Natural variations in MdNAC18 exert major genetic effect on apple fruit harvest date by regulating ethylene biosynthesis genes.

Dissecting the genetic control of apple fruit harvest date (AFHD) into multiple Mendelian factors poses a significant challenge in modern genetics. Here, a quantitative trait locus (QTL) for AFHD was fine-mapped to the NAC transcription factor (TF) MdNAC18 within the interval defined by the overlap of QTLs Z03.5/Z03.6 and F03.2/F03.3. One direct target of MdNAC18 is the ethylene biosynthesis gene MdACO1. The single nucleotide polymorphisms (SNPs) SNP517 and SNP958 in the MdNAC18 coding sequence modulated activation of MdACO1 by MdNAC18. SNP1229 in the MdACO1 promoter destroyed the MdNAC18 binding site and thus abolished MdNAC18 binding. SNP517 and SNP958 also affected MdNAC18 activation of the TF gene MdARF5; MdARF5 activates the ethylene biosynthesis gene MdACS1. SNP517 and SNP958 in MdNAC18, SNP1229 and SNP769 (linked to InDel62) in MdACO1, and InDel162 in MdACS1 constituted a genetic variation network. The genetic effect of this network on AFHD was estimated as 60.3 d, accounting for 52.6% of the phenotype variation of the training population. The joint effects of these polymorphisms increased the accuracy of a genomics-assisted prediction (GAP) model for AFHD (r = 0.7125). Together, our results suggest that genetic variation in MdNAC18 affects AFHD by modulating ethylene biosynthesis and provide an optimized GAP model for apple breeding.

Allele-specific Expression of AP2-like ABA repressor 1 Regulates Iron Uptake by Modulating Rhizosphere pH in Apple.

Genetic variation within a species can result in allelic expression for natural selection or breeding efforts. Here, we identified an iron (Fe) deficiency-inducible gene, AP2-like ABA repressor 1 (MdABR1), in apple (Malus domestica). MdABR1 exhibited differential expression at the allelic level (MdABR131A and MdABR131G) in response to Fe deficiency. The W-box insertion in the promoter of MdABR131A is essential for its induced expression and its positive role under Fe deficiency stress. MdABR1 binds to the promoter of basic-helix-loop-helix 105 (MdbHLH105), participating in the Fe-deficiency response, and activates its transcription. MdABR131A exerts a more pronounced transcriptional activation effect on MdbHLH105. Suppression of MdABR1 expression leads to reduced rhizosphere acidification in apple, and MdABR131A exhibits allelic expression under Fe-deficiency stress, which is substantially upregulated and then activates the expression of MdbHLH105, promoting the accumulation of plasma membrane proton ATPase 8 (MdAHA8) transcripts in response to proton extrusion, thereby promoting rhizosphere acidification. Therefore, variation in the ABR1 alleles results in variable gene expression and enables apple plants to exhibit a wider tolerance capability and Fe deficiency response. These findings also shed light on the molecular mechanisms of allele-specific expression in woody plants.

Nitenpyram in tea: Eco-friendly detection methodology and residue behavior.

Studies on nitenpyram determination and behavior within tea remain limited despite its widespread use as a neonicotinoid. An organic-saving analytical approach tailored for the detection of nitenpyram in tea was established. Nitenpyram was extracted by boiling water and cleaned up by Cleanert PCX solid-phase. The average recoveries were 75.1-94.5 %, with relative standard deviations (RSDs) of 0.7-8.6 % for saving 34.5-88.6 % organic solvent. The limits of quantification (LOQs) were 0.002 mg·kg-1 in fresh tea shoots, 0.005 mg·kg-1 in made tea, and 0.001 mg·L-1 in tea brew, satisfying the current minimum Maximum Residue Limit (MRL). Nitenpyram dissipated rapidly with half-lives of 1.2-1.4 days at the recommended dosage (27 g a.i. ha-1) in two locations. Remarkably, 20-110 % of nitenpyram was leached out from made tea in different brewing modes. This work provides insights into nitenpyram's rational application in tea cultivation and offers considerations to institutions tasked with unestablished MRLs in tea.

Acquired reactive perforating collagenosis triggered by trauma with eosinophilia: a case report and literature review.

Acquired reactive perforating collagenosis (ARPC) is a rare dermatological disorder condition defined by the perforation of altered collagen fibers through the epidermis. The presence of underlying conditions such as diabetes or renal disease is helpful in the ARPC diagnosis. Although skin rashes related to ARPC have been reported, the exact causative factors and mechanisms remain unclear. Here, we present a unique case of ARPC triggered by trauma in a 67-year-old male without concurrent systemic alterations. The diagnosis of ARPC with eosinophilia was made following comprehensive diagnostic testing, including clinical presentation, histological results, and blood tests, ruling out other possible diseases. Intriguingly, the histopathological examination revealed collagen penetration into the epidermis at different tissue sections. In addition, we reviewed existing literature on ARPC, which documented the causation. To help confirm the diagnosis, clinicians have to pay attention to traumatic triggers for ARPC and its rare manifestation with eosinophilia.

Honeycomb-like triazine-based conjugated microporous polymers exhibiting simultaneous and ultrasensitive detection of fifteen polycyclic aromatic hydrocarbons using solid-phase microextraction technique.

BACKGROUND: Since the severe hazard to the ecosystem and widespread distribution through biological and man-made ways of polycyclic aromatic hydrocarbons (PAHs), it is very urgent to establish the ultrasensitive analytical method to quantitatively and directly monitor PAHs in real samples. However, because of the complicated environmental matrix and their trace concentration, the pre-concentration process is a necessary step to analyze of these compounds. In this study, solid phase microextraction (SPME) technique was proposed to separate and enrich fifteen trace PAHs from environmental samples. RESULTS: In this work, a honeycomb-like triazine-based conjugated microporous polymers (T-CMPs) were prepared by Yamamoto reaction and firstly used as SPME coating material for the ultrasensitive direct-immersion-SPME of PAHs prior to high performance liquid chromatography-fluorescence detector (HPLC-FLD). The synthesized T-CMPs was characterized using various spectroscopy and electron microscopy techniques. The unique porous network of T-CMPs might deliver abundant adsorption sites for PAHs. Orthogonal experimental design (OED) was used to investigate the influence of four experimental parameters on the enrichment ability. Under optimal situation, a wide linear range (which lasted from 0.003 to 1000 µg L-1) with the coefficients of determination (R2) varying 0.9981 to 0.9993 was obtained. The limits of detection (LODs) for the analytes varied from 0.001 to 1.650 µg L-1, and the limits of quantification (LOQs) were between 0.003 and 4.960 µg L-1. The proposed method was effectively employed to the simultaneous and ultrasensitive detection of fifteen PAHs in industrial wastewaters. The relative recoveries for PAHs analysis varied from 74.6 % to 105 % with the relative standard deviations (RSD) of 0.1 %-7.5 % in real water samples. SIGNIFICANCE: The prepared SPME coating material exhibited a simultaneous, high extraction and adsorption capacity for fifteen PAHs due to its honeycomb-like porous structure, ultra-large specific surface area, strong π-π stacking, and hydrophobic interactions. The present research developed a novel strategy for the construction of SPME fiber coating composites and demonstrated great application potential in the field of sample pretreatment and environmental analytical chemistry.

Insight into the fate of tolfenpyrad in tea plant (Camellia sinensis L.) from root uptake.

Residual pesticides in agricultural environments, including soil and irrigation water, can be taken up by plants, and thus pose a potential risk to food safety. Although tolfenpyrad has been widely used in tea plantations, limited information is available on its root uptake and fate in tea plants (Camellia sinensis L.). Exploring the mechanisms involved is crucial for understanding the migration and accumulation of tolfenpyrad in tea plants, particularly in the edible parts. In this study, root uptake of tolfenpyrad and its subsequent translocation, distribution, and metabolism in tea seedlings were investigated. The results indicated that the passive transport and apoplastic pathway dominated the root uptake of tolfenpyrad. After uptake, tolfenpyrad distributed predominantly in the cell walls (90.8-92.0 %) of roots, resulting in limited upward translocation in water-soluble fractions through transpirational pull, with translocation factor values far <1 (TFstem/root = 0.115-0.453 and TFleaf/stem = 0.039-0.184). Similar accumulation patterns were observed for the carboxylated metabolite PT-CA as well as hydroxylated metabolite PT-OH. Interestingly, the subcellular distribution of PT-CA in stems was much different from that of the parent tolfenpyrad: PT-CA mainly distributed in the stem cell walls (41.72 %) and cell organelles (56.18 %) at 3 h, then gradually transferred into the cell-soluble fractions (33.07 %) after 120 h. Results from the present study indicated limited upward translocation of tolfenpyrad with its main metabolites to leaves. This finding helps to alleviate concerns about environmental residual tolfenpyrad in tea consumption and provides valuable information for the safety evaluation of tolfenpyrad.

Efficient Transformation of Water Vapor into Hydrogen by Dielectric Barrier Discharge Loaded with Bamboo Carbon Bed Structured by Fibrous Material.

A new method of efficiently transforming water vapor into hydrogen was investigated by dielectric barrier discharge (DBD) loaded with bamboo carbon bed structured by fibrous material in an argon medium. Hydrogen productivity was measured in three different reactors: a non-loaded DBD (N-DBD), a bamboo carbon (BC) bed DBD (BC-DBD), and a quartz wool (QW)-loaded BC DBD (QC-DBD). The effects of the quality ratio of BC to QW and relative humidity on hydrogen productivity were also investigated in QC-DBD at various flow rates. The reaction process and mechanism were analyzed by scanning electron microscopy, X-ray photoelectron spectroscopy, N2 physisorption experiments, infrared spectroscopy, and optical emission spectroscopy. A new reaction pathway was developed by loading BC into the fibrous structured material to activate the reaction molecules and capture the O-containing groups in the DBD reactor. A hydrogen productivity of 17.3 g/kWh was achieved at an applied voltage of 5 kV, flow rate of 4 L/min, and 100% relative humidity (RH) in the QC-DBD with a quality ratio of BC to QW of 3.0.

Novel insights into the regulation of exosomal PD-L1 in cancer: From generation to clinical application.

Programmed cell death ligand 1 (PD-L1) interacts with programmed cell death 1 (PD-1), leading to T cell exhaustion and promoting tumor cell survival, ultimately mediating immunosuppression. While FDA-approved monoclonal antibodies targeting the PD-1/PD-L1 interaction have shown success in cancer treatment, some patients experience limited and short-lived therapeutic outcomes. Recent studies have identified PD-L1 expression not only on tumor cell surfaces but also on exosomes, with secretion pathways including both conventional and unconventional endocytosis routes, presenting a unique therapeutic opportunity. Emerging evidence suggests that exosomal PD-L1 contributes to systemic immunosuppression, potentially counteracting the effects of anti-PD-1 checkpoint therapies. However, the significance of exosomal PD-L1 in clinical cancer patients unresponsive to anti-PD-1/PD-L1 immunotherapy, as well as the factors regulating its generation, remain unclear. Moreover, the mechanisms underlying PD-L1 expression on exosomes and its regulation in cancer are yet to be fully elucidated. This review primarily focuses on the mechanisms modulating exosomal PD-L1 generation in cancer, while also outlining its involvement in immunosuppression, tumor proliferation, and response to cancer immunotherapy. Additionally, we explore the potential of exosomal PD-L1 as a cancer biomarker and therapeutic target, aiming to provide a comprehensive overview of this emerging field and its implications for cancer treatment and diagnosis.

A ratiometric fluorescence and colorimetry dual-signal sensing strategy based on o-phenylenediamine and AuNCs for determination of Cu2+ and glyphosate.

A ratiometric fluorescence sensing strategy has been developed for the determination of Cu2+ and glyphosate with high sensitivity and specificity based on OPD (o-phenylenediamine) and glutathione-stabilized gold nanoclusters (GSH-AuNCs). Water-soluble 1.75-nm size GSH-AuNCs with strong red fluorescence and maximum emission wavelength at 682 nm were synthesized using GSH as the template. OPD was oxidized by Cu2+, which produced the bright yellow fluorescence oxidation product 2,3-diaminophenazine (DAP) with a maximum fluorescence emission peak at 570 nm. When glyphosate existed in the system, the chelation between glyphosate and Cu2+ hindered the formation of DAP and reduced the fluorescence intensity of the system at the wavelength of 570 nm. Meanwhile, the fluorescence intensity at the wavelength of 682 nm remained basically stable. It exhibited a good linear relationship towards Cu2+ and glyphosate in water in the range 1.0-10 µM and 0.050-3.0 µg/mL with a detection limit of 0.547 µM and 0.0028 µg/mL, respectively. The method was also used for the semi-quantitative determination of Cu2+ and glyphosate in water by fluorescence color changes visually detected by the naked eyes in the range 1.0-10 µM and 0.30-3.0 µg/mL, respectively. The sensing strategy showed higher sensitivity, more obvious color changes, and better disturbance performance, satisfying with the detection demands of Cu2+ and glyphosate in environmental water samples. The study provides a reliable detection strategy in the environment safety fields.

Bacillus B2 promotes root growth and enhances phosphorus absorption in apple rootstocks by affecting MhMYB15.

Due to the chelation of phosphorus in the soil, it becomes unavailable for plant growth and development. The mechanisms by which phosphorus-solubilizing bacteria activate immobilized phosphorus to promote the growth and development of woody plants, as well as the intrinsic molecular mechanisms, are not clear. Through the analysis of microbial communities in the rhizosphere 16S V3-V4 and a homologous gene encoding microbial alkaline phosphomonoesterase (phoD) in phosphate-efficient (PE) and phosphate-inefficient apple rootstocks, it was found that PE significantly enriched beneficial rhizobacteria. The best phosphorus-solubilizing bacteria, Bacillus sp. strain 7DB1 (B2), was isolated, purified, and identified from the rhizosphere soil of PE rootstocks. Incubating with Bacillus B2 into the rhizosphere of apple rootstocks significantly increased the soluble phosphorus and flavonoid content in the rhizosphere soil. Simultaneously, this process stimulates the root development of the rootstocks and enhances plant phosphorus uptake. After root transcriptome sequencing, candidate transcription factor MhMYB15, responsive to Bacillus B2, was identified through heatmap and co-expression network analysis. Yeast one-hybrid, electrophoretic mobility shift assay, and LUC assay confirmed that MhMYB15 can directly bind to the promoter regions of downstream functional genes, including chalcone synthase MhCHS2 and phosphate transporter MhPHT1;15. Transgenic experiments with MhMYB15 revealed that RNAi-MhMYB15 silenced lines failed to induce an increase in flavonoid content and phosphorus levels in the roots under the treatment of Bacillus B2, and plant growth was slower than the control. In conclusion, MhMYB15 actively responds to Bacillus B2, regulating the accumulation of flavonoids and the uptake of phosphorus, thereby influencing plant growth and development.

Movement of ACC oxidase 3 mRNA from seeds to flesh promotes fruit ripening in apple.

Xenia, the phenomenon in which the pollen genotype directly affects the phenotypic characteristics of maternal tissues (i.e., fruit ripening), has applications in crop production and breeding. However, the underlying molecular mechanism has yet to be elucidated. Here, we investigated whether mobile mRNAs from the pollen affect the ripening and quality-related characteristics of the fruit using cross-pollination between distinct Malus domestica (apple) cultivars. We demonstrated that hundreds of mobile mRNAs originating from the seeds are delivered to the fruit. We found that the movement of one of these mRNAs, ACC oxidase 3 (MdACO3), is coordinated with fruit ripening. Salicylic acid treatment, which can cause plasmodesmal closure, blocks MdACO3 movement, indicating that MdACO3 transcripts may move through the plasmodesmata. To assess the role of mobile MdACO3 transcripts in apple fruit, we created MdACO3-GFP-expressing apple seeds using MdACO3-GFP-overexpressing pollen for pollination and showed that MdACO3 transcripts in the transgenic seeds move to the flesh, where they promote fruit ripening. Furthermore, we demonstrated that MdACO3 can be transported from the seeds to fruit in the fleshy-fruited species tomato and strawberry. These results underscore the potential of mobile mRNAs from seeds to influence fruit characteristics, providing an explanation for the xenia phenomenon. Notably, our findings highlight the feasibility of leveraging diverse pollen genomic resources, without resorting to genome editing, to improve fruit quality.

Yolk-shell MOF-on-MOF hybrid solid-phase microextraction coatings for efficient enrichment and detection of pesticides: Structural regulation cause performance differences.

Metal-organic frameworks (MOFs) based composites with different structure-activity relationships have been widely used in the field of organic pollutant adsorption and extraction. Here, two MOF-on-MOF composites with different structures (yolk-shell and core-shell) from homologous sources were prepared by a simple in-situ growth synthesis method and structural regulation. In order to verify the effect of composite structure on the extraction capacity, the adsorption performance of the yolk-shell structure (YS-NH2-UiO-66@CoZn-ZIF) and the core-shell structured (NH2-UiO-66@CoZn-ZIF) material were compared by using them as coating material of direct immersion solid-phase microextraction (DI-SPME) to enrich six pesticides in five matrices. The results showed that because of the unique hollow hierarchical structure, high specific surface area (930.68 m2 g-1), abundant and open active sites, and synergistic and complementary adsorption forces, YS-NH2-UiO-66@CoZn-ZIF composites had the maximum adsorption amount of 36.01-66.31 mg g-1 under the same experiment condition, which was 6.81%-34.26 % higher than that of NH2-UiO-66@CoZn-ZIF. In addition, the adsorption mechanism of the prepared materials was verified and elaborated through theoretical simulations and material characterization. Under the optimized conditions, the YS-NH2-UiO-66@CoZn-ZIF-coated SPME-HPLC-UV method had a wide linear range (0.241-500 µg L-1), a good linear correlation coefficient (R2 > 0.9988), a low detection limits (0.072-0.567 µg L-1, S/N = 3) and low quantification limits (0.241-1.891 µg L-1, S/N = 10). The relative standard deviations of individual fibers and different batches of fibers were 0.47-6.20 % and 0.22-2.48 %, respectively, and individual fibers could be recycled more than 104 times. This work provided a good synthetic route and comparative ideas for exploring the in-situ growth synthesis of yolk-shell composites with reasonable structure-activity relationships.

In situ mass spectrometry imaging reveals pesticide residues and key metabolic pathways throughout the entire cowpea growth process.

Cowpea plants, renowned for their high edibility, pose a significant risk of pesticide residue contamination. Elucidating the behavior of pesticide residues and their key metabolic pathways is critical for ensuring cowpea safety and human health. This study investigated the migration of pesticide residues and their key metabolic pathways in pods throughout the growth process of cowpea plants via in situ mass spectrometry. To this end, four pesticides--including systemic (thiram), and nonsystemic (fluopyram, pyriproxyfen, and cyromazine) pesticides--were selected. The results indicate the direct upward and downward transmission of pesticides in cowpea stems and pods. Systemic pesticides gradually migrate to the core of cowpea plants, whereas nonsystemic pesticides remain on the surface of cowpea peels. The migration rate is influenced by the cowpea maturity, logarithmic octanol-water partition coefficient (log Kow) value, and molecular weight of the pesticide. Further, 20 types of key metabolites related to glycolysis, tricarboxylic acid cycle, and flavonoid synthesis were found in cowpea pods after pesticide treatment. These findings afford insights into improving cowpea quality and ensuring the safe use of pesticides.

MdARF3 switches the lateral root elongation to regulate dwarfing in apple plants.

Apple rootstock dwarfing and dense planting are common practices in apple farming. However, the dwarfing mechanisms are not understood. In our study, the expression of MdARF3 in the root system of dwarfing rootstock 'M9' was lower than in the vigorous rootstock from Malus micromalus due to the deletion of the WUSATAg element in the promoter of the 'M9' genotype. Notably, this deletion variation was significantly associated with dwarfing rootstocks. Subsequently, transgenic tobacco (Nicotiana tabacum) cv. Xanthi was generated with the ARF3 promoter from 'M9' and M. micromalus genotypes. The transgenic apple with 35S::MdARF3 was also obtained. The transgenic tobacco and apple with the highly expressed ARF3 had a longer root system and a higher plant height phenotype. Furthermore, the yeast one-hybrid, luciferase, electrophoretic mobility shift assays, and Chip-qPCR identified MdWOX4-1 in apples that interacted with the pMm-ARF3 promoter but not the pM9-ARF3 promoter. Notably, MdWOX4-1 significantly increased the transcriptional activity of MdARF3 and MdLBD16-2. However, MdARF3 significantly decreased the transcriptional activity of MdLBD16-2. Further analysis revealed that MdARF3 and MdLBD16-2 were temporally expressed during different stages of lateral root development. pMdLBD16-2 was mainly expressed during the early stage of lateral root development, which promoted lateral root production. On the contrary, pMmARF3 was expressed during the late stage of lateral root development to promote elongation. The findings in our study will shed light on the genetic causes of apple plant dwarfism and provide strategies for molecular breeding of dwarfing apple rootstocks.

Residue Degradation and Risk Assessment of Difenoconazole and Its Metabolite during Tea Growing, Processing and Brewing by Ultra-Performance Liquid Chromatography-Tandem Mass Spectrometry Determination.

Residue dissipation and risk assessment of difenoconazole and its metabolite difenoconazole-alcohol during tea growing, processing, and brewing was first investigated by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The limits of quantification for both difenoconazole and difenoconazole-alcohol were 0.001 mg/kg in fresh tea leaves and tea, and 0.0002 mg/L in tea infusion. In field trials, the dissipation half-lives of difenoconazole in fresh tea leaves was 1.77 days. After spraying, the residues of difenoconazole-alcohol increased and then gradually dissipated like difenoconazole. After 14 days, the dissipation rates of difenoconazole and difenoconazole-alcohol reached 99%. When fresh tea leaves were harvested on different days, the total processing factors (PFs) of difenoconazole and difenoconazole-alcohol for green tea were 0.86-1.05 and 0.78-0.85, respectively, while the total PFs for black tea were 0.83-1.13 and 0.82-1.66, respectively. Metabolism of difenoconazole was accelerated during tea processing. When brewing black tea, the leaching rates (LRs) of difenoconazole and difenoconazole-alcohol were 8.4-17.9% and 31.8-38.9%, respectively, while when brewing green tea, the LRs were 15.4-23.5% and 30.4-50.6%, respectively. The LRs of difenoconazole and difenoconazole-alcohol in black tea were higher than those in green tea. The potential threat to human health for dietary intake of difenoconazole and difenoconazole-alcohol residues from tea consumption is negligible. However, the dietary risk of difenoconazole in fruits and vegetables that are essential for daily diets is concerning, with a risk probability of 158%.

Mitogen-activated protein kinase MxMPK3-2 mediated phosphorylation of MxZR3.1 participates in regulating iron homoeostasis in apple rootstocks.

The micronutrient iron plays a crucial role in the growth and development of plants, necessitating meticulous regulation for its absorption by plants. Prior research has demonstrated that the transcription factor MxZR3.1 restricts iron absorption in apple rootstocks; however, the precise mechanism by which MxZR3.1 contributes to the regulation of iron homoeostasis in apple rootstocks remains unexplored. Here, MxMPK3-2, a protein kinase, was discovered to interact with MxZR3.1. Y2H, bimolecular fluorescence complementation and pull down experiments were used to confirm the interaction. Phosphorylation and cell semi-degradation tests have shown that MxZR3.1 can be used as a substrate of MxMPK3-2, which leads to the MxZR3.1 protein being more stable. In addition, through tobacco transient transformation (LUC and GUS) experiments, it was confirmed that MxZR3.1 significantly inhibited the activity of the MxHA2 promoter, while MxMPK3-2 mediated phosphorylation at the Ser94 site of MxZR3.1 further inhibited the activity of the MxHA2 promoter. It is tightly controlled to absorb iron during normal growth and development of apple rootstocks due to the regulatory effect of the MxMPK3-2-MxZR3.1 module on MxHA2 transcription level. Consequently, this research has revealed the molecular basis of how the MxMPK3-2-MxZR3.1 module in apple rootstocks controls iron homoeostasis by regulating the MxHA2 promoter's activity.

miR164-MhNAC1 regulates apple root nitrogen uptake under low nitrogen stress.

Nitrogen is an essential nutrient for plant growth and serves as a signaling molecule to regulate gene expression inducing physiological, growth and developmental responses. An excess or deficiency of nitrogen may have adverse effects on plants. Studying nitrogen uptake will help us understand the molecular mechanisms of utilization for targeted molecular breeding. Here, we identified and functionally validated an NAC (NAM-ATAF1/2-CUC2) transcription factor based on the transcriptomes of two apple rootstocks with different nitrogen uptake efficiency. NAC1, a target gene of miR164, directly regulates the expression of the high-affinity nitrate transporter (MhNRT2.4) and citric acid transporter (MhMATE), affecting root nitrogen uptake. To examine the role of MhNAC1 in nitrogen uptake, we produced transgenic lines that overexpressed or silenced MhNAC1. Silencing MhNAC1 promoted nitrogen uptake and citric acid secretion in roots, and enhanced plant tolerance to low nitrogen conditions, while overexpression of MhNAC1 or silencing miR164 had the opposite effect. This study not only revealed the role of the miR164-MhNAC1 module in nitrogen uptake in apple rootstocks but also confirmed that citric acid secretion in roots affected nitrogen uptake, which provides a research basis for efficient nitrogen utilization and molecular breeding in apple.

Review of published 467 achondroplasia patients: clinical and mutational spectrum.

AIM: Achondroplasia is the most common of the skeletal dysplasias that cause fatal and disabling growth and developmental disorders in children, and is caused by a mutation in the fibroblast growth factor receptor, type 3 gene(FGFR3). This study aims to analyse the clinical characteristics and gene mutations of ACH to accurately determine whether a patient has ACH and to raise public awareness of the disease. METHODS: The database of Pubmed, Cochrane Library, Wanfang and CNKI were searched with terms of "Achondroplasias" or "Skeleton-Skin-Brain Syndrome" or "Skeleton Skin Brain Syndrome" or "ACH" and "Receptor, Fibroblast Growth Factor, Type 3" or "FGFR3". RESULTS: Finally, four hundred and sixty-seven patients with different FGFR3 mutations were enrolled. Of the 138 patients with available gender information, 55(55/138, 40%) were female and 83(83/138, 60%) were male. Among the patients with available family history, 47(47/385, 12%) had a family history and 338(338/385, 88%) patients were sporadic. The age of the patients ranged from newborn babies to 36 years old. The mean age of their fathers was 37 ± 7 years (range 31-53 years). Patients came from 12 countries and 2 continents, with the majority being Asian (383/432, 89%), followed by European (49/432, 11%). Short stature with shortened arms and legs was found in 112(112/112) patients, the abnormalities of macrocephaly in 94(94/112) patients, frontal bossing in 89(89/112) patients, genu valgum in 64(64/112) patients and trident hand were found in 51(51/112) patients. The most common mutation was p.Gly380Arg of the FGFR3 gene, which contained two different base changes, c.1138G > A and c.1138G > C. Ten rare pathogenic mutations were found, including c.831A > C, c.1031C > G, c.1043C > G, c.375G > T, c.1133A > G, c.1130T > G, c.833A > G, c.649A > T, c.1180A > T and c.970_971insTCTCCT. CONCLUSION: ACH was caused by FGFR3 gene mutation, and c.1138G > A was the most common mutation type. This study demonstrates the feasibility of molecular genetic testing for the early detection of ACH in adolescents with short stature, trident hand, frontal bossing, macrocephaly and genu valgum.

Genetic variations in MdSAUR36 participate in the negative regulation of mesocarp cell division and fruit size in Malus species.

Final fruit size of apple (Malus domestica) cultivars is related to both mesocarp cell division and cell expansion during fruit growth, but it is unclear whether the cell division and/or cell enlargement determine most of the differences in fruit size between Malus species. In this study, by using an interspecific hybrid population between Malus asiatica "Zisai Pearl" and Malus domestica cultivar "Red Fuji," we found that the mesocarp cell number was the main causal factor of diversity in fruit size between Malus species. Rapid increase in mesocarp cell number occurred prior to 28 days after anthesis (DAA), while cell size increased gradually after 28 DAA until fruit ripening. Six candidate genes related to auxin signaling or cell cycle were predicted by combining the RNA-seq data and previous QTL data for fruit weight. Two InDels and 10 SNPs in the promoter of a small auxin upregulated RNA gene MdSAUR36 in Zisai Pearl led to a lower promoter activity than that of Red Fuji. One non-synonymous SNP G/T at 379 bp downstream of the ATG codon of MdSAUR36, which was heterozygous in Zisai Pearl, exerted significant genotype effects on fruit weight, length, and width. Transgenic apple calli by over-expressing or RNAi MdSAUR36 confirmed that MdSAUR36 participated in the negative regulation of mesocarp cell division and thus apple fruit size. These results could provide new insights in the molecular mechanism of small fruit size in Malus accession and be potentially used in molecular assisted breeding via interspecific hybridization. Supplementary Information: The online version contains supplementary material available at 10.1007/s11032-024-01441-4.

Pan-genome analysis of 13 Malus accessions reveals structural and sequence variations associated with fruit traits.

Structural variations (SVs) and copy number variations (CNVs) contribute to trait variations in fleshy-fruited species. Here, we assemble 10 genomes of genetically diverse Malus accessions, including the ever-green cultivar 'Granny Smith' and the widely cultivated cultivar 'Red Fuji'. Combining with three previously reported genomes, we assemble the pan-genome of Malus species and identify 20,220 CNVs and 317,393 SVs. We also observe CNVs that are positively correlated with expression levels of the genes they are associated with. Furthermore, we show that the noncoding RNA generated from a 209 bp insertion in the intron of mitogen-activated protein kinase homology encoding gene, MMK2, regulates the gene expression and affects fruit coloration. Moreover, we identify overlapping SVs associated with fruit quality and biotic resistance. This pan-genome uncovers possible contributions of CNVs to gene expression and highlights the role of SVs in apple domestication and economically important traits.