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 ...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.展开更多
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 ...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.展开更多
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. ...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.展开更多
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 diame...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.展开更多
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 ligh...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.展开更多
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 sequenc...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.展开更多
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 tar...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.展开更多
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)fertili...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.展开更多
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...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).展开更多
Self-incompatibility(SI)is an intraspecific reproductive barrier widely present in angiosperms.The SI system with the broadest occurrence in angiosperms is based on an S-RNase linked to a cluster of multiple S-locus F...Self-incompatibility(SI)is an intraspecific reproductive barrier widely present in angiosperms.The SI system with the broadest occurrence in angiosperms is based on an S-RNase linked to a cluster of multiple S-locus F-box(SLF)genes found in the Solanaceae,Plantaginaceae,Rosaceae,and Rutaceae.Recent studies reveal that non-self S-RNase is degraded by the Skip Cullin F-box(SCF)SLF-mediated ubiquitin–proteasome system in a collaborative manner in Petunia,but how self-RNase functions largely remains mysterious.Here,we show that S-RNases form S-RNase condensates(SRCs)in the self-pollen tube cytoplasm through phase separation and the disruption of SRC formation breaks SI in self-incompatible Petunia hybrida.We further find that the pistil SI factors of a small asparagine-rich protein HT-B and thioredoxin h together with a reduced state of the pollen tube all promote the expansion of SRCs,which then sequester several actin-binding proteins,including the actin polymerization factor PhABRACL,the actin polymerization activity of which is reduced by S-RNase in vitro.Meanwhile,we find that S-RNase variants lacking condensation ability fail to recruit PhABRACL and are unable to induce actin foci formation required for pollen tube growth inhibition.Taken together,our results demonstrate that phase separation of S-RNase promotes SI response in P.hybrida,revealing a new mode of S-RNase action.展开更多
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 ...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.展开更多
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....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.展开更多
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) ...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.展开更多
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 presen...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.展开更多
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...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.展开更多
基金supported by grants from the Ministry of Science and Technology of China(Grant No.2004AA222110)the National Natural Science Foundation of China(Grant No.30225029).
文摘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.
基金the Ministry of Science and Technology of China (2016YFD0100500)Chinese Academy of Sciences (XDA08020302, 2017PB0044)
文摘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.
基金supported by the Chinese National Natural Science Foundation (31271716)National High Technology Research and Development Program (2012AA10A308)National Key Program on Transgenic Research (2013ZX009-001)
文摘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.
基金supported by the National Basic Research Program of China (2011CB100302)the Knowledge Innovation Program of CAS (KSCX2-EW-N-02)
文摘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.
基金The authors thank ProfMary Lou Guerinot (Department of Biological Sciences, Dartmouth College, Hanover, New Hampshire) for providing IRT1 peptide antibody and for the critical reading of the manuscript. We are also grateful to Drs Zhentao Lin and Yongfu Fu (Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing) for providing the BiFC assay system and technical supporting. This work was supported by the National Natural Science Foundation of China (Grant nos, 30530460 and 30521001) and the Ministry of Science and Technology of China (Grant nos, 2005cb20904 and 2006AA 10A 105) and Chinese Academy of Sciences (Grant no. KSCX2-YW-N- 001) as well as by the Harvest Plus-China Program.
基金Acknowledgments This work was supported Science Foundation of China by the National Natural (grant numbers 30530460 and 30521001), the Ministry of Science and Technology of China (grant numbers 2005cb20904 and 2006AA10A105) and the Chinese Academy of Sciences (grant number KSCX2-YW-N-001).
基金supported by the National Natural Science Foundation of China(Grant No.30330390)National Science Fund of China for Distinguished Young Scholars(Grant No.30225005).
文摘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.
基金We acknowledge the financial support from the National Key Research and Development Program of China(2016YFD0101004,2016YFD0100300)National Natural Science Foundation of China(31830982,91731305,31661143007)CAAS Agricultural Science and Technology Innovation Program,China(CAAS-ZDRW202002).We thank the bioinformatics facility at the Institute of Crop Science,CAAS,China for providing the computing support.
文摘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.
基金the grants from the National Key Research and Development Program of China(Grant No.2016YFD0100400 to HZ)the National Natural Science Foundation of China(Grant Nos.31501069 to ZL,31601067 to HC,and 31571255 to HZ)+2 种基金the Guangdong Natural Science Funds for Distinguished Young Scholars,China(Grant No.2017A030306001 to HZ)the Pearl River S&T Nova Program of Guangzhou,China(Grant No.201710010106 to HZ)the Scientific Research Project of Guangzhou,China(Grant No.201504010004 to CZ)。
文摘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.
基金supported by grants from the National Key Research and Development Program of China(2016YFD0100901)National Natural Science Foundation of China(31971916)the Youth Innovation Promotion Association,Chinese Academy of Sciences(2019-100).
文摘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.
文摘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).
基金supported by the National Natural Science Foundation of China(32030007)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB27010302).
文摘Self-incompatibility(SI)is an intraspecific reproductive barrier widely present in angiosperms.The SI system with the broadest occurrence in angiosperms is based on an S-RNase linked to a cluster of multiple S-locus F-box(SLF)genes found in the Solanaceae,Plantaginaceae,Rosaceae,and Rutaceae.Recent studies reveal that non-self S-RNase is degraded by the Skip Cullin F-box(SCF)SLF-mediated ubiquitin–proteasome system in a collaborative manner in Petunia,but how self-RNase functions largely remains mysterious.Here,we show that S-RNases form S-RNase condensates(SRCs)in the self-pollen tube cytoplasm through phase separation and the disruption of SRC formation breaks SI in self-incompatible Petunia hybrida.We further find that the pistil SI factors of a small asparagine-rich protein HT-B and thioredoxin h together with a reduced state of the pollen tube all promote the expansion of SRCs,which then sequester several actin-binding proteins,including the actin polymerization factor PhABRACL,the actin polymerization activity of which is reduced by S-RNase in vitro.Meanwhile,we find that S-RNase variants lacking condensation ability fail to recruit PhABRACL and are unable to induce actin foci formation required for pollen tube growth inhibition.Taken together,our results demonstrate that phase separation of S-RNase promotes SI response in P.hybrida,revealing a new mode of S-RNase action.
基金This work was supported by the Ministry of Agriculture of China (grant no. 2016ZX08009003-005) and the National Natural Science Foundation of China (grant no. 31471930).
文摘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.
基金We would like to acknowledge support from the National Science Foundation of China,the National Program on Key Basic Research Project,the Key Basic Research Project of Applied Basic Research Program of Hebei Province,the National Transgenic Key Project of MOA,the Ministry of Science and Innovation of Spain,the International Exchange Program of the University of Naples ‘Federico Ⅱ' to G.B.No conflict of interest declared
文摘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.
基金supported by the Ministry of Science and Technology of China (No.2005CB120904 and 2006AA10A105)the National Natural Science Foundation of China (No.30890133 and 30521001)the Chinese Academy of Sciences (No.KSCX2-YW-N-001)
文摘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.
基金supported by the Ministry of Science and Technology of China (Grant No. 2014CB138104)Chinese Academy of Sciences (Grant No. XDA08010302)the National Science Foundation of China (Grant No. 31371611)
文摘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.
基金supported by the State Key Basic Research and Development Program of China (973 Program)(2009CB118300)the Hi-Tech Research and Development Program of China (863 Program) (2009AA101102)
文摘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.