RESUMEN

Epigenetic modifications are crucial for plant development. EFD (Exine Formation Defect) encodes a SAM-dependent methyltransferase that is essential for the pollen wall pattern formation and male fertility in Arabidopsis. In this study, we find that the expression of DRM2, a de novo DNA methyltransferase in plants, complements for the defects in efd, suggesting its potential de novo DNA methyltransferase activity. Genetic analysis indicates that EFD functions through HB21, as the knockout of HB21 fully restores fertility in efd mutants. DNA methylation and histone modification analyses reveal that EFD represses the transcription of HB21 through epigenetic mechanisms. Additionally, we demonstrate that HB21 directly represses the expression of genes crucial for pollen formation and anther dehiscence, including CalS5, RPG1/SWEET8, CYP703A2 and NST2. Collectively, our findings unveil a double negative regulatory cascade mediated by epigenetic modifications that coordinates anther development, offering insights into the epigenetic regulation of this process.

Asunto(s)

Proteínas de Arabidopsis , Arabidopsis , Metilación de ADN , Epigénesis Genética , Flores , Regulación de la Expresión Génica de las Plantas , Arabidopsis/genética , Arabidopsis/crecimiento & desarrollo , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Flores/genética , Flores/crecimiento & desarrollo , Polen/crecimiento & desarrollo , Polen/genética , Polen/metabolismo , Metiltransferasas/metabolismo , Metiltransferasas/genética , Mutación , Plantas Modificadas Genéticamente

RESUMEN

Herein, we report a visible light-enabled radical trihalomethylation/cyano-migration/carbonylation cascade reaction of 2-hydroxy-2-hex-5-enenitrile with CX3SO2Cl as the CX3-source (X = F, Cl) to obtain 5-oxo-2-(2,2,2-trihaloethyl)pentanenitrile compounds in the absence of a photocatalyst, transition metal and base. This reaction system is also effective to convert (benzo[d]thiazol-2-yl)-pent-4-enol to the corresponding 4-(benzo[d]thiazol-2-yl)-6,6,6-trihalo-hexanone products. These reactions occur under mild conditions, tolerate a wide range of functional groups, and provide alternative approaches for the 1,2-bifunctionalization reaction of unactivated olefins.

RESUMEN

Objective To explore the risk factors for lower extremity amputation in patients with diabetic foot.Methods The clinical data of 1 771 patients with diabetic foot at the Air Force General Hospital of PLA from November 2001 to April 2015 were retrospectively analyzed.The patients were divided into the non-amputation and amputation groups.Within the amputation group , subjects were further divided into the minor and major amputation subgroups.Binary logistic regression analyses were used to assess the association between risk factors and lower extremity amputation.Results Among 1 771 patients with diabetic foot , 323 of them ( 18.24%) were in the amputation group ( major amputation: 41; minor amputation:282 ) and 1 448 ( 81.76%) in the non-amputation group.Compared with non-amputation patients, those in the amputation group had a longer hospital stay and higher estimated glomerular filtration rate(eGFR)levels.Fasting plasma glucose (FPG), glycosylated hemoglobin (HbA1c), C-reaction protein (CRP), ESR, ferritin, fibrinogen and WBC levels of the amputation group were higher , while hemoglobin albumin, transferrin, TC, TG, HDL-C and LDL-C were lower than those of the non-amputation group (all P<0.05 ).The proportion of hypertension ( 52.48% vs 59.98%) , peripheral vascular disease ( PAD ) (68.11% vs 25.04%), and coronary heart disease (21.33% vs 28.71%) were different between the amputation and non-amputation groups (all P<0.05).Multivariable logistic regression analyses showed that Wagner′s grade , PAD and CRP were the independent risk factors associated with lower extremity amputation in hospitalized patients with diabetic foot.Conclusion Wagner′s grade, ischemia of lower limbs and infection are closely associated with amputation of diabetic foot patients.

RESUMEN

Objective To investigate the clinical effects and indications of the vacuum sealing drainage (VSD) in the treatment of severe diabetic foot gangrene.Methods We randomly recruited 60 cases,who had suffered from diabetic foot gangrene(DFG) at the grade of 3 -5,according to Wagner scale into VSD treatment groups and treated them with VSD methods.At the same time,62 DFG cases who had given routine drainage treatment one year ago were retrospectively analyzed as control group.The observed items included the wound healing time,number of dressing,outcome of treatment ( healing rate),the average days in hospital,total expenses of hospitalization and so on.Results The wound healing time of VSD treatment group and routine treatment group were ( 30.5 ± 6.8 ) days and ( 53.8 ± 5.5 ) days,respectively ( t =2.636,P ＜ 0.01 ).The numbers of dressing were( 15.0 ± 4.7) days and ( 29.5 ± 6.1 ) days,respectively ( t =2.374,P ＜ 0.01 ).The healing rates were 96.7％ (58/60) and 87.1％ (54/62),respectively(P ＜0.01 ).The average period in hospitalization were (20.1 ± 3.5 ) days and ( 36.5 ± 4.6 ) days,respectively ( t =2.564,P ＜ 0.01 ).Total expenses of hospitalization were(20 155.6 ± 153.8) yuan RMB and(41 465.5 ± 146.6) yuan RMB,respectively(t =2.873,P ＜0.01 ).All the differences were statistically significant.Conclusion The VSD method is effective for the treatment of severe diabetic foot gangrene(DFG).It is able to reduce the time of wound healing significantly,increase the healing rate,shorten the hospitalization period and cut the general expenses during hospitalization.It' s an effective method for the treatment of DFG.