Honghong Deng

The 2-oxoglutarate/iron-dependent dioxygenase (2OGD) superfamily contains anthocyanidin synthase (ANS) genes that play vital roles in anthocyanin biosynthesis. Here, we performed a genome-wide identification of PsANS genes in Prunus salicina Lindl., and characterized their phylogeny, gene structure, conserved domains, synteny, cis-elements, and expression patterns using qRT-PCR. In total, 137 PsANS members were identified, which were unevenly distributed across eight chromosomes. Structural and conserved-motif analyses revealed conserved domain organization and functional divergence among PsANS paralogs. Synteny analysis revealed high conservation of ANS genes within Rosaceae. Numerous cis-acting elements for light, temperature, phytohormone, and stress responses were predicted in PsANS promoters, implying multi-signal networks modulate anthocyanin biosynthesis. Two contrasting Nai plum genotypes (red-fleshed Huanai and green-fleshed Qingnai) were used to investigate tissue- and cultivar-specific pigment accumulation during fruit development. Spatiotemporal expression and Person correlation analysis showed that PsANS2-35, PsANS7-8 and PsANS6-1 are promising candidate genes associated with fruit anthocyanin accumulation. This study provides candidate gene resources and theoretical support for molecular breeding of colored plum varieties.

Plum is an economically important stone fruit crop worldwide, but its industrial production is limited by low propagation efficiency and disadvantages associated with conventional grafting. This study established a softwood cutting system for three elite Nai plum cultivars (‘Shibanwannai’, ‘Huangguanli’, and ‘Zaofurong’). Gradient concentrations of two plant growth regulators (PGRs), NAA and ABT, were tested in combination with integrated agronomic practices, including girdling pretreatment, a tested growing substrate formulation, and staged moisture management. The results showed that 100 mg·L⁻¹ NAA and 150 mg·L⁻¹ ABT yielded relatively high seedling survival rates (78% to 85%) and promoted the formation of well-developed mixed adventitious root systems. Distinct cultivar-specific differences in sensitivity to PGRs were detected among the three cultivars. This softwood cutting protocol shortens the nursery cycle to 3–4 months, compared with 18–24 months required by traditional grafting. The established high-efficiency cutting method supports standardized nursery production and may facilitate the sustainable development of the Nai plum industry.

Fruit color and phytochemical quality are essential commercial traits that determine the market value and consumer preference of plum (Prunus salicina Lindl.) fruits. Flavonoids are major bioactive phytochemicals closely associated with plum pigmentation and phytochemical properties; however, the metabolic mechanisms linking flavonoid variation to fruit color divergence remain unclear. Here, unbiased, widely targeted UHPLC MS/MS metabolomics was employed to comprehensively characterize tissue-specific (peel and flesh) and cultivar-dependent metabolic differences in three plum cultivars with distinct green, yellow, and red peel phenotypes. A total of 981 metabolites were successfully identified. Flavonoid biosynthesis was confirmed as the core pathway regulating tissue- and cultivar-specific metabolic divergence in plums. Reprogrammed flavonoid metabolic flux caused distinct accumulation of characteristic bioactive components, forming two distinct metabolite-based chemotypes: butein-dominant red plums and luteolin 7-glucoside-enriched yellow plums. Spatial metabolite profiling further confirmed the plum peel as the predominant tissue for flavonoid synthesis and accumulation, largely shaping phenotypic color differentiation and phytochemical variation. These findings clarify the intrinsic correlation between flavonoid profiles, visual appearance, and phytochemical characteristics of plum fruit, providing reliable metabolomic evidence for plum germplasm screening, quality evaluation, and resource utilization in the food industry.

Blood orange (BO) is a rare red-fleshed sweet orange (SWO) with a high anthocyanin content and is associated with numerous health-related benefits. Here, we reported a high-quality chromosome-scale genome assembly for Neixiu (NX) BO, reaching 336.63 Mb in length with contig and scaffold N50 values of 30.6 Mb. Furthermore, 96% of the assembled sequences were successfully anchored to 9 pseudo-chromosomes. The genome assembly also revealed the presence of 37.87% transposon elements and 7.64% tandem repeats, and the annotation of 30,395 protein-coding genes. A high level of genome synteny was observed between BO and SWO, further supporting their genetic similarity. The speciation event that gave rise to the Citrus species predated the duplication event found within them. The genome-wide variation between NX and SWO was also compared. This first high-quality BO genome will serve as a fundamental basis for future studies on functional genomics and genome evolution.

BACKGROUND: In agricultural pest management, especially in combatting the invasive red imported fire ant (RIFA, Solenopsis invicta), significant challenges emerge as a consequence of the constraints of solely depending on chemical insecticides or entomopathogenic nematodes (EPNs). The utilization of chemical insecticides carries environmental and ecological hazards, whereas EPNs, when applied independently, might not offer the immediate effectiveness necessary for adequate RIFA suppression. Acknowledging these hurdles, our study investigates a synergistic method that integrates EPNs with chemical insecticides, aiming to fulfill the urgent demand for more efficient and environmentally friendly pest control solutions.RESULTS: Our evaluation focused on the interaction between the highly pathogenic Steinernema riobrave 7–12 EPN strain and prevalent insecticides, specifically beta‐cypermethrin and a mixture of bifenthrin and clothianidin, applied at highly diluted recommended concentrations. The findings revealed a notable increase in RIFA mortality rates when EPNs and these insecticides were used together, outperforming the results achieved with each method individually. Remarkably, this enhanced efficacy was especially evident at lower concentrations of the bifenthrin–clothianidin mixture, indicating a valuable approach to minimizing reliance on chemical insecticides in agriculture. Furthermore, the high survival rates of EPNs alongside the tested insecticides indicate their compatibility and potential for sustained use in integrated pest management programs.CONCLUSION: Our research underscores the effectiveness of merging EPNs with chemical insecticides as a powerful and sustainable strategy for RIFA management. This combined approach not only meets the immediate challenges of pest control in agricultural settings, but also supports wider environmental objectives by reducing the dependency on chemical insecticides. © 2024 Society of Chemical Industry.

Plums are good sources of various bioactive phytochemical compounds such as vitamins, anthocyanins, and carotenoids, whereby all of which are noted for multiple potential health benefits. However, knowledge regarding plum carotenoid profiles remains limited. Hence, the total and individual carotenoids in the edible parts (skin and flesh) of ten plum cultivars were determined using a spectrophotometer and high-performance liquid chromatography–diode array detection, respectively. Total and individual carotenoid contents in skin were significantly higher (p < 0.05) than those in flesh among all plum cultivars tested. The cultivars with the highest content of total carotenoids in skin were Naili (36.73 μg/g FW), followed by Yinhongli (21.81 μg/g FW) and Yuhuangli (19.70 μg/g FW), with the lowest in Angeleno (8.97 μg/g FW). Lutein, zeaxanthine, β-cryptoxanthin, α-carotene, and β-carotene were the major types of carotenoids detected, with lutein and β-carotene being the predominant constituents of the skin and flesh tissues, respectively. Lutein, zeaxanthine, and total carotenoid contents were positively correlated with the expressions of PSY, LCYB, and LCYE, and negatively correlated with the expressions of PDS and CRTISO. Characterizing the carotenoid profiles and investigating variations in carotenoid biosynthetic gene expressions among plum cultivars are crucial for advancing genetic improvements in plums.

In autumn and spring, citrus leaves with a Ponkan (Citrus reticulata Blanco cv. Ponkan) genetic background (Harumi, Daya, etc.) are prone to abnormal physiological chlorosis. The effects of different degrees of chlorosis (normal, mild, moderate and severe) on photosynthesis and the chlorophyll metabolism of leaves of Citrus cultivar (Harumi) were studied via field experiment. Compared with severe chlorotic leaves, the results showed that chlorosis could break leaf metabolism balance, including reduced chlorophyll content, photosynthetic parameters, antioxidant enzyme activity and enzyme activity related to chlorophyll synthesis, increased catalase and decreased enzyme activity. In addition, the content of chlorophyll synthesis precursors showed an overall downward trend expected for uroporphyrinogen III. Furthermore, the relative expression of genes for chlorophyll synthesis (HEMA1, HEME2, HEMG1 and CHLH) was down-regulated to some extent and chlorophyll degradation (CAO, CLH, PPH, PAO and SGR) showed the opposite trend with increased chlorosis. Changes in degradation were more significant. In general, the chlorosis of Harumi leaves might be related to the blocked transformation of uroporphyrinogen III (Urogen III) to coproporphyrinogen III (Coprogen III), the weakening of antioxidant enzyme system activity, the weakening of chlorophyll synthesis and the enhancement in degradation.

Xyloglucan endotransglycosylase (XET) genes are widely distributed in most plants, but the codon usage bias of XET genes has remained uncharacterized. Thus, we analyzed the codon usage bias using 4500 codons of 20 XET genes to elucidate the genetic and evolutionary patterns. Phylogenetic and hierarchical cluster analyses revealed that the 20 XET genes belonged to two groups. The closer the genetic distance, the more similar the codon usage preference. The codon usage bias of most XET genes was weak, but there was also some codon usage bias. AGA, AGG, AUC, and GUG were the top four codons (RSCU > 1.5) in the 20 XET genes. CitXET had a stronger codon usage bias, and there were eight optimal codons of CitXET (i.e., AGA, AUU, UCU, CUU, CCA, GCU, GUU, and AAA). The RSCU values underwent a correspondence analysis. The two main factors affecting codon usage bias (i.e., Axes 1 and 2) accounted for 54.8% and 17.6% of the total variation, respectively. Multiple correspondence analysis revealed that XET genes were widely distributed, with Group 1 genes being closer to Axis 1 than Group 2 genes, which were closer to Axis 2. Codons with A/U at the third codon position were distributed closer to Axis 1 than codons with G/C at the third codon position. PgXET, ZmXET, VlXET, VrXET, and PcXET were biased toward codons ending with G/C. In contrast, CitXET, DpXET, and BrpXET were strongly biased toward codons ending with A/U, indicating that these XET genes have a strong codon usage bias. Translational selection and base composition (especially A and U at the third codon position), followed by mutation pressure and natural selection, may be the most important factors affecting codon usage of 20 XET genes. These results may be useful in clarifying the codon usage bias of XET genes and the relevant evolutionary characteristics.

Loquats have gained increasing attention from consumers and growers for their essential nutrients and unusual phenology, which could help plug a gap period at market in early spring. Fruit acid is a critical contributor to fruit quality. The dynamic changes in organic acid (OA) during fruit development and ripening of common loquat (Dawuxing, DWX) and its interspecific hybrid (Chunhua, CH) were compared, as well as the corresponding enzyme activity and gene expression. At harvest, titratable acid was significantly lower (p ≤ 0.01) in CH (0.11%) than in DWX loquats (0.35%). As the predominant OA compound, malic acid accounted for 77.55% and 48.59% of the total acid of DWX and CH loquats at harvest, followed by succinic acid and tartaric acid, respectively. PEPC and NAD-MDH are key enzymes that participate in malic acid metabolism in loquat. The OA differences in DWX loquat and its interspecific hybrid could be attributed to the coordinated regulation of multiple genes and enzymes associated with OA biosynthesis, degradation, and transport. The data obtained in this work will serve as a fundamental and important basis for future loquat breeding programs and even for improvements in loquat cultural practices.