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IntroductionThis study addresses the urgent need for non-destructive identification of commercially valuable Dalbergia species, which are threatened by illegal logging. Effective identification methods are crucial for ecological conservation, biodiversity preservation, and the regulation of the timber trade.MethodsWe integrate Visible/Near-Infrared (Vis/NIR) Hyperspectral Imaging (HSI) with advanced machine learning techniques to enhance the precision and efficiency of wood species identification. Our methodology employs various modeling approaches, including Principal Component Analysis (PCA), Partial Least Squares Discriminant Analysis (PLS-DA), Support Vector Machine (SVM), and Convolutional Neural Networks (CNN). These models analyze spectral data across Vis (383–982 nm), NIR (982–2386 nm), and full spectral ranges (383 nm to 2386 nm). We also assess the impact of preprocessing techniques such as Standard Normal Variate (SNV), Savitzky-Golay (SG) smoothing, normalization, and Multiplicative Scatter Correction (MSC) on model performance.ResultsWith optimal preprocessing, both SVM and CNN models achieve 100% accuracy across NIR and full spectral ranges. The selection of an appropriate wavelength range is critical; utilizing the full spectrum captures a broader array of the wood's chemical and physical properties, significantly enhancing model accuracy and predictive power.DiscussionThese findings underscore the effectiveness of Vis/NIR HSI in wood species identification. They also highlight the importance of precise wavelength selection and preprocessing techniques to maximize both accuracy and cost-efficiency. This research contributes substantially to ecological conservation and the regulation of the timber trade by providing a reliable, non-destructive method for identifying threatened wood species.

To investigate the role of sugar metabolism in desiccation-sensitive seeds, we performed a natural desiccation treatment on Phoebe chekiangensis seeds in a room and systematically analyzed the changes in seed germination, sugar compounds, malondialdehyde, and relative electrical conductivity during the seed desiccation. The results revealed that the initial moisture content of P. chekiangensis seed was very high (37.06%) and the seed was sensitive to desiccation, the germination percentage of the seed decreased to 5.33% when the seed was desiccated to 22.04% of moisture content, therefore, the seeds were considered recalcitrant. Based on the logistic model, we know that the moisture content of the seeds is 29.05% when the germination percentage drops to 50% and that it is desirable to keep the seed moisture content above 31.74% during ambient transportation. During seed desiccation, sucrose and trehalose contents exhibited increasing trends, and raffinose also increased during the late stage of desiccation, however, low levels of the non-reducing sugar accumulations may not prevent the loss of seed viability caused by desiccation. Glucose and fructose predominated among sugar compounds, and they showed a slight increase followed by a significant decrease. Their depletion may have contributed to the accumulation of sucrose and raffinose family oligosaccharides. Correlation analysis revealed a significant relationship between the accumulation of sucrose, trehalose, and soluble sugars, and the reduction in seed viability. Sucrose showed a significant negative correlation with glucose and fructose. Trehalose also exhibited the same pattern of correlation. These results provided additional data and theoretical support for understanding the mechanism of sugar metabolism in seed desiccation sensitivity.

Abstract Near infrared hyperspectral imaging (NIR-HSI) spectroscopy can be a rapid, precise, low-cost and non-destructive way for wood identification. In this study, samples of five Guiboutia species were analyzed by means of NIR-HSI. Partial least squares discriminant analysis (PLS-DA) and support vector machine (SVM) were used after different data treatment in order to improve the performance of models. Transverse, radial, and tangential section were analyzed separately to select the best sample section for wood identification. The results obtained demonstrated that NIR-HSI combined with successive projections algorithm (SPA) and SVM can achieve high prediction accuracy and low computing cost. Pre-processing methods of SNV and Normalize can increase the prediction accuracy slightly, however, high modelling accuracy can still be achieved by raw pre-processing. Both models for the classification of G. conjugate , G. ehie and G. demeusei perform nearly 100% accuracy. Prediction for G. coleosperma and G. tessmannii were more difficult when using PLS-DA model. It is evidently clear from the findings that the transverse section of wood is more suitable for wood identification. NIR-HSI spectroscopy technique has great potential for Guiboutia species analysis.

Abstract Background Elevated temperature and drought stress have substantial impacts on fruit quality, especially in terms of sugar metabolism and content. β-Amylase (BAM) plays a critical role in regulating jujube fruit sugar levels and abiotic stress response. Nevertheless, little is known about the regulatory functions of the BAM genes in jujube fruit. Results Nine jujube BAM genes were identified, clustered into four groups, and characterized to elucidate their structure, function, and distribution. Multiple sequence alignment and gene structure analysis showed that all ZjBAM genes contain Glu-186 and Glu-380 residues and are highly conserved. Phylogenetic and synteny analysis further indicated that the ZjBAM gene family is evolutionarily conserved and formed collinear pairs with the BAM genes of peach, apple, poplar, Arabidopsis thaliana, and cucumber. A single tandem gene pair was found within the ZjBAM gene family and is indicative of putative gene duplication events. We also explored the physicochemical properties, conserved motifs, and chromosomal and subcellular localization of ZjBAM genes as well as the interaction networks and 3D structures of ZjBAM proteins. A promoter cis-acting element analysis suggested that ZjBAM promoters comprise elements related to growth, development, phytohormones, and stress response. Furthermore, a metabolic pathways annotation analysis showed that ZjBAMs are significantly upregulated in the starch and sucrose metabolism, thereby controlling starch-maltose interconversion and hydrolyzing starch to maltose. Transcriptome and qRT-PCR analyses revealed that ZjBAMs respond positively to elevated temperature and drought stress. Specifically, ZjBAM1, ZjBAM2, ZjBAM5, and ZjBAM6 are significantly upregulated in response to severe drought. Bimolecular fluorescence complementation analysis demonstrated ZjBAM1-ZjAMY3, ZjBAM8-ZjDPE1, and ZjBAM7-ZjDPE1 protein interactions that were mainly present in the plasma membrane and nucleus. Conclusion The jujube BAM gene family exhibits high evolutionary conservation. The various expression patterns of ZjBAM gene family members indicate that they play key roles in jujube growth, development, and abiotic stress response. Additionally, ZjBAMs interact with α-amylase and glucanotransferase. Collectively, the present study provides novel insights into the structure, evolution, and functions of the jujube BAM gene family, thus laying a foundation for further exploration of ZjBAM functional mechanisms in response to elevated temperature and drought stress, while opening up avenues for the development of economic forests in arid areas.

Abstract Background Clematis species are attractive ornamental plants with a variety of flower colors and patterns. Heat stress is one of the main factors restricting the growth, development, and ornamental value of Clematis. Clematis lanuginosa and Clematis crassifolia are large-flowered and evergreen Clematis species, respectively, that show different tolerance to heat stress. We compared and analyzed the transcriptome of C. lanuginose and C. crassifolia under heat stress to determine the regulatory mechanism(s) of resistance. Results A total of 1720 and 6178 differentially expressed genes were identified from C. lanuginose and C. crassifolia, respectively. The photosynthesis and oxidation–reduction processes of C. crassifolia were more sensitive than C. lanuginose under heat stress. Glycine/serine/threonine metabolism, glyoxylic metabolism, and thiamine metabolism were important pathways in response to heat stress in C. lanuginose, and flavonoid biosynthesis, phenylalanine metabolism, and arginine/proline metabolism were the key pathways in C. crassifolia. Six sHSPs (c176964_g1, c200771_g1, c204924_g1, c199407_g2, c201522_g2, c192936_g1), POD1 (c200317_g1), POD3 (c210145_g2), DREB2 (c182557_g1), and HSFA2 (c206233_g2) may be key genes in the response to heat stress in C. lanuginose and C. crassifolia. Conclusions We compared important metabolic pathways and differentially expressed genes in response to heat stress between C. lanuginose and C. crassifolia. The results increase our understanding of the response mechanism and candidate genes of Clematis under heat stress. These data may contribute to the development of new Clematis varieties with greater heat tolerance.

Root growth potential (RGP) is a popular physiological indicator used to evaluate seedling vigor. However, the time scale used in the RGP test is the order of days, which leads to poor performance of the RGP method. We propose an optical interference method, called statistical interferometry, to measure minute root elongation at a sub-nanometer scale, which can decrease the time used in measuring RGP. The time scale of this method is also 104 times less than that of the RGP method. Because we can measure the length of root elongation continuously, we can compute the root elongation rate (RER), which is the variety of the length of root elongation per second. Continuous monitoring can help determine the quality of Masson pine seedling as soon as possible. To show the effectiveness of our proposed method, we designed an experiment, in which we applied different water stresses to our collected Masson pine seedlings and acquired two groups of pines, representing two different qualities: one stressed by water and one not. After measuring the RER of the groups in our experiments, we found that RER is interrelated with the quality of seedlings.

An amendment to this paper has been published and can be accessed via the original article.

Camellia japonica ‘Huaheling’ is a rare subtropical Camellia species in China with high ornamental and medicinal value. The complete chloroplast genome of C. japonica ‘Huaheling’ is a 157,001-bp circular DNA molecule containing a large single-copy region (LSC, 86,704 bp), a small single-copy region (SSC, 18,393 bp), and two inverted repeat sequences (IR). Of the 131 genes identified, 86 are protein-coding genes, 8 are rRNA genes, and 37 are tRNA genes. A total of 54 simple sequence repeats (SSRs) were identified in the chloroplast genome. The phylogenetic analysis showed that C. japonica ‘Huaheling’ is clustered with C. japonica. This work provides valuable information for future study of the evolution and genetic diversity of C. japonica ‘Huaheling.’

The composition and content of sugar play a pivotal role in goji berry (Lycium barbarum L.) fruits, determining fruit quality. Long-term exposure of goji berry to elevated CO2 (eCO2) was frequently demonstrated to reduce sugar content and secondary metabolites. In order to understand the regulatory mechanisms and improve the quality of fruit in the changing climate, it is essential to characterize sugar metabolism genes that respond to eCO2. The objectives of this study were to clone full-length cDNA of three sugar metabolism genes—LBGAE (Lycium barbarum UDP-glucuronate 4-epimerase), LBGALA (Lycium barbarum alpha-galactosidase), and LBMS (Lycium barbarum malate synthase)—that were previously identified responding to eCO2, and to analyze sequence characteristics and expression regulation patterns. Sugar metabolism enzymes regulated by these genes were also estimated along with various carbohydrates from goji berry fruits grown under ambient (400 μmol mol−1) and elevated (700 μmol mol−1) CO2 for 90 and 120 days. Homology-based sequence analysis revealed that the protein-contained functional domains are similar to sugar transport regulation and had a high sequence homology with other Solanaceae species. The sucrose metabolism-related enzyme’s activity varied significantly from ambient to eCO2 in 90-day and 120-day samples along with sugars. This study provides fundamental information on sugar metabolism genes to eCO2 in goji berry to enhance fruit quality to climate change.

Accumulation of phenolic acids in monocropping plantations led to declining soil fertility and reduced productivity due to allelopathic effects. The effects of mixed versus mono-specific plantations on the seasonal turnover of phenolic acids in soil remains unclear. This study explored in plantations of Eucalyptus grandis × Eucalyptus urophylla and Erythrophleum fordii Oliv. (mixed) versus E. grandis × E. urophylla only (pure) the effect of species mixture on the phenolic acid content in the soil. We analyzed both total phenolic acid content as well as six phenolic acids separately and our measurements were conducted over four seasons and in an entire year. We expected that the mixed plantation would exhibit lower accumulation of both total and individual phenolic acids in soil versus the pure plantation. Contrary to our hypothesis, the total content of phenolic acids in the mixed plantation was significantly (p < 0.001) higher than that in the pure Eucalyptus plantation in all seasons. We also observed a significant effect of stand type (mixed or pure), season, and interaction between stand type and season on total soil phenolic acid content (p < 0.001). This may cause an enhanced allelopathic effect of phenolic acids in the soil of the mixed stand. In terms of the individual phenolic acids, the mixed plantation resulted in significantly higher (p < 0.001) p-hydroxybenzoic acid and vanillic acid contents in all seasons, as compared with the pure Eucalyptus plantation. Species mixture appears to reduce the content of ferulic acid, coumaric acid, benzoic acid, and salicylic acid in most seasons. A significant effect (p < 0.001) of stand type, season, and their interaction on the content of all individual phenolic acids in the soil, with the exception of benzoic acid, was observed. This study thus strongly suggests that both total and individual phenolic acids should be studied to evaluate the possible allelopathic effects in forest ecosystems and verify that species mixture can also increase phenolic acid concentration. [ABSTRACT FROM AUTHOR]