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The spatial shifts and vulnerability assessments of ecological niches for trees will offer fresh perspectives for sustainable development and preservation of forests, particularly within the framework of rapid climate change. Betula luminifera is a fast-growing native timber plantation species in China, but the natural resources have been severely damaged. Here, a comprehensive habitat suitability model (including ten niche-based GIS modeling algorithms) was developed that integrates three types of environmental factors, namely, climatic, soil, and ultraviolet variables, to assess the species contemporary and future distribution of suitable habitats across China. Our results suggest that the habitats of B. luminifera generally occur in subtropical areas (about 1.52 × 106 km2). However, the growth of B. luminifera is profoundly shaped by the nuances of its local environment, the most reasonable niche spaces are only 1.15 × 106 km2 when limiting ecological factors (soil and ultraviolet) are considered, generally considered as the core production region. Furthermore, it is anticipated that species-suitable habitats will decrease by 10 and 8% with climate change in the 2050s and 2070s, respectively. Our study provided a clear understanding of species-suitable habitat distribution and identified the reasons why other niche spaces are unsuitable in the future, which can warn against artificial cultivation and conservation planning.

Bamboo cultivation, particularly Moso bamboo (Phyllostachys edulis), holds significant economic importance in various regions worldwide. Bamboo shoot degradation (BSD) severely affects productivity and economic viability. However, despite its agricultural consequences, the molecular mechanisms underlying BSD remain unclear. Consequently, we explored the dynamic changes of BSD through anatomy, physiology and the transcriptome. Our findings reveal ruptured protoxylem cells, reduced cell wall thickness and the accumulation of sucrose and reactive oxygen species (ROS) during BSD. Transcriptomic analysis underscored the importance of genes related to plant hormone signal transduction, sugar metabolism and ROS homoeostasis in this process. Furthermore, BSD appears to be driven by the coexpression regulatory network of senescence‐associated gene transcription factors (SAG‐TFs), specifically PeSAG39, PeWRKY22 and PeWRKY75, primarily located in the protoxylem of vascular bundles. Yeast one‐hybrid and dual‐luciferase assays demonstrated that PeWRKY22 and PeWRKY75 activate PeSAG39 expression by binding to its promoter. This study advanced our understanding of the molecular regulatory mechanisms governing BSD, offering a valuable reference for enhancing Moso bamboo forest productivity. Summary statement: The bamboo shoot degradation occurs first in the protoxylem and impacts phytohormone signalling, starch and sucrose metabolism, as well as reactive oxygen species homoeostasis. PeWRKY22 and PeWRKY75 activate PeSAG39 by binding to its promoters. [ABSTRACT FROM AUTHOR]

Premise: The impact of inbreeding on biological processes is well documented in individuals with severe inbreeding depression. However, the biological processes influencing the adaptive growth of normal selfed individuals are unknown. Here, we aimed to investigate how inbreeding affects gene expression for adaptive growth of normal selfed seedlings from a self‐fertilizing parent in Chinese fir (Cunninghamia lanceolata). Methods: Using RNA‐seq data from above‐ and underground tissues of abnormal and normal selfed seedlings, we analyzed GO biological processes network. We also sequenced small RNAs in the aboveground tissues and measured the copy number variations (CNV) of the hub genes. Results: Phenotypic fitness analysis revealed that the normal seedlings were better adapted than their abnormal counterparts. Upregulated differentially expressed genes (DEGs) were associated with development processes, and downregulated DEGs were mainly enriched in fundamental metabolism and stress response. Results of mRNA‐miRNA parallel sequencing revealed that upregulated target genes were predominantly associated with development, highlighting their crucial role in phosphorylation in signal transduction networks. We also discovered a moderate correlation (0.1328 < R2 < 0.6257) between CNV and gene expression levels for three hub genes (TMKL1, GT2, and RHY1A). Conclusions: We uncovered the key biological processes underpinning the growth of normal selfed seedlings and established the relationship between CNV and the expression levels of hub genes in selfed seedlings. Understanding the candidate genes involved in the growth of selfed seedlings will help us comprehend the genetic mechanisms behind inbreeding depression in the evolutionary biology of plants. [ABSTRACT FROM AUTHOR]

Prior to Ginkgo leaf harvest, we implemented four exogenous applications of salicylic acid (SA: 50, 80, and 100 mg * [L.sup.-1]) or methyl jasmonate (MJ: 20, 40, and 80 mg * [L.sup.-1]) as leaf spray to investigate their effect on flavonoids content and related enzyme activity. Compared with the control, a significant increase of 12% and 26% in flavonoid content was observed 7 days after the first application of 100 mg * [L.sup.-1] SA and 20 mg * [L.sup.-1] MJ, respectively; both were determined to be the best treatments. Operationally, administering either elicitor (SA or MJ) 1 week prior to leaf harvest is deemed to be the most practical and economic option. Additionally, enzymes activity involved in flavonoid metabolism (phenylalanine ammonialyase, cinnamate 4-hydroxylase, and 4-coumarate:coenzyme A ligase) and antioxidants (peroxidase, superoxide dismutase, and catalase) significantly increased in most SA and MJ treatments. The results strongly support Ginkgo leaf response to SA- or MJ-induced stress through increased nonenzymatic antioxidant compounds (flavonoids) and activity of antioxidant enzymes. Key words: Ginkgo leaves, flavonoids, antioxidant enzymes, salicylic acid, methyl jasmonate. Avant la recolte des feuilles de Ginkgo, nous avons procede a quatre vaporisations foliaires d'acide salicylique (AS : 50, 80 et 100 mg * [L.sup.-1]) ou de jasmonate de methyle (JM : 20, 40 et 80 mg * [L.sup.-1]) pour etudier leur effet sur la teneur en flavonoides et l'activite enzymatique associee. Comparativement au temoin, une augmentation significative de 12 et 26 % de la teneur en flavonoides a ete observee sept jours apres la premiere application de respectivement 100 mg * [L.sup.-1] de AS et 20 mg * [L.sup.-1] de JM; ces deux traitements etaient les meilleurs. De facon operationnelle, l'application de l'un ou l'autre des eliciteurs (AS ou JM) une semaine avant la recolte des feuilles est consideree comme l'option la plus pratique et la plus economique. De plus, l'activite des enzymes impliquees dans le metabolisme des flavonoides (phenylalanine ammonia-lyase, cinnamate 4-hydroxylase, et 4-coumarate : CoA ligase) et des antioxydants (peroxydase, superoxyde dismutase et catalase) ont significativement augmente dans la plupart des traitements avec AS et JM. Les resultats concordent etroitement avec la reaction des feuilles de Ginkgo au stress induit par AS et JM par le biais de l'augmentation de la teneur en composes antioxydants (flavonoides) et de l'activite des enzymes antioxydantes. [Traduit par la Redaction] Mots-cles : feuilles de Ginkgo, flavonoides, enzymes antioxydantes, acide salicylique, jasmonate de methyle., Introduction Ginkgo biloba L., commonly known as Ginkgo, is a native Chinese tree species whose leaves have been used in ancient traditional medicine. The medicinal applications of Ginkgo leaf extract [...]

As the most abundant form of methylation modification in messenger RNA (mRNA), the distribution of N6‐methyladenosine (m6A) has been preliminarily revealed in herbaceous plants under salt stress, but its function and mechanism in woody plants were still unknown. Here, we showed that global m6A levels increased during poplar response to salt stress. Methylated RNA immunoprecipitation sequencing (MeRIP‐seq) revealed that m6A significantly enriched in the coding sequence region and 3′‐untranslated regions in poplar, by recognising the conserved motifs, AGACU, GGACA and UGUAG. A large number of differential m6A transcripts have been identified, and some have been proved involving in salt response and plant growth and development. Further combined analysis of MeRIP‐seq and RNA‐seq revealed that the m6A hypermethylated and enrich in the CDS region preferred to positively regulate expression abundance. Writer inhibitor, 3‐deazaneplanocin A treatment increased the sensitivity of poplar to salt stress by reducing mRNA stability to regulate the expression of salt‐responsive transcripts PagMYB48, PagGT2, PagNAC2, PagGPX8 and PagARF2. Furthermore, we verified that the methyltransferase PagFIP37 plays a positively role in the response of poplar to salt stress, overexpressed lines have stronger salt tolerance, while RNAi lines were more sensitive to salt, which relied on regulating mRNA stability in an m6A manner of salt‐responsive transcripts PagMYB48, PagGT2, PagNAC2, PagGPX8 and PagARF2. Collectively, these results revealed the regulatory role of m6A methylation in poplar response to salt stress, and revealed the importance and mechanism of m6A methylation in the response of woody plants to salt stress for the first time. Summary statement: We revealed the regulatory role of m6A methylation in poplar response to salt stress, and revealed the importance and mechanism of m6A methylation in the response of woody plants to salt stress for the first time. [ABSTRACT FROM AUTHOR]

Summary: Leaf development is a multifaceted and dynamic process orchestrated by a myriad of genes to shape the proper size and morphology. The dynamic genetic network underlying leaf development remains largely unknown.Utilizing a synergistic genetic approach encompassing dynamic genome‐wide association study (GWAS), time‐ordered gene co‐expression network (TO‐GCN) analyses and gene manipulation, we explored the temporal genetic architecture and regulatory network governing leaf development in Populus.We identified 42 time‐specific and 18 consecutive genes that displayed different patterns of expression at various time points. We then constructed eight TO‐GCNs that covered the cell proliferation, transition, and cell expansion stages of leaf development. Integrating GWAS and TO‐GCN, we postulated the functions of 27 causative genes for GWAS and identified PtoGRF9 as a key player in leaf development. Genetic manipulation via overexpression and suppression of PtoGRF9 revealed its primary influence on leaf development by modulating cell proliferation. Furthermore, we elucidated that PtoGRF9 governs leaf development by activating PtoHB21 during the cell proliferation stage and attenuating PtoLD during the transition stage.Our study provides insights into the dynamic genetic underpinnings of leaf development and understanding the regulatory mechanism of PtoGRF9 in this dynamic process. [ABSTRACT FROM AUTHOR]

Summary: Wood formation, intricately linked to the carbohydrate metabolism pathway, underpins the capacity of trees to produce renewable resources and offer vital ecosystem services. Despite their importance, the genetic regulatory mechanisms governing wood fibre properties in woody plants remain enigmatic. In this study, we identified a pivotal module comprising 158 high‐priority core genes implicated in wood formation, drawing upon tissue‐specific gene expression profiles from 22 Populus samples. Initially, we conducted a module‐based association study in a natural population of 435 Populus tomentosa, pinpointing PtoDPb1 as the key gene contributing to wood formation through the carbohydrate metabolic pathway. Overexpressing PtoDPb1 led to a 52.91% surge in cellulose content, a reduction of 14.34% in fibre length, and an increment of 38.21% in fibre width in transgenic poplar. Moreover, by integrating co‐expression patterns, RNA‐sequencing analysis, and expression quantitative trait nucleotide (eQTN) mapping, we identified a PtoDPb1‐mediated genetic module of PtoWAK106‐PtoDPb1‐PtoE2Fa‐PtoUGT74E2 responsible for fibre properties in Populus. Additionally, we discovered the two PtoDPb1 haplotypes that influenced protein interaction efficiency between PtoE2Fa‐PtoDPb1 and PtoDPb1‐PtoWAK106, respectively. The transcriptional activation activity of the PtoE2Fa‐PtoDPb1 haplotype‐1 complex on the promoter of PtoUGT74E2 surpassed that of the PtoE2Fa‐PtoDPb1 haplotype‐2 complex. Taken together, our findings provide novel insights into the regulatory mechanisms of fibre properties in Populus, orchestrated by PtoDPb1, and offer a practical module for expediting genetic breeding in woody plants via molecular design. [ABSTRACT FROM AUTHOR]

Ecological niche partitioning is crucial in reducing interspecific competition, fostering species coexistence, and preserving biodiversity. Our research, conducted in a hybrid mixed oak forest in Yushan, Jiangsu, China, focuses on Quercus acutissima, Q. variabilis, Q. fabri, and Q. serrata var. brevipetiolata. Using Point Pattern Analysis, we investigated the spatial relationships and ecological trait autocorrelation, including total carbon (TC), nitrogen (TN), phosphorus (TP), potassium (TK), and breast height diameter (DBH). Our findings show aggregated distribution patterns within the oak populations. The Inhomogeneous Poisson Point model highlights the impact of environmental heterogeneity on Q. variabilis, leading to distinct distribution patterns, while other species showed wider dispersion. This study reveals aggregated interspecific interactions, with a notable dispersal pattern between Q. acutissima and Q. variabilis. We observed significant variability in nutrient elements, indicating distinct nutrient dynamics and uptake processes. The variations in total carbon (TC), nitrogen (TN), phosphorus (TP), and potassium (TK) suggest distinct nutrient dynamics, with TK showing the highest variability. Despite variations in TC, TK, and TP, the species did not form distinct classes, suggesting overlapping nutritional strategies and environmental adaptations. Furthermore, spatial autocorrelation analysis indicates strong positive correlations for DBH, TC, and TP, whereas TK and TN correlations are non-significant. The results suggest habitat filtering as a key driver in intraspecific relationships, with a finer spatial scale of ecological niche division through TC and TP, which is crucial for maintaining coexistence among these oak species. [ABSTRACT FROM AUTHOR]