Strigolactones modulate cotton fiber elongation and secondary cell wall thickening

Cotton is one of the most important economic crops in the world,and it is a major source of fiber in the textile industry.Strigolactones(SLs)are a class of carotenoid-derived plant hormones involved in many processes of plant growth and development,although the functions of SL in fiber development remain largely unknown.Here,we found that the endogenous SLs were significantly higher in fibers at 20 days post-anthesis(DPA).Exogenous SLs significantly increased fiber length and cell wall thickness.Furthermore,we cloned three key SL biosynthetic genes,namely GhD27,GhMAX3,and GhMAX4,which were highly expressed in fibers,and subcellular localization analyses revealed that GhD27,GhMAX3,and GhMAX4 were localized in the chloroplast.The exogenous expression of GhD27,GhMAX3,and GhMAX4 complemented the physiological phenotypes of d27,max3,and max4 mutations in Arabidopsis,respectively.Knockdown of GhD27,GhMAX3,and GhMAX4 in cotton resulted in increased numbers of axillary buds and leaves,reduced fiber length,and significantly reduced fiber thickness.These findings revealed that SLs participate in plant growth,fiber elongation,and secondary cell wall formation in cotton.These results provide new and effective genetic resources for improving cotton fiber yield and plant architecture.

Chemokine platelet factor 4 accelerates peripheral nerve regeneration by regulating Schwann cell activation and axon elongation

Schwann cells in peripheral nerves react to traumatic nerve injury by attempting to grow and regenerate.Howeve r,it is unclear what factors play a role in this process.In this study,we searched a GEO database and found that expression of platelet factor 4 was markedly up-regulated after sciatic nerve injury.Platelet factor is an important molecule in cell apoptosis,diffe rentiation,survival,and proliferation.Further,polymerase chain reaction and immunohistochemical staining confirmed the change in platelet factor 4 in the sciatic nerve at different time points after injury.Enzyme-linked immunosorbent assay confirmed that platelet factor 4 was secreted by Schwann cells.We also found that silencing platelet factor 4 decreased the proliferation and migration of primary cultured Schwann cells,while exogenously applied platelet factor 4 stimulated Schwann cell prolife ration and migration and neuronal axon growth.Furthermore,knocking out platelet factor 4 inhibited the prolife ration of Schwann cells in injured rat sciatic nerve.These findings suggest that Schwann cell-secreted platelet factor 4 may facilitate peripheral nerve repair and regeneration by regulating Schwann cell activation and axon growth.Thus,platelet factor 4 may be a potential therapeutic target for traumatic peripheral nerve injury.

Vital contribution of brassinosteroids to hypoxia-stimulated coleoptile elongation in submerged rice

The rapid elongation of rice(Oryza sativa)coleoptile is pivotal for the plant plumule to evade hypoxia stress induced by submergence,a condition often arising from overirrigation,ponding,rainstorms,or flooding.While brassinosteroids(BRs)are recognized for their diverse roles in plant growth and development,their influence on coleoptile elongation under hypoxic conditions remains largely unexplored.In this study,we demonstrate the significant requirement of BRs for coleoptile elongation in deep water.During coleoptile development,Glycogen Synthase Kinase3-Like Kinase2(GSK2),the central inhibitor of BR signaling in rice,undergoes substantial suppression in deep water but induction in air.In contrast,the dephosphorylated form of BRASSINAZOLE RESISTANT1(OsBZR1),representing the active form of the key BR signaling transcription factor,is induced in water but suppressed in air.Remarkably,the knockout of GSK3-like kinase genes significantly enhances coleoptile elongation in deep water,strongly indicating a vital contribution of BR response to hypoxia-stimulated coleoptile elongation.Transcriptome analysis uncovers both BR-associated and BR-independent hypoxia responses,implicating substance metabolism,redox reactions,abiotic stress responses,and crosstalk with other hormones in the regulation of BR-induced hypoxia responses.In summary,our findings suggest that rice plumules rapidly elongate coleoptiles through the activation of BR response in deep water,enabling them to escape from submergence-induced hypoxia stress.

The bHLH transcription factor CsPIF4 positively regulates high temperature-induced hypocotyl elongation in cucumber

High temperature-induced hypocotyl elongation is a typical thermomorphogenesis trait that may significantly affect early seedling growth and subsequent crop yield.The ambient temperature and endogenous auxin are two critical factors that regulate hypocotyl growth.However,the mechanism of temperature and auxin integration in horticultural plants remains poorly understood.In this study,the roles of the basic helix-loop-helix transcription factor CsPIF4 in regulating auxin biosynthesis genes and the auxin content in the hypocotyl of cucumber(Cucumis sativus L.)seedlings under high temperature were investigated.qRT-PCR and in situ hybridization analysis revealed that expression of CsPIF4 was enhanced in the epidermis and vascular bundles in the hypocotyl of cucumber seedlings in response to high temperature.qRT-PCR and HPLC analysis showed that CsPIF4 positively regulated transcription of the auxin biosynthesis gene CsYUC8 and the auxin content in the hypocotyl under high temperature(35℃).The CRISPR/Cas9-mediated knockout of CsPIF4 resulted in a shorter hypocotyl compared with that of the wild type,together with decreased expression of CsYUC8 and lower auxin content in response to high temperature.Furthermore,biochemical assays showed that CsPIF4 could bind directly to the G-box motif of the CsYUC8 promoter and thereby activate CsYUC8 expression.These findings provide insight into the molecular mechanism of high temperature-mediated hypocotyl elongation in cucumber.

Chain Elongation Using Native Soil Inocula:Exceptional n-Caproate Biosynthesis Performance and Microbial Mechanisms

This study demonstrates the feasibility and effectiveness of utilizing native soils as a resource for inocula to produce n-caproate through the chain elongation(CE)platform,offering new insights into anaerobic soil processes.The results reveal that all five of the tested soil types exhibit CE activity when supplied with high concentrations of ethanol and acetate,highlighting the suitability of soil as an ideal source for n-caproate production.Compared with anaerobic sludge and pit mud,the native soil CE system exhibited higher selectivity(60.53%),specificity(82.32%),carbon distribution(60.00%),electron transfer efficiency(165.00%),and conductivity(0.59 ms∙cm^(-1)).Kinetic analysis further confirmed the superiority of soil in terms of a shorter lag time and higher yield.A microbial community analysis indicated a positive correlation between the relative abundances of Pseudomonas,Azotobacter,and Clostridium and n-caproate production.Moreover,metagenomics analysis revealed a higher abundance of functional genes in key microbial species,providing direct insights into the pathways involved in n-caproate formation,including in situ CO_(2)utilization,ethanol oxidation,fatty acid biosynthesis(FAB),and reverse beta-oxidation(RBO).The numerous functions in FAB and RBO are primarily associated with Pseudomonas,Clostridium,Rhodococcus,Stenotrophomonas,and Geobacter,suggesting that these genera may play roles that are involved or associated with the CE process.Overall,this innovative inoculation strategy offers an efficient microbial source for n-caproate production,underscoring the importance of considering CE activity in anaerobic soil microbial ecology and holding potential for significant economic and environmental benefits through soil consortia exploration.

Lateral root elongation in maize is related to auxin synthesis and transportation mediated by N metabolism under a mixed NO_(3)^(–) and NH_(4)^(+) supply

A mixed nitrate (NO_(3)^(–)) and ammonium (NH_(4)^(+)) supply can promote root growth in maize (Zea mays),however,the changes in root morphology and the related physiological mechanism under different N forms are still unclear.Here,maize seedlings were grown hydroponically with three N supplied in three different forms (NO_(3)^(–)only,75/25 NO_(3)^(–)/NH_(4)^(+)and NH_(4)^(+)only).Compared with sole NO_(3)^(–)or NH_(4)^(+),the mixed N supply increased the total root length of maize but did not affect the number of axial roots.The main reason was the increased total lateral root length,while the average lateral root (LR) length in each axle was only slightly increased.In addition,the average LR density of 2nd whorl crown root under mixed N was also increased.Compared with sole nitrate,mixed N could improve the N metabolism of roots (such as the N influx rate,nitrate reductase (NR) and glutamine synthase (GS)enzyme activities and total amino content of the roots).Experiments with exogenously added NR and GS inhibitors suggested that the increase in the average LR length under mixed N was related to the process of N assimilation,and whether the NR mediated NO synthesis participates in this process needs further exploration.Meanwhile,an investigation of the changes in root-shoot ratio and carbon (C) concentration showed that C transportation from shoots to roots may not be the key factor in mediating lateral root elongation,and the changes in the sugar concentration in roots further proved this conclusion.Furthermore,the synthesis and transportation of auxin in axial roots may play a key role in lateral root elongation,in which the expression of ZmPIN1B and ZmPIN9 may be involved in this pathway.This study preliminarily clarified the changes in root morphology and explored the possible physiological mechanism under a mixed N supply in maize,which may provide some theoretical basis for the cultivation of crop varieties with high N efficiency.

Prokaryotic Expression of Rubber Elongation Factor Gene and Preparation of Its Polyclonal Antibody

[Objective] The aim of this study was to prepare the recombination protein of rubber elongation factor and its polyclonal antibodies.[Method] The encoding gene of rubber elongation factor(REF)was amplified by RT-PCR,and cloned into the prokaryotic expression vector pDEST17 to transform into Escherichia coil BI2I-AI.The recombinant protein induced by L-Arabinose was purified by the affinity chromatography.As the immunogen,the recombination protein was used to immunize mice for preparing polyclonal antibodies,while ELISA and Western blot hybridization were used to detect the titers and specificity.[Result] The purified recombination protein of REF with high expression was used to immunize house mice for preparing polyclonal antibodies with high titer and specificity.The western blot hybridization showed that the antibody could recognize the natural REF from latex.[Conclusion] The recombination protein of REF was successfully obtained and the mouse anti REF antibody with high titer and specificity was prepared,which lays a basis for further studies on biological functions of rubber elongation factor and other membrane proteins in rubber particles.

Inducible Expression of Translation Elongation Factor 1A Gene in Rice Seedlings in Response to Environmental Stresses

Differences of gene expression between salinity_stressed and control rice ( Oryza sativa L. ssp. indica ) cultivar “Zhaiyeqing 8' were compared using differential display PCR (DD_PCR) technique. Sequence analysis of one salt_inducible cDNA clone revealed that this clone represented a new member of rice translation elongation factor 1A (eEF1A) gene family and was tentatively named REF1A. Northern blot hybridization using REF1A fragment as a probe was performed to investigate the expression of rice translation elongation factor 1A gene in response to various environmental factors. It was observed that expression of the eEF1A gene in rice shoots was dramatically induced by salinity stress or exogenous application of abscisic acid (ABA). The induction of this gene by ABA stress occurred more quickly than that by salinity stress. In addition, expression of rice translation elongation factor 1A gene was also induced by drought (15% PEG6000), cold (4 ℃) or heat_shock (37 ℃) stresses. The results suggested that the induction of translation elongation factor 1A gene expression by environmental stresses might reflect the general adaptive response of rice plants to the adverse circumstances.

Tolerance of Salix matsudana to Heavy Metals Determined by Root Elongation Method

[Objective]The research aimed to discuss the tolerance of Salix matsudana to single or compound heavy metals and provide theoretical basis for renovating polluted soil by heavy metals with woody plants.[Method]Using root elongation method,the effects of heavy metal Cu^2＋,Pb^2＋,Zn^2＋ and their mixed solution on the adventitious roots growth of S.matsudana cuttings were studied.[Result]The adventitious roots growth of S.matsudana cuttings was obviously affected by different concentrations of heavy metals solution.Adventitious roots of S.matsudana cuttings could not grow while the concentration of Cu^2＋ was higher than 15 mg/L,the mixture solution concentration was higher than 20 mg/L and Zn^2＋ concentration was higher than 30 mg/L.When the solution concentration reached 40 mg/L,adventitious roots of S.matsudana cuttings could grow only in Pb^2＋ treatment group.With the increasing of the solution concentration,the number of adventitious roots of S.matsudana cuttings gradually decreased.In 5 mg/L Zn^2＋ treatment group,the number of adventitious roots of S.matsudana cuttings was the most,the longest root length and average root length were the longest and the rooting rate was the highest.[Conclusion]The tolerance of S.matsudana to Pb^2＋ was strongest and its tolerance to Cu^2＋ was the weakest.The tolerance order of S.matsudana to three kinds of heavy metals and their mixed solution was as following：Pb^2＋〉Zn^2＋〉Cu^2＋＋Pb^2＋＋Zn^2＋〉Cu^2＋.

羊驼transcription elongation factor B(S III)(Tceb2)cDNA的获取与序列分析

【研究目的】分离和鉴定羊驼transcription elongation factorB(S III)(Tceb2)基因,分析其序列特征,为今后研究其生物学功能奠定理论基础。【方法】用Southern Blotting法从羊驼皮肤cDNA文库中筛选Tceb2基因,通过BLAST等生物学相关软件对其进行结果分析。【结果】有6个阳性克隆,测序结果得知,序列片段大小大约为472bp,具有完整的开放阅读框,可编码119AA,分子量为13.2KDa。序列特征、结构和同源性分析表明:该序列预测为全长cDNA序列,该基因序列及其编码的氨基酸序列与大鼠和小鼠的troponinc2同源性可达100%。【结论】该基因是获得的羊驼全长Tceb2(GenBank DQ646397)(命名为AlpTceb2)。

Relationship between elongation and porosity for high porosity metal materials

A simplified model was proposed targeting at the isotropic high porosity metal materials with well distributed structure. From the model the mathematical relationship between elongation and porosity was deduced for those materials, and the relationship formula was derived generally for actual high porosity metals at last, whose validity is supported by the representative experiment on a nickel foam prepared by electrodeposition. A simplified model was proposed targeting at the isotropic high porosity metal materials with well distributed structure. From the model the mathematical relationship between elongation and porosity was deduced for those materials, and the relationship formula was derived generally for actual high porosity metals at last, whose validity is supported by the representative experiment on a nickel foam prepared by electrodeposition.

Gene expression and metabolite profiles of cotton fiber during cell elongation and secondary cell wall synthesis

Cotton fibers elongate rapidly after initiation of elongation, eventually leading to the deposit of a large amount of cellulose. To reveal features of cotton fiber cells at the fast elongation and the secondary cell wall synthesis stages, we compared the respective transcriptomes and metabolite profiles. Comparative analysis of transcriptomes by cDNA array identified 633 genes that were differentially regulated during fiber development. Principal component analysis （PCA） using expressed genes as variables divided fiber samples into four groups, which are diagnostic of developmental stages. Similar grouping results are also found if we use non-polar or polar metabolites as variables for PCA of developing fibers. Auxin signaling, wall-loosening and lipid metabolism are highly active during fiber elongation, whereas cellulose biosynthesis is predominant and many other metabolic pathways are downregulated at the secondary cell wall synthesis stage. Transcript and metabolite profiles and enzyme activities are consistent in demonstrating a specialization process of cotton fiber development toward cellulose synthesis. These data demonstrate that cotton fiber cell at a certain stage has its own unique feature, and developmental stages of cotton fiber cells can be distinguished by their transcript and metabolite profiles. During the secondary cell wall synthesis stage, metabolic pathways are streamed into cellulose synthesis.

Eukaryotic elongation factor-1α 2 knockdown inhibits hepatocarcinogenesis by suppressing PI3K/Akt/NF-κB signaling

AIM: To assess the impact of eukaryotic elongation factor 1 alpha 2 (eEF1A2) on hepatocellular carcinoma (HCC) cell proliferation, apoptosis, migration and invasion, and determine the underlying mechanisms.METHODS: eEF1A2 levels were detected in 62 HCC tissue samples and paired pericarcinomatous specimens, and the human HCC cell lines SK-HEP-1, HepG2 and BEF-7402, by real-time PCR and immunohistochemistry. Experimental groups included eEF1A2 silencing in BEL-7402 cells with lentivirus eEF1A2-shRNA (KD group) and eEF1A2 overexpression in SK-HEP-1 cells with eEF1A2 plasmid (OE group). Non-transfected cells (control group) and lentivirus-based empty vector transfected cells (NC group) were considered control groups. Cell proliferation (MTT and colony formation assays), apoptosis (Annexin V-APC assay), cell cycle (DNA ploidy assay), and migration and invasion (Transwell assays) were assessed. Protein levels of PI3K/Akt/NF-κB signaling effectors were evaluated by Western blot.RESULTS: eEF1A2 mRNA and protein levels were significantly higher in HCC cancer tissue samples than in paired pericarcinomatous and normal specimens. SK-HEP-1 cells showed lower eEF1A2 mRNA levels; HepG2 and BEL-7402 cells showed higher eEF1A2 mRNA levels, with BEL-7402 cells displaying the highest amount. Efficient eEF1A2 silencing resulted in reduced cell proliferation, migration and invasion, increased apoptosis, and induced cell cycle arrest. The PI3K/Akt/NF-κB signaling pathway was notably inhibited. Inversely, eEF1A2 overexpression resulted in promoted cell proliferation, migration and invasion.CONCLUSION: eEF1A2, highly expressed in HCC, is a potential oncogene. Its silencing significantly decreases HCC tumorigenesis, likely by inhibiting PI3K/Akt/NF-κB signaling.

Elevated temperature intensity,timing,and duration of exposure affect soybean internode elongation,mainstem node number,and pod number per plant

A study was conducted in four compartments of a polycarbonate greenhouse at Gainesville,FL, USA to investigate how a soybean(Glycine max L. Merr.) cultivar, Maverick(maturity group III, indeterminate), responded to three elevated temperatures, ELT,(day/night of 34/26 °C, 38/30 °C, and 42/34 °C) in comparison to a control growth temperature(30/22 °C).Carbon dioxide(CO_2) concentration was maintained at 700 μmol mol^(-1) in each compartment by a processor controlled air-sampling and CO_2-injection system. Three sequential experiments were conducted at different times of year(summer, autumn, and early spring)to investigate the effect of intensity, timing, and duration of ELT on soybean node number,internode elongation, mainstem length, and number of pods set per plant. At the control temperature, the soybean plants grown in the polycarbonate greenhouse were taller than field-grown plants. When plants were grown under continuous ELT applied soon after sowing or at initial flowering, the number of nodes increased with increasing ELT intensity,whereas the length of individual internodes decreased. When ELT treatment was applied during the beginning of flowering stage(R1–R2) or earlier, more nodes were produced and the length of affected internodes was decreased. When the ELT was imposed later at reproductive stage R5+ just before the beginning of seed filling, effects on node numbers and internode lengths were negligible. Short-term(10-day) duration of ELT applied at four stages from V3 to R5+ did not significantly affect final mean numbers of nodes or mean mainstem lengths. Possible mechanisms of elevated temperature effects on soybean internode elongation and node number(internode number) are discussed. Total pod numbers per plant increased linearly with mainstem node numbers and mainstem length.Furthermore, total pod numbers per plant were greatest at 34/26 °C rather than at the control temperature of 30/22 °C(and remained high at 38/30 °C). Mild increases in temperature might not threaten, but actually increase, yields of soybean in northerly zones where this crop is currently grown at slightly suboptimal temperatures. However, a sustained increase in ambient temperature would likely threaten soybean yields.

Effect of Testing Conditions on Fibre-Bundle Tensile Properties-Part Ⅱ: the Gauge Length and Elongation Speed in Wool Fibre Bundle Measurement

The testing conditions of a fibre bundle tensile tester (TENSOR) are elongation speed (ES), gauge length (GL), pretension, jaw pressure, environmental temperature and relative humidity, instrument linearity and sensitivity. The effects on fibre-bundle tensile properties at different GL and ES have been discussed in detail and compared with Peirce’s theories on the weaklinks and the breaking time effect. The experimental results indicate that the tensile properties of fibre bundles are strongly affected by GL and vary with different GL. The reasonable GL should be 5 15 mm rather than 3.2 mm for wool bundle measurements. The ES ranging from 20 mm/min to 40 mm/min is beneficial for obtaining comparatively stable and accurate tensile values, whereas 20 mm/min used in current testing for wool fibre bundles is at the lower limit of the suggested range. For bundle modulus measurement, the sampling interval must be selected appropriately. The new calculation of the sampling interval has been established.

Basal internode elongation of rice as affected by light intensity and leaf area

Short basal internodes are important for lodging resistance of rice(Oryza sativa L.).Several canopy indices affect the elongation of basal internodes,but uncertainty as to the key factors determining elongation of basal internodes persists.The objectives of this study were(1)to identify key factors affecting the elongation of basal internodes and(2)to establish a quantitative relationship between basal internode length and canopy indices.An inbred rice cultivar,Yinjingruanzhan,was grown in two split-plot field experiments with three N rates(0,75,and 150 kg N ha−1 in early season and 0,90,and 180 kg N ha−1 in late season)as main plots,three seedling densities(16.7,75.0,and 187.5 seedlings m−2)as subplots,and three replications in the 2015 early and late seasons in Guangzhou,China.Light intensity at base of canopy(Lb),light quality as determined from red/far-red light ratio(R/FR),light transmission ratio(LTR),leaf area index(LAI),leaf N concentration(NLV)and final length of second internode(counted from soil surface upward)(FIL)were recorded.Higher N rate and seedling density resulted in significantly longer FIL.FIL was negatively correlated with Lb,LTR,and R/FR(P<0.01)and positively correlated with LAI(P<0.01),but not correlated with NLV(P>0.05).Stepwise linear regression analysis showed that FIL was strongly associated with Lb and LAI(R2=0.82).Heavy N application to pot-grown rice at the beginning of first internode elongation did not change FIL.We conclude that FIL is determined mainly by Lb and LAI at jointing stage.NLV has no direct effect on the elongation of basal internodes.N application indirectly affects FIL by changing LAI and light conditions in the rice canopy.Reducing LAI and improving canopy light transmission at jointing stage can shorten the basal internodes and increase the lodging resistance of rice.

Prevention and Treatment of Postoperative Complications of the Penile Elongation

To explore the causes of the postoperative complications of the penile elongation and the measures to prevent them in order to raise the success rate of the penile elongation. 1000 patients who had received the penile elongation were reviewed and analyzed for the causes of postoperative complications, and the measures of prevention and treatment were discussed. Our results showed that, of the 1000 cases, 64 had the postoperative complications, including 20 cases of edema of prepuce, 15 cases of flap necrosis, 12 hematoma, 9 infections, and 8 cases of fat and clumsy penis. It is concluded that correct operative manipulation, strict aseptic measures and necessary postoperative care and management could avoid or reduce the postoperative complications. When complications happened , a satisfactory result can be achieved with timely and correct treatment in the majority of the patients.

Superplastic elongation characteristic of fine grained magnesium alloy ZK60

This paper employs simple rolling process plus annealing to refine the grain size of magnesium alloy ZK60. This goal is effectively achieved, obtaining grains as fine as -3.7 um. Such a specimen shows an elongation of 642%, and its ultimate fracture surface exhibits intergranular separation and significant grain growth. Additionally, the effects of the specimen＇s geometry and tensile test axis with respect to the rolling direction on superplastic elongation is studied, which has not been done before.

The tumor-selective over-expression of the human Hsp 70 gene is attributed to the aberrant controls at both initiation and elongation levels of transcription

The tumor selective over-expression of the human Hsp70 gene has been well documented in human tumors,linked to the poor prognosis,being refractory to chemo-and radio-therapies as well as the advanced stage of tumorous lesions in particular.However,both the nature and details of aberrations in the control of the Hsp70 expression in tumor remain enigmatic.By comparing various upstream segments of the Hsp70 gene for each''s ability to drive the luciferase reporter genes in the context of the tumor cell lines varying in their p53 status and an immortal normal liver cell line,we demonstrated in a great detail the defects in the control mechanisms at the both initiation and elongation levels of transcription being instrumental to the tumor selective profile of its expression.Our data should not only offer new insights into our understanding of the tumor specific over-expression of the human Hsp70 gene,but also paved the way for the rational utilization of the tumor selective mechanism with the Hsp70 at the central stage fortargeting the therapeutic gene expression to human tumors.

Alterative Expression and Sequence of Human Elongation Factor-1δ during Malignant Transformation of Human Bronchial Epithelial Cells Induced by Cadmium Chloride

Objective To study the alternative expression and sequence of human elongation factor-1δ （human EF-1δ p31） during malignant transformation of human bronchial epithelial cells induced by cadmium chloride （CdCl2） and its possible mechanism. Methods Total RNA was isolated at different stages of transformed human bronchial epithelial cells （16HBE） induced by CdCl2 at a concentration of 5.0 μM. Special primers and probe for human EF-1δ p31 were designed and expression of human EF-18 mRNA from different cell lines was detected with fluorescent quantitative PCR technique. EF-18 cDNA from different cell lines was purified and cloned into pMD 18-T vector followed by confirming and sequencing analysis. Results The expressions of human EF-1δ p31 at different stages of 16HBE cells transformed by CdCl2 was elevated （P〈0.01 or P〈0.05）. Compared with their corresponding non-transformed ceils, the overexpression level of EF-15 p31 was averagely increased 2.9 folds in Cd-pretransformed cells, 4.3 folds in Cd-transformed ceils and 7.2 folds in Cd-tumorigenic cells. No change was found in the sequence of overexpressed EF-1δ p31 at different stages of 16HBE cells transformed by CdCl2. Conclusion Overexpression of human EF-1δ p31 is positively correlated with malignant transformation of 16HBE cells induced by CdCl2, but is not correlated with DNA mutations.