Molecular and genetic regulations of fleshy fruit shape and lessons from Arabidopsis and rice

Fleshy fruit shape is an important external quality trait influencing the usage of fruits and consumer preference.Thus,modification of fruit shape has become one of the major objectives for crop improvement.However,the underlying mechanisms of fruit shape regulation are poorly understood.In this review we summarize recent progress in the genetic basis of fleshy fruit shape regulation using tomato,cucumber,and peach as examples.Comparative analyses suggest that the OFP-TRM(OVATE Family Protein-TONNEAU1 Recruiting Motif)and IQD(IQ67 domain)pathways are probably conserved in regulating fruit shape by primarily modulating cell division patterns across fleshy fruit species.Interestingly,cucumber homologs of FRUITFULL(FUL1),CRABS CLAW(CRC)and 1-aminocyclopropane-1-carboxylate synthase 2(ACS2)were found to regulate fruit elongation.We also outline the recent progress in fruit shape regulation mediated by OFP-TRM and IQD pathways in Arabidopsis and rice,and propose that the OFP-TRM pathway and IQD pathway coordinate regulate fruit shape through integration of phytohormones,including brassinosteroids,gibberellic acids,and auxin,and microtubule organization.In addition,functional redundancy and divergence of the members of each of the OFP,TRM,and IQD families are also shown.This review provides a general overview of current knowledge in fruit shape regulation and discusses the possible mechanisms that need to be addressed in future studies.

Overexpression of Wheat TaELF3-1BL Delays Flowering in Arabidopsis

EARLY FLOWERING 3(ELF3),a light zeitnehmer(time-taker)gene,regulates circadian rhythm and photoperiodic flowering in Arabidopsis,rice,and barley.The three orthologs of ELF3(TaELF3-1AL,TaELF3-1BL,and TaELF3-1DL)have been identified in wheat too,and one gene,TaELF3-1DL,has been associated with heading date.However,the basic characteristics of these three genes and the roles of the other two genes,TaELF3-1BL and,TaELF3-1AL,remain unknown.Therefore,the present study obtained the coding sequences of the three orthologs(TaELF3-1AL,TaELF3-1BL,and TaELF3-1DL)of ELF3 from bread wheat and characterized them and investigated the role of TaELF3-1BL in Arabidopsis.Protein sequence comparison revealed similarities among the three TaELF3 genes of wheat;however,they were different from the Arabidopsis ELF3.Real-time quantitative PCR revealed TaELF3 expression in all wheat tissues tested,with the highest expression in young spikes;the three genes showed rhythmic expression patterns also.Furthermore,the overexpression of the TaELF3-1BL gene in Arabidopsis delayed flowering,indicating their importance in flowering.Subsequent overexpression of TaELF3-1BL in the Arabidopsis ELF3 nonfunctional mutant(elf3 mutant)eliminated its early flowering phenotype,and slightly delayed flowering.The wild-type Arabidopsis overexpressing TaELF3-1BL demonstrated reduced expression levels of flowering-related genes,such as CONSTANS(AtCO),FLOWERING LOCUS T(AtFT),and GIGANTEA(AtGI).Thus,the study characterized the three TaELF3 genes and associated TaELF3-1BL with flowering in Arabidopsis,suggesting a role in regulating flowering in wheat too.These findings provide a basis for further research on TaELF3 functions in wheat.

Biochemical and Physiological Responses of Arabidopsis thaliana Leaves to Moderate Mechanical Stimulation

Mechanical stimulation of plants can be caused by various abiotic and biotic environmental factors.Apart from the negative consequences,it can also cause positive changes,such as acclimatization of plants to stress conditions.Therefore,it is necessary to study the physiological and biochemical mechanisms underlying the response of plants to mechanical stimulation.Our aim was to evaluate the response of model plant Arabidopsis thaliana to a moderate force of 5 N(newton)for 20 s,which could be compared with the pressure caused by animal movement and weather conditions such as heavy rain.Mechanically stimulated leaves were sampled 1 h after exposure and after a recovery period of 20 h.To study a possible systemic response,unstimulated leaves of treated plants were collected 20 h after exposure alongside the stimulated leaves from the same plants.The effect of stimulation was assessed by measuring oxidative stress parameters,antioxidant enzymes activity,total phenolics,and photosynthetic performance.Stimulated leaves showed increased lipid peroxidation 1 h after treatment and increased superoxide dismutase activity and phenolic oxidation rate after a 20-h recovery period.Considering photosynthetic performance after the 20-h recovery period,the effective quantum yield of the photosystem II was lower in the stimulated leaves,whereas photochemical quenching was lower in the unstimulated leaves of the treated plants.Nonphotochemical quenching was lower in the stimulated leaves 1 h after treatment.Our study suggested that plants sensed moderate force,but it did not induce pronounced change in metabolism or photosynthetic performance.Principal component analysis distinguished three groups–leaves of untreated plants,leaves analysed 1 h after stimulation,while stimulated and unstimulated leaves of treated plants analysed 20 h after treatment formed together the third group.Observed grouping of stimulated and unstimulated leaves of treated plants could indicate signal transduction from the stimulated to distant leaves,that is,a systemic response to a local application of mechanical stimuli.

Glucosinolates and Their Hydrolysis Products in Arabidopsis thaliana Influence Performance and Feeding Choice of Pieris rapae and Spodoptera exigua

Glucosinolates and their hydrolysis products, found in plants of the order Brassicales, are well-known for their defensive properties against insect herbivores. Arabidopsis thaliana (Col-0) genetic lines with mutations that modify the type of glucosinolates (i.e. myb28myb29 and cyp79B2cyp79B3 are deficient in the production of aliphatic and indolyl glucosinolates, respectively) make it possible to test for the specific effects of these secondary chemicals on insect herbivores. The Pad3 mutant (deficient in camalexin), which has a role in resistance to pathogens, was also tested. Likewise, the effects of different glucosinolate hydrolysis products can be evaluated using genetically modified (GM) lines of the wild type Col-0 ecotype, which naturally produces isothiocyanates. These GM lines include the nitrile-producing 35S: ESP and the double knockout tgg1tgg2, which virtually lacks hydrolysis products. In both no-choice and choice experiments, the crucifer specialist Pieris rapae was virtually unaffected by differences in the type of glucosinolates or hydrolysis products. In contrast, the generalist insect Spodoptera exigua had statistically significant increases in pupae/adult weight and faster developmental times when reared on mutants deficient in the production of aliphatic and indolyl glucosinolates and their hydrolysis products. There were no differences in the performance of either insect species when reared on wild type Col-0 or Pad3. Results from feeding choice trials showed that Pieris rapae had no statistically significant preference for any of the genetic lines. In contrast, Spodoptera exigua had a significant feeding preference for the double mutant tgg1tgg2. This study provides evidence that variation in the type of glucosinolates and their hydrolysis products can influence insect performance and feeding choices, and that responses are species-specific.

新疆短命植物小拟南芥(Arabidopsis pumila)种子萌发特性及其生态适应性

通过显微结构及不同处理条件下种子萌发率的观察,对早春短命植物小拟南芥(Arabidopsis pumila)种子萌发特性及影响因素进行了研究,并对其生态适应性进行了讨论。结果表明:(1)温度和光照变化对自然生境和温室收获种子的萌发率影响均不显著,说明此种群在前期萌发阶段对光、温不敏感;(2)自然生境中采收的小拟南芥种子萌发率显著低于温室收获种子,说明环境条件的变化对短命植物种子的发育具有重要作用,可显著改变种子的萌发行为;(3)赤霉素使自然生境收获种子胚活性增强从而对萌发有较大促进作用,可使萌发率增加50%以上;(4)对种皮进行各种机械损伤处理使得种皮松弛或透气,可以显著提高自然生境种子的萌发率(超过70%);(5)盐和干旱胁迫对种子萌发均具有明显的抑制作用,但复水后部分被抑制种子可重新萌发,显示盐和干旱胁迫可导致种子产生浅度休眠。结合小拟南芥自然生存环境及本研究的结果,显示其种子萌发特性与生境具有高度适应性。

天山北麓中段拟南芥(Arabidopsis thaliana)与相邻物种的分布格局及相互关系

天山山脉是世界拟南芥(Arabidopsis thaliana)及其近缘种的分布中心之一,资源优势明显。在北天山中段浅山地带选择拟南芥分布的典型样地50m×50m,分析了样地物种的结构、组成和土壤理化性质,用Ripley’sK(d)函数分析了拟南芥与相邻物种的空间特征和相互关系。发现样地由7科23个物种组成,以新疆绢蒿(Seriphidium kaschgaricum)为建群种,短命植物物种占近70%。拟南芥仅分布于北坡,在3m内聚集强度高于所有分析物种,在5m范围内与新疆绢蒿中株呈显著正关联,与十字花科的涩芥(Malcolmia africana)、藜科的散枝猪毛菜(Salsola brachiata)、木碱蓬(Suaeda dendroides)、角果藜(Ceratocarpus arenarius)呈一定尺度显著负关联。分析认为拟南芥空间分布依赖于新疆绢蒿大株、中株生长塑造的遮阴、保湿和丰富土壤有机质,生态位与藜科物种差异极大,生境特异性高于同属近缘种小鼠耳芥(Arabidopsis pumila),以及涩芥(M.africana)、庭芥(Alyssumdesertorum)、四齿芥(Tetracme quadricornis)、丝叶芥(Leptaleum filifolium)、狭果鹤虱(Lappula semiglabra)等短命植物。在干旱胁迫下,拟南芥环境选择强度大于种内作用,密度依赖的种子扩散表现不明显。扩散对策是通过大量生产种子,依靠果实不易开裂控制种子短距离扩散,充分利用原适宜生境来维持种群繁衍。

生态因子及其交互作用对拟南芥(Arabidopsis thaliana)表型可塑性的影响

以拟南芥(Arabidopsis thaliana)两种基因型(ws-0和col-0)材料,采用复因子混合水平正交试验设计开展盆栽实验,研究了土壤盐分、土壤水分、光照强度、去叶处理等生态因子及其交互作用对受试植株18个表型特征的影响。结果表明生态因子对植物表型可塑性的影响是有针对性的:土壤水分主要影响植物体构件数目;土壤盐分主要影响生物量、角果数及种籽总数等直接反映植株适合度的表型特征;光照条件则主要影响植物的物候表型特征。植物体表型可塑性的方向随水分梯度的变化而发生改变。生态因子交互作用对植物表型可塑性的影响效果不是各因子独立作用的简单加和:对某个表型特征都有显著影响的两个生态因子其交互作用对该特征可能没有影响;反之,受两个生态因子交互作用影响显著的表型特征也可能不受它们的独立影响。在对生态因子交互作用作出响应时,col-0的9个特征表现出可塑性,而ws-0仅有4个表型是可塑的;同一基因型内彼此相关的表型特征在可塑性上也具一致性。抽苔时莲座叶数与角果平均籽粒数不受任何生态因子及其交互作用的影响,这两个表型作为数量特征而未表现出可塑性。

黑腐病菌(Xanthomonas campestris)与拟南芥(Arabidopsis thaliana)品种间的致病性测定

甘蓝黑腐病菌(Xanthomonas campeatris pv.campestris)主要以十字花科植物为寄主.引起黑腐病的病原菌,是在世界范围对农业造成严重危害的病原菌之一.拟南芥(Arabidopsis thaliana)是十字花科植物,做为经典遗传学实验材料已有40多年历史.它具有较少染色体组和重复 DNA 序列,易诱变、易种植、个体小、

Identification and genetic mapping of four novel genes that regulate leaf development in Arabidopsis

Molecular and genetic characterizations of mutants have led to a better understanding of many developmental processes in the model system Arabidopsis thaliana. However, the leaf development that is specific to plants has been little studied. With the aim of contributing to the genetic dissection of leaf development, we have performed a large-scare screening for mutants with abnormal leaves. Among a great number of leaf mutants we have generated by T-DNA and transposon tagging and ethylmethae sulfonate (EMS) mutagenesis, four independent mutant lines have been identified and studied genetically. Phenotypes of these mutant lines represent the defects of four novel nuclear genes designated LL1 (LOTUS LEAF 1), LL2 (LOTUS LEAF 2), URO (UPRIGHT ROSETTE), and EIL (ENVIRONT CONDITION INDUCED LESION). The phenotypic analysis indicates that these genes play important roles during leaf development. FOr the further genetic analysis of these genes and the map-based cloning of LL1 and LL2, we have mapped these genes to chromosome regions with an efficient and rapid mapping method.

AtbHLH29 of Arabidopsis thaliana is a functional ortholog of tomato FER involved in controlling iron acquisition in strategy I plants

AtbHLH29 of Arabidopsis, encoding a bHLH protein, reveals a high similarity to the tomato FER which is proposed as a transcriptional regulator involved in controlling the iron deficiency responses and the iron uptake in tomato. For identification of its biological functions, AtbHLH29 was introduced into the genome of the tomato FER mutant T3238fer mediated by Agrobacterium tumefaciencs. Transgenic plants were regenerated and the stable integration of AtbHLH29 into their genomes was confirmed by Southern hybridization. Molecular analysis demonstrated that expression of the exogenous AtbHLH29 of Arabidopsis in roots of the FER mutant T3238fer enabled to complement the defect functions of FER. The transgenic plants regained the ability to activate the whole iron deficiency responses and showed normal growth as the wild type under iron-limiting stress. Our transformation data demonstrate that AtbHLH29 is a functional ortholog of the tomato FER and can completely replace FER in controlling the effective iron acquisition in tomato. Except of iron, FER protein was directly or indirectly involved in manganese homeostasis due to that loss functions of FER in T3238fer resulted in strong reduction of Mn content in leaves and the defect function on Mn accumulation in leaves was complemented by expression of AtbHLH29 in the transgenic plants. Identification of the similar biological functions of FER and AtbHLH29, which isolated from two systematically wide-diverged “strategy I” plants, suggests that FER might be a universal gene presented in all strategy I plants in controlling effective iron acquisition system in roots.

A wheat gene Ta SAP17-D encoding an AN1/AN1 zinc finger protein improves salt stress tolerance in transgenic Arabidopsis

The stress-associated protein(SAP) multigene family is conserved in both animals and plants. Its function in some animals and plants are known, but it is yet to be deciphered in wheat(Triticum aestivum L.). We identified the wheat gene Ta SAP17-D, a member of the SAP gene family with an AN1/AN1 conserved domain. Subcellular localization indicated that TaS AP17-D localized to the nucleus, cytoplasm, and cell membrane. Expression pattern analyses revealed that TaS AP17-D was highly expressed in seedlings and was involved in Na Cl response, polyethylene glycol(PEG), cold, and exogenous abscisic acid(ABA). Constitutive expression of TaS AP17-D in transgenic Arabidopsis resulted in enhanced tolerance to salt stress, confirmed by improved multiple physiological indices and significantly upregulated marker genes related to salt stress response. Our results suggest that Ta SAP17-D is a candidate gene that can be used to protect crop plants from salt stress.

Effect of acid phosphatase produced by Trichoderma asperellum Q1 on growth of Arabidopsis under salt stress

Salt stress is a major environmental factor that inhibits crop growth.Trichoderma spp.are the most efficient biocontrol fungi and some of the strains can stimulate plant growth.Phosphate solubilization is known as one of the main mechanisms in promoting plant growth,but the underlying mechanisms of phosphate solubilization in the salinity still need to be explored.The Trichoderma asperellum Q1 isolated and identified in our lab is a beneficial rhizosphere biocontrol fungus with a high phosphate solubilization activity.It could produce acid and alkaline phosphatases when using insoluble organic phosphorus as the sole phosphorus source,the salt stress increased the phosphorus-solubilization ability of the strain and the activities of the two enzymes.Furthermore,an acid phosphatase was purified from the fermentation broth by ammonium sulphate precipitation,ion-exchange,and gel filtration chromatography.Its molecular weight was 55 k Da as determined by SDS-PAGE.The purified acid phosphatase was used to investigate growth performance of Arabidopsis thaliana by plate assay and the result showed that it contributed to Arabidopsis growth by transforming organic phosphate into a soluble inorganic form under salt stress.To our knowledge,this is the first report on acid phosphatase purification from T.asperellum and its function in regulation of plant growth under salt stress.

Overexpression of GmBIN2,a soybean glycogen synthase kinase 3 gene,enhances tolerance to salt and drought in transgenic Arabidopsis and soybean hairy roots

Glycogen synthase kinase 3(GSK3)is a kind of serine/threonine kinase widely found in eukaryotes.Many plant GSK3 kinases play important roles in regulating stress responses.This study investigated BRASSINOSTEROID-INSENSITIVE 2(GmBIN2)gene,a member of the GSK3 protein kinase family in soybean and an orthologue of Arabidopsis BIN2/At SK21.GmBIN2 expression was increased by salt and drought stresses,but was not significantly affected by the ABA treatment.To examine the function of GmB IN2,transgenic Arabidopsis and transgenic soybean hairy roots were generated.Overexpression of GmBIN2 in Arabidopsis resulted in increased germination rate and root length compared with wild-type plants under salt and mannitol treatments.Overexpression of GmBIN2 increased cellular Ca^(2+) content and reduced Na+content,enhancing salt tolerance in transgenic Arabidopsis plants.In the soybean hairy root assay,overexpression of GmBIN2 in transgenic roots also showed significantly higher relative root growth rate than the control when subjected to salt and mannitol treatments.Measurement of physiological indicators,including proline content,superoxide dismutase(SOD)activity,and relative electrical conductivity,supported this conclusion.Furthermore,we also found that GmBIN2 could up-regulate the expression of some stress-related genes in transgenic Arabidopsis and soybean hairy roots.Overall,these results indicated that GmBIN2 improved tolerance to salt and drought in transgenic Arabidopsis and soybean hairy roots.

Targeted deletion of floral development genes in Arabidopsis with CRISPR/Cas9 using the RNA endoribonuclease Csy4 processing system

The formation of flowers in higher plants is controlled by complex gene regulatory networks.The study of floral development in Arabidopsis is promoted and maintained by transposon-tagged mutant lines.In this study,we report a CRISPR/Cas9 genome-editing system based on RNA endoribonuclease Csy4 processing to induce high-efficiency and inheritable targeted deletion of transcription factors involved in floral development in Arabidopsis.Using AP1,SVP,and TFL1 as the target genes,multisite and multiple-gene mutations were achieved with a tandemly arrayed Csy4-sgRNA architecture to express multiplexed sgRNAs from a single transcript driven by the Pol II promoter in transgenic lines.Targeted deletions of chromosomal fragments between the first exon and second exon in either one or three genes were generated by using a single binary vector.Interestingly,the efficiency of site-targeted deletion was comparable to that of indel mutation with the multiplexed sgRNAs.DNA sequencing analysis of RT-PCR products showed that targeted deletions of AP1 and TFL1 could lead to frameshift mutations and introduce premature stop codons to disrupt the open-reading frames of the target genes.In addition,no RT-PCR amplified product was acquired after SVPtargeted deletion.Furthermore,the targeted deletions resulted in abnormal floral development in the mutant lines compared to that of wild-type plants.AP1 and SVP mutations increased plant branching significantly,while TFL1 mutant plants displayed a change from indeterminate to determinate inflorescences.Thus,our results demonstrate that CRISPR/Cas9 with the RNA endoribonuclease Csy4 processing system is an efficient tool to study floral development and improve floral traits rapidly and simply.

Ethylene response factor BnERF2-like (ERF2.4) from Brassica napus L.enhances submergence tolerance and alleviates oxidative damage caused by submergence in Arabidopsis thaliana

Ethylene response factor proteins play an important role in regulating a variety of stress responses in plants,but their exact functions in submergence stress are not well understood.In this study,we isolated BnE RF2.4 from Brassica napus L.to study its function in submergence tolerance.The expression of the BnE RF2.4 gene in B.napus and the expression of antioxidant enzyme genes in transgenic Arabidopsis were analyzed by quantitative RT-PCR.The expression of BnE RF2.4 was induced by submergence in B.napus and the overexpression of BnE RF2.4 in Arabidopsis increased the level of tolerance to submergence and oxidative stress.A histochemical method detected lower levels of H_2O_2,O^(·-)_2and malondialdehyde(MDA) in transgenic Arabidopsis.Compared to the wild type,transgenic lines also had higher soluble sugar content and higher activity of antioxidant enzymes,which helped to protect plants against the oxidative damage caused by submergence.It was concluded that BnE RF2.4 increased the tolerance of plants to submergence stress and may be involved in regulating soluble sugar content and the antioxidant system in defense against submergence stress.

Harpin_(xoo) and Its Functional Domains Activate Pathogen-inducible Plant Promoters in Arabidopsis

Harpins are bacterial proteins that can enhance plant growth and defense against pathogens and insects. To elaborate whether harpins perform the diverse functions in coordination with the activation of specific promoters that contain particular elements, we cloned pathogen-inducible plant promoters PPP1, PPP2, and PPP3 from tobacco and investigated their responses to harpinxoo or its truncated fragments DEG, DIR, and DPR (domains for enhancing plant growth, insect resistance and pathogen resistance). PPP1 contains an internal repeat composed of two tandem 111bp fragments; 111bp in the repeat was deleted in PPP2. PPP3 contains a bacteria-inducible element; PPP1 and PPP2 additionally contain TAC-1 and Eli boxes inducible correspondingly by salicylic acid (SA) and elicitors. Function of cloned PPPs was confirmed based on their activation in transgenic Arabidopsis plants by Ralstonia solanacearum (Ralston) or SA. Harpinxoo, DEG, DIR, or DPR activated PPP1 and PPP2 but not PPP3, consistent with the presence of Eli boxes in promoters. PPP1 was ca. 3-fold more active than PPP2, suggesting that the internal repeat affects levels of the promoter activation.

Accession-specific flowering time variation in response to nitrate fluctuation in Arabidopsis thaliana

Flowering time,a key transition point from vegetative to reproductive growth,is regulated by an intrinsic complex of endogenous and exogenous signals including nutrient status.For hundreds of years,nitrogen has been well known to modulate flowering time,but the molecular genetic basis on how plants adapt to ever-changing nitrogen availability remains not fully explored.Here we explore how Arabidopsis natural variation in flowering time responds to nitrate fluctuation.Upon nitrate availability change,we detect accession-and photoperiod-specific flowering responses,which also feature a accession-specific dependency on growth traits.The flowering time variation correlates well with the expression of floral integrators,SOC1 and FT,in an accession-specific manner.We find that gene expression variation of key hub genes in the photoperiod-circadian-clock(GI),aging(SPLs)and autonomous(FLC)pathways associates with the expression change of these integrators,hence flowering time variation.Our results thus shed light on the molecular genetic mechanisms on regulation of accession-and photoperiod-specific flowering time variation in response to nitrate availability.

Expressional Profiling of Genes Related to Cotton Fiber Initiation and Isolation of GHIAA16 Homologus to Arabidopsis IAA16

The Aux/IAA genes are rapidly and specificallyinduced by the plant hormone auxin and encodeshort-lived nuclear proteins that are capable offorming homo-and hetero-dimer.Molecular,biochemical,and genetic data suggest that theyplay a central role in auxin signaling and plantdevelopment.In order to investigate

Transcriptome-wide effect of Salix SmSPR1 in etiolated seedling of Arabidopsis

Microtubules and their regulatory proteins are involved in the regulation of plant cell morphology.SPIRAL1(SPR1),a plant-specific microtubule-binding protein,is critical in regulating the anisotropic growth of plant cells.Our previous study showed that overexpressed S alix SmS PR1 genes in Arabidopsis thaliana caused right-handed spiral elongation in etiolated seedlings,but there were no morphological differences between wild-type and transgenic seedlings under varied light conditions.We then studied the transcriptional regulation patterns in transgenic plants engineered with the S mSPR1 gene.Transcriptomic results showed that a large number of differentially expressed genes were involved in plant light signal reception,chlorophyll synthesis and photosystem structure.Eleven gene families with 42 photosynthesis-related genes and 6 light-responsive genes were involved in regulation of cell morphology.Our results showed that these genes in the SmSPR1-ox line were particularly down-regulated under dark conditions.In addition,33 TFs showed differences between S mSPR1-ox and wild-type lines.Taken together,the transcriptome analysis provides new insight into investigating the molecular mechanisms of light-induced cell morphological changes mediated by the microtubule binding protein SPR1.

Constitutive Overexpression of Myo-inositol-1-Phosphate Synthase Gene (GsMIPS2) from Glycine soja Confers Enhanced Salt Tolerance at Various Growth Stages in Arabidopsis

The enzyme myo-inositol-1-phosphate synthase(MIPS EC 5.5.1.4) catalyzes the first step of myo-inositol biosynthesis, a product that plays crucial roles in plants as an osmoprotectant, transduction molecule, cell wall constituent and production of stress related molecule. Previous reports highlighted an important role of MIPS family genes in abiotic stresses particularly under salt stress tolerance in several plant species; however, little is known about the cellular and physiological functions of MIPS2 genes under abiotic conditions. In this study, a novel salt stress responsive gene designated Gs MIPS2 from wild soybean Glycine soja 07256 was functionally characterized contained an open reading frame(ORF) of 1 533 bp coding a peptide sequence of 510 amino acids along with mass of 56 445 ku. Multiple sequence alignment analysis revealed its 92%-99% similarity with other MIPS family members in legume proteins. Quantitative real-time PCR results demonstrated that Gs MIPS2 was induced by salt stress and expressed in roots of soybean. The positive function of Gs MIPS2 under salt response at different growth stages of transgenic Arabidopsis was also elucidated. The results showed that Gs MIPS2 transgenic lines displayed increased tolerance as compared to WT and atmips2 mutant lines under salt stress. Furthermore, the expression levels of some salt stress responsive marker genes, including KIN1, RD29 A, RD29 B, P5 Cs and COR47 were significantly up-regulated in Gs MIPS2 overexpression lines than wild type and atmips2 mutant. Collectively, these results suggested that Gs MIPS2 gene was a positive regulator of plant tolerance to salt stress. This was the first report to demonstrate that overexpression of Gs MIPS2 gene from wild soybean improved salt tolerance in transgenic Arabidopsis.