园艺研究(英文)最新文献

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.

Flower color is an essential biological and ornamental trait in plants. Paeonia rockii (flare tree peony, FTP) exhibits diverse flower colors, characterized by a distinctive basal flare in petals, which enhances its ornamental and ecological value. However, while previous research has mainly focused on flare formation, the regulatory mechanisms controlling the background color of petals remain unclear. This study identifies a novel regulatory module governing petal background coloration in FTP. Within this module, PrMYB75a acts as the central regulator to promote anthocyanin accumulation, as evidenced by stable transformation in Arabidopsis thaliana and tobacco (Nicotiana tabacum), as well as virus-induced gene silencing in FTP. Furthermore, yeast one-hybrid, dual-luciferase reporter, and electrophoretic mobility shift assays collectively demonstrated that PrMYB75a directly activates two key anthocyanin structural genes, PrCHS1 and PrANS, by interacting with MYB-binding sites nearest to the ATG start codon in their promoters. Additionally, we identified an upstream regulator, PrFRS2, which activates both PrMYB75a and PrANS by binding to the FAR1/FHY3-binding sites in their promoters. Modulation of PrFRS2 expression levels through gene silencing and overexpression resulted in alterations in flower pigmentation in both FTP and tobacco. In summary, within the PrFRS2-PrMYB75a module, PrFRS2 indirectly activates PrCHS1 and PrANS by regulating PrMYB75a, or directly activates PrANS, leading to anthocyanin accumulation in FTP purple petals. This module represents a novel regulatory mechanism of petal background coloration in FTP, providing new perspectives on color variation in flowering plants and offering genetic resources for the improvement of the flower color trait in tree peonies.

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.

Vegetable and grain soybeans are typically distinguished by harvest time and pod size, yet their nutritional differences are often overlooked in breeding programs. This study compared 10 varieties each of vegetable and grain soybeans to find key nutritional markers distinguishing them. Results showed that vegetable soybeans have higher concentrations of sucrose, total soluble sugar, and crude protein, along with lower concentrations of crude oil and total fatty acid. Specifically, vegetable soybeans contain a relatively higher amount of unsaturated fatty acids, particularly oleic acid, at green edible stages. Principal component analysis of 12 nutritional components revealed clear distinctions between vegetable and grain soybeans. Additionally, machine learning algorithms identified sucrose as the most critical nutritional marker for distinguishing these two types. Dynamic RNA-seq analysis combined with weighted gene co-expression network analysis identified a sucrose-related module, highlighting GmSPS17 as a predominant sucrose phosphate synthase encoding gene involved in sucrose accumulation in soybean seeds. Furthermore, we identified GmZF-HD1 as an upstream transcription factor regulating GmSPS17. Yeast one-hybrid, luciferase, and electrophoretic mobility shift assays confirmed that GmZF-HD1 directly activates GmSPS17 transcription. Overexpression experiments in hairy roots validated that GmZF-HD1 enhances GmSPS17 expression, thereby increasing sucrose accumulation. In summary, this study establishes sucrose as a key nutritional marker for distinguishing vegetable soybeans from grain soybeans and elucidates the GmZF-HD1-GmSPS17 regulatory pathway, providing valuable insights into sugar accumulation mechanisms and offering guidance for breeding high-sugar vegetable soybean varieties.

As a bridge between human health and plant nutrition, Selenium (Se) phytofortification represents a promising strategy for achieving a safe and effective dietary Se supplementation. Due to chemical similarities, Se absorption, transformation, and storage in crops primarily follow the sulfur metabolic pathway. Se enhances horticultural crop resilience against abiotic and biotic stresses by: (i) boosting antioxidant capacity, (ii) inducing hormonal cascades, (iii) promoting the accumulation of key metabolites (e.g. amino acids, flavonoids), (iv) strengthening cellular functions, and (v) harnessing plant-microbiome interactions. In horticultural crops, most Se exists in organic forms, such as selenoamino acids, selenoproteins, selenium-polysaccharides, and selenium-polyphenols, which contribute to unique quality traits. Additionally, Se regulates the synthesis of core nutrients, including amino acids, flavonoids, phenolic compounds, soluble sugars, mineral elements, alkaloids, and volatile compounds. It also extends postharvest shelf life by delaying senescence and deterioration. Current phytofortification strategies focus on enhancing bioavailable Se in edible parts through agronomic interventions and plant breeding. Artificial Se fertilization is the most common agronomic approach, classified by the application method (soil fertilization, foliar spraying, hydroponic supplementation, and seed soaking) and fertilizer type (inorganic, organic, nano-Se, and biosynthesized fertilizers). Optimizing plant species, fertilization methods, dosage, timing, and elemental synergies maximize phytofortification efficiency.