Molecular and functional characterization of sulfiredoxin homologs from higher plants

由在氧化 peroxiredoxin 减少 cysteine-sulfinic 酸， sulfiredoxin (Srx ) 在酵母和人的房间在氧化压力抵抗起一个重要作用。这里，我们从更高的植物报导 Srx 相当或相同的事物的第一分子、功能的描述。生物信息的分析揭示了把序列编码为两张单音的简易窄床和 dicot 植物种类的潜在的 Srx 的存在。通常认为的植物 Srx 蛋白质从酵母和人展出了重要身份到他们的 orthologs，并且为催化作用包含了保存签名顺序和残余必需品。然而，植物 Srxs 不同于酵母和人的 orthologs，都被预言在他们的主要结构拥有叶绿体运输肽。从 Arabidopsis 和米饭的 Srx 蛋白质(指定了为 AtSrx 和 OsSrx，分别地) 在 SRX1 删除酵母房间的 Srx 的补充功能的缺乏。AtSrx 的 GFP 熔化蛋白质在 Arabidopsis 叶肉原物被指向到叶绿体。AtSrx 抄写在植物、繁殖的机关发生了，并且最高的抄本水平在叶子被检测。在氧化应力下面， AtSrx 抄本水平实质地被增加，哪个有在维持被发现必要的 2-Cys peroxiredoxins 的提高的抄写的 paralleled 叶绿体氧化还原作用平衡。除了氧化应力， osmotic/water 赤字或冷处理也提起了 AtSrx 抄本水平。与上面的调查结果一致， AtSrx 的猛烈异种是显著地，产生氧化的更多比野类型 Arabidopsis 强调植物。总起来说，这个工作的结果在是必要的让工厂应付氧化应力的更高的工厂显示功能的 Srx 相当或相同的事物的存在。

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.

Molecular genetic and genomic analysis of wheat milling and end-use traits in China:Progress and perspectives

Wheat is the most widely cultivated staple food crop, and multiple types of food derivatives are processed and consumed globally. Wheat grain quality(WGQ) is central to food processing and nutritional value, and is a decisive factor for consumer acceptance and commercial value of wheat cultivars. Hence, improvement in WGQ traits is top priority for both conventional and molecular wheat breeding. In this review we will focus on two important WGQ traits, grain milling and end-use, and will summarize recent progress in China. Chinese scientists have invested substantial effort in molecular genetic and genomic analysis of these traits and their effects on end-use properties. The insights and resources generated have contributed to the understanding and improvement of these traits. As high-quality genomics information and powerful genome engineering tools are becoming available for wheat, more fundamental breakthroughs in dissecting the molecular and genomic basis of WGQ are expected. China will strive to make further significant contributions to the study and improvement of WGQ in the genomics era.

Identification of AtENT3 as the main transporter for uridine uptake in Arabidopsis roots

当在酵母细胞生产了，差别在 Arabidopsis 器官被表示时，以前的研究证明了 Arabidopsis equilibrative nucleoside 运输 ers (AtENTs ) 拥有运输活动。此处，我们在 nucleoside 运输活动和 AtENT 成员的 transcriptional 模式报导进一步的分析。AtENTs 3 的 recombinant 蛋白质， 6，和 7，然而并非那些 AtENTs 1， 2， 4，和 8，被发现与高亲密关系搬运 thymidine。与以前的建议相反，那 AtENT1 不能搬运 uridine，这个工作证明 recombinant AtENT1 是 uridine 的 pH 依赖、高亲密关系的 transporter。当在 MS 盘子上成长时， AtENT3 猛烈植物比野类型的植物和 AtENT1 或 AtENT6 的猛烈植物对细胞毒素的 uridine 类似物 5-fluorouridine 更容忍。与这观察一致， AtENT3 猛烈的线展出了一个显著地减少的能力收起[(3 ) H ] 经由根的 uridine 什么时候与有变异的 AtENT1 或 AtENT6 的野类型的植物和植物相比。这显示那 AtENT3，然而并非 AtENTs 1 并且 6，是为在 Arabidopsis 根的 uridine 举起的主要 transporter。AtENTs 1 的抄写， 3， 4， 6， 7，和 8 在叶开发和老朽期间以一种复杂方式被调整。相反，六个 AtENT 成员并列地在种子萌芽期间被劝诱。这个工作为未来研究在 recombinant AtENT 蛋白质和新线索的运输性质上提供新信息在里面 vivo 运输活动和在 Arabidopsis 工厂的不同 ENT 蛋白质的生理的功能。

Divergence in homoeolog expression of the grain length-associated gene GASR7 during wheat allohexaploidization

Hexaploid wheat has triplicated homoeologs for most of the genes that are located in subgenomes A, B, and D. GASR7, a member of the Snakin/GASA gene family, has been associated with grain length development in wheat. However, little is known about divergence of its homoeolog expression in wheat polyploids. We studied the expression patterns of the GASR7 homoeologs in immature seeds in a synthetic hexaploid wheat line whose kernels are slender like those of its maternal parent(Triticum turgidum, AABB, PI 94655) in contrast to the round seed shape of its paternal progenitor(Aegilops tauschii, DD, AS2404). We found that the B homoeolog of GASR7 was the main contributor to the total expression level of this gene in both the maternal tetraploid progenitor and the hexaploid progeny, whereas the expression levels of the A and D homoeologs were much lower. To understand possible mechanisms regulating different GASR7 homoeologs, we firstly analyzed the promoter sequences of three homoeologous genes and found that all of them contained gibberellic acid(GA) response elements, with the TaG ASR7 B promoter(pT aG ASR7B) uniquely characterized by an additional predicted transcriptional enhancer. This was confirmed by the GA treatment of spikes where all three homoeologs were induced, with a much stronger response for TaG ASR7 B. McrB C enzyme assays showed that the methylation status at pT aG ASR7 D was increased during allohexaploidization, consistent with the repressed expression of TaG ASR7 D. For pT aG ASR7 A, the distribution of repetitive sequence-derived 24-nucleotide(nt) small interfering RNAs(siR NAs) were found which suggests possible epigenetic regulation because 24-nt siR NAs are known to mediate RNA-dependent DNA methylation. Our results thus indicate that both genetic and epigenetic mechanisms may be involved in the divergence of GASR7 homoeolog expression in polyploid wheat.

Anatomical and chemical characteristics associated with lodging resistance in wheat

Anatomical and chemical characteristics of stems affect lodging in wheat(Triticum aestivum L.) cultivars. Traits associated with lodging resistance, such as plant height, stem strength, culm wall thickness, pith diameter, and stem diameter, were extensively investigated in earlier studies. However, the solid stem trait was rarely considered. In this study, we measured a range of anatomical and chemical characteristics on solid and hollow stemmed wheat cultivars. Significant correlations were detected between resistance to lodging and several anatomical features, including width of mechanical tissue, weight of low internodes, and width of stem walls. Morphological features that gave the best indication of improved lodging resistance were increased stem width, width of mechanical tissue layer, and stem density. Multiple linear regression analysis showed that 99% of the variation in lodging resistance could be explained by the width of the mechanical tissue layer, suggesting that solid stemmed wheat has several anatomical features for increasing resistance to lodging. In addition, microsatellite markers GWM247 and GWM340 were linked to a single solid stem QTL on chromosome 3BL in a population derived from the cross Xinongshixin(solid stem)/Line 3159(hollow stem). These markers should be valuable in breeding wheat for solid stem.

FIT interacts with AtbHLH38 and AtbHLH39 in regulating iron uptake gene expression for iron homeostasis in Arabidopsis

铁是为植物生长和开发的一个必要元素。在植物的铁动态平衡紧在 transcriptional 和 posttranscriptional 水平被调整。涉及铁动态平衡的几个 bHLH 抄写因素最近被识别了。然而，他们的规章的机制仍然保持未知。在这个工作，我们证明抄写因素适合与 AtbHLH38 和 AtbHLH39 交往了并且直接在 Arabidopsis 为铁动态平衡授与铁举起基因的表示规定。在 Arabidopsis 原物的酵母二混血儿的分析和短暂表示证明那 AtbHLH38 或 AtbHLH39 交往了与合适，在 Arabidopsis 涉及铁动态平衡的一个中央抄写因素。在酵母房间的 FIT/AtbHLH38 或 FIT/AtbHLH39 的表示激活铁的螯的 reductase (FRO2 ) 和铁的 transporter (IRT1 ) 驾驶的 GUS 表示倡导者。Overexpression 与在变换的工厂的 AtbHLH38 或 AtbHLH39 合适铁举起基因 FRO2 和 IRT1 从的表示导致了到组成。因为 IRT1 蛋白质累积和高铁的螯的 reductase 活动被检测在，进一步的分析表明 FRO2 和 IRT1 没在这些工厂在 posttranscriptional 水平被调整过去在铁缺乏和铁充足下面的表示工厂。在更积累的植物在表示任何一个 AtbHLH38 上比野生型或植物在他们的射击熨的表示上双， AtbHLH39 或合适。我们铁螯的 reductase FRO2 和铁运输的 IRT1 是三个抄写因素的目标和 FRO2 和 IRT1 的抄写的数据支持被 FIT/AtbHLH38 或 FIT/AtbHLH39 的建筑群直接调整。

Transgenic expression of DwMYB2 impairs iron transport from root to shoot in Arabidopsis thaliana

在植物，铁举起和动态平衡紧被调整从土壤保证它的吸收并且在房间避免过量铁。涉及这个过程的许多基因在过去的几年期间被识别了，但是有在整个植物铁交通国王和分配的基因规定未解决的许多问题遗体。MYB 抄写因素包含约 50 氨基酸的双人脚踏车重复 DNA 有约束力的主题(R) 并且涉及植物开发，荷尔蒙发信号和新陈代谢的许多方面的规定。这里，我们报导在 Arabidopsis thaliana 的兰花 R2R3-MYB 基因 DwMYB2 的宫外的表示授与转基因的植物超敏性熨缺乏。在 DwMYB2 转基因的植物，在根的铁内容在野类型的根与那相比更高是双重的，当颠倒在射击是真的时。在根和射击的铁内容的这不平衡建议到射击的从根的铁的 translocation 被 DwMYB2 的表示在转基因的植物影响。一致地，基因薄片和反向的抄写聚合酶链反应分析表明铁螯的 reductase 基因， AtFRO2，和铁 transporter 基因， AtIRT1 和 AtIRT2，当象 AtIREG1， AtFRD3 和 NRAMP1 那样的另外的潜在的铁运输 ers 是下面调整的时，由 DwMYB2 表示是起来调整的。另外， ers 和抄写因素也是的几通常认为的肽运输的表示在 35S::DwMYB2 改变了转基因的线。这些数据提供我们卓见进整个植物 translocation 尽管 heterologous 基因被表示，在植物为铁动态平衡熨并且识别候选人基因。

AtTHIC, a gene involved in thiamine biosynthesis in Arabidopsis thaliana

抗神经炎素(维生素 B (1 )) 是为有机体的必要混合物。它包含嘧啶戒指结构和噻唑戒指结构。抗神经炎素的这二一半独立地被综合然后一起联合了。这里，我们报导 AtTHIC 的分子的描述，它在 Arabidopsis 涉及抗神经炎素生合成。AtTHIC 类似于 Escherichia 关口 i ThiC，它在初核质涉及嘧啶生合成。AtTHIC 的 Heterologous 表示能机能上地补充 E 的 thiC 大美人异种。关口 i。由在它的倡导者区域的 T-DNA 插入的 AtTHIC 表示的 Downregulation 在植物导致了抗神经炎素内容的激烈的减小，击倒的变异的 thic1 在正常文化条件下面显示出白化体(白叶子) 和致命的显型。thic1 异种能被抗神经炎素的补充救，它的缺点功能能被 AtTHIC cDNA 的表示补充。短暂表示分析表明 AtTHIC 蛋白质指向质体和叶绿体。AtTHIC 强烈在叶子，花和 siliques 被表示， AtTHIC 的抄写是外来的抗神经炎素调整的 down。在结论， AtTHIC 是在 Arabidopsis 的抗神经炎素生合成小径涉及嘧啶合成的基因，并且我们的结果为阐明提供一些新线索在植物的抗神经炎素生合成的小径。

Effects of stem structure andcell wall components on bending strength in wheat

Morphological traits, anatomical features, chemical components and bending stress in the stems of three genotypes of wheat (Triticum aestivum L.), namely Xiaoyan54, 8602 and Xiaoyan81, were ex- amined by means of light microscopy coupled with Fourier transform infrared spectroscopy (FTIR). No- ticeable changes in morphological and anatomical traits were observed, including outer radius of stem, the ratio of stem outer radius to stem wall thickness, various tissue proportions and variations among dif- ferent types of vascular bundles. The results of chemical analysis revealed that Xiaoyan81 had the highest cellulose content in comparison with Xiao- yan54 and 8602, whereas lignin level in Xiaoyan81 was lower than that in 8602 but higher that that in Xiaoyan54. Bending stress analysis demonstrated that Xiaoyan81 may be the main target for identifica- tion, for it had the highest bending stress among the stems of three genotypes. Associated with bending stress, all the results presented here suggested that the ratio of stem wall thickness to its outer radius, schlerenchyma tissue proportion, the average num- ber of big VB per unit and the cellulose content are four important factors affecting the mechanical strength of Xiaoyan81 wheat stems, which can be considered as the key parameters for selecting varie- ties with bending stress. Therefore, it was suggested that in the selection of lodging resistant cultivars one should consider those characterized with large ratio of outer radius of stem to stem wall thickness, great-erschlerenchyma tissue proportion, high average number of big VB per unit with high cellulose content in their stems.

Wheat breeding history reveals synergistic selection of pleiotropic genomic sites for plant architecture and grain yield

Diversity surveys of crop germplasm are important for gaining insights into the genomic basis for plant architecture and grain yield improvement,which is still poorly understood in wheat.In this study,we exome sequenced 287 wheat accessions that were collected in the past 100 years.Population genetics analysis identified that 6.7%of the wheat genome falls within the selective sweeps between landraces and cultivars,which harbors the genes known for yield improvement.These regions were asymmetrically distributed on the A and B subgenomes with regulatory genes being favorably selected.Genome-wide association study(GWAS)identified genomic loci associated with traits for yield potential,and two underlying genes,TaARF12 encoding an auxin response factor and TaDEP1 encoding the G-proteinγ-subunit,were located and characterized to pleiotropically regulate both plant height and grain weight.Elite single-nucleotide haplotypes with increased allele frequency in cultivars relative to the landraces were identified and found to have accumulated over the course of breeding.Interestingly,we found that TaARF12 and TaDEP1 function in epistasis with the classical plant height Rht-1 locus,leading to propose a“Green Revolution”-based working model for historical wheat breeding.Collectively,our study identifies selection signatures that fine-tune the gibberellin pathway during modern wheat breeding and provides a wealth of genomic diversity resources for the wheat research community.

Ubiquitinome Profiling Reveals the Landscape of Ubiquitination Regulation in Rice Young Panicles

Ubiquitination,an essential post-transcriptional modification(PTM),plays a vital role in nearly every biological process,including development and growth.Despite its functions in plant reproductive development,its targets in rice panicles remain unclear.In this study,we used proteome-wide profiling of lysine ubiquitination in rice(O.sativa ssp.indica)young panicles.We created the largest ubiquitinome dataset in rice to date,identifying 1638 lysine ubiquitination sites on916 unique proteins.We detected three conserved ubiquitination motifs,noting that acidic glutamic acid(E)and aspartic acid(D)were most frequently present around ubiquitinated lysine.Enrichment analysis of Gene Ontology(GO)annotations and Kyoto Encyclopedia of Genes and Genomes(KEGG)pathways of these ubiquitinated proteins revealed that ubiquitination plays an important role in fundamental cellular processes in rice young panicles.Interestingly,enrichment analysis of protein domains indicated that ubiquitination was enriched on a variety of receptorlike kinases and cytoplasmic tyrosine and serine-threonine kinases.Furthermore,we analyzed the crosstalk between ubiquitination,acetylation,and succinylation,and constructed a potential protein interaction network within our rice ubiquitinome.Moreover,we identified ubiquitinated proteins related to pollen and grain development,indicating that ubiquitination may play a critical role in the physiological functions in young panicles.Taken together,we reported the most comprehensive lysine ubiquitinome in rice so far,and used it to reveal the functional role of lysine ubiquitination in rice young panicles.

Improving coordination of plant growth and nitrogen metabolism for sustainable agriculture

The agricultural green revolution of the 1960s boosted cereal crop yield was in part due to cultivation of semi-dwarf green revolution varieties.The semi-dwarf plants resist lodging and require high nitrogen(N)fertilizer inputs to maximize yield.To produce higher grain yield,inorganic fertilizer has been overused by Chinese farmers in intensive crop production.With the ongoing increase in the food demand of global population and the environmental pollution,improving crop productivity with reduced N supply is a pressing challenge.Despite a great deal of research efforts,to date only a few genes that improve N use efficiency(NUE)have been identified.The molecular mechanisms underlying the coordination of plant growth,carbon(C)and N assimilation is still not fully understood,thus preventing significant improvement.Recent advances have shed light on how explore NUE within an overall plant biology system that considered the co-regulation of plant growth,C and N metabolisms as a whole,rather than focusing specifically on N uptake and assimilation.There are several potential approaches to improve NUE discussed in this review.Increasing knowledge of how plants sense and respond to changes in N availability,as well as identifying new targets for breeding strategies to simultaneously improve NUE and grain yield,could usher in a new green revolution.

Dissecting and Enhancing the Contributions of High-Molecular-Weight Glutenin Subunits to Dough Functionality and Bread Quality

Dear Editor,Seed storage proteins （SSPs） are frequently important determinants of crop quality traits （Shewry and Casey, 1999）. Dissecting and enhancing the genetic contributions of individual SSPs to their target traits are essential for effectively improving crop quality attributes. However, such a task is often difficult to accomplish, because SSPs are frequently expressed from multigene families and exhibit strong allelic variation. Consequently, detailed knowledge of the function of individual SSPs in crop quality trait is still limited. This scenario is well illustrated by high-molecular-weight glutenin subunits （HMW- GSs）, a complex family of SSPs that are involved in wheat enduse quality through affecting dough functionality （Bek6s, 2012; Rasheed et al., 2014）.

Four IVa bHLH Transcription Factors Are Novel Interactors of FIT and Mediate JA Inhibition of Iron Uptake in Arabidopsis

Plants have evolved sophisticated genetic networks to regulate iron （Fe） homeostasis for their survival. Several classes of plant hormones including jasmonic acid （JA） have been shown to be involved in regulating the expression of iron uptake and/or deficiency-responsive genes in plants. However, the molecular mechanisms by which JA regulates iron uptake remain unclear. In this study, we found that JA negatively modulates iron uptake by downregulating the expression of FIT （bHLH29）, bHLH38, bHLH39, bHLHIO0, and bHLHI01 and promoting the degradation of FIT protein, a key regulator of iron uptake in Arabidopsis. We further demonstrated that the subgroup IVa bHLH proteins, bHLH18, bHLH19, bHLH20, and bHLH25, are novel interactors of FIT, which promote JA-induced FIT protein degradation. These four IVa bHLHs function redundantly to antagonize the activity of the Ib bHLHs （such as bHLH38） in regulating FIT protein stability under iron deficiency. The four IVa bHLH genes are primarily expressed in roots, and are inducible by JA treatment. Moreover, we found that MYC2 and JAR1, two critical components of the JA signaling pathway, play critical roles in mediating JA suppression of the expression of FIT and Ib bHLH genes, whereas they differentially modulate the expression of bHLH18, bHLH19, bHLH20, and bHLH25 to regulate FIT accumulation under iron deficiency. Taken together, these results indicate that by transcriptionally regulating the expression of different sets of bHLH genes JA signaling promotes FIT degradation, resulting in reduced expression of iron-uptake genes, IRT1 and FRO2, and increased sensitivity to iron deficiency. Our data suggest that there is a multilayered inhibition of iron-deficiency response in the presence JA in Arabidopsis.

The Salt Overly Sensitive （SOS） Pathway： Established and Emerging Roles

Soil salinity is a growing problem around the world with special relevance in farmlands. The ability to sense and respond to environmental stimuli is among the most fundamental processes that enable plants to survive. At the cellular level, the Salt Overly Sensitive （SOS） signaling pathway that comprises SOS3, SOS2, and SOS1 has been proposed to mediate cellular signaling under salt stress, to maintain ion homeostasis. Less well known is how cellularly heterog- enous organs couple the salt signals to homeostasis maintenance of different types of cells and to appropriate growth of the entire organ and plant. Recent evidence strongly indicates that different regulatory mechanisms are adopted by roots and shoots in response to salt stress. Several reports have stated that, in roots, the SOS proteins may have novel roles in addition to their functions in sodium homeostasis. SOS3 plays a critical role in plastic development of lateral roots through modulation of auxin gradients and maxima in roots under mild salt conditions. The SOS proteins also play a role in the dynamics of cytoskeleton under stress. These results imply a high complexity of the regulatory networks involved in plant response to salinity. This review focuses on the emerging complexity of the SOS signaling and SOS protein functions, and highlights recent understanding on how the SOS proteins contribute to different responses to salt stress besides ion homeostasis.

Characterization of the promoter of phosphate transporter TaPHT1.2 differentially expressed in wheat varieties

TaPHT1.2 is a functional, root predominantly expressed and low phosphate （Pi） inducible high-affinity Pi transporter in wheat, which is more abundant in the roots of P-efficient wheat genotypes （e.g., Xiaoyan 54） than in P-inefficient genotypes （e.g., Jing 411） under both Pi-deficient and Pi-sufficient conditions. To characterize TaPHT1.2 further, we genetically mapped a TaPHT1.2 transporter, TaPHT1.2-D1, on the long arm of chromosome 4D using a recombinant inbred line population derived from Xiaoyan 54 and Jing 411, and isolated a 1,302 bp fragment of the TaPHT1.2-D1 promoter （PrTaPHT1.2-D1） from Xiaoyan 54. TaPHT1.2-D1 shows collinearity with OsPHT1.2 that has previously been reported to mediate the translocation of Pi from roots to shoots. PrTaPHT1.2-D contains a number of Pi-starvation responsive elements, including P1BS, WRKY-binding W-box, and helix-loop-helix-binding elements. PrTaPHT1.2-D1 was then used to drive expression of 13-glucuronidase （GUS） reporter gene in Arabidopsis through Agrobacterium-mediated transformation. Histochemical analysis of transgenic Arabidopsis plants showed that the reporter gene was specifically induced by Pi-starvation and predominantly expressed in the roots. As there is only one SNP between the TaPHT1.2-D1 promoters of Xiaoyan 54 and Jing 411, and this SNP does not exist within the Pi-starvation responsive elements, the differential expression of TaPHT1.2 in Xiaoyan 54 and Jing 411 may not be caused by this SNP.

Genetic Analysis of Chromosomal Loci Affecting the Content of Insoluble Glutenin in Common Wheat

In common wheat, insoluble glutenin （IG） is an important fraction of flour glutenin macropolymers, and insoluble glutenin content （IGC） is positively associated with key end-use quality parameters. Here, we present a genetic analysis of the chromosomal loci affecting IGC with the data collected from 90 common wheat varieties cultivated in four environments. Statistical analysis showed that IGC was controlled mainly genetically and influenced by the environment. Among the major genetic components known to affect end-use quality, 1BL/1RS translocation had a significantly negative effect on IGC across all four environments. As to the different alleles of Glu-A1, -B1 and -D1 loci, Glu-Ala, Glu-Blb and Glu-Dld exhibited relatively strong positive effects on IGC in all environments. To identify new loci affecting IGC, association mapping with 1355 DArT markers was conducted. A total of 133 markers were found associated with IGC in two or more environments （P 〈 0.05）, ten of which consistently affected IGC in all four environments. The phenotypic variance explained by the ten markers varied from 4.66% to 8.03%, and their elite alleles performed significantly better than the inferior counterparts in enhancing IGC. Among the ten markers, wPt-3743 and wPt-733835 reflected the action of Glu-D1, and wPt-664972 probably indicated the effect of GIu-A1. The other seven markers, forming three clusters on 2AL. 3BL or 7BL chromosome arms, represented newly identified genetic determinants of IGC. Our work provided novel insights into the genetic control of IGC, which may facilitate wheat end- use quality improvement through molecular breeding in the future.

Genomic Distribution of Quantitative Trait Loci for Yield and Yield-related Traits in Common Wheat

A major objective of quantitative trait locus （QTL） studies is to find genes/markers that can be used in breeding programs via marker assisted selection （MAS）.We surveyed the QTLs for yield and yieldrelated traits and their genomic distributions in common wheat （Triticum aestivum L.） in the available published reports.We then carried out a meta-QTL （MQTL） analysis to identify the major and consistent QTLs for these traits.In total,55 MQTLs were identified,of which 12 significant MQTLs were located on wheat chromosomes 1A,1B,2A,2D,3B,4A,4B,4D and 5A.Our study showed that the genetic control of yield and its components in common wheat involved the important genes such as Rht and Vrn.Furthermore,several significant MQTLs were found in the chromosomal regions corresponding to several rice genomic locations containing important QTLs for yield related traits.Our results demonstrate that meta-QTL analysis is a powerful tool for confirming the major and stable QTLs and refining their chromosomal positions in common wheat,which may be useful for improving the MAS efficiency of yield related traits.

New insights into plant nutrient signaling and adaptation to fluctuating environments

Over the past 50 years, the Green Revolution and exploitation of heterosis have allowed cereal grain yield to keep pace with world- wide population growth. Unfortunately, plant growth and crop productivity are heavily dependent on the application of synthetic fertilizers.