Jingli Zhang

Sugars play a pivotal regulatory role in floral bud dormancy release in Prunus mume, a process that critically determines subsequent flowering time. However, the precise molecular mechanisms linking sugar metabolism to this developmental transition remain poorly understood. To address this gap, we integrated physiological profiling and transcriptomic sequencing using two cultivars with contrasting flowering phenologies: the early-flowering ‘Chaotang Gongfen’ (CTGF) and the late-flowering ‘Shichu Jin’ (SCJ). Exogenous sugar treatments were applied separately to floral buds of the cultivar ‘Yilian’ to evaluate the effect of sugars on dormancy release. During dormancy release, glucose and sucrose contents increased progressively and showed significant positive correlations with bud break rates in both CTGF and SCJ (r > 0.75). Consistently, exogenous application of glucose and sucrose significantly accelerated bud break in ‘Yilian’, whereas mannose exhibited an inhibitory effect. Transcriptome analysis of CTGF and SCJ revealed significant enrichment of starch and sucrose metabolism, hormone signal transduction, and stress-responsive pathways. Key metabolic genes, notably the α-amylase gene PmAMY1-2 and the cell wall invertase genes PmCWINV1/4, were upregulated during this transition. Weighted gene co-expression network analysis (WGCNA) further identified PmFRK4, PmSUS6, and the aforementioned invertases as candidate genes within a sugar-associated regulatory module. Collectively, these findings support a model in which glucose and sucrose accumulation promotes endodormancy release via the transcriptional activation of starch and sucrose catabolic pathways. This study provides a theoretical framework for deciphering dormancy regulation in woody perennials and offers potential targets for the precise manipulation of flowering time.

Background/Objectives: The 3-ketoacyl-CoA synthase (KCS) enzyme is a key and rate-limiting component in the biosynthesis of very long-chain fatty acids (VLCFAs). Through controlling VLCFA production, KCS plays an essential role in plant cuticle formation. The necrotrophic fungus Botrytis cinerea can infect all aboveground parts of rose plants (flowers, leaves, and stems), causing severe economic losses. KCS restricts pathogen invasion by influencing cuticle formation and enhances tolerance to environmental stresses. While the KCS gene family has been well-studied in some plants, it remains unexplored in rose (Rosa × hybrida Hort.), a species of significant ornamental and economic value. Methods: In this study, we conducted a genome-wide analysis of the RcKCS gene family in rose, identifying 18 non-redundant genes. Phylogenetic, structural, and synteny analyses were performed to investigate the evolutionary relationships, gene architecture, and duplication events. The expression patterns of RcKCS genes in rose petals during B. cinerea infection were examined, and transient overexpression and silencing of RcKCS6 were used to study its function. Results: RcKCS6 was found to be upregulated during gray mold infection, and transient overexpression reduced lesion size on infected petals. Conclusions: Our study provides the first comprehensive analysis of the RcKCS gene family in rose and highlights RcKCS6 as a potential candidate for improving resistance to gray mold in rose through molecular breeding.

Background: Given the need to optimize Panax notoginseng cultivation, screen high-quality germplasm, and clarify its insufficiently elucidated genetic–phenotype–quality associations (e.g., saponin accumulation), this study was conducted. Methods: Agronomic traits were measured, saponin accumulation was determined via high-performance liquid chromatography (HPLC), and comprehensive performance was evaluated through integrated cluster analysis and fuzzy membership function assessment; additionally, single-nucleotide polymorphism (SNP)-based genetic diversity analysis was conducted to explore the genetic basis of trait variations. Results: Agronomic traits exhibited coefficients of variation (CVs) of 2.95–18.12%, with primary root length showing the highest variability. Phenotypic cluster analysis divided the materials into three groups. Group I (“Miaoxiang No.1”, “Dianqi No.1”, “Miaoxiang Kangqi No.1”) was characterized by tall plants, sturdy stems, heavy roots, and long/large leaves. Saponin determination results revealed significant differences in notoginsenoside R1, ginsenoside Rb1, ginsenoside Re, ginsenoside Rd, and total saponins among cultivars (order: “Zijing” > “Dianqi No.1” > original cultivar > “Miaoxiang Kangqi No.1” > “Miaoxiang No.1” > “Miaoxiang No.2”), with “Zijing” having the highest total saponin accumulation (18.13%); no significant difference was observed in ginsenoside Rg1 accumulation. The GATK initially identified 16,329,600 SNPs, and 115,930 high-quality SNPs were retained after Samtools filtration. SNP-based Neighbor-joining (NJ) clustering grouped the cultivars into three categories, with the original cultivar clustered alone as one category. Through comprehensive evaluation, three superior germplasm lines (“Miaoxiang Kangqi No.1”, “Miaoxiang No.1”, “Dianqi No.1”) were identified. A significant negative correlation (p < 0.05) was found between compound leaf petiole length and saponin accumulation. Conclusions: This integrated analytical strategy clarifies the links between genetics, phenotype, and quality, providing a scientific foundation for P. notoginseng germplasm screening and facilitating future molecular breeding efforts.

Background: Camellia species are highly ornamental but sensitive to habitat temperature, making cross-border domestication challenging. Methods: In this study, physiological indicators and transcriptome data of Camellia reticulata ‘shizhitou’ were analyzed to identify key factors involved in the response to cold. Results: The findings provide a scientific basis for the conservation of Camellia germplasm resources and breeding of cold-tolerant varieties. Under prolonged low-temperature stress, significant changes were observed in the physiological indices of C. reticulata ‘shizhitou’. Among soluble substances, soluble protein content continuously increased, while soluble sugar content exhibited a fluctuation pattern of increase–decrease–increase. Under prolonged low-temperature stress, significant changes were observed in the physiological indexes of C. reticulata ‘shizhitou’, while soluble sugar content exhibited a fluctuation pattern of increase–decrease–increase. Overall, soluble sugar and soluble protein contents were significantly positively correlated. Chlorophyll content initially decreased and then increased, whereas peroxidase (POD) and catalase (CAT) activities fluctuated and were negatively correlated with chlorophyll content. Malondialdehyde (MDA) content showed an irregular fluctuation trend. A total of 56,424 unigenes were obtained by transcriptome sequencing, of which 39,278 were annotated, while 10,816 differentially expressed genes (DEGs) were identified, including 5748 up-regulated and 5068 down-regulated genes, with 143 DEGs commonly shared across conditions. Congclusions: Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses revealed that low-temperature stress significantly influenced glucose metabolism, lipid metabolism, and amino acid metabolism, and the core pathways of cold stress included zeatin synthesis, hormone signaling, and galactose metabolism. Both physiological responses and transcriptome-based enrichment of DEGs indicate that the redox system and metabolic pathways play crucial regulatory roles in C. reticulata under cold stress.

Ecosystem services are pivotal in assessing environmental health and societal well-being. Focusing on Lake Dianchi Basin (LDB), China, our research evaluated the IESV (Integrated Ecosystem Service Value) from 2000 to 2020, utilizing remote sensing and multiple statistical datasets. The analysis incorporates LSV (Landscape Service Value), CSV (Carbon Sequestration Value), and NPPV (Net Primary Productivity Value). The results show that LSV and CSV exhibited an expansion of low-yield zones near urban areas, contrasted by NPPV’s growth in high-yield outskirt areas. LSV’s normal distribution indicates stability, while CSV’s bimodal structure points to partial integration and systemic divergence. IESV pronounced clustering in both low- and high-yield regions, with low-yield zones congregating near urban centers and high-yield zones dispersed along the basin’s periphery. Despite an overall downward trajectory in IESV, NPPV’s augmentation suggested an underlying systemic resilience. A southeastward shift in IESV’s focus was driven by patterns of urban expansion. Finally, we produced projections with the CA-MC (Cellular Automata–Markov Chain) model to analyze the ongoing distribution of IESV areas around Kunming. By 2030, IESV’s aggregate value is expected to modestly diminish, with NPPV’s ascension mitigating the declines in LSV and CSV. In essence, IESV fluctuations within the LDB are intricately linked to urban development.

A comprehensive study of the genetic characteristics of endangered species is a prerequisite for their effective conservation and management. Rhododendron farinosum is an endangered ornamental species with extremely small populations located in northeastern Yunnan Province. To unravel the reasons behind the endangerment of this species and provide guidance for the rational conservation of this species, this study obtained a large number of SNP loci by using double-digest restriction-site-associated DNA sequencing (ddRAD-seq) to evaluate the genetic diversity and genetic structure of R. farinosum, as well as to infer the population history of this species. Our findings reveal that, at the population level, R. farinosum exhibited a high genetic diversity (π = 0.1948 ± 0.0020, H_E = 0.1880 ± 0.0020). The F_ST values (0.1383–0.2231) indicated high genetic differentiation among the three populations. The AMOVA revealed that 62.83% of the genetic variation originated within populations and 37.17% between populations. The PCA, Structure, and UPGMA consistently depicted that the three populations of R. farinosum are clearly distinguished into three clusters. Furthermore, the effective population size of R. farinosum was inferred to date back to 95,000 years ago using the stairway plot, with a continuous decline from 3292 years. Based on these findings, we propose conservation strategies and management measures for R. farinosum.

Background: The bHLH genes play a crucial role in plant growth, development, and stress responses. However, there is currently limited research on bHLH genes in the important horticultural plant Rhododendron delavayi Franch. Methods: In this study, we conducted a comprehensive genome-wide identification and in-depth analysis of the bHLH gene family in R. delavayi using bioinformatics approaches. Results: A total of 145 bHLH family members were identified, encoding proteins ranging from 98 to 3300 amino acids in length, with molecular weights ranging from 11.44 to 370.51 kDa and isoelectric points ranging from 4.22 to 10.80. These 145 bHLH genes were unevenly distributed across 13 chromosomes, with three bHLH genes located on contig 52. Chromosome 8 contained the highest number of bHLH family members with 19 genes, while chromosomes 9 and 13 had the lowest, with 7 genes each. Phylogenetic analysis revealed a close evolutionary relationship between bHLH genes in R. delavayi and Arabidopsis thaliana. Subcellular localization analysis indicated that most bHLH genes were located in the nucleus. Promoter analysis of R. delavayi bHLH genes revealed the presence of various cis-regulatory elements associated with light responses, methyl jasmonate responses, low-temperature responses, and coenzyme responses, suggesting that bHLH genes are involved in multiple biological processes in R. delavayi. Through transcriptome analysis, we identified three key functional genes—Rhdel02G0041700, Rhdel03G0013600, and Rhdel03G0341200—that may regulate flower color in R. delavayi. Conclusions: In conclusion, our study comprehensively identified and analyzed the bHLH gene family in R. delavayi and identified three bHLH genes related to flower color, providing a foundation for molecular biology research and breeding in R. delavayi.

Rhododendron delavayi Franch. predominantly thrives in broad-leaved evergreen forests and bushes at altitudes of 1,200–3,200 meters. It favors a cool, moist climate and thrives in acidic soils. Due to its high ornamental, medicinal, and scientific values, understanding its ecological needs and optimal cultivation ranges is crucial. This study analyzing the key environmental factors and their thresholds affecting its distribution and predicts the future potential habitats of R. delavayi using existing distribution data alongside current and projected climate data. The results indicate that the primary environmental influencers are soil pH (4.9–5.4), precipitation in the driest month (10–20 mm), and altitude, contributing 41.8, 24.1, and 18.3%, respectively. It also shows a declining trend in suitable habitats: from 27.75 × 10⁴ km² under current conditions, to 3.69 × 10⁴ km² by the 2050s, and further to 2.65 × 10⁴ km² by the 2070s.