A new nomogram to predict in-hospital mortality in patients with acute decompensated chronic heart failure and diabetes after 48 Hours of Intensive Care Unit.

BACKGROUND: The study set out to develop an accurate and clinically valuable prognostic nomogram to assess the risk of in-hospital death in patients with acute decompensated chronic heart failure (ADCHF) and diabetes. METHODS: We extracted clinical data of patients diagnosed with ADCHF and diabetes from the Medical Information Mart for Intensive Care III database. Risk variables were selected utilizing least absolute shrinkage and selection operator regression analysis, and were included in multivariate logistic regression and presented in nomogram. bootstrap was used for internal validation. The discriminative power and predictive accuracy of the nomogram were estimated using the area under the receiver operating characteristic curve (AUC), calibration curve and decision curve analysis (DCA). RESULTS: Among 867 patients with ADCHF and diabetes, In-hospital death occurred in 81 (9.3%) patients. Age, heart rate, systolic blood pressure, red blood cell distribution width, shock, ß-blockers, angiotensin converting enzyme inhibitors or angiotensin receptor blockers, assisted ventilation, and blood urea nitrogen were brought into the nomogram model. The calibration curves suggested that the nomogram was well calibrated. The AUC of the nomogram was 0.873 (95% CI: 0.834-0.911), which was higher that of the Simplified Acute Physiology Score II [0.761 (95% CI: 0.711-0.810)] and sequential organ failure assessment score [0.699 (95% CI: 0.642-0.756)], and Guidelines-Heart Failure score [0.782 (95% CI: 0.731-0.835)], indicating that the nomogram had better ability to predict in-hospital mortality. In addition, the internally validated C-index was 0.857 (95% CI: 0.825-0.891), which again verified the validity of this model. CONCLUSIONS: This study constructed a simple and accurate nomogram for predicting in-hospital mortality in patients with ADCHF and diabetes, especially in those who admitted to the intensive care unit for more than 48 hours, which contributed clinicians to assess the risk and individualize the treatment of patients, thereby reducing in-hospital mortality.

Melittin induces autophagy to alleviate chronic renal failure in 5/6-nephrectomized rats and angiotensin II-induced damage in podocytes.

BACKGROUND/OBJECTIVES: Chronic renal failure (CRF) is a complex pathological condition that lacks a cure. Certain Chinese medicines, such as melittin, a major component in bee venom, have shown efficacy in treating CRF patients. On the other hand, the mechanisms underlying the therapeutic effects of melittin are unclear. MATERIALS/METHODS: A 5/6 nephrectomy model (5/6 Nx) of renal failure was established on rats for in vivo assays, and mouse podocyte clone 5 (MPC5) mouse podocyte cells were treated with angiotensin II (AngII) to establish an in vitro podocyte damage model. The 24-h urine protein, serum creatinine, and blood urea nitrogen levels were evaluated after one, 2, and 4 weeks. Hematoxylin and eosin staining, Masson staining, and periodic acid-Schiff staining were used to examine the pathological changes in kidney tissues. A cell counting kit 8 assay was used to assess the cell viability. Reverse transcription polymerase chain reaction and Western blot were used to assess the mRNA and protein levels in the cells, respectively. RESULTS: In the rat 5/6 Nx, melittin reduced the 24-h urinary protein excretion and the serum creatinine and blood urea nitrogen levels. Furthermore, the renal pathology was improved in the melittin-treated 5/6 Nx rats. Melittin promoted podocin, nephrin, Beclin 1, and the LC3II/LC3I ratio and inhibited phosphorylated mammalian target of rapamycin (mTOR)/mTOR in 5/6 Nx-induced rats and AngII-induced MPC5 mouse podocyte cells. Moreover, inhibiting autophagy with 3-MA weakened the effects of melittin on podocin, nephrin, and the LC3II/LC3I ratio in podocytes. CONCLUSION: Melittin may offer protection against kidney injury, probably by regulating podocyte autophagy. These results provide the theoretical basis for applying melittin in CRF therapy.

Enhancing therapeutic efficacy in luminal androgen receptor triple-negative breast cancer: exploring chidamide and enzalutamide as a promising combination strategy.

Extensive exploration of the molecular subtypes of triple-negative breast cancer (TNBC) is critical for advancing precision medicine. Notably, the luminal androgen receptor (LAR) subtype has attracted attention for targeted treatment combining androgen receptor antagonists and CDK4/6 inhibitors. Unfortunately, this strategy has proven to be of limited efficacy, highlighting the need for further optimization. Using our center's comprehensive multiomics dataset (n = 465), we identified novel therapeutic targets and evaluated their efficacy through multiple models, including in vitro LAR cell lines, in vivo cell-derived allograft models and ex vivo patient-derived organoids. Moreover, we conducted flow cytometry and RNA-seq analysis to unveil potential mechanisms underlying the regulation of tumor progression by these therapeutic strategies. LAR breast cancer cells exhibited sensitivity to chidamide and enzalutamide individually, with a drug combination assay revealing their synergistic effect. Crucially, this synergistic effect was verified through in vivo allograft models and patient-derived organoids. Furthermore, transcriptomic analysis demonstrated that the combination therapeutic strategy could inhibit tumor progression by regulating metabolism and autophagy. This study confirmed that the combination of histone deacetylase (HDAC) inhibitors and androgen receptor (AR) antagonists possessed greater therapeutic efficacy than monotherapy in LAR TNBC. This finding significantly bolsters the theoretical basis for the clinical translation of this combination therapy and provides an innovative strategy for the targeted treatment of LAR TNBC.

The melanin pigment gene black mediates body pigmentation and courtship behaviour in the German cockroach Blattella germanica.

Genes involved in melanin production directly impact insect pigmentation and can affect diverse physiology and behaviours. The role these genes have on sex behaviour, however, is unclear. In the present study, the crucial melanin pigment gene black was functionally characterised in an urban pest, the German cockroach, Blattella germanica. RNAi knockdown of B. germanica black (Bgblack) had no effect on survival, but did result in black pigmentation of the thoraxes, abdomens, heads, wings, legs, antennae, and cerci due to cuticular accumulation of melanin. Sex-specific variation in the pigmentation pattern was apparent, with females exhibiting darker coloration on the abdomen and thorax than males. Bgblack knockdown also resulted in wing deformation and negatively impacted the contact sex pheromone-based courtship behaviour of males. This study provides evidence for black function in multiple aspects of B. germanica biology and opens new avenues of exploration for novel pest control strategies.

Geniposide ameliorates psoriatic skin inflammation by inhibiting the TLR4/MyD88/NF-κB p65 signaling pathway and MMP9.

Psoriasis is an incurable immune-mediated disease affecting the skin or the joints. There are continuing studies on drugs for psoriasis prevention and treatment. This research found that Geniposide (GE) significantly thinned IMQ mice's skin lesions, reduced the scales, and lowered the presence of inflammatory cells in the pathology in a dose-dependent manner. GE inhibited IL-23, IL-22, IL-17A, IL-12, IL-6, and TNF-α levels in psoriatic mice serum. AKT1, TNF, TLR4, MMP9, MAPK3, and EGFR were selected as the top 6 targets of GE against psoriasis via network pharmacology, and GE-TLR4 has the most robust docking score value by molecular docking. Taken together, GE significantly inhibited TLR4 and MMP9 protein expression and influenced MyD88/NF-κB p65 signaling pathway. Finally, TLR4 was verified as the critical target of GE, which engaged in immunomodulatory activities and reduced MMP9 production in LPS and TAK-242-induced HaCaT cells. GE had a medium affinity for TLR4, and the KD value was 1.06 × 10-5 M. GE is an effective treatment and preventative strategy for psoriasis since it impacts TLR4.

High-efficient separation of deoxyribonucleic acid from pathogenic bacteria by hedgehog-inspired magnetic nanoparticles microextraction.

Efficient separation of deoxyribonucleic acid (DNA) through magnetic nanoparticles (MN) is a widely used biotechnology. Hedgehog-inspired MNs (HMN) possess a high-surface-area due to the distinct burr-like structure of hedgehog, but there is no report about the usage of HMN for DNA extraction. Herein, to improve the selection of MN and illustrate the performance of HMN for DNA separation, HMN and silica-coated Fe3O4 nanoparticles (Fe3O4@SiO2) were fabricated and compared for the high-efficient separation of pathogenic bacteria of DNA. Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) are typical Gram-negative and Gram-positive bacteria and are selected as model pathogenic bacteria. To enhance the extraction efficiency of two kinds of MNs, various parameters, including pretreatment, lysis, binding and elution conditions, have been optimized in detail. In most separation experiments, the DNA yield of HMN was higher than that of Fe3O4@SiO2. Therefore, a HMN-based magnetic solid-phase microextraction (MSPE) and quantitative real-time PCR (qPCR) were integrated and used to detect pathogenic bacteria in real samples. Interestingly, the HMN-based MSPE combined qPCR strategy exhibited high sensitivity with a limit of detection of 2.0 × 101 CFU mL-1 for E. coli and 4.0 × 101 CFU mL-1 for S. aureus in orange juice, and 2.8 × 102 CFU mL-1 for E. coli and 1.1 × 102 CFU mL-1 for S. aureus in milk, respectively. The performance of the proposed strategy was significantly better than that of commercial kit. This work could prove that the novel HMN could be applicable for the efficient separation of DNA from complex biological samples.

In vitro inhibition of α-Synuclein aggregation and disaggregation of preformed fibers by polyphenol hybrids with 2-conjugated benzothiazole.

The misfolding and aggregation of α-Syn play a pivotal role in connecting diverse pathological pathways in Parkinson's disease (PD). Preserving α-Syn proteostasis and functionality by inhibiting its aggregation or disaggregating existing aggregates using suitable inhibitors represents a promising strategy for PD prevention and treatment. In this study, a series of benzothiazole-polyphenol hybrids was designed and synthesized. Three identified compounds exhibited notable inhibitory activities against α-Syn aggregation in vitro, with IC50 values in the low micromolar range. These inhibitors demonstrated sustained inhibitory effects throughout the entire aggregation process, stabilizing α-Syn proteostasis conformation. Moreover, the compounds effectively disintegrated preformed α-Syn oligomers and fibers, potentially by binding to specific domains within the fibers, inducing fibril instability, collapse, and ultimately resulting in smaller-sized aggregates and monomers. These findings offer valuable insights into the therapeutic potential of polyphenol hybrids with 2-conjugated benzothiazole targeting α-Syn aggregation in the treatment of PD.

RNAi of yellow-y, required for normal cuticle pigmentation, impairs courtship behavior and oviposition in the German cockroach (Blattella germanica).

The insect cuticle plays a key role in maintaining the insect's physiological function and behavior. Herein, the yellow-y protein is required to produce black melanin, and is expressed in a pattern that correlates with the distribution of this pigment. However, yellow-y can also have other functions, for instance, in insect behavior, but not much is known. In this study, we have studied the yellow-y gene in one important model and pest species, namely the German cockroach (Blattella germanica), which is to our knowledge the first time reported. In essence, we identified the yellow-y gene (BgY-y) and characterized its function by using RNA interference (RNAi). Silencing of BgY-y gene led to different developmental abnormalities (body weight and wings) in both genders. Specifically, there was an abundant decrease in melanin, turning the body color in pale yellow and the cuticle softer and more transparent. Interestingly, we also observed that the knockdown of BgY-y impaired the male cockroaches to display a weaker response to female-emitted contact sex pheromones, and also that the oviposition ability was weakened in the RNAi females. This study comprehensively analyzed the biological functions of the yellow-y gene in German cockroaches from the perspectives of development, body color, courtship behavior and oviposition, and as a consequence, this may opens new avenues to explore it as a novel pest control gene.

Prenatal, perinatal and parental risk factors for autism spectrum disorder in China: a case- control study.

BACKGROUND: Autism spectrum disorder (ASD) is heritable neurodevelopmental disorders (NDDs), but environmental risk factors have also been suggested to a play a role in its development. Prenatal, perinatal and parental factors have been associated with an increased risk of ASD in children. The aim of the present study was to explore the prenatal, perinatal, and parenting risk factors in children with autism spectrum disorder (ASD) from Beijing, China by comparing them with typically developing (TD) children. METHODS: A sample of 151 ASD children's parents who from rehabilitation institutions in Beijing were enrolled in this study, and an additional 151 children from kindergartens in Beijing were recruited as a control group (child age: mean = 4.4 years). TD children were matched according to age, sex and maternal education. We explored the maternal AQ (Autism Spectrum Quotient) scores (mean:19.40-19.71, no significant difference between two groups) to referring the genetic baseline. This study evaluated 17 factors with unadjusted and adjusted analyses. RESULTS: Birth asphyxia was associated with a more than a thirteen-fold higher risk of ASD (adjusted odds ratio (AOR) = 13.42). Breastfeeding difficulties were associated with a higher risk of ASD(AOR = 3.46). Parenting influenced the risk of ASD, with low responding (LR) and harsh or neglectful parenting associated with a higher risk of ASD in offspring (AOR = 2.37 for LR, AOR = 3.42 for harsh parenting and AOR = 3.01 for neglectful parenting). Maternal fever during pregnancy was associated with a higher risk of ASD in offspring (AOR = 3.81). CONCLUSIONS: Many factors were associated with ASD in offspring. Further assessment is needed to elucidate the role of modifiable environmental factors to inform prevention strategies.

Threatment Strategies for Recurrent Hepatocellular Carcinoma Patients: Ablation and its Combination Patterns.

With the development of guidance technology and ablation equipment, ablative procedures have emerged as important loco-regional alternatives to surgical resection for recurrent hepatocellular carcinoma (rHCC) patients. Currently, ablation modalities used in clinical practice mainly include radiofrequency ablation (RFA), microwave ablation (MWA), laser ablation (LA), cryoablation (CRA), high-intensity focused ultrasound (HIFU), and irreversible electroporation (IRE). Accumulated comparative data of ablation versus surgical resection reveal noninferior responses and outcomes but superior adverse effects. Moreover, studies demonstrate that ablation may serve as an excellent procedure for rHCC given its exact minimal invasiveness and immune modulation. We focus on the current status of ablation in clinical practice for rHCC and discuss new research in the field, including ablation combined with these other modalities, such as targeted therapy and immunotherapy.

A novel pectin polysaccharide from vinegar-baked Radix Bupleuri absorbed by microfold cells in the form of nanoparticles.

Polysaccharides of vinegar-baked Radix Bupleuri (VBCP) have been reported to exhibit liver-targeting and immunomodulatory activities through oral administration, but the absorption behavior and mechanism of VBCPs have not been extensively studied. In this study, a novel HG type pectin polysaccharide, VBCP1-4, with a high molecular weight of 2.94 × 106 Da, was separated from VBCP. VBCP1-4 backbone was contained 1,4-α-D-GalpA, 1,4-α-D-GalpA6OMe, 1,3,4-α-D-GalpA and 1,2,4-α-D-Rhap. The branches were mainly contained 1,5-α-L-Araf, 1,3,5-α-L-Araf, t-α-L-Araf and t-α-D-Galp, which linked to the 3 position of 1,3,4-α-D-GalpA and the 4 position of 1,2,4-α-D-Rhap. VBCP1-4 could self-assemble to nanoparticles in water, with CMC values of 106.41 µg/mL, particle sizes of 178.20 ± 2.82 nm and zeta potentials of -23.19 ± 1.44 mV. The pharmacokinetic study of VBCP1-4, which detected by marking with FITC, revealed that it could be partially absorbed into the body through Peyer's patches of the ileum. In vitro absorption study demonstrated that VBCP1-4 was difficult to be absorbed by Caco-2 cell monolayer, but could be absorbed by M cells in a time and concentration dependent manner. The absorption mechanism was elucidated that VBCP1-4 entered M cells through clathrin-mediated endocytosis in the form of nanoparticles. These findings provide valuable insights into the absorption behavior of VBCP and contribute to its further development.

Purinergic P2X7 receptor involves in anti-retinal photodamage effects of berberine.

Berberine (BBR) is a Chinese herb with antioxidant and anti-inflammatory properties. In a previous study, we found that BBR had a protective effect against light-induced retinal degeneration in BALB/c mice. The purinergic P2X7 receptor (P2X7R) plays a key role in retinal degeneration via inducing oxidative stress, inflammatory changes, and cell death. The aim of this study was to investigate whether BBR can induce protective effects in light damage experiments and whether P2X7R can get involved in these effects. C57BL/6 J mice and P2X7 knockout (KO) mice on the C57BL/6 J background were used. We found that BBR preserved the outer nuclear layer (ONL) thickness and retinal ganglion cells following light stimulation. Furthermore, BBR significantly suppressed photoreceptor apoptosis, pro-apoptotic c-fos expression, pro-inflammatory responses of Mϋller cells, and inflammatory factors (TNF-α, IL-1ß). In addition, protein levels of P2X7R were downregulated in BBR-treated mice. Double immunofluorescence showed that BBR reduced overexpression of P2X7R in retinal ganglion cells and Mϋller cells. Furthermore, BBR combined with the P2X7R agonist BzATP blocked the effects of BBR on retinal morphology and photoreceptor apoptosis. However, in P2X7 KO mice, BBR had an additive effect resulting in thicker ONL and more photoreceptors. The data suggest that the P2X7 receptor is involved in retinal light damage, and BBR inhibits this process by reducing histological impairment, cell death, and inflammatory responses.

AACFlow: an end-to-end model based on attention augmented convolutional neural network and flow-attention mechanism for identification of anticancer peptides.

MOTIVATION: Anticancer peptides (ACPs) have natural cationic properties and can act on the anionic cell membrane of cancer cells to kill cancer cells. Therefore, ACPs have become a potential anticancer drug with good research value and prospect. RESULTS: In this article, we propose AACFlow, an end-to-end model for identification of ACPs based on deep learning. End-to-end models have more room to automatically adjust according to the data, making the overall fit better and reducing error propagation. The combination of attention augmented convolutional neural network (AAConv) and multi-layer convolutional neural network (CNN) forms a deep representation learning module, which is used to obtain global and local information on the sequence. Based on the concept of flow network, multi-head flow-attention mechanism is introduced to mine the deep features of the sequence to improve the efficiency of the model. On the independent test dataset, the ACC, Sn, Sp, and AUC values of AACFlow are 83.9%, 83.0%, 84.8%, and 0.892, respectively, which are 4.9%, 1.5%, 8.0%, and 0.016 higher than those of the baseline model. The MCC value is 67.85%. In addition, we visualize the features extracted by each module to enhance the interpretability of the model. Various experiments show that our model is more competitive in predicting ACPs.

Neutrophil Membrane-Camouflaged Polyprodrug Nanomedicine for Inflammation Suppression in Ischemic Stroke Therapy.

Neuroinflammation has emerged as a major concern in ischemic stroke therapy because it exacebates neurological dysfunction and suppresses neurological recovery after ischemia/reperfusion. Fingolimod hydrochloride (FTY720) is an FDA-approved anti-inflammatory drug which exhibits potential neuroprotective effects in ischemic brain parenchyma. However, delivering a sufficient amount of FTY720 through the blood-brain barrier into brain lesions without inducing severe cardiovascular side effects remains challenging. Here, a neutrophil membrane-camouflaged polyprodrug nanomedicine that can migrate into ischemic brain tissues and in situ release FTY720 in response to elevated levels of reactive oxygen species. This nanomedicine delivers 15.2-fold more FTY720 into the ischemic brain and significantly reduces the risk of cardiotoxicity and infection compared with intravenously administered free drug. In addition, single-cell RNA-sequencing analysis identifies that the nanomedicine attenuates poststroke inflammation by reprogramming microglia toward anti-inflammatory phenotypes, which is realized via modulating Cebpb-regulated activation of NLRP3 inflammasomes and secretion of CXCL2 chemokine. This study offers new insights into the design and fabrication of polyprodrug nanomedicines for effective suppression of inflammation in ischemic stroke therapy.

Maize requires Arogenate Dehydratase 2 for resistance to Ustilago maydis and plant development.

Maize (Zea mays) smut is a common biotrophic fungal disease caused by Ustilago maydis and leads to low maize yield. Maize resistance to U. maydis is a quantitative trait. However, the molecular mechanism underlying the resistance of maize to U. maydis is poorly understood. Here, we reported that a maize mutant caused by a single gene mutation exhibited defects in both fungal resistance and plant development. maize mutant highly susceptible to U. maydis (mmsu) with a dwarf phenotype forms tumors in the ear. A map-based cloning and allelism test demonstrated that one gene encoding a putative arogenate dehydratase/prephenate dehydratase (ADT/PDT) is responsible for the phenotypes of the mmsu and was designated as ZmADT2. Combined transcriptomic and metabolomic analyses revealed that mmsu had substantial differences in multiple metabolic pathways in response to U. maydis infection compared with the wild type. Disruption of ZmADT2 caused damage to the chloroplast ultrastructure and function, metabolic flux redirection, and reduced the amounts of salicylic acid (SA) and lignin, leading to susceptibility to U. maydis and dwarf phenotype. These results suggested that ZmADT2 is required for maintaining metabolic flux, as well as resistance to U. maydis and plant development in maize. Meanwhile, our findings provided insights into the maize response mechanism to U. maydis infection.

Metastasis-associated protein 1 participates in regulating luminal acidification of the epididymis via repressing estrogen receptor alpha transcription.

BACKGROUND: As a component of the nucleosome remodeling and deacetylating (NuRD) complex, metastasis-associated protein 1 (MTA1) has been reported to be abundant in male reproductive system and might participate in spermatogenesis and sperm maturation, whereas the precise functional role of MTA1 in these processes is still undetermined. OBJECTIVE: To investigate the effect and potential function of MTA1 in male fertility. MATERIALS AND METHODS: Mta1 knockout mice (Mta1-/- ) were employed to detect their reproductive phenotype. The pH value of Mta1-/- epididymal luminal fluid was measured, and the potential mechanism of MTA1 involved in regulating luminal acidification was detected in vivo and in vitro. A vasectomy model with abnormal pH of epididymal lumen was established to further detect the effect of MTA1 on epididymal luminal microenvironment. RESULTS: Mta1-/- mice were fertile without any detectable defects in spermatogenesis or sperm motility while the deficiency of MTA1 could acidify the initial segment of epididymis to a certain extent. MTA1 could interact with estrogen receptor alpha (ERα) and inhibit the transcription of ERα target gene, hydrogen exchanger 3 (NHE3), and ultimately affect the epididymal luminal milieu. After vasectomy, the Mta1-/- mice presented a more acidic epididymal lumen which was closer to the normal state compared to the wild-type model. DISCUSSION AND CONCLUSION: MTA1 is dispensable for male fertility in mice, but plays a potentially important function in regulating luminal acidification of the epididymis.

Nanoparticle-delivered RNAi-based pesticide target screening for the rice pest white-backed planthopper and risk assessment for a natural predator.

Vacuolar-type (H+)-ATPase (vATPase) is a conserved multi-subunit eukaryotic enzyme composed of 14 subunits that form a functional complex consisting of an ATP-hydrolytic domain (V1) and a proton-translocation domain (V0). ATP hydrolysis and subsequent H+ translocation rely heavily on a fully assembled V1/V0 complex. Since vATPase is crucial for insect survival, it is a viable molecular target for pest control. However, detailed functional analyses of the 14 subunits and their suitability for pest control have not been fully explored in a single insect species. In this study, we identified 22 vATPase subunit transcripts that correspond to 13 subunits (A1, A2, B, C, D, E, F, G, H, a1, a2, c and d) in the white-backed planthopper (WBPH), Sogatella furcifera, a major hemipteran pest of rice. RNAi screens using microinjection and spray-based methods revealed that the SfVHA-F, SfVHA-a2 and SfVHA-c2 subunits are critical. Furthermore, star polymer (SPc) nanoparticles were utilized to conduct spray-induced and nanoparticle-delivered gene silencing (SI-NDGS) to evaluate the pest control efficacy of RNAi targeting the SfVHA-F, SfVHA-a2 and SfVHA-c2 transcripts. Target mRNA levels and vATPase enzymatic activity were both reduced. Honeydew excreta was likewise reduced in WBPH treated with dsRNAs targeting SfVHA-F, SfVHA-a2 and SfVHA-c2. To assess the environmental safety of the nanoparticle-wrapped dsRNAs, Cyrtorhinus lividipennis Reuter, a major natural enemy of planthoppers, was also sprayed with dsRNAs targeting SfVHA-F, SfVHA-a2 and SfVHA-c2. Post-spray effects of dsSfVHA-a2 and dsSfVHA-c2 on C. lividipennis were innocuous. This study identifies SfVHA-a2 and SfVHA-c2 as promising targets for biorational control of WBPH and lays the foundation for developing environment-friendly RNAi biopesticides.

Partially knocking out NtPDK1a/1b/1c/1d simultaneously in Nicotiana tabacum using CRISPR/CAS9 technology results in auxin-related developmental defects.

The eukaryotic AGC protein kinase subfamily (protein kinase A/ protein kinase G/ protein kinase C-family) is involved in regulating numerous biological processes across kingdoms, including growth and development, and apoptosis. PDK1(3-phosphoinositide-dependent protein kinase 1) is a conserved serine/threonine kinase in eukaryotes, which is both a member of AGC kinase and a major regulator of many other downstream AGC protein kinase family members. Although extensively investigated in model plant Arabidopsis, detailed reports for tobacco PDK1s have been limited. To better understand the functions of PDK1s in tobacco, CRISPR/CAS9 transgenic lines were generated in tetraploid N. tabacum, cv. Samsun (NN) with 5-7 of the 8 copies of 4 homologous PDK1 genes in tobacco genome (NtPDK1a/1b/1c/1d homologs) simultaneously knocked out. Numerous developmental defects were observed in these NtPDK1a/1b/1c/1d CRISPR/CAS9 lines, including cotyledon fusion leaf shrinkage, uneven distribution of leaf veins, convex veins, root growth retardation, and reduced fertility, all of which reminiscence of impaired polar auxin transport. The severity of these defects was correlated with the number of knocked out alleles of NtPDK1a/1b/1c/1d. Consistent with the observation in Arabidopsis, it was found that the polar auxin transport, and not auxin biosynthesis, was significantly compromised in these knockout lines compared with the wild type tobacco plants. The fact that no homozygous plant with all 8 NtPDK1a/1b/1c/1d alleles being knocked out suggested that knocking out 8 alleles of NtPDK1a/1b/1c/1d could be lethal. In conclusion, our results indicated that NtPDK1s are versatile AGC kinases that participate in regulation of tobacco growth and development via modulating polar auxin transport. Our results also indicated that CRISPR/CAS9 technology is a powerful tool in resolving gene redundancy in polyploidy plants.

Characterization of the powdery mildew resistance locus in wheat breeding line Jimai 809 and its breeding application.

Powdery mildew, caused by Blumeria graminis f. sp. tritici (Bgt), is a severe disease that affects the yield and quality of wheat. Popularization of resistant cultivars in production is the preferred strategy to control this disease. In the present study, the Chinese wheat breeding line Jimai 809 showed excellent agronomic performance and high resistance to powdery mildew at the whole growth stage. To dissect the genetic basis for this resistance, Jimai 809 was crossed with the susceptible wheat cultivar Junda 159 to produce segregation populations. Genetic analysis showed that a single dominant gene, temporarily designated PmJM809, conferred the resistance to different Bgt isolates. PmJM809 was then mapped on the chromosome arm 2BL and flanked by the markers CISSR02g-1 and CIT02g-13 with genetic distances 0.4 and 0.8 cM, respectively, corresponding to a physical interval of 704.12-708.24 Mb. PmJM809 differed from the reported Pm genes on chromosome arm 2BL in origin, resistance spectrum, physical position and/or genetic diversity of the mapping interval, also suggesting PmJM809 was located on a complex interval with multiple resistance genes. To analyze and screen the candidate gene(s) of PmJM809, six genes related to disease resistance in the candidate interval were evaluated their expression patterns using an additional set of wheat samples and time-course analysis post-inoculation of the Bgt isolate E09. As a result, four genes were speculated as the key candidate or regulatory genes. Considering its comprehensive agronomic traits and resistance findings, PmJM809 was expected to be a valuable gene resource in wheat disease resistance breeding. To efficiently transfer PmJM809 into different genetic backgrounds, 13 of 19 closely linked markers were confirmed to be suitable for marker-assisted selection. Using these markers, a series of wheat breeding lines with harmonious disease resistance and agronomic performance were selected from the crosses of Jimai 809 and several susceptible cultivars. Supplementary Information: The online version contains supplementary material available at 10.1007/s11032-024-01467-8.