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Introduction: Wood formation is a crucial developmental stage in the life cycle of a woody plant; this process has substantial scientific research implications and practical applications. However, the mechanisms underlying woody plant development, especially the process of wood formation, remain poorly understood. As eucalyptus is one of the fastest growing tree species in the world, understanding the mechanism of wood formation in eucalyptus will greatly promote the development of molecular breeding technology for forest trees. Results: In this study, we investigated the proteomic profile of immature xylem at four different ages of Eucalyptus urophylla × Eucalyptus grandis (E. urograndis) using iTARQ technology. We identified 5236 proteins and 492 differentially abundant proteins (DAPs). The expression profiles of the DAPs corresponding to coding genes associated with wood formation were assessed using qRT-PCR. From the different expression profiles, it is inferred that the genes encoding kinesin, CDKD3, EXPA13, EXPA2, XTH27, EGases, UGT76E2, LAC, CCoAMT, CesA3, PAL, and CAD may undergo posttranscriptional regulation (PTR). Additionally, the genes encoding EIN2, ETR, MC4-like, and XCP may undergo posttranslational modifications (PTMs). Conclusions: We investigated changes in wood formation-related proteins at the protein abundance level in the immature xylem of E. urograndis , thereby elucidating potential regulatory mechanisms of key proteins involved in eucalyptus wood formation. This study may provide theoretical guidance for further research on molecular breeding techniques and genetic improvement related to the cultivation of rapidly growing and high-quality trees. [ABSTRACT FROM AUTHOR]

Eucalyptus is an important plantation tree with a high economic value in China. The tree contributes significantly to China's timber production. The stable and efficient Eucalyptus regeneration system and genetic transformation system are of great significance for exploring the regulatory function and possible genetic breeding capacity of important genes in the species. However, as a woody plant, Eucalyptus has problems, such as a long generation cycle, strong specificity of the regeneration system, and a low genetic conversion rate, which seriously limit the rapid development of Eucalyptus genetics and breeding programs. The present review summarizes the status of research on Eucalyptus regeneration and genetic transformation, with a focus on the effects of explants, media, plant growth regulators (PGRs), and concentrations in the Eucalyptus regeneration process. In addition, the effects of genotype, Agrobacterium, antibiotics, preculture, and co-culture on the genetic transformation efficiency of Eucalyptus are discussed. Furthermore, the study also summarizes the problems encountered in Eucalyptus regeneration and genetic transformation, with reference to previous studies, and it outlines future developments and prospects. The aim was to provide a reference for solving the problems of genetic instability and the low transformation efficiency of eucalyptus, and to establish an efficient and stable eucalyptus regeneration and transformation system to accelerate the process of its genetic improvement. [ABSTRACT FROM AUTHOR]

Acanthus ilicifolius is an important medicinal plant in mangrove forests, which is rich in secondary metabolites with various biological activities. In this study, we used transcriptomic analysis to obtain differentially expressed genes in the flavonoid metabolic pathway and metabolomic methods to detect changes in the types and content in the flavonoid metabolic synthesis pathway. The results showed that DEGs were identified in the mature roots vs. leaves comparison (9001 up-regulated and 8910 down-regulated), mature roots vs. stems comparison (5861 up-regulated and 7374 down-regulated), and mature stems vs. leaves comparison (10,837 up-regulated and 11,903 down-regulated). Furthermore, two AiCHS genes and four AiCHI genes were up-regulated in the mature roots vs. stems of mature A. ilicifolius, and were down-regulated in mature stems vs. leaves, which were highly expressed in the A. ilicifolius stems. A total of 215 differential metabolites were found in the roots vs. leaves of mature A. ilicifolius, 173 differential metabolites in the roots vs. stems, and 228 differential metabolites in the stems vs. leaves. The metabolomic results showed that some flavonoids in A. ilicifolius stems were higher than in the roots. A total of 18 flavonoid differential metabolites were detected in the roots, stems, and leaves of mature A. ilicifolius. In mature leaves, quercetin-3-O-glucoside-7-O-rhamnoside, gossypitrin, isoquercitrin, quercetin 3,7-bis-O-β-D-glucoside, and isorhamnetin 3-O-β-(2″-O-acetyl-β-D-glucuronide) were found in a high content, while in mature roots, di-O-methylquercetin and isorhamnetin were the major compounds. The combined analysis of the metabolome and transcriptome revealed that DEGs and differential metabolites were related to flavonoid biosynthesis. This study provides a theoretical basis for analyzing the molecular mechanism of flavonoid synthesis in A. ilicifolius and provides a reference for further research and exploitation of its medicinal value. [ABSTRACT FROM AUTHOR]

With the depletion of peat resources, local agricultural and forestry wastes represent potential seedling substrate materials. We investigated the effects of mixed substrates supplemented with peat replacements, such as decomposed eucalyptus bark, coconut bran, and carbonized rice husk, on the growth of Handroanthus chrysanthus (Jacq.). We screened suitable organic substrates for the production of seedlings of H. chrysanthus to provide a theoretical basis for its scientific cultivation. The proportions of 15 types of substrates were determined by using simplex center-of-gravity mixing. The physical properties of different mixed substrates were studied, and the growth, biomass, root development, and photosynthesis of seedlings were analyzed. The quality of seedlings was comprehensively evaluated, and the optimal substrate ratio was obtained through regression analysis. Substrate compositions had significantly different effects on growth, biomass, root morphology, and photosynthesis. The results of these single-index analyses were corroborated by using principal component analysis. Adding decomposed eucalyptus bark was beneficial to the growth of seedlings, whereas coconut bran and perlite restricted growth. The results show that decomposed eucalyptus bark can replace peat as a container seedling substrate. The substrate formula can be used to provide technical support and a theoretical basis for the scientific cultivation of high-quality light matrix seedlings of H. chrysanthus. [ABSTRACT FROM AUTHOR]

Plukenetia volubilis is a highly promising plant with high nutritional and economic values. In our previous studies, the expression levels of ricin encoded transcripts were the highest in the maturation stage of P. volubilis seeds. The present study investigated the transcriptome and proteome profiles of seeds at two developmental stages (Pv-1 and Pv-2) using RNA-Seq and iTRAQ technologies. A total of 53,224 unigenes and 6026 proteins were identified, with functional enrichment analyses, including GO, KEGG, and KOG annotations. At two development stages of P. volubilis seeds, 8815 unique differentially expressed genes (DEGs) and 4983 unique differentially abundant proteins (DAPs) were identified. Omics-based association analysis showed that ribosome-inactivating protein (RIP) transcripts had the highest expression and abundance levels in Pv-2, and those DEGs/DAPs of RIPs in the GO category were involved in hydrolase activity. Furthermore, 21 RIP genes and their corresponding amino acid sequences were obtained from libraries produced with transcriptome analysis. The analysis of physicochemical properties showed that 21 RIPs of P. volubilis contained ricin, the ricinBlectin domain, or RIP domains and could be divided into three subfamilies, with the largest number for type II RIPs. The expression patterns of 10 RIP genes indicated that they were mostly highly expressed in Pv-2 and 4 transcripts encoding ricinBlike lectins had very low expression levels during the seed development of P. volubilis. This finding would represent valuable evidence for the safety of oil production from P. volubilis for human consumption. It is also notable that the expression level of the Unigene0030485 encoding type I RIP was the highest in roots, which would be related to the antiviral activity of RIPs. This study provides a comprehensive analysis of the physicochemical properties and expression patterns of RIPs in different organs of P. volubilis and lays a theoretical foundation for further research and utilization of RIPs in P. volubilis. [ABSTRACT FROM AUTHOR]

Handroanthus and Tabebuia are known for their ornamental and medicinal value, which are attributed to metabolites. However, the mechanisms underlying the synthesis of these metabolites are poorly understood. In this study, the expression levels of secondary metabolites and the mechanism of flavonoid biosynthesis in the bark and leaves of Handroanthus chrysantha (Jaq.) were examined using transcriptomic and metabolomic techniques. Metabolic analysis identified several differentially accumulated metabolites (DAMs), most of which were flavonoids, isoprenoids, and sterols. Additionally, 30 flavonoids were identified in the bark and leaves of H. chrysantha. Transcriptomic analysis identified 69 genes involved in flavonoid biosynthesis, among which 49 were significantly different between the bark and leaves. qRT-PCR analysis of eight genes involved in flavonoid biosynthesis showed that the expression patterns of the genes were consistent with the transcriptome sequencing data. Integrative transcriptomic and metabolomic analysis showed that 20 differentially expressed genes (DEGs) associated with flavonoid biosynthesis were strongly correlated with seven DAMs, confirming the involvement of the DEGs in flavonoid biosynthesis. These findings considerably contribute to the understanding of the biosynthesis of secondary metabolites in H. chrysantha and serve as a reference for further pharmacological studies. [ABSTRACT FROM AUTHOR]

The ω-3 fatty acid desaturase (FAD3) gene encodes a rate-limiting enzyme in the synthesis of α-linolenic acid. In this study, homologous cloning was used to obtain the full-length sequence of the PvFAD3 gene of Plukenetia volubilis. The full-length DNA sequence was 1871 bp long, with 8 exons and 7 introns. The structural analysis of the amino acid sequence revealed that the PvFAD3 protein contained three histidine-conserved regions and an endoplasmic reticulum retention signal. The real-time reverse transcription-polymerase chain reaction performed for determining the expression patterns of the PvFAD3 gene in different tissues of P. volubilis showed that PvFAD3 expression was highly expressed in the fast oil accumulation stage of seed. The analysis of subcellular localization assay in epidermal cells of tobacco (Nicotiana benthamiana) leaves showed that the PvFAD3 protein was mainly localized in the endoplasmic reticulum. Seed-specific overexpression vectors were constructed, and Agrobacterium-mediated genetic transformation was performed to obtain transgenic tobacco plants overexpressing PvFAD3. The results of fatty acid assays performed using harvested seeds showed a significant increase in α-linolenic acid content, a dramatic decrease in linoleic acid content, and an obvious increase in oil content in transgenic tobacco seeds. Collectively, the PvFAD3 gene of P. volubilis was confirmed as a key enzyme gene for α-linolenic acid synthesis; thus, indicating that the PvFAD3 gene can be used for fatty acid fraction improvement in oilseed plants. [ABSTRACT FROM AUTHOR]

Cellulose, an essential structural component in the plant cell wall and a renewable biomass resource, plays a significant role in nature. Eucalyptus's excellent timber tree species (including Eucalyptus grandis Hill) provide many raw materials for the paper and wood industries. The synthesis of cellulose is a very complex process involving multiple genes and regulated by various biological networks. However, research on regulating associated genes and non-coding RNAs during cellulose synthesis in E. grandis remains lacking. In this study, the wood anatomical characteristics and chemical indexes of E. grandis were analyzed by taking three different parts (diameter at breast height (DBH), middle and upper part of the trunk) from the main stem of E. grandis as raw materials. The role of non-coding RNAs (Long non-coding RNA, lncRNA; Micro RNA, miRNA; Circle RNA, circRNA) on regulating candidate genes was presented, and the network map of ceRNA (Competing endogenous RNA) regulation during wood cellulose biosynthesis of E. grandis was constructed. The transcriptome sequencing of nine samples obtained from the trunk of the immature xylem in E. grandis at DBH, middle and upper parts had a 95.81 G clean reading, 57,480 transcripts, 7365 lncRNAs, and 5180 circRNAs. Each sample had 172–306 known miRNAs and 1644–3508 new miRNAs. A total of 190 DE-lncRNAs (Differentially expressed long non-coding RNAs), 174 DE-miRNAs (Differentially expressed micro RNAs), and 270 DE-circRNAs (Differentially expressed circle RNAs) were obtained by comparing transcript expression levels. Four lncRNAs and nine miRNAs were screened out, and the ceRNA regulatory network was constructed. LncRNA1 and lncRNA4 regulated the genes responsible for cellulose synthesis in E. grandis, which were overexpressed in 84K (Populus Alba × Populus glandulosa) poplar. The cellulose and lignin content in lncRNA4-oe were significantly higher than wild type 84K poplar and lncRNA1-oe. The average plant height, middle and basal part of the stem diameter in lncRNA4-oe were significantly higher than the wild type. However, there was no significant difference between the growth of lncRNA1-oe and the wild type. Further studies are warranted to explore the molecular regulatory mechanism of cellulose biosynthesis in Eucalyptus species. [ABSTRACT FROM AUTHOR]

Cellulose is the world's most abundant renewable energy resource, and a variety of cellulose synthase genes are involved in the biosynthesis of cellulose. In the process of cellulose synthesis, all cellulose synthases are interrelated and act synergistically. In this study, we analyzed the contents of cellulose, hemicellulose, and lignin in the different parts and tissues of E. grandis. The results showed that the cellulose content had greater differences among three different heights. On this basis, we carried out the transcriptome-wide profiling of gene expression patterns using RNA sequencing. A total of 2066 differentially expressed genes were identified for three pairwise comparisons between three different heights, most of which were related to the programmed photosynthetic membrane and photosystem. A total of 100 transcripts of CSs (58 CesA and 42 Csl) were obtained from transcriptome libraries. The expression pattern of these genes indicated that different CS genes had a wide range of expression profiles. A phylogenetic analysis of 135 reference CS genes showed that the CSs of E. grandis were clustered into six major groups (CesA1-9, CslA, CslB/H, CslD, CslE, and CslG). Based on the weighted gene co-expression network analysis, a dual-directional regulation mechanism between Csl and CesA proteins in the cellulose biosynthesis was identified. The gene expression profile analysis, using qRT-PCR in different tissues of E. grandis, demonstrated that the CSs were highly expressed in xylem, and CesAs had a higher relative expression than Csls. The analysis of sequence similarity combined with the expression pattern indicated that the CesA1, 3, and 6 transcripts were associated with the biosynthesis of the secondary cell wall, and CesA4, 5, and 7 transcripts were more likely to associate with the biosynthesis of the primary cell wall. Finally, the qRT-PCR analysis confirmed the expression of 11 selected CSs in three different parts of E. grandis. [ABSTRACT FROM AUTHOR]

Eucalyptus camaldulensis Dehn. is one of the most morphologically and genetically variable Eucalyptus species. Growth, Leptocybe invasa Fisher & La Salle susceptibility, pilodyn penetration and other traits up to age 36 months were assessed in a seed source/family trial in China comprising 112 seedlots representing five natural stand and six exotic seed sources. Genetic diversity and population structure of this trial population were also analyzed using 48 simple sequence repeat (SSR) markers. The key objective was to examine whether the genomic data could provide value over information obtained from just quantitative trait data. Significant genetic variation was found among seed sources and among families within seed sources for most quantitative traits. The ratio of variance among seed sources to variance among families within seed sources, based on variances estimated from quantitative trait data, varied from 0.1% (height at 9 months) up to 75.2% (bark thickness). Equivalent ratios estimated from the AMOVA on SSR loci data were similar for height (ages 24 and 36 months) and also pilodyn penetration at 36 months, but not for 9-month height or 36-month bark thickness. From 48 SSR loci examined, the genetic differentiation coefficient (among seed sources) was 0.086, indicating low genetic differentiation among seed sources. While overall genetic diversity in the trial population examined was high, the levels within the different seed sources varied markedly. Prior to this study, genetic distances among families from the three exotic seed sources (from domesticated Indian populations) in the trial, along with their genetic distances from, and relatedness to, families from five natural stand seed sources (Australian) in the trial were unknown. The SSR loci data removed uncertainties and revealed that the exotic sources increased the breadth of genetic origins represented in the trial population—information that could not have been obtained from just the quantitative trait data. [ABSTRACT FROM AUTHOR]

Aims: China is one of the countries in the world most seriously affected by typhoons, which pose a great threat to the eucalyptus plantation industry. However, few studies have comprehensively accounted for the impact of key traits on the wind damage/resistance of eucalyptus., Methods: To identify the key factors affecting the wind resistance of eucalyptus, 20 eucalyptus genotypes were selected; a total of 18 traits, including the wind damage index, growth traits, and wood traits, were measured, and the wind resistance was determined via the tree-pulling test., Results: Correlation, principal component, canonical correlation, and path analyses were performed to evaluate these traits. Correlation analysis revealed that the wind resistance of eucalyptus plants was related to the tree height, volume, and duration of stress wave propagation. Principal components and tree-pulling variables were further used for correlation and path analyses. Canonical correlation analysis and the PA-OV model showed that holocellulose and lignin contents and fiber width, as well as growth traits, were important factors affecting the stability of standing trees under typhoon conditions. The key traits influencing the wind resistance of Eucalyptu s camaldulensis , which may provide a reference for evaluating the wind resistance of Eucalyptus varieties for forest management, were identified., Conclusion: This study provides a knowledge base for forest management and planning in typhoon-prone coastal areas, and provides a theoretical basis for the breeding and genetically improving eucalyptus stocks based on wind resistance characteristics., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Shang, Zhang, Li, Wang and Wu.)

Mangrove plants contain a variety of secondary metabolites, including flavonoids, polyphenols, and volatiles, which are important for their survival and adaptation to the coastal environment, as well as for producing bioactive compounds. To reveal differences in these compounds among five mangrove species' leaf, root, and stem, the total contents of flavonoids and polyphenols, types and contents of volatiles were determined, analyzed and compared. The results showed that Avicennia marina leaves contained the highest levels of flavonoids and phenolics. In mangrove parts, flavonoids are usually higher than phenolic compounds. A total of 532 compounds were detected by a gas chromatography-mass spectrometry (GC-MS) method in the leaf, root, and stem parts of five mangrove species. These were grouped into 18 classes, including alcohols, aldehydes, alkaloids, alkanes, etc . The number of volatile compounds in A. ilicifolius (176) and B. gymnorrhiza (172) was lower than in the other three species. The number of volatile compounds and their relative contents differed among all three parts of five mangrove species, where the mangrove species factor had a greater impact than the part factor. A total of 71 common compounds occurring in more than two species or parts were analyzed by a PLS-DA model. One-way ANOVA revealed 18 differential compounds among mangrove species and nine differential compounds among parts. Principal component analysis and hierarchical clustering analysis showed that both unique and common compounds significantly differed in composition and concentration between species and parts. In general, A. ilicifolius and B. gymnorrhiza differed significantly from the other species in terms of compound content, while the leaves differed significantly from the other parts. VIP screening and pathway enrichment analysis were performed on 17 common compounds closely related to mangrove species or parts. These compounds were mainly involved in terpenoid pathways such as C10 isoprenoids and C15 isoprenoids and fatty alcohols. The correlation analysis showed that the content of flavonoids/phenolics, the number of compounds, and the content of some common compounds in mangroves were correlated with their salt and waterlogging tolerance levels. These findings will help in the development of genetic varieties and medicinal utilization of mangrove plants., Competing Interests: The authors declare there are no competing interests., (©2023 Wu et al.)

Background: The age of 6-12 yr show different degrees of learning adaptability problems. We aimed to explore the influence of comprehensive psychological intervention on the psychological behavior problems and learning adaptability of students at age of 6-12 yr old., Method: In March 2022, 768 students were selected from two primary schools in Harbin of China, and divided into control and observation groups. The changes in the scores of Achenbach Child Behavior Checklist (CBCL) for parent use and Mental Health Rate Scale for Pupil (MHRSP), and self-cognitive ability and learning adaptability level before and after the intervention were compared between the two groups., Results: After the intervention, the discipline violation, hostility, compulsion, immaturity, evil communication, schizoid personality, and physical symptom scores in the observation group (boys) were reduced compared with those before the intervention. In comparison with the situation before the intervention, the cruelty, aggression, immaturity, depression and withdrawal, physical symptom, anxiety, and compulsion scores in the observation group (girls) were reduced, and the CBCL scores were improved better than those in the control group ( P <0.05). In comparison with the situation before the intervention, the scores of MHRSP, self-cognitive ability, and learning adaptability score and level in the observation group were elevated after the intervention, and the above scores were improved obviously to a greater extent than those in the control group ( P <0.05)., Conclusion: Comprehensive psychological intervention can effectively improve the psychological behavior problems of children at the age of 6-12 yr, and enhance their self-cognitive ability and learning adaptability., Competing Interests: Conflict of Interest The authors declare that there is no conflict of interests., (Copyright © 2023 Liu et al. Published by Tehran University of Medical Sciences.)

The timber species Eucalyptus camaldulensis is one of the most important in southern China. Therefore, it is essential to understand the photosynthetic pattern in eucalyptus leaves. In the present study, eighteen photosynthesis-related genes were analyzed using bioinformatics methods. The results indicated that there were ten differentially expressed ribose-5-phosphate isomerase genes ( RPI ), and six of them were up-regulated in the mature leaves compared to the young leaves, while others were down-regulated. The differential expression of four rubisco methyltransferase genes ( RBCMT ) were observed. Two of them were up-regulated, while two were down-regulated in mature leaves compared to young leaves. Furthermore, two ribulose-phosphate-3-epimerase genes ( RPE ) were up-regulated in the mature leaves compared to the young leaves. In contrast, two genes involved in triosephosphate isomerase (TIM) were down-regulated in mature leaves compared with young leaves. The current study provides basic information about the transcriptome of E. camaldulensis and lays a foundation for further research in developing and utilizing important photosynthetic genes., Competing Interests: The authors declare there are no competing interests., (©2022 Zhan et al.)

Background: Wind, an important abiotic stress factor, affects forests in coastal areas, causes tree damage and timber loss., Methods: Two genotypes of Eucalyptus camaldulensis- strong wind-resistant CA5 and weak wind-resistant C037 were used for RNA-seq analysis to screen for candidate wind-resistance genes and transcription factors (TFs) by comparing the transcriptome analysis of the two varieties in response to wind stress., Results: It showed that 7061 differentially expressed unigenes could be annotated including 4,110 up-regulated unigenes and 2,951 down-regulated unigenes. Gene Ontology (GO) analysis revealed that six cellulose pathways were involved in response to wind stress. The unigenes in phenylpropanoid biosynthesis, phenylalanine metabolism, and flavonoid biosynthesis pathways were found to be differentially expressed based on Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis. Moreover, 37 differentially expressed genes were functionally annotated to be involved in the secondary metabolism of phenylalanine (ko00940). Seventy-eight TFs related to the regulating cellulose and lignin synthesis were expressed differently from the various treatments. The expressions of C3H, POX, MYB, NAC, Gene008307, and Gene011799 were significantly upregulated in CA5. Overall, the main response of Eucalyptus to wind stress was associated with cell wall biosynthesis; key genes of cellulose and lignin biosynthesis pathways and related TFs were involved in the tree response to wind stress., Competing Interests: The authors declare there are no competing interests., (©2022 Shang et al.)