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Dendrocalamus brandisii is a high-quality bamboo species that can be used for both bamboo shoots and wood. The nutritional components and flavors of D. brandisii vary from different geographical provenances. However, the unique biological characteristics of bamboo make morphological classification methods unsuitable for distinguishing them. Although the new cultivar ‘Manxie No.1’ has significant differences in the branch characteristics and the color of shoot sheaths compared to the D. brandisii, it still lacks precise genetic information at the molecular level. This study identified 231,789 microsatellite markers based on the whole genome of D. brandisii and analyzed their type composition and distribution on chromosomes in detail. Then, using TP-M13-SSR fluorescence-labeling technology, 34 pairs of polymorphic primers were screened to identify the new cultivar ‘Manxie No.1’ and 11 different geographical provenances of D. brandisii. We also constructed DNA fingerprinting profiles for them. At the same time, we mapped six polymorphic SSRs to the gene of D. brandisii, among which SSR673 was mapped to DhB10G011540, which is related to plant immunity. The specific markers selected in this study can rapidly identify the provenances and the new cultivar of D. brandisii and help explore candidate genes related to some important traits.

IntroductionTranspiration is the driving force of water transport, which plays a crucial role in the rapid growth of bamboo shoots. Nonetheless, the transpiration changes that occur in the shoot sheath of Moso bamboo during the leafless stage and the physiological processes involved in water transport from the mother bamboo to bamboo shoots are not completely understood.MethodsThis study investigated the temporal dynamics of the transpiration rate (Tr) and stomatal conductance (gs) of the sheaths from bamboo shoots to culms and diurnal variations in Tr and gs as well as the spatial dynamics of Tr and gs in various parts of the shoot sheaths. Water distribution patterns in bamboo shoots were analyzed using the isotope tracer method, and the water transportation path in bamboo shoots was determined by soaking the shoots in fuchsine dye solution.ResultsWe observed that the Tr was higher in bamboo shoots at heights of 4 and 7 m compared to that at 0.5, 1, 2, and 13 m, with rates ranging from 6.8 mmol/m2/s1 to 8.3 mmol/m2/s. Additionally, the Tr and gs of the shoot sheath were lower at noon, but higher in the morning and evening. The Tr in the lower parts of the culm sheath was higher than that that in the upper part (height: 0.5–4 m). However, when injected into the mother bamboo, D2O was not immediately transported to the shoots via the mother culms but was transported upward through the vascular bundle, with a larger vascular bundle near the pulp cavity transporting high volumes of water.DiscussionThese findings provide the foundation for further studies on the rapid growth of Moso bamboo and establish a theoretical basis for water management during its shoot developmental period.

Dendrocalamus brandisii (Munro) Kurz is a sympodial bamboo species with a wide distribution in tropical and subtropical regions. Due to its remarkable regenerative ability and exceptional flavor, this species plays a pivotal role in bolstering the economies of numerous nations across these regions. We recently published a high-quality genome of this species. To date, no study results have identified the optimal reference genes for quantitative real-time polymerase chain reaction (qRT-PCR) normalization in Dendrocalamus brandisii. qRT-PCR offers a highly accurate and effective approach to analyzing gene expression. However, the precision of the resulting quantitative data hinges on the correct choice of reference genes. Twenty-one potential reference genes were identified from the D. brandisii transcriptomes. Their expression in 23 samples, including 8 different tissue organs and 15 samples of D. brandisii under various treatment conditions, were evaluated through qRT-PCR. Subsequently, four software programs—Delta CT, geNorm, NormFinder, and RefFinder—were employed to compare their expression stability. The results revealed that the selection of optimal reference genes varied based on the particular organ and condition being examined. EF-1-α-2 consistently exhibits the most stable expression across diverse tissues, while ACTIN-1, TUBULIN-1, and EF-1-α-2 were the most consistent reference genes in roots, culms, and leaves under various treatments, respectively. In this study, we identified and characterized appropriate internal genes utilized for calibrating qRT-PCR analyses of D. brandisii across different tissue organs and under various treatments. This research will provide key insights for advancing the study of gene functionality and molecular biology in D. brandisii and related species

Phosphoenolpyruvate carboxylase (PEPC), as a necessary enzyme for higher plants to participate in photosynthesis, plays a key role in photosynthetic carbon metabolism and the stress response. However, the molecular biology of the PEPC family of Bambusoideae has been poorly studied, and the function of its members in the growth and development of Bambusoideae is still unclear. Here, we identified a total of 62 PEPC family members in bamboo. All the PEPC genes in the bamboo subfamily were divided into twelve groups, each group typically containing significantly fewer PEPC members in Olyra latifolia than in Phyllostachys edulis, Dendrocalamus latiflorus and Dendrocalamus brandisii. The results of an intraspecific and interspecies collinearity analysis showed that fragment replication and whole genome replication were the main driving forces of bamboo PEPC members. Furthermore, the Ka/Ks values of collinear genes showed that bamboo PEPC experienced purification selection. In addition, the promoter region of PEPC genes contains cis-acting elements related to light response, plant hormone response and response to stress. An analysis of the expression levels of the PEPC family in different developmental stages and tissues of bamboo shoots has shown that PhePEPC7, PhePEPC9 and PhePEPC10 were highly expressed in the leaves of non-flowering plants and culms. Furthermore, PhePEPC6 was significantly upregulated in leaves after GA treatment. Further research has shown that PhePEPC6 was mainly localized in the cell membrane. This provides a solid bioinformatics foundation for further understanding the biological functions of the bamboo PEPC family.

Sucrose (Suc) and gibberellin (GA) can promote the elongation of certain internodes in bamboo. However, there is a lack of field studies to support these findings and no evidence concerning how Suc and GA promote the plant height of bamboo by regulating the internode elongation and number. We investigated the plant height, the length of each internode, and the total number of internodes of Moso bamboo (Phyllostachys edulis) under exogenous Suc, GA, and control group (CTRL) treatments in the field and analyzed how Suc and GA affected the height of Moso bamboo by promoting the internode length and number. The lengths of the 10th–50th internodes were significantly increased under the exogenous Suc and GA treatments, and the number of internodes was significantly increased by the exogenous Suc treatment. The increased effect of Suc and GA exogenous treatment on the proportion of longer internodes showed a weakening trend near the plant height of 15–16 m compared with the CTRL, suggesting that these exogenous treatments may be more effective in regions where bamboo growth is suboptimal. This study demonstrated that both the exogenous Suc and GA treatments could promote internode elongation of Moso bamboo in the field. The exogenous GA treatment had a stronger effect on internode elongation, and the exogenous Suc treatment had a stronger effect on increasing the internode numbers. The increase in plant height by the exogenous Suc and GA treatments was promoted by the co-elongation of most internodes or the increase in the proportion of longer internodes.

Guttation is the process of exudating droplets from the tips, edges, and adaxial and abaxial surfaces of the undamaged leaves. Guttation is a natural and spontaneous biological phenomenon that occurs in a wide variety of plants. Despite its generally positive effect on plant growth, many aspects of this cryptic process are unknown. In this study, the guttation phenomenon characteristic of bamboo shoots and the anatomical feature of these and culm sheaths were systematically observed. In addition, the water transport pathway and the compounds in guttation droplets of bamboo shoots were analyzed, and the effect of bamboo sheaths’ guttation on the growth of bamboo shoots was assessed. The results revealed that bamboo shoots began to exudate liquid in the evening through to the next morning, during which period the volume of guttation liquid gradually increases and then decreases before sunrise. Many vascular bundles are in bamboo shoots and culm sheaths to facilitate this water transport. The exudate liquid contains organic acids, sugars, and hormones, among other compounds. Our findings suggest that the regular guttation of the sheath blade is crucial to maintain the normal growth of bamboo shoots.

The Loess Plateau in China is renowned for its dense gullies and complex terrain, with drastic changes primarily due to soil erosion and human activities, significantly affecting the evolution of the ecological environment. The complex terrains and dense vegetation make precise terrain measurement and modeling challenging. Although the development of Unmanned Aerial Vehicle (UAV) light detection and ranging (LiDAR) scanning and photogrammetry technologies has improved data acquisition precision, relying solely on one remote sensing technology struggles with accurately extracting bare earth information. This study adopted a method that fuses UAV lidar scanning with aerial photogrammetric imagery, generating detailed lidar point cloud data that includes coordinate, reflectance, true color, and texture information to enhance data classifiability and interpretability. Subsequently, a point cloud classification model based on the Transformer architecture (Stratified Transformer) is introduced to intelligently complete the initial ground point cloud extraction in complex gully terrains. Further, to address residual non-ground noise in the initial ground point clouds, a new point cloud classification optimization algorithm (MDD, Multi-scale C2M Distance Difference) is proposed. This algorithm, based on the characteristics of discrete and non-continuous with the ground surface of the noisy point clouds, effectively eliminates the discrete noisy point clouds by analyzing the distances between the point clouds and TINs (Triangular Irregular Networks) of different scales and their differences. This study effectively addresses the technical challenges of ground point cloud extraction in the mixed environment of complex terrain and vegetation, solving the problem of precise terrain measurement and intelligent data processing in complex gully terrains, and offering new technical pathways for detecting geomorphological changes.

Lifestyle behaviors, defined as a combination of dietary behavior, physical activity (PA), screen time (ST), and sleep duration indicators, are strongly associated with blood pressure (BP) in students. Our aim was to characterize the joint trajectories of lifestyle behaviors among middle school students and evaluate their association with BP. Data were obtained from the monitoring dataset on common diseases and health factors among students in Jiading District, Shanghai, China, conducted from 2019 to 2023. Lifestyle behavior data were collected annually from middle school students aged 12–18 years through questionnaires covering dietary behavior score, PA, ST, and sleep duration. Students’ BP was measured in 2023. Joint trajectories of lifestyle behaviors were determined using group-based multi-trajectory modeling. Associations between lifestyle trajectories and students’ BP were examined using multiple linear regression and modified Poisson regression. A total of 1378 middle school students (759 [58.98%] boys, median age 14.36 years [IQR: 13·30–13.28]) with lifestyle behaviors data assessed at least three times were included, and they were categorized into four joint lifestyle trajectories as follows: “remain unhealthy with low PA and increasing ST” (n = 141, 10.46%), “remain unhealthy with only low PA” (n = 305, 22.63%), “change towards unhealthy with decreasing sleep duration” (n = 776, 57.57%), and “relatively healthy” (n = 126, 9.35%). After adjusting for important confounders, the “remain unhealthy with low PA and increasing ST” group was associated with higher diastolic BP (DBP) [β: 3.49, 95% CI: 0.55–6.44] and higher mean arterial pressure (MAP) [β: 3.19, 95% CI: 0.37–6.01] in students compared with the “relatively healthy” group. Additionally, compared with the “relatively healthy” group, students in the “remain unhealthy with low PA and increasing ST” group had a 1.12-fold increase in the risk of hypertension (risk ratios: 1.12, 95% CI: 1.03–1.24). All trend p values in DBP, MAP, and hypertension from the “relatively healthy” group to the “remain unhealthy with low PA and increasing ST” group were less than 0.05. Four distinct lifestyle trajectories were identified among middle school students. Students who remained in the “unhealthy with low PA and increasing ST” lifestyle trajectory were associated with later elevations in BP.

The spatial–temporal variability of soil moisture plays a pivotal role in the reconstruction and management of ecosystems in mining areas. However, the actual driving mechanisms behind long-term, continuous mining disturbances remain unclear due to a lack of continuous data. To address this gap, a network of instrumented sites, known as Disturbed Critical Zone Observatories (DCZO), has been established for ecological monitoring in mining areas. In this study, we used Sentinel-1A images of the Dafosi Mine from 2014 to 2022 and one year of continuous DCZO monitoring data. We employed Theil-Sen median trend analysis, empirical orthogonal function (EOF), and structural equation modeling (SEM) to quantitatively explore the factors influencing the variability of soil moisture and soil nutrients under continuous mining disturbances. The results showed: (1) Inter-annual variations in soil moisture differed among coal seams mined in various years, with the steepest decline observed in seams mined in 2021–2022 > 2018–2020 > 2015–2017 > 2013–2014. (2) Mining areas exhibited a significant reduction in Available Nitrogen (AN), Available Phosphorus (AP), and Available Potassium (AK), with decreases of 25.12 %, 25.38 %, and 22.59 %, respectively, compared to non-mining areas. (3) The first two EOFs explained 80.42 % of the observed spatiotemporal soil moisture pattern, 77.69 % of AN, 70.21 % of AP, and 88.32 % of AK, accounting for the total variability in soil moisture and soil nutrients. (4) The contribution rates of mining to soil moisture and nutrient variation were 27.31 % and 13.91 %, with subsidence having the most pronounced negative impact. Additionally, our study revealed that while soil moisture can partially recover through natural processes, soil nutrients require artificial reclamation during mining. This study offers valuable insights for sustainable mining management.