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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 [...]