园艺研究(英文)最新文献

The tea plant (Camellia sinensis), native to warm and humid low-latitude regions of southwestern China, has expanded to higher altitudes, including southeastern Xizang, where cultivation above 2500 m poses challenges due to low accumulated temperatures. However, the impact of high-altitude climatic conditions, particularly temperature, on tea growth remains underexplored. To investigate, weather stations were deployed at three altitudes in southeastern Xizang to monitor spring temperature fluctuations: Medog (MD, 1200 m), Zayü (ZY, 1720 m), and Layue in Bayi District (BY, 2600 m). Field observations and meteorological data indicated that the milder spring temperatures in MD and ZY facilitated normal budburst and growth, whereas the lower temperatures in BY delayed budburst and resulted in leaf yellowing and browning. Comparative experiments revealed that seedlings exposed to fluctuating low temperatures (10°C/4°C) experienced the most severe cold injury and exhibited the lowest germination rates compared to seedlings under constant-temperature treatments. Transcriptome analysis uncovered differential expression of genes involved in chlorophyll degradation, lignin biosynthesis, and flavonoid pathways under cold stress. Functional characterization of the cold-induced transcription factor CsABF2 revealed its central role in activating these pathways, as evidenced by antisense oligodeoxynucleotide (AsODN) silencing and promoter activation assays, to activate key downstream genes: CsSGR1 (chlorophyll degradation), CsPALa (phenylpropanoid pathway), and CsMYB6c (flavonoid biosynthesis). These results provide mechanistic insights into how spring temperature variability at high altitudes impairs tea plant development and alters quality-related metabolites, offering a molecular basis for improving cold resilience in tea cultivation.

Munage, an ancient grape variety that has been cultivated for thousands of years in Xinjiang, China, is renowned for its exceptional fruit traits. There are two main types of Munage: white fruit (WM) and red fruit (RM). However, the lack of a high-quality genomic resources has impeded effective breeding and restricted the potential for expanding these varieties to other growing regions. In this study, we assembled haplotype-resolved genome assemblies for WM and RM, alongside integrated whole genome resequencing (WGS) data and transcriptome data to illuminate the origin, private mutations and selection in Munage. Our analyses suggest that Munage likely shares a common ancestor with Eurasian grapes that originated in West Asia. Selective analysis between Munage clones and Eurasian grapes mapped genomic signals of selection in Munage grapes, with genes enriched in processes including cell maturation, plant epidermal cell differentiation, and root epidermal cell differentiation. We also identified 283 somatic mutation sites between WM and RM, along with differential selection on genome and expressed genes. These findings provide crucial genetic resources for investigating the genetics of the ancient Chinese grape variety, Munage, and will facilitate the genetic improvement in grapevine using this ancient cultivar as a gene donor.

Fruit growth and development are generally initiated following successful pollination and fertilization. Seedless chestnut rose (Rosa sterilis), an elite promising fruit tree for both edible and medicinal purposes due to the extremely high vitamin C and superior quality, exhibits a naturally parthenocarpic character, however the underlying mechanism has been still unclear so far. Currently, gibberellins (GAs) were justified as the key hormone for parthenocarpy induction in seedless chestnut rose by endogenous hormone analysis and exogenous plant growth regulator (PGR) application. In total, 43 members of the GA oxidase gene family (RsGAoxs) were systematically identified and characterized based on genome-wide analysis of seedless chestnut rose. On the basis of transcriptomic analysis, overexpression experiments in tomato, as well as virus-induced gene silencing (VIGS) assay in seedless chestnut rose, RsGA3ox9 was substantially justified to be involved in the parthenocarpic fruitsetting of this species. Transcription factors RsMYB3, RsMYB8, and RsMYB73 were proven to positively regulate the expression of RsGA3ox9. Further, yeast two-hybrid (Y2H) and luciferase complementation assay illuminated that RsMYB8 and RsMYB73 may interact, leading to upregulating RsGA3ox9. Thereby, RsGA3ox9 substantially regulates parthenocarpy of seedless chestnut rose, and RsMYB8-RsMYB73 complex promotes parthenocarpic fruitsetting by upregulating RsGA3ox9, which may facilitate the seedless fruit breeding in chestnut rose (Rosa roxburghii Tratt.), as well as provide novel insights for better understanding the mechanism underlying the parthenocarpic fruitsetting in fruit species.

AP2/ERF transcription factors (TFs) constitute a large, plant-specific family that acts as a central hub integrating developmental and environmental signals to modulate the biosynthesis of secondary metabolites. These compounds, including terpenoids, phenolic compounds, and alkaloids, are vital for plant survival and are of immense value to human health and industry. This review provides a comprehensive synthesis of the molecular mechanisms by which AP2/ERF TFs regulate these crucial metabolic pathways. We systematically classify and dissect their regulatory modes, including direct binding to cis-elements (e.g. GCC-box, CE1, and DRE/CRT), indirect control via upstream signaling cascades, co-regulation through physical interactions with other TF families (e.g. MYB, bHLH, WRKY), and feedback regulation. We present numerous case studies across diverse plant species, highlighting both conserved principles and species-specific adaptations in the control of high-value natural products like artemisinin, tanshinones, anthocyanins, and nicotine. Furthermore, we discuss the emerging roles of AP2/ERF TFs in metabolic engineering and synthetic biology, and outline future research directions, emphasizing the application of multi-omics and CRISPR/Cas9 technologies to unravel and engineer these complex regulatory networks for targeted overproduction of valuable phytochemicals.

The tea plant is an important nonalcoholic beverage crop known for its abundant secondary metabolites, particularly in buds and leaves. However, the coordinated regulation of bud-to-leaf development and metabolism remains poorly understood. Here, we applied single-nucleus RNA sequencing (snRNA-Seq), bulk RNA sequencing (RNA-Seq), and metabolomics to comprehensively profile the developmental trajectory and metabolic characteristics of tea plant buds and leaves. The snRNA-Seq analysis revealed 17 cell clusters and 8 cell types in buds and leaves, respectively. Notably, the proportion of palisade mesophyll (PM) cells increased progressively during development, while proliferating cells (PC) decreased. Interestingly, key enzymes in the flavonoid biosynthetic pathway were specifically localized to PM cells. Metabolomic analyses demonstrated dynamic accumulation patterns of various metabolites, including phytohormones, flavonoids, and amino acids, as the buds transitioned to mature leaves. Using multi-omics profiling, we identified CsmiRNA396b, CsUGT94P1, CsTCP3, and CsTCP14 as critical regulatory components. Enzyme activity assays confirmed that CsUGT94P1 catalyzes the conversion of flavonols into flavonol glycosides in vitro. Furthermore, CsmiRNA396b was found to regulate leaf development by inhibiting CsGRF3 expression, while CsTCP3 and CsTCP14 played antagonistic roles in leaf development and flavonoid biosynthesis. Our findings provide novel insights into the regulatory mechanisms underlying bud-to-leaf development and metabolite production in tea plants.

Centromeres are essential for centromere-specific histone H3 (CENH3) recruitment and kinetochore assembly, ensuring accurate chromosome segregation and maintaining genome stability in plants. Although extensively studied in model species, the structural organization of centromeres in nonmodel plants, such as fruit trees, remains poorly explored. Our previous study revealed that jujube centromeres lack the typical tandem repeat (TR)-rich structure, complicating their precise identification. In this study, we updated the genome assembly of jujube (Ziziphus jujuba Mill. 'Dongzao') to a haplotype-resolved T2T version, enabling accurate mapping and comparison of centromeres between haplotypes using CENH3 ChIP-seq. These centromeres, ranging from 0.75 to 1.40 Mb, are largely conserved between haplotypes, except for a localized inversion on chromosome 10. Unlike the TR-rich centromeres found in many plant species, jujube centromeres are predominantly composed of Gypsy-type long-terminal repeat retrotransposons (LTR-RTs). Among these, we identified a centromere-enriched LTR family, centromeric retrotransposons of jujube (CRJ), which is particularly abundant in terminal LTRs compared to the internal transposon regions. Comparative analysis across plant species revealed that centromeric retrotransposons primarily fall into three subfamilies-CRM, Tekay, and Athila-highlighting strong subfamily specificity. Notably, early insertions of CRJ-derived LTR segments contributed to the formation of TR-like structures, suggesting a mechanistic link between transposable elements and the evolution of centromeric tandem repeats. This work provides the first in-depth characterization of a TE-dominated centromere architecture in a fruit tree, offering new insights into the diversity and evolution of plant centromeres.