Evaluation of the early defoliation trait and identification of resistance genes through a comprehensive transcriptome analysis in pears

Early defoliation,which usually occurs during summer in pear trees,is gradually becoming a major problem that poses a serious threat to the pear industry in southern China.However,there is no system for evaluating the responses of different cultivars to early defoliation,and our knowledge of the potential molecular regulation of the genes underlying this phenomenon is still limited.In this study,we conducted field investigations of 155 pear accessions to assess their resistance or susceptibility to early defoliation.A total of 126 accessions were found to be susceptible to early defoliation,and only 29 accessions were resistant.Among them,19 resistant accessions belong to the sand pear species(Pyrus pyrifolia).To identify the resistance genes related to early defoliation,the healthy and diseased samples of two sand pear accessions,namely,the resistant early defoliation accession‘Whasan’and the susceptible early defoliation accession‘Cuiguan’,were used to perform RNA sequencing.Compared with‘Cuiguan’,a total of 444 genes were uniquely differentially expressed in‘Whasan’.Combined with GO and KEGG enrichment analyses,we found that early defoliation was closely related to the stress response.Furthermore,a weighted gene co-expression network analysis revealed a high correlation of WRKY and ethylene responsive factor(ERF)transcription factors with early defoliation resistance.This study provides useful resistant germplasm resources and new insights into potentially essential genes that respond to early defoliation in pears,which may facilitate a better understanding of the resistance mechanism and molecular breeding of resistant pear cultivars.

The PcHY5 methylation is associated with anthocyanin biosynthesis and transport in ‘Max Red Bartlett' and ‘Bartlett' pears

The red coloring of pear fruits is mainly caused by anthocyanin accumulation. Red sport, represented by the green pear cultivar ‘Bartlett’(BL) and the red-skinned derivative ‘Max Red Bartlett’(MRB), is an ideal material for studying the molecular mechanism of anthocyanin accumulation in pear. Genetic analysis has previously revealed a quantitative trait locus(QTL) associated with red skin color in MRB. However, the key gene in the QTL and the associated regulatory mechanism remain unknown. In the present study, transcriptomic and methylomic analyses were performed using pear skin for comparisons between BL and MRB. These analyses revealed differential PcHY5 DNA methylation levels between the two cultivars;MRB had lower PcHY5 methylation than BL during fruit development, and PcHY5 was more highly expressed in MRB than in BL. These results indicated that PcHY5 is involved in the variations in skin color between BL and MRB. We further used dual luciferase assays to verify that PcHY5 activates the promoters of the anthocyanin biosynthesis and transport genes PcUFGT, PcGST, PcMYB10 and PcMYB114, confirming that PcHY5 not only regulates anthocyanin biosynthesis but also anthocyanin transport. Furthermore, we analyzed a key differentially methylated site between MRB and BL, and found that it was located in an intronic region of PcHY5. The lower methylation levels in this PcHY5 intron in MRB were associated with red fruit color during development, whereas the higher methylation levels at the same site in BL were associated with green fruit color. Based on the differential expression and methylation patterns in PcHY5 and gene functional verification, we hypothesize that PcHY5, which is regulated by methylation levels, affects anthocyanin biosynthesis and transport to cause the variations in skin color between BL and MRB.

PEARS课程在儿科急诊护士急救能力培训中的应用

[目的]探讨儿童急症的评估、识别和干预(PEARS)课程对提高儿科急诊护士急救能力的作用。[方法]采用美国心脏协会的PEARS课程对急诊护士进行培训,在培训前对护士进行理论摸底考试,培训后进行理论、技能和仿真案例考核,考核结束后进行课程评价的问卷调查。[结果]培训后护士的理论成绩(88.83分±7.86分)较培训前(76.75分±6.21分)提高(P<0.01);护师组的技能考核和仿真案例考核优秀率高于护士组(P<0.01)。[结论]儿科急诊护士经PEARS课程培训后对急诊患儿的评估、识别和干预能力提高。

基于移动终端的小学英语词汇句型整合课实践——“Do you like pears?”教学实录与评析

本文详细记录＂Do you like pears？＂一课的教学过程,授课教师熟练运用信息技术,通过课前问卷调查提升课堂教学的针对性,创设饱含童趣的情境激发学生学习热情并在情境中有效整合新旧知识,通过有梯度的操练强化学生听、说、认、读能力,结合课文创编新情境实现情感升华,分层拓展练习提升学生的语用能力。

Zhaoxian County,Home of the Pears

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Bleeding canker of pears caused by Dickeya fangzhongdai:Symptoms,etiology and biology

Bleeding canker,a devastating disease of pear trees(Pyrus pyrifolia L.),was first reported in the 1970 s in Jiangsu,China and more recently in other provinces in China.Trees infected with bleeding canker pathogen,Dickeya fangzhongdai,develop cankers on the trunks and branches,and a rust-colored mixture of bacterial ooze and tree sap could be seen all over the trunks and branches.In this study,we provided detail descriptions of the symptoms and epidemiology of bleeding canker disease.Based on pathogenic and phenotypic characterizations,we identified the causal agent of bleeding canker of pear as D.fangzhongdai.Dickeya fangzhongdai strains isolated from pear were also pathogenic on Solanum tuberosum,Brassica pekinensis,Lycopersicon esculentum,and Phalaenopsis aphrodite based on artificial inoculation,and the pathogen were more virulent on potato than that of D.solani strain.This study provides new information about this disease and bleeding canker disease of pear.

Model for estimating the weight-loss ratio of damaged Korla fragrant pears

To predict the weight-loss ratio of Korla fragrant pears effectively,improve commodity value and study the variation laws of the weight-loss ratio of damaged fragrant pears during storage,this study predicted the weight-loss ratio of fragrant pears by utilizing the generalized regression neural network(GRNN),support vector regression(SVR),partial least squares regression(PLSR)and error back propagation neural network(BPNN).The prediction performances of GRNN,SVR,PLSR and BPNN models were compared comprehensively,and the optimal model was determined.In addition,the optimal prediction model was verified.The results show that weight-loss ratio of fragrant pears increases gradually with the extension of storage time.During storage,the weight-loss ratio of fragrant pears is positively related to the degree of damage.The trained GRNN,SVR,PLSR and BPNN models can be used to predict the weight-loss ratio of fragrant pears.The BPNN model is the most accurate in predicting the weight-loss ratio of damaged fragrant pears(R^(2)=0.9929;RMSE=0.2138).It has also been proved to have good predictive effect in production practice(R^(2)=0.9377,RMSE=0.7138).The research findings can provide references to predict the delivery quality and time of delivery of Korla fragrant pears.

阿司匹林单药抗血小板治疗的缺血性卒中患者复发危险因素分析

目的 探讨使用阿司匹林进行单抗二级预防的缺血性卒中患者复发的危险因素。方法 对200例使用阿司匹林单抗治疗1 a后的轻型和中型缺血性卒中患者进行回顾性的分析,根据患者卒中是否复发分为未复发组和复发组,使用单因素分析和多因素Logistic回归模型分析探讨相关指标是否为复发的高危因素,并利用ROC曲线预测危险因素的临界值。结果 单因素分析显示有统计学意义的危险因素为血小板计数、同型半胱氨酸水平和PEAR1基因rs12041331位点的A等位基因(P <0.05)。多因素分析表明复发的独立危险因素为同型半胱氨酸水平[OR=1.16(1.089~1.240),P <0.001]。采用ROC预测的临界值为8.35μmol/L(灵敏度0.847,特异度0.532)。结论 PEAR1基因rs12041331位点的A等位基因、血小板计数和Hcy水平是导致阿司匹林单抗治疗的缺血性卒中患者复发的危险因素,Hcy水平是导致阿司匹林单抗治疗的缺血性卒中患者复发的独立危险因素,可利用Hcy水平预测阿司匹林单抗治疗的缺血性卒中患者复发的风险。

Genome-wide identification and characterization of the PbrATG family in Pyrus bretschneideri and functional analysis of PbrATG1a in response to Botryosphaeria dothidea

The pear is an economic fruit that is widely planted around the world and is loved by people for its rich nutritional value. Autophagy is a self-protection mechanism in eukaryotes, and its occurrence often accompanied by the degradation of damaged substances in cells and the recycling of nutrients. Autophagy is one of the mechanisms through which plants respond to environmental stress and plays an important role in plant development and stress resistance. Functional studies of autophagy-related genes (ATGs) have been performed on a variety of plant species, but little information is available on the ATG family in pear (Pyrus bretschneideri Rehd). Therefore, we analyzed the evolutionary dynamics and performed a genome-wide characterization of the PbrATG gene family. A total of 28 PbrATG members were identified.Phylogenetic analysis showed that PbrATGs were more closely related to ATGs of European pear and apple. Evolutionary analysis revealed that whole-genome duplication (WGD) and dispersed duplication events were the main driving forces of PbrATG family expansion.Expression analysis of different pear tissues showed that all the genes were expressed in different pear tissues, and different PbrATGs are expressed at different times and in different locations. Moreover, all PbrATGs also responded to different abiotic stresses, especially salt and drought stress, which elicited the highest expression levels. Pear seedlings were subsequently infected with Botryosphaeria dothidea (B.dothidea). The results showed that different PbrATGs had different expression patterns at different infection stages. According to the gene expression data, PbrATG1a was selected as a key autophagy gene for further analysis. Silencing of PbrATG1a reduced the resistance of pear to B. dothidea, which resulted in increased lesions, reactive oxygen species (ROS) contents, antioxidant enzyme activity, and gene expression levels in the silenced pear seedlings after B. dothidea inoculation. In this study, a comprehensive bioinformatic analysis of ATGs was conducted, and the functions of PbrATGs in pear development and in response to stress were elucidated, which laid a foundation for further study of the molecular mechanism of autophagy and a new strategy for pear resistance breeding.

PbrARF4 contributes to calyx shedding of fruitlets in ‘Dangshan Suli’ pear by partly regulating the expression of abscission genes

Fruitlet calyx shedding in pear plants is apparently regulated via numerous pathways that involve both environmental triggers and phytohormones cues such as auxin. In this study, we found at 10 days after full bloom (DAFB) higher levels of indoleacetic acid (IAA) and tryptophan (Trp) in calyx persistence fruitlet (CPF) than calyx shedding fruitlet (CSF) ofDanshan Suli’ pear (Pyrus bretschneideri Rhed.). Consisting with this, the activity of indolealdehyde oxidase (IAAIdO), which promotes IAA synthesis, was remarkably increased, and that of peroxidase(POD), which degrades IAA, dropped markedly in CPF but not in CSF. Further, qRT-PCR results revealed that most of 31 PbrARFs (encoding auxin response factors) in Pyrus bretschneideri were highly expressed in CPF, whereas PbrARF4, PbrARF24 and PbrARF26 were significantly downregulated in CPF vis-a-vis CSF. Phylogenetic analysis revealed that 6 PbrARFs clustered in the group III, where PbrARF4 showed the closest affinity with AtARF1 that promotes organ abscission, indicating a putative role of PbrARF4 in mediating the process of calyx shedding in pear. In fact, the ectopic overexpression of PbrARF4 in Solanum lycopersicum resulted in an earlier-formed and deeper abscission layer (AL) in the transgenic plants, whose calyxes were more prone to wilt at the mature red stage (MR) compared with the control plants (wild-type). More importantly, expression levels of the abscission genes SILS and Sl Cel2 in transgenic plants overexpressing PbrARF4 were significantly upregulated in comparation with the WT, whereas those of Sl BI and Sl TAPG2 were considerably inhibited. Further, PbrJOINTLESS and PbrIDA,the two genes related to calyx shedding in pear, were up-regulated more in CSF than CPF. The findings contribute to a better understanding of PbrARFs involved in fruitlet calyx shedding of pear, which could prove beneficial to improving the quality of pear fruit.

Genomic selection of eight fruit traits in pear

Genomic selection (GS) has the potential to improve selection efficiency and shorten the breeding cycle in fruit tree breeding. In this study,we evaluated the effect of prediction methods, marker density and the training population (TP) size on pear GS for improving its performance and reducing cost. We evaluated GS under two scenarios:(1) five-fold cross-validation in an interspecific pear family;(2) independent validation. Based on the cross-validation scheme, the prediction accuracy (PA) of eight fruit traits varied between 0.33 (fruit core vertical diameter)and 0.65 (stone cell content). Except for single fruit weight, a slightly better prediction accuracy (PA) was observed for the five parametrical methods compared with the two non-parametrical methods. In our TP of 310 individuals, 2 000 single nucleotide polymorphism (SNP) markers were sufficient to make reasonably accurate predictions. PAs for different traits increased by 18.21%-46.98%when the TP size increased from 50to 100, but the increment was smaller (-4.13%-33.91%) when the TP size increased from 200 to 250. For independent validation, the PAs ranged from 0.11 to 0.45 using rrBLUP method. In summary, our results showed that the TP size and SNP numbers had a greater impact on the PA than prediction methods. Furthermore, relatedness among the training and validation sets, and the complexity of traits should be considered when designing a TP to predict the test panel.

A method for Improving the Efficiency of Pear Tree Crossbreeding

In view of the short blooming period of pear tree crossbreeding and the complexity of pollination process, a method that can improve the efficiency of crossbreeding of pear trees was provided. Meanwhile, this method can also be applied to the study of pollen xenia effect, pollination tree selection and pure pollen collection in pear tree cultivation.

急性脑梗死患者发生阿司匹林抵抗相关危险因素分析

目的:探讨急性脑梗死患者发生阿司匹林抵抗与相关危险因素的关系。方法:潍坊益都市中心医院2022年10月至2023年5月急性脑梗死患者共358名,患者于入院当日开始口服阿司匹林肠溶片100 mg/d,服用阿司匹林10 d后,根据血小板聚集实验结果将患者分为阿司匹林抵抗(Aspirin Resistance, AR)组和阿司匹林敏感(Aspirin sensitivity, AS)组,分别就AR组和AS组的血小板内皮聚集受体1 (Platelet-endothelial aggregation receptor 1, PEAR1)基因型的分布情况、高血压、2型糖尿病、性别、年龄、吸烟、饮酒等数据进行收集。结果:与AS组患者比较,AR组患者在性别、高血压、2型糖尿病、吸烟史等方面差异有统计学意义(P 0.05);AR组PEAR1野生型GG基因频率低于AS组,差异有统计学意义(P < 0.05);AR组PEAR1纯合突变型AA基因频率高于AS组,差异有统计学意义(P < 0.05)。结论:急性脑梗死患者发生阿司匹林抵抗与患者PEAR1基因的多态性、高血压、2型糖尿病、性别和吸烟等因素有关。

英语课堂教学设计案例 Unit 4 Do you like pears? B Let's talk

一、教学设计 总体思路:本节课主要采用小组合作学习的学习方式,以学生为主体,充分发挥学生的自主性,借助实物和多媒体辅助教学,合作、竞争与评价贯穿于整个教学过程中.……

Comprehensive evaluation of Korla fragrant pears and optimization of plucking time during the harvest period

To optimize the harvest of Korla fragrant pears and to provide a theoretical basis for post-harvest processing,a total of 26 basic indices of Korla fragrant pears,including their morphology,quality,and softening age,were investigated.The harvest period ranged from August 22nd to October 6th,samples were collected every 5 d(totally 10 plucking days,indicated as H1-H10).The results indicated that changes in pectin content were the main causes of softening in fragrant pears.The scavenging of free radicals mainly occurred because of the collaborative effects of superoxide dismutase(SOD)and catalase(CAT).In the harvest periods H1-H3,the hardness,titratable acid(TA),chlorophyll content,density,and diameter of the stone cells,as well as the cellulose and hemicellulose content of the Korla fragrant pears were at their highest.During the periods H7-H10,the single-fruit weight,fruit horizontal and vertical diameter,color coordinates L,a*,b*,soluble-solids content(SSC),SOD activity,CAT activity,and water-soluble pectin were higher than in the other plucking periods.The highest vitamin C(VC)content and moderate values for a variety of indicators were observed during H3-H7.Variations in the Korla fragrant pears during H1-H3 mainly manifested through changes in softening-related parameters.During H3-H10,changes in the softening-related,aging-related,color-related,and quality indices had a dominant role.On this basis,some suggestions for the post-harvest processing of fragrant pears have been proposed.Fruit,during H1-H3,are suitable for transportation and storage;during H7-H10 are suitable for fresh-eating and further processing;and during H3-H7,exhibited moderate values for a variety of indicators and had the highest commercial value.This research provides a systematic evaluation of the characteristics of mature Korla fragrant pears during the harvest period and can form the basis for fruit quality control and processing of Korla fragrant pears.

Rapid and non-destructive decay detection of Yali pears using hyperspectral imaging coupled with 2D correlation spectroscopy

The black spot disease caused by Alternaria alternata on Yali pears is a great concern as it compromises their edible quality and commercial value.To realize rapid and non-destructive classification of this disease,hyperspectral imaging(HSI)technology was combined with two-dimensional correlation spectroscopy(2DCOS)analysis.A total of 150 pear samples at different decay grades were prepared.After obtaining the HSI images,the whole sample was demarcated as the region of interest,and the spectral information was extracted.Seven preprocessing methods were applied and compared to build the classification models.Thereafter,using the inoculation day as an external perturbation,2DCOS was used to select the feature-related wavebands for black spot disease identification,and the result was compared to those obtained using competitive adaptive reweighting sampling and the successive projections algorithm.Results demonstrated that the simplified least squares support vector model based on 2DCOS-identified feature wavebands yielded the best performance with the identification accuracy,precision,sensitivity,and specificity of 97.30%,94.60%,96.16%,and 98.21%,respectively.Therefore,2DCOS can effectively interpret the feature-related wavebands,and its combination with HSI is an effective tool to predict black spot disease on Yali pears.

PEAR1、GSTP1基因型与脑梗死预后的相关性分析

目的 探讨PEAR1、GSTP1基因型与脑梗死预后的相关性,为脑梗死个体化精准治疗及二级预防提供理论参考.方法 选取首发症状型脑梗死患者,入院后遵循抑制血小板聚集、营养神经、改善循环及对症治疗原则,患者24 h内口服阿司匹林100 mg, 1次/d,并长期维持治疗.收集患者的一般资料、既往史、血小板相关指标、PEAR1及GSTP1基因型、相关待测量表评分及脑梗死复发周期,出院随访13个月.根据脑梗死复发及复发周期进行分组,比较PEAR1、GSTP1基因多态性及其他临床资料与脑梗死预后是否具有关联.结果 入组患者PEAR1基因突变型(AA+AG)占60.1%,未突变型(GG)占39.9%;GSTP1基因突变型(AG+GG)占31.8%,未突变型(AA)占68.2%.对比分析两组患者冠心病病史、出院时NIHSS评分、血小板计数及GSTP1基因型与脑梗死复发有关联.多因素Logistic回归分析显示冠心病病史、出院时低NIHSS评分、低血小板计数及GSTP1基因突变型(AG+GG)为脑梗死复发的独立危险因素(P<0.05).结论 首发症状型脑梗死患者年龄越大、出院时低NIHSS评分、低血小板计数或GSTP1为基因突变型(AG+GG)脑梗死预后较差.

Arbuscular mycorrhizal fungi improve biomass, photosynthesis, and water use efficiency of Opuntia ficus-indica (L.) Miller under different water levels

Opuntia ficus-indica(L.)Miller is a CAM(crassulacean acid metabolism)plant with an extraordinary capacity to adapt to drought stress by its ability to fix atmospheric CO_(2) at nighttime,store a significant amount of water in cladodes,and reduce root growth.Plants that grow in moisture-stress conditions with thick and less fine root hairs have a strong symbiosis with arbuscular mycorrhizal fungi(AMF)to adapt to drought stress.Water stress can limit plant growth and biomass production,which can be rehabilitated by AMF association through improved physiological performance.The objective of this study was to investigate the effects of AMF inoculations and variable soil water levels on the biomass,photosynthesis,and water use efficiency of the spiny and spineless O.ficus-indica.The experiment was conducted in a greenhouse with a full factorial experiment using O.ficus-indica type(spiny or spineless),AMF(presence or absence),and four soil water available(SWA)treatments through seven replications.Water treatments applied were 0%–25%SWA(T1),25%–50%SWA(T2),50%–75%SWA(T3),and 75%–100%SWA(T4).Drought stress reduced biomass and cladode growth,while AMF colonization significantly increased the biomass production with significant changes in the physiological performance of O.ficus-indica.AMF presence significantly increased biomass of both O.ficus-indica plant types through improved growth,photosynthetic water use efficiency,and photosynthesis.The presence of spines on the surface of cladodes significantly reduced the rate of photosynthesis and photosynthetic water use efficiency.Net photosynthesis,photosynthetic water use efficiency,transpiration,and stomatal conductance rate significantly decreased with increased drought stress.Under drought stress,some planted mother cladodes with the absence of AMF have not established daughter cladodes,whereas AMF-inoculated mother cladodes fully established daughter cladodes.AMF root colonization significantly increased with the decrease of SWA.AMF caused an increase in biomass production,increased tolerance to drought stress,and improved photosynthesis and water use efficiency performance of O.ficus-indica.The potential of O.ficus-indica to adapt to drought stress is controlled by the morpho-physiological performance related to AMF association.

Genome-wide identification of the MATE gene family and functional characterization of PbrMATE9 related to anthocyanin in pear

Plant multidrug and toxic compound extrusion(MATE) genes play an important role in the process of detoxification, plant morphogenesis, and anthocyanin accumulation. However, whether the MATE gene family functions in pear peel coloration is still unknown. To evaluate and identify the MATE gene family members which are involving in anthocyanin accumulation and coloration in pear. In this study, 85 MATE genes were identified in the reference pear genome of ‘Dangshansuli’ through genome-wide identification. Based on gene structure and phylogenetic tree analysis, the MATE family was divided into five subfamilies. RNA sequencing and quantitative real-time polymerase chain reaction(qRTPCR) indicated that the expression patterns of PbrMATEs were tissue-specific. 28.24%(24) of PbrMATE genes were expressed in the fruits, and44.71%(38) of PbrMATE genes were expressed in the leaves. Additionally, we found that the expression levels of PbrMATE9, PbrMATE26,PbrMATE50, and PbrMATE69 in debagged fruits with red peel were significantly higher than those in bagged fruits without red peel, according to our bagging/debagging treatment of ‘Mantianhong’. The expression pattern of PbrMATE9 was consistent with the variation trend in anthocyanin content, suggesting that it might play an important role in anthocyanin accumulation in response to light exposure. Subcellular localization showed that PbrMATE9 was a membrane protein. More strikingly, the transient overexpression of PbrMATE9 promoted anthocyanin accumulation in the peel of pear, and the expression of structural genes(PbrCHI, PbrANS, PbrDFR, and PbrUFGT) in the anthocyanin biosynthesis pathway also increased significantly. Through co-expression network analysis, the transcription factors were identified, such as WRKY, COL,GATA, and BBX, which might be involved in the regulation of PbrMATE9. The study has enriched the genetic resources and improved the understanding of the regulation network of anthocyanin accumulation in pear.