百草枯中毒大鼠TNF-a、IL-10的表达及大黄保护作用的研究

目的：观察大黄对急性百草枯中毒大鼠TNF-α、IL-10的干预作用,探讨其可能的作用机制。方法：90只SD大鼠随机分为生理盐水对照组（A组）、PQ（60 mg/kg）灌胃染毒组（B组）、生大黄（300mg/kg.d）干预组（C组）,每组30只。中毒后6h、24h、72h分批处死存活的大鼠,并且检测大鼠血浆TNF-α、IL-10水平。结果：B组、C组TNF-α、IL-10水平在染毒后6h开始升高,72h达到高峰,与A组相比,差异有统计学意义（P〈0.05、P〈0.01）,在相同时间点C组TNF-α和IL-10的表达低于B组,差异均有统计学意义（P〈0.01）。B组、C组血浆TNF-α、IL-10水平与中毒时间呈显著正性相关关系（r=0.849,P〈0.01;r=0.790,P〈0.01;r=0.0.943,P〈0.01;r=0.892,P〈0.01）。结论：大黄能够通过降低百草枯中毒大鼠体内的TNF-α、IL-10水平,减轻百草枯对大鼠的损伤作用     

虾青素对运动性肾缺血再灌注损伤ECM表达的影响

本文对虾青素对运动性肾缺血再灌注损伤大鼠肾组织炎症因子及ECM表达的影响进行了研究。72只SPF级Wistar大鼠随机分为4组:安静对照组(C组,n=12)、一般训练组(M组,n=12)、过度训练组(OM组,n=24)和虾青素+过度训练组(AM组,n=24)。实验中对大鼠以20 mg/(kg·d)虾青素灌胃56 d,并进行递增负荷游泳训练。末次训练24 h后观察肾小球ECM沉积情况并测试血清尿素氮、肌酐及肾组织炎症因子蛋白和基因表达、TGF-β1基因表达等生化指标。结果显示,8周的训练导致大鼠运动性肾缺血再灌注,ECM沉积加强,肾功能损伤。肾小球ECM沉积,C、M组间无显著差异(P0.05);OM组较C、M组显著增加(P0.01);AM组显著低于OM组(P0.05)。血清尿素氮和肌酐水平,OM组和AM组显著高于C组(P0.01),AM组显著低于OM组(P0.05);肾组织TNF-α、IL-1β、IL-6和IL-18蛋白表达,OM组和AM组显著高于C组(P0.05或P0.01),AM组显著低于OM组(P0.05);肾组织TNF-αmRNA、IL-1βmRNA、IL-6 mRNA和IL-18 mRNA表达,OM、AM组显著高于C组(P0.01),AM组显著低于OM组(P0.05);肾组织TGF-β1mRNA表达,AM组(P0.05)和OM组(P0.01)显著高于C组,AM组显著低于OM组(P0.05)。从而说明补充虾青素可以有效地抑制肾组织中炎症因子表达从而减轻过度训练诱导的运动性肾脏缺血再灌注发生时肾脏组织TGF-β1的表达,维护ECM的动态平衡,延缓或避免对肾脏的损伤。     

脂多糖和石墨粉诱导小鼠急性肺损伤病理形态学比较

目的通过比较脂多糖（LPS）和石墨粉颗粒分别诱导小鼠急性肺损伤的病理形态学差异,探讨不同来源细颗粒物成分导致急性肺损伤的可能机制。方法将140只SPF级18~20 g雄性KM小鼠随机分为7组,除正常对照组外其他组经气管内分别滴注LPS溶液及石墨粉混悬液制备急性肺损伤小鼠。记录各组动物死亡率,光镜和透射电镜下观察各组小鼠不同时间点肺组织病理变化。Western Blot检测肺组织中NE的蛋白表达,实时定量PCR法检测肺组织中MCP-1的mRNA表达。结果与正常对照组相比,G（石墨粉）组和L（LPS）组均有不同程度病理学改变,G组小鼠肺部有大量巨噬细胞渗出,L组小鼠肺部渗出物以中性粒细胞为主;肺组织中NE蛋白表达均高于正常对照组（P〈0.05）,且L组与G组之间差异有显著性（P〈0.05）;肺组织中MCP-1mRNA表达均高于正常对照组（P〈0.01）,且L组与G组之间也有显著差异（P〈0.01）。结论不同来源颗粒物引起肺部的病理损伤不同,可能引起炎症反应的机制也存在差异,即成分复杂的细颗粒物导致急性肺损伤的机制可能存在混合性。     

支原体肺炎患儿血清中相关炎性因子的表达变化情况及其临床意义探讨

目的：探讨支原体肺炎（Mycoplasma Pneumoniae Pneumonia,MPP）患儿血清中细胞因子IL-8,IL-12的表达水平及hs-CRP、IgG和血清补体（C）的变化及其临床意义。方法：收集MPP患儿50例,分为重症组、轻症组。健康儿童42例作为对照组;用ELISA法测定MPP患儿急性期、恢复期及对照组儿童血清IL-8、IL-12的水平,用血浆蛋白分析仪速率散射比浊法测定hs-CRP,Ig和C含量。结果：在急性期和恢复期MPP患儿血清IL-12含量明显低于正常对照组（P〈0.05）;而血清IL-8含量在急性期明显高于正常对照组（P〈0.01）。重症组患儿血清中IL-12明显低于轻症组,而血清中IL-8较轻症组高（P均〈0.01）。急性期MPP患儿血清IgM,IgG与对照组相比明显升高（P均〈0.01）;而IgA明显降低（P〈0.05）。急性期MPP患儿hs-CRP、C3、C4与对照组比较显著升高（分别为P〈0.01、P〈0.01、P〈0.05）。重症组患儿血清中IgM,IgG与轻症组相比明显升高（P均〈0.01）;IgA与轻症组相比明显降低（P〈0.05）;重症组患儿血清中hs-CRP、C3、C4与轻症组相比明显升高（P均〈0.01）。结论：检测相关血清炎性细胞因子对判定MPP患儿的病情和预后有较高的临床应用价值。     

急性肺损伤大鼠肺组织基质金属蛋白酶2及其抑制因子蛋白和mRNA的表达

目的探讨内毒素致急性肺损伤（ALI）大鼠肺组织核转录因子-κB（NF-κB）、基质金属蛋白酶2（MMP-2）及其抑制因子（TIMP-2）蛋白和mRNA表达的变化。方法 20只雄性Wistar大鼠随机分为2组：对照组、LPS模型组,每组再分为4 h和8 h两个亚组。尾静脉注射脂多糖（LPS）（10 mg/kg）建立大鼠急性肺损伤模型。检测血白细胞计数、支气管肺泡灌洗液（BALF）蛋白含量,采用免疫组化ABC法和实时荧光定量PCR分别测定肺组织NF-κB、MMP-2、TIMP-2蛋白及其mRNA的表达,并观察肺组织病理变化。结果与对照组相比,模型组4 h和8 h时大鼠肺组织中的NF-κB、MMP-2蛋白染色阳性面积率及其mRNA表达均显著增高（P〈0.01）、TIMP-2蛋白染色阳性面积率及其mRNA表达均明显降低（P〈0.05或P〈0.01）。病理学观察显示,模型组大鼠肺组织出现出血及坏死。结论内毒素致急性肺损伤的发病机制可能与NF-κB、MMP-2蛋白及其mRNA表达升高、TIMP-2蛋白及其mRNA表达降低有关。     

小鼠烟雾吸入伤后肺组织中IKK／NF-KB表达的变化及意义

目的：探讨IKK／NF—kB调控的炎症反应在小鼠烟雾吸入伤后早期肺组织损伤中的作用。方法：建立小鼠烟雾吸入伤模型,将60只C57BL／6小鼠随机分成正常对照组,烟雾吸入性损伤后2h、8h和24h组,观察肺组织病理改变,免疫组织化学测定肺组织NF-kBp65,IKK1和IKK2的表达,酶联免疫吸附法（ELISA）测定肺组织TNF-α,IL-6和IL-1β含量。结果：病理切片显示正常对照组小鼠肺组织无明显异常,烟雾吸入后2h,8h,24h组肺部出现不同程度的炎细胞浸润、出血、水肿等;伤后2h组、8h组、24h组肺组织NF—KBp65、IKK1、IKK2免疫组化评分均高于正常组小鼠（P〈0．05）;肺组织TNFa、IL-6和IL-18含量在烟雾吸入后2h、8h、24h均高于正常对照组（P〈0．05）。结论：NF—KB信号通路与烟雾吸入伤早期肺内大量炎症因子的释放密切相关,可能是导致伤后肺组织病理性损伤的重要因素。     

姜黄素诱导Nrf2核转位对脂多糖引起库普弗细胞分泌炎症细胞因子的影响

目的：研究姜黄素诱导大鼠Kupffer细胞Nrf2核转位对脂多糖（LPS）引起的炎症细胞因子分泌的影响。方法：分别用10μM、20μM和30μM干预Kupffer细胞8h,诱导Nrf2核转位水平;将Kupffer细胞随机分为对照组、LPS组和干预组,对照组正常培养未加姜黄素和LPS,LPS组用10μg／mL的LPS加入Kupffer细胞培养液共同培养2h;干预组用30μM姜黄素干预8h后,余处理同LPS组。Western blot检测Nrf2核转位水平,分光光度法检测细胞MDA、GSH水平,ELISA法检测上清液TNF-α和IL-6,放免法检测IL-1β。结果：①姜黄素诱导Kupffer细胞Nrf2核转位,核转位水平随浓度增加而增高。②LPS组MDA水平较对照组显著升高（P〈0．01）,干预组MDA水平较LPS组显著降低（P〈0．01）,仍显著高于对照组（P〈0．01）。LPS组GSH水平较对照组显著降低（P〈0．01）,干预组GSH水平较LPS组显著升高（P〈0．01）,仍显著低于对照组（P〈0．01）。③LPS组上清液TNF-α,IL-1β和IL-6显著高于对照组（P〈0．01）,干预组均显著低于模型组（P〈0．01）,但显著高于对照组（P〈0．01）。结论：姜黄素通过诱导Kupffer细胞Nrf2核转位,降低LPS诱导的氧化应激损伤,抑制Kupffer细胞分泌炎症细胞因子。     

冠心病患者介入治疗前后血清IL-18、sCD40L和hs-CRP水平的变化及其意义

目的：探讨冠心病患者血清白介素18（Interleukin-18,IL-18）、白细胞分化抗原40配体（CD40L）、及高敏C反应蛋白（hs-CRP）水平在经皮冠状动脉介入术治疗前后的变化和意义。方法：选择经冠状动脉造影确诊的冠心病患者85例,根据病变程度分为单支病变组（n=32）、双支病变组（n=28）和多支病变组（n=25）,采用双抗体夹心ELISA法测定PCI术前术后血清IL-18、CD40L和hs-CRP水平。结果：血清IL-18水平测定结果：多支病变组高于双支病变组,双支病变组高于单支病变组;支架置入术后显著高于术前,差异均有统计学意义（P〈0.01）。血清CD40L水平测定结果：多支病变组高于双支病变组和单支病变组,差异均有统计学意义（P〈0.01）,双支病变组与单支病变组间差异无统计学意义（P〉0.05）;支架置入术后较术前显著升高,差异有统计学意义（P〈0.01）。血清hs-CRP水平测定结果：多支病变组高于双支病变组,双支病变组高于单支病变组;支架置入术后显著高于术前,差异均有统计学意义（P〈0.01）。结论：冠心病患者血清IL-18、CD40L和hs-CRP与冠脉病变程度密切相关,介入治疗可使冠心病患者血清IL-18、CD40L和hs-CRP水平升高,监测血清中IL-18、CD40L和hs-CRP水平变化可了解治疗效果和炎症程度。     

依达拉奉对犬自体肾移植缺血再灌注损伤的保护作用研究

目的：探讨依达拉奉对犬自体肾移植缺血再灌注损伤的影响及机制。方法：将18 只体重匹配的健康杂种犬随机分为假手术组（S组）、依达拉奉组（ED组）、生理盐水组（PS 组）,每组各6只。S 组仅进行肾手术切除;ED组在阻断前在供体静脉内注入依达拉奉10 mg/kg,然后使用200 mL加入依达拉奉10 mg/kg 的UW液灌洗供体肾并在同样的保存液中保存供体肾8 小时,且再灌注开始时立即在受体静脉内给予依达拉奉10 mg/kg;PS 组同法使用相同体积的生理盐水。再灌注4 h 后检测MDA、MPO、SOD、iNOS、eNOS等活性;术后24 h 检测血清肌酐（Cr）、尿素氮（BUN）浓度;光镜下观察肾组织病理学改变。结果：PS 组MDA显著高于S 组及ED组（P〈0.05）,PS组MPO 含量亦低于S 组及ED组（P〈0.05）。PS组SOD、eNOS 含量显著低于于S组及ED组（P〈0.05）,PS 组iNOS含量高于S 组及ED 组（P〈0.05）,ED组的肾损伤明显减轻。结论：依达拉奉能减轻肾移植缺血再灌注损伤,其机制可能与减轻肾脂质过氧化反应有关。     

Fmr1基因敲除小鼠脏器重量和脏器系数的比较分析

目的通过对Fmr1基因敲除小鼠雌雄两性和FVB小鼠的脏器重量和脏器系数进行比较分析,了解其脏器重量的差异,探讨Fmr1基因对动物生长发育等方面的影响。方法分别测定Fmr1基因敲除小鼠雌雄两性和FVB小鼠内脏器官的绝对重量和脏器系数,并进行统计学处理和分析。结果相同年龄的Fmr1基因敲除小鼠雄性的体重、心、肺、肝和肾的绝对重量均极显著的大于雌性（P〈0.01）。雌雄间脏器系数除肾脏（P〈0.05）和脑（P〈0.01）外,其余无显著差异。与FVB小鼠比较,Fmr1基因敲除小鼠心脏较轻（P〈0.01）,肾脏（P〈0.01）、体重和脑较重（P〈0.05）。脏器系数肾脏较大（P〈0.01）,心脏（P〈0.01）、脑和脾（P〈0.05）较小。结论Fmr1基因可影响动物的某些脏器重量和脏器系数。     

Organelle pH in the Arabidopsis Endomembrane System

The pH of intracellular compartments is essential for the viability of cells. Despite its relevance, little is known about the pH of these compartments. To measure pH in vivo, we have first generated two pH sensors by combining the improved-solubility feature of solubility-modified green fluorescent protein （GFP） （smGFP） with the pH-sensing capabil- ity of the pHluorins and codon optimized for expression in Arabidopsis. PEpHluorin （plant-solubility-modified ecliptic pHluorin） gradually loses fluorescence as pH is lowered with fluorescence vanishing at pH 6.2 and PRpHluorin （plant- solubility-modified ratiomatric pHluorin）, a dual-excitation sensor, allowing for precise measurements. Compartment- specific sensors were generated by further fusing specific sorting signals to PEpHluorin and PRpHluorin. Our results show that the pH of cytosol and nucleus is similar （pH 7.3 and 7.2）, while peroxisomes, mitochondrial matrix, and plastidial stroma have alkaline pH. Compartments of the secretory pathway reveal a gradual acidification, spanning from pH 7.1 in the endoplasmic reticulum （ER） to pH 5.2 in the vacuole. Surprisingly, pH in the trans-Golgi network （TGN） and mul- tivesicular body （MVB） is, with pH 6.3 and 6.2, quite similar. The inhibition of vacuolar-type H＋-ATPase （V-ATPase） with concanamycin A （ConcA） caused drastic increase in pH in TGN and vacuole. Overall, the PEpHluorin and PRpHluorin are excellent pH sensors for visualization and quantification of pH in vivo, respectively.     

Cybertaxonomy to accomplish big things in aphid systematics

Biodiversity sciences have progressed at such a pace that the taxonomic community has been unable to grow concomitantly to keep up with the influx of biologicaldata. This ＂taxonomic impediment＂ has led some to suggest that taxonomy is no longer pertinent and to the development of methodologies that circumvent the taxonomic process.This article does not seek to argue for the importance of taxonomy but rather is a call to the aphid taxonomy community to rise to the challenge by dramatically increasing the volume and comprehensiveness of its output without sacrificing quality. Recent informatics technology allows us to mobilize the 2 most important aphid taxonomy resources： expertsand specimens, both distributed globally. ＂Cyberspecimens,＂ museum specimens digitally rendered at a resolution sufficient for remote identification, and open ＂cybertaxonomic＂tools will allow the international aphid taxonomic community to carry out large, ambitious, projects. The global aphid cybertaxonomy proposed here will serve not only the ends ofresearch aphidologists, but also provide a model for other taxonomic communities to adapt and adopt as we confront both the taxonomic impediment and the taxonomic naysayers.     

Redox Regulation of Arabidopsis Mitochondrial Citrate Synthase

Citrate synthase has a key role in the tricarboxylic （TCA） cycle of mitochondria of all organisms, as it cata- lyzes the first committed step which is the fusion of a carbon-carbon bond between oxaloacetate and acetyl CoA. The regulation of TCA cycle function is especially important in plants, since mitochondrial activities have to be coordinated with photosynthesis. The posttranslational regulation of TCA cycle activity in plants is thus far almost entirely unexplored. Although several TCA cycle enzymes have been identified as thioredoxin targets in vitro, the existence of any thioredoxin-dependent regulation as known for the Calvin cycle, yet remains to be demonstrated. Here we have investigated the redox regulation of the Arabidopsis citrate synthase enzyme by site-directed mutagenesis of its six cysteine residues. Our results indicate that oxidation inhibits the enzyme activity by the formation of mixed disulfides, as the partially oxidized citrate synthase enzyme forms large redox-dependent aggregates. Furthermore, we were able to demonstrate that thioredoxin can cleave diverse intraas well as intermolecular disulfide bridges, which strongly enhances the activity of the enzyme. Activity measurements with the cysteine variants of the enzyme revealed important cysteine residues affecting total enzyme activity as well as the redox sensitivity of the enzyme.     

Cell Wall,Cytoskeleton, and Cell Expansion in Higher Plants

To accommodate two seemingly contradictory biological roles in plant physiology, providing both the rigid structural support of plant cells and the adjustable elasticity needed for cell expansion, the composition of the plant cell wall has evolved to become an intricate network of cellulosic, hemicellulosic, and pectic polysaccharides and protein. Due to its complexity, many aspects of the cell wall influence plant cell expansion, and many new and insightful observations and technologies are forthcoming. The biosynthesis of cell wall polymers and the roles of the variety of proteins involved in polysaccharide synthesis continue to be characterized. The interactions within the cell wall polymer network and the modification of these interactions provide insight into how the plant cell wall provides its dual function. The complex cell wall architecture is controlled and organized in part by the dynamic intracellular cytoskeleton and by diverse trafficking pathways of the cell wall polymers and cell wall-related machinery. Meanwhile, the cell wall is continually influenced by hormonal and integrity sensing stimuli that are perceived by the cell. These many processes cooperate to construct, maintain, and manipulate the intricate plant cell wall--an essential structure for the sustaining of the plant stature, growth, and life.     

Plastid Signals and the Bundle Sheath： Mesophyll Development in Reticulate Mutants

The development of a plant leaf is a meticulously orchestrated sequence of events producing a complex organ comprising diverse cell types. The reticulate class of leaf variegation mutants displays contrasting pigmentation between veins and interveinal regions due to specific aberrations in the development of mesophyll cells. Thus, the reticulate mutants offer a potent tool to investigate cell-type-specific developmental processes. The discovery that most mutants are affected in plastid-localized, metabolic pathways that are strongly expressed in vasculature-associated tis- sues implicates a crucial role for the bundle sheath and their chloroplasts in proper development of the mesophyll cells. Here, we review the reticulate mutants and their phenotypic characteristics, with a focus on those in Arabidopsis thali- ana. Two alternative models have been put forward to explain the relationship between plastid metabolism and meso- phyll cell development, which we call here the supply and the signaling hypotheses. We critically assess these proposed models and discuss their implications for leaf development and bundle sheath function in C3 species. The characteriza- tion of the reticulate mutants supports the significance of plastid retrograde signaling in cell development and highlights the significance of the bundle sheath in C3 photosynthesis.     

Emerging roles of miR-210 and other non-coding RNAs in the hypoxic response

Hypoxia is a key component of the tumor microenviron- merit and represents a well-documented source of thera- peutic failure in clinical oncology. Recent work has provided support for the idea that non-coding RNAs, and in particular, microRNAs, may play important roles in the adaptive response to low oxygen in tumors. Specifically, all published studies agree that the induction of microRNA- 210 （miR-210） is a consistent feature of the hypoxic re- sponse in both normal and malignant cells, miR-210 is a robust target of hypoxia-inducible factors, and its overex- pression has been detected in a variety of diseases with a hypoxic component, including most solid tumors. High levels of miR-210 have been linked to an in vivo hypoxic sig- nature and to adverse prognosis in breast and pancreatic cancer patients. A wide variety of miR-210 targets have been identified, pointing to roles in mitochondrial metabol- ism, angiogenesis, DNA damage response, apoptosis, and cell survival. Such targets are suspected to affect the devel- opment of tumors in multiple ways; therefore, an increased knowledge about miR-210＇s functions may lead to novel diagnostic and therapeutic approaches in cancer.     

Dissecting the Heat Stress Response in Chlamydomonas by Pharmaceutical and RNAi Approaches Reveals Conserved and Novel Aspects

To study how conserved fundamental concepts of the heat stress response （HSR） are in photosynthetic eukaryotes, we applied pharmaceutical and antisense/amiRNA approaches to the unicellular green alga Chlamydomonas reinhardtii. The Chlamydomonas HSR appears to be triggered by the accumulation of unfolded proteins, as it was induced at ambient temperatures by feeding cells with the arginine analog canavanine. The protein kinase inhibitor staurosporine strongly retarded the HSR, demonstrating the importance of phosphorylation during activation of the HSR also in Chlamydomonas. While the removal of extracellular calcium by the application of EGTA and BAPTA inhibited the HSR in moss and higher plants, only the addition of BAPTA, but not of EGTA, retarded the HSR and impaired thermotoler- ance in Chlamydomonas. The addition of cycloheximide, an inhibitor of cytosolic protein synthesis, abolished the attenu- ation of the HSR, indicating that protein synthesis is necessary to restore proteostasis. HSP90 inhibitors induced a stress response when added at ambient conditions and retarded attenuation of the HSR at elevated temperatures. In addition, we detected a direct physical interaction between cytosolic HSP90A/HSP70A and heat shock factor 1, but surprisingly this interaction persisted after the onset of stress. Finally, the expression of antisense constructs targeting chloroplast HSP70B resulted in a delay of the cell＇s entire HSR, thus suggesting the existence of a retrograde stress signaling cascade that is desensitized in HSP7OB-antisense strains.     

Aphis （Hemiptera： Aphididae） species groups found in the Midwestern United States and their contribution to the phylogenetic knowledge of the genus

A phylogeny of the genus Aphis Linnaeus, 1 758 was built primarily from specimens collected in the Midwest of the United States. A data matrix was constructedwith 68 species and 41 morphological characters with respective character states of alate and apterous viviparous females. Dendrogram topologies of analyses performed usingUPGMA （Unweighted Pair Group Method with Arithmetic Mean）, Maximum Parsimony and Bayesian analysis of Cytochrome Oxidase I, Elongation Factor 1-α and primary endosymbiont Buchnera aphidicola 16S sequences were not congruent. Bayesian analysis strongly supported most terminal nodes of the phylogenetic trees. The phylogeny wasstrongly supported by EFI-α, and analysis of COl and EFI-α molecular data combined with morphological characters. It was not supported by single analysis of COI or Buch-hera aphidicola 16S. Results from the Bayesian phylogeny show 4 main species groups： asclepiadis,fabae, gossypii, and middletonii. Results place Aphis and species of the generaProtaphis Bōrner, 1952, Toxoptera Koch, 1856 and Xerobion Nevsky, 1928 in a monophyletic clade. Morphological characters support this monophyly as well. The phylogenyshows that the monophyletic clade of the North American middletonii species group belong to the genus Protaphis： P. debilicornis （Gillette ＆ Palmer, 1929）, comb. nov., P. echinaceae（Lagos and Voegtlin, 2009）, comb. nov., and P. middletonii （Thomas, 1879）. The genus Toxoptera should be considered a subgenus of Aphis （stat. nov.）. The analysis also indicatesthat the current genus Iowana Frison, 1954 should be considered a subgenus of Aphis （stat. nov.）.     

How does the host-specialized aphid deal with food deficiency？

Aphis gossypii Glover shows obvious host specialization, with cucurbit- and cotton-specialized biotypes or host races in many regions. Because its annual natal hostcrops senesce earlier the cucurbit-specialized biotype may suffer food deficiency. The method this biotype uses to overcome this challenge is still poorly understood. In orderto understand the potential of the cucurbit-specialized biotype aphids in host shift and usage, the performance of this biotype on cotton （Gossypium hirsutum）, a common butpoor quality host plant, was explored in this study. The cucurbit-specialized aphids could establish populations on cotton only when these plants had at least nine leaves, and subsequent populations developed rather slowly. The presence of whitefly populations on cotton improved the success rate of cucurbit-specialized aphids. The cucurbit-specialized aphidswere mainly distributed on the older leaves of cotton, with only a few settling on the upper leaves. The cucurbit-specialized aphids reared on cotton for 40, 54 and 61 days stillmaintained strong preference for their natal host plant, cucumber （Cucumis sativus）, rather than cotton, and their net reproductive rates and intrinsic rates of natural increase weredramatically lower when they were transferred onto new six-leaf cotton plants or detached leaves. Therefore, we concluded that the cucurbit-specialized aphids have the potentialto utilize mature or whitefly-stressed cotton plants, but that this feeding experience on cotton did not alter their specialization for cucurbits. Some cotton plants could act as atemporary host for the cucurbit-specialized aphids to overcome food deficiency arising from senescing cucurbits.