principal pigment responsible for color presentation in ornamental plants. We employ a multi-omics approach to investigate the regulatory mechanisms of anthocyanins in Ph. nigra. Firstly, we found that the pigments of the culm of Ph. nigra accumulated only in one to four layers of cells below the epidermis. The levels of total anthocyanins and total flavonoids gradually increased during the process of bamboo culm color formation. Metabolomics analysis indicated that the predominant pigment metabolites observed were petunidin 3-O-glucoside and malvidin O-hexoside, exhibiting a significant increase of up to 9.36-fold and 13.23-fold, respectively, during pigmentation of Ph. nigra culm. Transcriptomics sequencing has revealed that genes involved in flavonoid biosynthesis, phenylpropanoid biosynthesis, and starch and sucrose metabolism pathways were significantly enriched, leading to color formation. A total of 62 differentially expressed structural genes associated with anthocyanin synthesis were identified. Notably, PnANS2, PnUFGT2, PnCHI2, and PnCHS1 showed significant correlations with anthocyanin metabolites. Additionally, certain transcription factors such as PnMYB6 and PnMYB1 showed significant positive or negative correlations with anthocyanins. With the accumulation of sucrose, the expression of PnMYB6 is enhanced, which in turn triggers the expression of anthocyanin biosynthesis genes. Based on these findings, we propose that these key genes primarily regulate the anthocyanin synthesis pathway in the culm and contribute to the accumulation of anthocyanin, ultimately resulting in the purple-black coloration of Ph. nigra.

With the increasing pollution caused by plastic products, people’s awareness of environmental protection has gradually increased. Based on the advantages of China’s bamboo resources and bamboo industry, the International Network for Bamboo and Rattan launched the ‘Utilizing bamboo as a sustainable alternative to plastic’ initiative in November 2022 to accelerate the implementation of the United Nations 2030 Agenda for Sustainable Development. This initiative provides a nature-based solution for global sustainable development, which will have a profound impact on promoting global green development, industrial science and technology, social services, cultural exchanges, and other fields. It has a huge market capacity and application potential. This study aims to understand the research status, hotspots, development trends, and prospects of this initiative. WoS and China National Knowledge Infrastructure (CNKI) were searched for the relevant literature on ‘utilizing bamboo as a sustainable alternative to plastic bamboo as plastic’ and ‘bamboo resources’ from the establishment of the database to 2024. Bibliometric methods and VOSviewer were used to analyze 1855 literatures with the above two keywords published in the Web of Science core set database from 2000 to 2024. A visual analysis was performed on the number of publications, national research institutions, researchers, number of citations, and research topics of the literature. For example, China, the United States, and India ranked in the top three in terms of the number of articles published, with 1103, 267, and 167, respectively. China had the highest number of citations, reaching 26,607. At the same time, the literature with ‘bamboo’ as the keyword in CNKI was analyzed to understand the species of bamboo currently studied. A literature investigation was carried out around the resource cultivation of the bamboo industry in our country, and it was found that the research on ‘use bamboo as plastic’ and ‘bamboo resources’ had been valued by scholars at home and abroad, and had formed a relatively stable research group. Using scientific and technological innovation to improve the product quality of ‘bamboo instead of plastic’, expanding its application scope and market demand, and realizeing the sustainable industry development of ‘bamboo instead of plastic’ is the current research hotspot and the future development direction.

There are limited studies on the cytology of bamboo leaf development from primordium to maturity. This study delves into the leaf morphological characteristics and growth patterns of Sasaella kogasensis ‘Aureostriatus’ and provides a three-dimensional anatomical analysis of cell division, expansion, and degradation. Leaves on the same branch develop bottom-up, while individual leaves develop the other way around. Like bamboo shoots and culms, the leaves follow a “slow–fast–slow” growth pattern, with longitudinal growth being predominant during their development. The growth zones of individual leaves included division, elongation, and maturation zones based on the distribution of growth space. By measuring 13,303 epidermal long cells and 3293 mesophyll cells in longitudinal sections of rapidly elongating leaves, we observed that in the rapid elongation phase (S4–S5), the division zone was located in the 1–2 cm segment at the bottom of the leaf blade and maintained a constant size, continuously providing new cells for leaf elongation, whereas in the late rapid elongation phase (S6), when the length of the leaf blade was approaching that of a mature leaf, its cells at the bottom of the blade no longer divided and were replaced by the ability to elongate. Furthermore, to gain an insight into the dynamic changes in the growth of the S. kogasensis ‘Aureostriatus’ leaves in the lateral and periclinal directions, the width and thickness of 1459 epidermal and 2719 mesophyll cells were counted in the mid-cross section of leaves at different developmental stages. The results showed that during the early stages of development (S1–S3), young leaves maintained vigorous division in the lateral direction, while periplasmic division gradually expanded from the bottom to the top of the leaf blade and the number of cell layers stabilized at S4. The meristematic tissues on both sides of the leaf were still able to divide at S4 but the frequency of the division gradually decreased, while cell division and expansion occurred simultaneously between the veins. At S6, the cells at the leaf margins and between the veins were completely differentiated and the width of the leaf blade no longer expanded. These findings revealed changes in cell growth anisotropically during the leaf development of S. kogasensis ‘Aureostriatus’ and demonstrated that leaf elongation was closely related to the longitudinal expansion of epidermal cells and proliferative growth of mesophyll cells, whereas the cell division of meristematic tissues and expansion of post-divisional cells contributed to the increases in blade width and thickness. The presented framework will facilitate a further exploration of the molecular regulatory mechanisms of leaf development in S. kogasensis ‘Aureostriatus’ and provide relevant information for developmental and taxonomic studies of bamboo plants.

To systematically elucidate the molecular regulatory mechanisms underlying leaf development in Moso bamboo, this study conducted transcriptome sequencing and systematic analysis on leaves across three key developmental stages: the division stage, the elongation stage, and the mature stage. A total of 25,256 differentially expressed genes (DEGs) were identified. Functional enrichment analysis revealed the sequential molecular events during leaf development: pathways related to cell division and hormone signal transduction were highly active in the early developmental stages, whereas photosynthesis and secondary metabolism were significantly enriched in the mature stage. This reflects the dynamic transition of leaves from morphogenesis to physiological function. Further analysis screened out 3390 transcription factors, among which the AP2/EREBP and bHLH families exhibited notably dynamic expression patterns. Subsequent transgenic functional validation demonstrated that the overexpression of PheANT led to an increased number of leaves and morphological abnormalities in Arabidopsis, while the overexpression of PhebHLH137 resulted in slender leaves and early flowering. This study systematically maps the transcriptomic landscape of Moso bamboo leaf development and identifies multiple key regulatory genes, providing important theoretical insights and candidate gene resources for revealing the unique leaf development mechanisms in bamboo plants.