“Grafting from”法制备高载量大孔弱阳离子交换层析介质

针对大孔聚合物层析介质孔径大、比表面积低而导致的蛋白结合容量低的问题,采用“graftingfrom”策略,以大孔聚丙烯酸酯微球为基质,通过氧化还原引发甲基丙烯酸在微球表面接枝聚合,制备了高载量弱阳离子交换层析介质.研究了单体浓度、过硫酸钾浓度及反应温度等因素对蛋白结合容量的影响.所得介质的蛋白静态结合容量和动态结合容量分别达到252.21和157.25mg/mL;同时发现具有一定离子交换容量的该类介质能够在0.2 mol/L NaCl缓冲液中保持100 mg/mL的蛋白结合容量.将该层析介质用于鸡卵清中溶菌酶的纯化,获得了较高的纯化效率.

Outcomes of surgical correction of Peyronie’s disease with plaque excision and grafting: Comparison of testicular tunica vaginalis graft versus bovine pericardium graft

Objective:Peyronie’s disease(PD)is an abnormal wound healing in the penile tunica albuginea.After fibrotic plaque excision,different graft materials have been used to repair the defects,but the optimal graft remains unknown.This study aimed to compare the functional outcomes of testicular tunica vaginalis grafts and bovine pericardium grafts in patients with severe PD.Methods:A retrospective comparative study was conducted on 33 PD patients undergoing partial plaque excision and grafting from September 2015 to May 2021.The patients were divided into two groups depending on the type of graft used.For 15 patients in Group B,testicular tunica vaginalis grafts were used to repair the defect,while for 18 patients in Group A,bovine pericardium grafts were used.Data of the patient’s age,comorbidities,sexual function,penile curvature,postoperative complications,need for further treatment,change in penile length,and satisfaction were gathered and compared between the groups.Sexual function was evaluated using the 5-item version of the International Index of Erectile Function(IIEF-5),and a functional less than 20-degree penile curvature after surgery was considered a successful intervention.Results:There was no difference in age,comorbidities,degree of curvature,perioperative IIEF-5,operative time,plaque size,or complication rates.After surgery,a statistically significant improvement in curvature degree(p<0.05)and satisfactory penile appearance(p<0.05)were seen in both groups without any superiority between the two groups(p=0.423 and p=0.840,respectively).With a 30-month follow-up,the IIEF-5 was consistent in both groups,with no statistical significance between the groups(p=0.492).The main change in penile length during the operation was increased and still positive in the last follow-up in both groups without statistical significance(p=0.255 and p=0.101,respectively).Conclusion:Partial plaque excision and corporoplasty with both testicular tunica vaginalis or bovine pericardium grafts are equally effective in treating males with clinically significant PD.

Late infection after peri-orbital autologous micro-fat graft:a case presentation and literature review

Citation:Pakdel F,Asadigandomani H,Arab Bafrani M,Nozarian Z,Abedinifar Z,Pirmarzdashti N,Jafari B,Siami Z.Late infection after peri-orbital autologous micro-fat graft:a case presentation and literature review.Int J Ophthalmol 2024;17(3):603-606.

Implications of Elevated Serum Cortisol in the Onset of Postoperative Delirium Following Off-Pump Coronary Artery Bypass Grafting: Insights from a Bangladesh-Based Single Center Experience

Background: Following coronary artery bypass grafting (CABG), delirium emerges as a prevalent complication. This study aimed to assess the correlation between elevated serum cortisol levels and the occurrence of postoperative delirium subsequent to off-pump CABG. Methods: Conducted in the Department of Cardiac Surgery at BSMMU from October 2020 to September 2022, this comparative cross-sectional study included a total of 44 participants. Subjects, meeting specific criteria, were purposefully assigned to two groups based on off-pump CABG. Group A (n = 22) consisted of patients with normal serum cortisol levels, while Group B (n = 22) comprised individuals with high serum cortisol levels on the first postoperative day. Delirium onset was assessed at the bedside in the ICU on the 1st, 2nd, 3rd, 4th, and 5th postoperative days using standard tools, namely the Richmond Agitation Sedation score (RASS) and The Confusion Assessment Method (CAM-ICU). Data were collected based on the presence or absence of delirium. Statistical analysis utilized SPSS version 26.0, employing an independent Student’s t-test for continuous data and chi-square and Fischer’s exact test for categorical data. A p-value ≤ 0.05 was considered statistically significant. Results: Group-A had a mean age of 54.50 ± 17.97, and Group-B had a mean age of 55.22 ± 15.45, both with a male predominance (81.81% and 86.36% respectively). The mean serum cortisol level was significantly higher in Group B (829.71 ± vs. 389.98 ± 68.77). Postoperative delirium occurred in 27.3% of Group B patients, statistically significant compared to the 4.5% in Group A. However, patients in Group B who developed delirium experienced significantly longer postoperative ICU and hospital stays (79.29 ± 12.27 vs. 11.44 ± 2.85, p ≤ 0.05). There was one mortality in Group B, which was statistically not significant. Conclusion: This study observed a significant association between elevated serum cortisol levels in the postoperative period and the occurrence of postoperative delirium after off-pump coronary artery bypass grafting.

Surgical Treatment of Osteonecrosis of the Femoral Head Using Minimally Invasive Surgical Drilling and Cancellous Grafting at Brazzaville University Hospital

Introduction: Osteonecrosis of the femoral head (ONTF) is a debilitating condition. Several treatments have been proposed with controversial results. The aim of our study was to evaluate treatment by surgical drilling coupled with in situ cancellous grafting. Materials and methods: Our study was a case-control study conducted at Brazzaville University Hospital from 1st January 2018 to 31 December 2023. It compared two groups of patients with ONTF: non-operated (13 patients, 20 hips) and operated (22 patients, 35 hips). We used the visual digital scale (VDS) for pain assessment, the Merle D’Aubigne-Postel (MDP) scoring system for clinical and functional assessment, and the evolution of necrosis. Results: The group of non-operated patients had a mean age of 35.69 ± 3.4 years, no improvement in pain with an EVN above seven at the last recoil and a mean global MDP score falling from 12.7 before offloading to 10.13 at one year. The group of patients operated on had a mean age of 37.86 ± 7.02 years, a significant reduction in pain (p = 0.00004) and a significantly increased MDP score (p = 0.0034). A comparison of the two groups of patients showed significant stabilization of the necrotic lesions in the operated patients (p = 0.00067), with better satisfaction in the same group. Conclusion: Surgical drilling combined with grafting in the treatment of early-stage ONTF has improved progress in our series. The technique is reproducible and less invasive. It has made it possible to delay unfavorable progression and, consequently, hip replacement surgery.

Clinical effect of botulinum toxin type A combined with autologous fat grafting in patients with nasolabial fold depression

BACKGROUND Nasolabial fold(NLF)depression can affect the facial appearance of patients to some extent and increase their psychological burdens.In recent years,autologous fat grafting(AFG)combined with botulinum toxin A(BTX-A)injection(AFG+BTX-A injection)has been gradually applied in the treatment of patients with NLF depression.Although studies have been conducted on the efficacy and safety of AFG+BTX-A injection in treating NLF depression,the experimental design,observational indicators,and sample enrollment criteria vary remarkably,making it difficult to draw convincing and consistent conclusions.Thus,further relevant research is warranted.AIM To assess the esthetic improvement,efficacy,and safety of AFG+BTX-A injections in patients with NLF depression.METHODS This study included 60 patients with NLF depression who were treated in our hospital from February 2019 to April 2021.These patients were categorized into control(n=30)and observation(n=30)groups.The observation group received AFG+BTX-A injection,whereas the control group underwent AFG only.All patients were evaluated using the wrinkle severity rating scale(WSRS)and global aesthetic improvement scale.The compactness of facial contours,skin evaluation indexes,adverse reactions,and satisfaction of the two groups were evaluated 3 months postoperatively.RESULTS The WSRS scores of the observation group at 1,3,and 6 months postoperatively were lower than those of the control group(P<0.05).Three months postoperatively,facial fine lines and pores showed obvious improvement and the skin index score was higher in the observation group than in the control group(P<0.05).The compactness of facial contours was better in the observation group than in the control group(P<0.05).In addition,no remarkable differences were noted in the incidence of postoperative adverse reactions such as facial stiffness,facial asymmetry,facial bruising,and facial concavity inequality(P>0.05).CONCLUSION AFG+BTX-A injection is a highly safe,cost-effective,effective,and long-lasting treatment for NLF depression with high esthetic value,which should be promoted in the future.

Negative pressure device-assisted autologous fat grafting: A case report

This report describes a novel technique for improving depressed scars using negative pressure suction-assisted autologous fat grafting.A 35-year-old woman presented with a 20-year history of bilateral central buttock con-cavities,causing aesthetic concerns.To maximize fat graft survival and enhance tissue volume,we implemented intermittent negative pressure suction on the recipient area for one month preoperatively.The patient expressed satisfaction with the cosmetic outcome,and a three-month follow-up confirmed a significantly improved fat graft survival rate.This minimally invasive,cost-effective,and easily reproducible technique offers a promising clinical strategy for treating depressed scars.

Efficient and selective removal of Pb(Ⅱ) from landfill leachate using L-serine-modified polyethylene/polypropylene nonwoven fabric synthesized via radiation grafting technique

In this study,to efficiently remove Pb(Ⅱ) from aqueous environments,a novel L-serine-modified polyethylene/polypropylene nonwoven fabric sorbent(NWF-serine)was fabricated through the radiation grafting of glycidyl methacrylate and subsequent L-serine modification.The effect of the absorbed dose was investigated in the range of 5–50 kGy.NWF-serine was characterized by Fourier transform infrared spectroscopy,thermogravimetric analysis,and scanning electron microscopy.Batch adsorption tests were conducted to investigate the influences of pH,adsorption time,temperature,initial concentration,and sorbent dosage on the Pb(Ⅱ) adsorption performance of NWF-serine.The results indicated that Pb(Ⅱ) adsorption onto NWF-serine was an endothermic process,following the pseudo-second-order kinetic model and Langmuir isotherm model.The saturated adsorption capacity was 198.1 mg/g.NWF-serine exhibited Pb(Ⅱ) removal rates of 99.8% for aqueous solutions with initial concentrations of 100 mg/L and 82.1% for landfill leachate containing competitive metal ions such as Cd,Cu,Ni,Mn,and Zn.Furthermore,NWF-serine maintained 86% of its Pb(Ⅱ) uptake after five use cycles.The coordination of the carboxyl and amino groups with Pb(Ⅱ) was confirmed using X-ray photoelectron spectroscopy and extended X-ray absorption fine structure analysis.

Off-Pump Coronary Artery Bypass Grafting in Patients with Left Ventricular Dysfunction: Short-Term Results from a Single Center in Bangladesh

Background: Off-pump coronary artery bypass grafting (OPCAB) is considered a safer alternative to on-pump surgery, especially in patients with left ventricular dysfunction (LVD). Objectives: This study assessed short-term outcomes and functional improvements in LVD patients post-OPCAB. Methods: The study included 200 coronary artery disease patients who underwent isolated off-pump coronary artery bypass grafting (OPCAB) at the National Heart Foundation Hospital and Research Institute between January 2019 and June 2020. Patients were categorized into Group 1, with a left ventricular ejection fraction (LVEF) of 30% - 39%, and Group 2, with an LVEF of 40% or higher. Echocardiographic assessments of left ventricular dimensions and ejection fraction were performed preoperatively, at discharge, and one month postoperatively. Results: In Group 1, preoperative left ventricular internal dimensions during diastole (LVIDd) and systole (LVIDs) were 53.48 ± 4.40 mm and 44.23 ± 3.93 mm, respectively, with a left ventricular ejection fraction (LVEF) of 35.28% ± 2.26%. At discharge, these values improved to 51.58 ± 4.04 mm (LVIDd), 41.23 ± 5.30 mm (LVIDs), and 39.25% ± 3.75% (LVEF). One month postoperatively, further improvements were observed: 46.29 ± 3.76 mm (LVIDd), 37.45 ± 3.68 mm (LVIDs), and 43.22% ± 4.67% (LVEF). Group 2 showed similar positive outcomes, with preoperative values of 47.09 ± 5.06 mm (LVIDd), 35.11 ± 5.25 mm (LVIDs), and 50.13% ± 7.25% (LVEF), improving to 42.37 ± 4.18 mm (LVIDd), 31.05 ± 4.19 mm (LVIDs), and 55.33% ± 7.05% (LVEF) at one month postoperatively. Both groups demonstrated significant improvements in left ventricular function and NYHA class, with most patients moving from class III/IV to I/II. Complications were minimal, and no mortality was observed. Conclusion: OPCAB is safe and effective for patients with LVEF 30% - 39% and LVEF ≥ 40%, providing significant short-term functional improvements without increased risk.

Impact of specialized nursing outpatient case management on postcoronary artery bypass grafting patients

BACKGROUND Some patients with coronary atherosclerotic heart disease experience major adverse cardiac events(MACE)and require readmission after Coronary Artery Bypass Grafting(CABG)surgery.This is often attributed to patients'unhealthy lifestyles and dietary habits,inadequate understanding of the disease,and poor disease management compliance.Thus,searching for more targeted nursing intervention models that can enhance patients'self-management abilities and reduce the risk of readmission after CABG surgery is significant.AIM To observe the impact of specialized nursing outpatient case management on patients after CABG surgery.METHODS A total of 103 patients who underwent CABG surgery in our hospital between April 2021 and April 2022 comprised the study sample.The patients were divided into two groups using an odd-even number grouping method.The control group received routine nursing care,while the case management group received specialized nursing outpatient case management.The differences in psychological status,adherence to medical treatment,self-care ability,knowledge mastery,quality of life scores,and the occurrence rate of MACE were compared between the two groups.RESULTS After the intervention,the case management group had lower scores on the selfrating depression scale and self-rating anxiety scale and lower MACE rate,as well as higher scores for adherence to a healthy diet,medication adherence,good lifestyle habits,regular exercise,and timely follow-up,higher scores on the Coronary Heart Disease Self-Management Scale,higher scores for managing adverse habits,symptoms,emotional cognition,emergency response,disease knowledge,general lifestyle,and treatment adherence,higher scores for understanding coronary heart disease,recognizing the importance of medication adherence,understanding selfcare points after CABG surgery,and being aware of post-CABG precautions,higher scores for physical well-being,disease condition,general health,social-psychological well-being,and work-related aspects(P<0.05).CONCLUSION Specialized nursing outpatient case management can enhance patient adherence to medical treatment,knowledge mastery,psychological well-being,and overall quality of life in patients after CABG surgery.

Delayed Grafting as a Valid Technique in Burn Management: Experience from a Burn Unit in Oman

Background: Early excision and grafting has been the preferred method of managing major burns around the world since 1970. Considering the advances in health care and the development of new antibiotics over the past 50 years, delayed grafting as a technique for the management of burns over 15%-20% of total body surface area (TBSA) could have comparable results to that of early excision. This study aims to highlight the outcomes of practicing delayed grafting in burn patients. Methods: A case series analysis was performed of 51 patients who were admitted to the burns unit in Sultan Qaboos Hospital Salalah with over 20% TBSA between January 2014 and December 2019. The patients received prophylactic antibiotics and silver sulphadiazine dressing until the burn eschar had completely separated, followed by grafting. Results: Two patients were lost during the entire duration of the study. The mortality rate was comparable to that of early excision, while the rate of hypertrophic scarring was lower than the range reported by other studies. Conclusion: In the management of patients with over 20% TBSA, delayed grafting after complete separation of eschar is still a valid technique.

Impact of coronary artery bypass grafting surgery on the chorioretinal biomicroscopic characteristics

BACKGROUND Most patients with cardiovascular disorders suffer from coronary artery diseases,which can be treated successfully using coronary artery bypass grafting(CABG).One of the unpleasant events following CABG is postoperative vision loss(POVL).Vulnerability of retinal vessels to hemodynamic changes,an expectable event following CABG,may contribute to the development of POVL,which might be associated with the changes in the choroidal and retinal structures.AIM To investigate postoperative changes in chorioretinal and peripapillary nerve fiber layer(NFL)thickness,and progression of diabetic and hypertensive retinopathy after CABG.METHODS In this prospective,cross-sectional study,49 eyes in 25 candidates for CABG underwent both ophthalmic and cardiovascular examinations within 6 mo prior to and 9 mo after surgery.RESULTS Among the study participants,56%were male with a mean age of 62.84 years±10.49 years(range 33–80 years).Diabetes mellitus was observed in eight participants(32%).None of the patients suffered from postoperative anterior or posterior ischemic optic neuropathy,central retinal artery occlusion,and cortical blindness.The mean value of the preoperative best corrected visual acuity was 0.11±0.10 logMAR(range,0–0.4),which worsened to 0.15±0.08 logMAR(range,0–0.4)after CABG(P=0.031).No significant difference was observed between the preand postsurgical choroidal(P=0.853)and macular(P=0.507)thickness,NFL thickness in the subfoveal(P>0.999)and peripapillary areas(P=0.659),as well as the severity of diabetic and hypertensive retinopathy.CONCLUSION CABG may reduce visual acuity without affecting ocular structures.Postoperative vision reduction might be attributable to molecular or cellular variations,changes in visual pathway function,or central nervous system.

不同方法对根管内氢氧化钙去除效果的micro-CT评价

目的:应用显微CT(micro-computed tomography,micro-CT)建立磨牙根管模型,评价不同方法对氢氧化钙的清除效率。方法:收集2023年10月—2024年2月口腔综合科门诊拔除的11颗磨牙(24个根管),按照标准根管治疗流程,镍钛器械预备完成后,在根管内置入氢氧化钙,1周后,根据不同冲洗方法将样本随机分为侧方开口注射器组、超声荡洗组(EMS组)和声波震荡组(EDDY组)等3组(n=8)。冲洗前后使用micro-CT重建根管系统并使用不同颜色标记独立根管,计算各个根管氢氧化钙体积,比较各组氢氧化钙清除率。采用SPSS 19.0软件包对数据进行统计学分析。结果:3种方法均无法完全去净根管内氢氧化钙。使用次氯酸钠作为冲洗液时,超声荡洗和声波震荡清除效果优于侧方开口冲洗器(P<0.05);超声荡洗和声波震荡去除氢氧化钙效率相当,差异无统计学意义(P>0.05);氢氧化钙残留部位集中于根尖区。结论:Micro-CT能较为高效地重建磨牙根管模型,可用于评价氢氧化钙去除效果。超声荡洗组和声波震荡组清除氢氧化钙效率相当,优于侧方开口注射器组。

Antimicrobial Expanded Polytetrafluoroethylene Film Prepared by 3-ray Radiation Induced Grafting of Poly（acrylic acid）

The simultaneous γ-ray-radiation-induced grafting polymerization of acrylic acid on ex- panded polytetrafluoroethylene （ePTFE） film was investigated. It was found that the degree of grafting （DG） of poly（acrylic acid） （PAA） can be controlled by the monomer concentration, absorbed dose, and dose rate under an optimal inhibitor concentration of [Fe2＋]=18 mmol/L. SEM observation showed that the macroporous structure in ePTFE films would be covered gradually with the increase of the DG of PAA. The prepared ePTFE-g-PAA film was im- mersed in a neutral silver nitrate solution to fabricate an ePTFE-g-PAA/Ag hybrid film after the addition of NaBH4 as a reduction agent of Ag＋ to Ag atom. SEM, XRD, and XPS results proved that Ag nanoparticles with a size of several tens of nanometers to 100 nanometers were in situ immobilized on ePTFE film. The loading capacity of Ag nanoparticles could be tuned by the DG of PAA, and determined by thermal gravimetric analysis. The quart- titative antibacterial activity of the obtained ePTFE-g-PAA/Ag hybrid films was measured using counting plate method. It can kill all the Escherichia coli in the suspension in 1 h. Moreover, this excellent antibacterial activity can last at least for 4 h. This work provides a facile and practical way to make ePTFE meet the demanding antimicrobial requirement in more and more practical application areas.

Micro LED车灯投影光学系统设计与优化

本文提出了一种基于Micro LED阵列的车灯投影方案,设计了以像素尺寸为80μm×80μm的200×150白光Micro LED阵列作为显示光源,视场角为16°×34°的车灯投影光学系统,并对物面倾斜角度和光学系统结构进行了优化。此外,分别采用反向畸变处理方法和像素灰度调制方法用以解决车灯投影图像的梯形畸变和照度均匀性问题,并搭建了投影实验平台,对图像校正方法进行了验证。实验结果表明:校正后图像梯形畸变系数p1,p2分别从0.0932和0.3680下降至0.0835和0.0373,像面照度均匀性从83.2%提高到93.2%。本文通过对基于Micro LED的倾斜投影车灯光学系统进行优化设计及采用图像校正方法,实现了高光效、低畸变的车灯投影。

Grafting effects on bioactive compounds,chemical and agronomic traits of‘Corbarino’tomato grown under greenhouse healthy conditions

In tomatoes,grafting onto resistant rootstocks represents an effective strategy to control several soil-borne diseases that reduce crop profitability,especially for landraceswith little or no resistance tomultiple pathogens/pests.In this study,the high-value‘Corbarino’tomato landrace was grafted onto seven commercial Solanum interspecific rootstocks to evaluate graft compatibility,yield performance,and qualitative characteristics under greenhouse healthy conditions.Three rootstocks were themost effective in improving fruit yield without negatively affecting the carpometric,technological,and health-related traits of the traditional tomato.‘Dinafort’rootstock increased fresh and dry yield,harvest index,and fruit/clusters,while mean fruit weight,shape index,total and soluble solid content,simple sugars,organic acids,flavonoids,ascorbic acid,and trans-lycopene content did not differ with respect to the ungrafted‘Corbarino’.‘Interpro’rootstock also showed promising results for the overall yield and quality traits,although it reduced the trans-lycopene content in the fruit.‘Silex’rootstock showed the highest harvest index as result of decreased vigour.The fruit quality induced by‘Silex’was satisfactory and high levels of simple sugars,flavonoids,ascorbic acid,and trans-lycopene were also observed.However,graft success,especially for‘Dinafort’and‘Silex’,needs to be improved by investigating more suitable methods for seedling production,grafting,acclimatization,etc.

光子晶体Micro LED微显示阵列加工及光学特性分析

Micro LED器件具有高亮度、低功耗和高可靠性等优点,但Micro LED显示像素巨量转移和光提取效率低的问题为其应用带来挑战。开发了具有高转移效率和出光效率的单片64×64 Micro LED微显示阵列,提出了倒装型GaN基单片Micro LED微显示阵列芯片和Si基驱动电路的设计方法及集成工艺。通过时域有限差分(FDTD)方法对Micro LED微显示阵列光学特性进行了建模分析,设计了一种提高Micro LED微显示阵列出光效率的光提取结构。结合仿真结果,开发了一种在Micro LED蓝宝石衬底表面制备光子晶体结构的聚焦离子束(FIB)微纳加工工艺,并进行了器件加工。测试结果表明,蓝宝石衬底上加工的光子晶体结构可以提高Micro LED器件的表面出光效率,光功率平均值提升了16.36%,对Micro LED微显示阵列加工及微显示像素光提取问题具有借鉴意义。

基于Micro CT的铜导线短路熔痕孔洞特征分析

导线短路是造成电气火灾的重要原因之一。现行国家标准中将导线短路熔痕分为起火前发生的一次短路熔痕和起火后造成的二次短路熔痕,然而现行国家标准中的鉴定仅停留在定性判断的阶段。火灾现场铜导线短路熔痕特征的量化分析研究是国内外研究人员主要关注的重点。本文应用Micro CT技术对铜导线短路熔痕进行断层扫描检测并重构铜导线短路熔痕的3D图像数据,在此基础上统计、归纳、总结铜导线短路熔痕内部孔洞形态及分布等孔洞特征。研究表明,Micro CT能够全面采集铜导线短路熔痕的整体形态和内部孔洞特征,一次短路熔痕与二次短路熔痕内部孔洞半径、表面积、紧密度的特征数据存在差别,可为短路熔痕定性和定量分析判据研究提供新的理论依据。

Nicotiana benthamiana XYLEM CYSTEINE PROTEASE genes facilitate tracheary element formation in interfamily grafting

Grafting is a plant propagation technique widely used in agriculture.A recent discovery of the capability of interfamily grafting in Nicotiana has expanded the potential combinations of grafting.In this study,we showed that xylem connection is essential for the achievement of interfamily grafting and investigated the molecular basis of xylem formation at the graft junction.Transcriptome and gene network analyses revealed gene modules for tracheary element(TE)formation during grafting that include genes associated with xylem cell differentiation and immune response.The reliability of the drawn network was validated by examining the role of the Nicotiana benthamiana XYLEM CYSTEINE PROTEASE(NbXCP)genes in TE formation during interfamily grafting.Promoter activities of NbXCP1 and NbXCP2 genes were found in differentiating TE cells in the stem and callus tissues at the graft junction.Analysis of a Nbxcp1;Nbxcp2 loss-of-function mutant indicated that NbXCPs control the timing of de novo TE formation at the graft junction.Moreover,grafts of the NbXCP1 overexpressor increased the scion growth rate as well as the fruit size.Thus,we identified gene modules for TE formation at the graft boundary and demonstrated potential ways to enhance Nicotiana interfamily grafting.

The role of DNA methylation in the maintenance of phenotypic variation induced by grafting chimerism in Brassica

Grafting facilitates the interaction between heterologous cells with different genomes,resulting in abundant phenotypic variation,which provides opportunities for crop improvement.However,how grafting-induced variation occurs and is transmitted to progeny remains elusive.A graft chimera,especially a periclinal chimera,which has genetically distinct cell layers throughout the plant,is an excellent model to probe the molecular mechanisms of grafting-induced variation maintenance.Here we regenerated a plant from the T-cell layer of a periclinal chimera,TCC(where the apical meristem was artificially divided into three cell layers–from outside to inside,L1,L2,and L3;T=Tuber mustard,C=red Cabbage),named rTTT0(r=regenerated).Compared with the control(rsTTT,s=self-grafted),rTTT0 had multiple phenotypic variations,especially leaf shape variation,which could be maintained in sexual progeny.Transcriptomes were analyzed and 58 phenotypic variation-associated genes were identified.Whole-genome bisulfite sequencing analyses revealed that the methylome of rTTT0 was changed,and the CG methylation level was significantly increased by 8.74%.In rTTT0,the coding gene bodies are hypermethylated in the CG context,while their promoter regions are hypomethylated in the non-CG context.DNA methylation changes in the leaf shape variation-associated coding genes,ARF10,IAA20,ROF1,and TPR2,were maintained for five generations of rTTT0.Interestingly,grafting chimerism also affected transcription of the microRNA gene(MIR),among which the DNA methylation levels of the promoters of three MIRs associated with leaf shape variation were changed in rTTT0,and the DNA methylation modification of MIR319 was maintained to the fifth generation of selfed progeny of rTTT0(rTTT5).These findings demonstrate that DNA methylation of coding and non-coding genes plays an important role in heterologous cell interaction-induced variation formation and its transgenerational inheritance.