Forestry research最新文献

Here, a DNA-free genetic editing approach is presented for larch by delivering ribonucleoprotein complexes (RNPs) of CRISPR/Cas9 through particle bombardment. The detailed procedure encompasses creating a transgenic system via particle bombardment for the transformation of embryogenic callus, validating the functionality of RNPs, optimizing coating and delivery techniques, enhancing somatic embryo maturation, regenerating plantlets, and precisely identifying mutants. The optimal particle bombardment parameters were determined at 1,100 psi and a distance of 9 cm and the editing efficiency of the targets was verified in vitro. Subsequently, the RNPs were transferred into the embryogenic callus. Mutant plants were obtained in targets 1 and target 2. The efficiencies of obtaining albino somatic embryos were 1.423% and 2.136%, respectively. A DNA-free particle bombardment transformation method suitable for larch has been established. The present study demonstrates that the DNA-free editing technology has been successfully implemented in larch. This method can achieve targeted genome editing in the larch genome, avoiding the risks of genomic integration and the lengthy breeding cycles associated with traditional transgenic methods. Moreover, it may be widely applicable for producing genome-edited conifer plants and holds great promise for commercialization.

UGT catalyzes the transfer of glycosyl molecules from donors to acceptors, and the glycosylation catalyzed by them is a modification reaction essential for plant cell growth, development, and metabolic homeostasis. Members of this class of enzymes are found in all areas of life and are involved in the biosynthesis of an extensive range of glycosides. This review aims to screen and collate relevant properties of the UGT71 family in plants and their functions in plant secondary metabolites. Firstly, we conducted a retrospective analysis of information about plant UGTs, before focusing on UGT71s through glycosylation of secondary metabolites (triterpenoids, flavonoids) and glycosylation of phytohormones (ABA, SA). Consequently, they play a pivotal role in plant defence, hormone regulation, and the biosynthesis of secondary metabolites, thereby enabling plants to adapt to changing environments. Further investigation revealed that UGTs (UGT71s) can enhance the adaptive and resistant potential of plants in the context of today's deteriorating growing conditions due to climate change impacts caused by global warming. Nevertheless, further in-depth studies on the intricate interactions among UGTs in plants are required to fully exploit the potential of UGTs in protecting plants against stress.

Taxodium plants have good flood tolerance and thus were introduced into China from North America in the early 1900s. The subsequent decades of cross-breeding experiments within Taxodium have produced many new hybrid cultivars in China while also creating confusion in the genetic background of Taxodium plants. In the present study, target capture sequencing-derived SNP markers were used to reveal the genomic composition of different species and cultivars of Taxodium. The results unraveled the phylogenetic relationship within Taxodium and suggested the possibility of recent interspecific natural hybridization events. The introduced (Chinese) population is genetically similar to the native (North American) population, thus providing genetic evidence for historical introductions of Taxodium. Hybrid categories of different cultivars of Taxodium hybrid 'Zhongshanshan' were further identified, and their differences in parentage were revealed. Collectively, the findings provide evidence for understanding the genetics and hybridization of Taxodium and shed light on the future breeding and cultivation of cultivars with great ecological and economic potential.

In this investigation, the effects of exogenous indole-3-acetic acid (IAA), indole-3-butyric acid (IBA), and 1-aminocyclopropane-1-carboxylic acid (ACC) on anatomical development within cultured segments of Abies balsamea (L.) Mill. were compared, using debudded and defoliated leaders produced in the preceding year as bioassay material. In stem apical regions, IAA promoted radial enlargement of pre-existing cortical resin ducts and attending parenchyma enlargement, whereas IBA promoted cell division and expansion of parenchyma on the outer edge of phloem without altering cortical duct shape. Cortical woody ducts, each partially surrounded by cambium, were observed as a novel but infrequent feature. A single cortical woody duct was spatially associated with each mature leaf as its vascular trace, and they were not encountered elsewhere in the cortex, nor were they induced to form in response to any hormone application. An unknown leaf factor induces the development of cortical woody ducts. Both IAA and IBA promoted cell division in the vascular cambium. The common cellular response at the interface between the latewood boundary and cambial zone was the radial expansion of primary-walled fusiform cambial cell derivatives with little if any ensuing tracheary element (TE) differentiation. Enhanced TE production at basal stem positions occurred when ACC was provided with IAA and/or IBA, and an IAA + IBA + ACC combination produced a basal stem response similar to that in untreated segments having intact leaves. The data support the conclusion that IAA, IBA, and ACC have distinct but complementary roles in the overall regulation of the types of cellular differentiation that contribute to cortex histogenesis and diameter growth of balsam-fir leaders.

Browning presents a significant challenge in the in vitro culture of economically important woody plants, primarily due to high levels of lignification and the accumulation of secondary metabolites. This phenomenon hampers the development of efficient regeneration and genetic transformation systems across diverse species. This review examines the internal and external factors contributing to browning, including genetic attributes, tree genotypes, physiological state of explants, explant surface sterilization, medium composition, and overall culture conditions. It explores the underlying mechanisms of browning, particularly enzymatic browning caused by the oxidation of phenolic compounds, and highlights the crucial role of redox pathways and phenolic metabolism. Conventional methods for assessing browning, such as sensory evaluation by researchers and the examination of paraffin sections stained with toluidine blue, are commonly used but introduce significant delays and potential biases. The review emphasizes the importance of accurate and timely browning assessment methods, notably the use of Fluorescein diacetate (FDA) staining, as a reliable and quantitative measure of cell viability to better evaluate browning intensity and progression. Additionally, this review explores the potential manipulation of key genes in the phenylpropanoid pathway to lower phenolic biosynthesis. Advanced strategies, such as regenerative gene manipulation and natural product encapsulation, are also discussed for their potential to improve regeneration outcomes. By integrating recent advancements in molecular biology and tissue culture techniques, this review offers novel insights and potential solutions for mitigating browning, thereby enhancing the regeneration capacities of woody plants. This comprehensive approach addresses the mechanistic bases of browning and underscores the importance of optimizing cultural practices and genetic strategies to overcome this challenge.

Lignin is a polyphenolic polymer present in the cell walls of specialized plant cell types in vascular plants that provides structural support and plays a major role in plant protection. The lignin biosynthesis pathway is regulated by transcription factors from the MYB (myeloblastosis) family. While several MYB members positively regulate lignin synthesis, only a few negatively regulate lignin synthesis. These lignin suppressors are well characterized in model plant species; however, their role has not been fully explored in gymnosperms. Lignin forms one of the major hurdles for the forest-based industry e.g. paper, pulp, and biofuel production. Therefore, the detailed mechanisms involved in the regulation of lignin synthesis are valuable, especially in conifers that form the major source of softwood for timber and paper production. In this review, the potential and differential domains present in the MYB suppressors in gymnosperms are discussed, along with their phylogenetic analysis. Sequence analysis revealed that the N-terminal regions of the MYB suppressor members were found to be conserved among the gymnosperms and angiosperms containing the R2, R3, and bHLH domains, while the C-terminal regions were found to be highly variable. The typical repressor motifs like the LxLxL-type EAR motif and the TLLLFR motif were absent from the C-terminal regions of MYB suppressors from most gymnosperms. However, although the gymnosperms lacked the characteristic repressor domains, a R2R3-type MYB member from Ginkgo was reported to repress the lignin biosynthetic pathway. It is proposed that gymnosperms possess unique kinds of repressors that need further functional validation.

Alternative splicing (AS) is an important post-transcriptional process that generates multiple mRNA isoforms. FLOWERING LOCUS C (FLC) is a pivotal gene in both the vernalization and autonomous pathways of flowering plants, and MaMADS33 is one of the FLC homologs in white mulberry (Morus alba). Recent studies have revealed that MaMADS33 is involved in endodormancy, but the underlying molecular mechanism remains to be characterized. Here, a comparison of MaMADS33 expression among three mulberry cultivars with different degrees of dormancy revealed a positive association between MaMADS33 expression and dormancy. Further 3' and 5' rapid amplification of cDNA ends (RACE) analyses led to identifying four MaMADS33 isoforms derived from AS and designated MaMADS33-AS1-4. Analysis of their coding potential revealed that MaMADS33-AS1 was a long non-coding RNA. Expression profiling and splicing-efficiency analyses showed that cold stress during endodormancy induced AS of MaMADS33, resulting in a predominance of truncated isoforms, especially MaMADS33-AS1. MaMADS33-AS2 expression was upregulated during both endodormancy and ecodormancy, whereas MaMADS33-AS3 and MaMADS33-AS4 were endodormancy-associated isoforms that were upregulated during endodormancy and then downregulated during ecodormancy. MaMADS33-AS4 was used as bait for a yeast two-hybrid screen because its gene expression was higher than that of MaMADS33-AS3, and mulberry winter-accumulating 18 kDa protein (MaWAP18) was identified as an MaMADS33-AS4 interaction partner. The interaction between MaWAP18 and MaMADS33-AS4 was confirmed by a bimolecular fluorescence complementation assay. These findings offer insight into the role of FLC homologs in the endodormancy of woody plants.

The plastid is an essential organelle for its role in photosynthesis and energy production and its genomic information is always employed as important evolutionary markers to explore the relationship among species. Agarwood (Aquilaria), prized for its aromatic blend, finds extensive use in various cultures as incense and perfume. Despite its high economic importance, the phylogenetic status among Aquilaria based on plastomes remains ambiguous due to the lack of available plastomic resources. To bridge this knowledge gap, 22 Aquilaria plastomes were newly sequenced, similar variation patterns in this genus were determined, including a shared 16 bp extension of the rps19 gene and seven highly variable regions. The analysis highlighted the highest prevalence of the A/T motif among simple sequence repeats in these plastomes. Further phylogenetic analysis revealed Aquilaria's phylogenetic implications with an expanded dataset. This comprehensive plastomic resource not only enhances our understanding of Aquilaria evolution but also presents potential molecular markers for DNA barcoding.

In recent years, the importance of microorganisms for plant survival has been increasingly recognized. Endophytic fungi, as part of holobiont, can confer growth advantages to plants. Most studies have shown that the endophytic fungi of forest trees can promote host plant growth, increase adversity resistance, and thus improve the survival competitiveness of forest trees. However, the beneficial examples of endophytic fungi on the growth and development of woody plants have not been systematically summarized. This review is focused on various aspects of beneficial endophytic fungi in forest trees (definition, classification, colonization mechanisms, etc.), with an emphasis on their beneficial roles in woody plant growth, protection against biotic and abiotic stresses, as well as the response of forest trees to endophytic fungi. In addition, this review lists a series of experiments on screening beneficial endophytic fungi from Chinese fir (Cunninghamia lanceolata) and verifying their beneficial functions, to explore the mutualistic relationships between them. This review not only provides a theoretical basis for the study of beneficial endophytic fungi in forest trees in the future but also sheds light on the molecular perspectives for a mechanistic understanding of their potential future significance for the sustainable utilization of forest resources and ecological environment protection.

Mulberry is a critical economic tree with a high diversity of germplasm resources. However, the lack of primary data on genome size, chromosome number, and ploidy for this species limits the exploitation of mulberry resources. In this study, the genome size of 323 mulberry germplasm resources were examined using flow cytometry and chromosome numbers analyzed. The genome sizes ranged from 0.36 to 3.08 Gb, and seven different ploidies of mulberry germplasm resources were identified, with chromosome numbers ranging from 14 to 308. Correlation analysis indicated that genome size (1C) and chromosome number positively correlated. Here, the genome size, chromosome number, and ploidy database MGCPdb (https://mgcpdb.biodb.org) were constructed for mulberry plants, which contains 323 core mulberry germplasm resources and provides raw data of flow cytometry analysis, genome size, and chromosome count. This database is significant and valuable for mulberry genome evolution, polyploidy breeding, and genetic diversity research.