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1.
Genome Res ; 31(12): 2276-2289, 2021 Dec.
Article in English | MEDLINE | ID: mdl-34503979

ABSTRACT

More than 80% of the wheat genome consists of transposable elements (TEs), which act as major drivers of wheat genome evolution. However, their contributions to the regulatory evolution of wheat adaptations remain largely unclear. Here, we created genome-binding maps for 53 transcription factors (TFs) underlying environmental responses by leveraging DAP-seq in Triticum urartu, together with epigenomic profiles. Most TF binding sites (TFBSs) located distally from genes are embedded in TEs, whose functional relevance is supported by purifying selection and active epigenomic features. About 24% of the non-TE TFBSs share significantly high sequence similarity with TE-embedded TFBSs. These non-TE TFBSs have almost no homologous sequences in non-Triticeae species and are potentially derived from Triticeae-specific TEs. The expansion of TE-derived TFBS linked to wheat-specific gene responses, suggesting TEs are an important driving force for regulatory innovations. Altogether, TEs have been significantly and continuously shaping regulatory networks related to wheat genome evolution and adaptation.

2.
New Phytol ; 242(2): 641-657, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38379453

ABSTRACT

Nitrate is the main source of nitrogen (N) available to plants and also is a signal that triggers complex regulation of transcriptional networks to modulate a wide variety of physiological and developmental responses in plants. How plants adapt to soil nitrate fluctuations is a complex process involving a fine-tuned response to nitrate provision and N starvation, the molecular mechanisms of which remain largely uncharted. Here, we report that the wheat transcription factor TaLBD41 interacts with the nitrate-inducible transcription factor TaNAC2 and is repressed by nitrate provision. Electrophoretic mobility shift assay and dual-luciferase system show that the TaLBD41-NAC2 interaction confers homeostatic coordination of nitrate uptake, reduction, and assimilation by competitively binding to TaNRT2.1, TaNR1.2, and TaNADH-GOGAT. Knockdown of TaLBD41 expression enhances N uptake and assimilation, increases spike number, grain yield, and nitrogen harvest index under different N supply conditions. We also identified an elite haplotype of TaLBD41-2B associated with increased spike number and grain yield. Our study uncovers a novel mechanism underlying the interaction between two transcription factors in mediating wheat adaptation to nitrate availability by antagonistically regulating nitrate uptake and assimilation, providing a potential target for designing varieties with efficient N use in wheat (Triticum aestivum).


Subject(s)
Nitrates , Nitrogen , Nitrates/metabolism , Nitrogen/metabolism , Biological Transport , Edible Grain/metabolism , Transcription Factors/genetics , Transcription Factors/metabolism
3.
Plant Cell ; 33(4): 865-881, 2021 05 31.
Article in English | MEDLINE | ID: mdl-33594406

ABSTRACT

Wheat (Triticum aestivum) has a large allohexaploid genome. Subgenome-divergent regulation contributed to genome plasticity and the domestication of polyploid wheat. However, the specificity encoded in the wheat genome determining subgenome-divergent spatio-temporal regulation has been largely unexplored. The considerable size and complexity of the genome are major obstacles to dissecting the regulatory specificity. Here, we compared the epigenomes and transcriptomes from a large set of samples under diverse developmental and environmental conditions. Thousands of distal epigenetic regulatory elements (distal-epiREs) were specifically linked to their target promoters with coordinated epigenomic changes. We revealed that subgenome-divergent activity of homologous regulatory elements is affected by specific epigenetic signatures. Subgenome-divergent epiRE regulation of tissue specificity is associated with dynamic modulation of H3K27me3 mediated by Polycomb complex and demethylases. Furthermore, quantitative epigenomic approaches detected key stress responsive cis- and trans-acting factors validated by DNA Affinity Purification and sequencing, and demonstrated the coordinated interplay between epiRE sequence contexts, epigenetic factors, and transcription factors in regulating subgenome divergent transcriptional responses to external changes. Together, this study provides a wealth of resources for elucidating the epiRE regulomics and subgenome-divergent regulation in hexaploid wheat, and gives new clues for interpreting genetic and epigenetic interplay in regulating the benefits of polyploid wheat.


Subject(s)
Epigenesis, Genetic , Regulatory Sequences, Nucleic Acid , Stress, Physiological/genetics , Triticum/genetics , Gene Expression Regulation, Plant , Genome, Plant , Histones/genetics , Histones/metabolism , Lysine/genetics , Lysine/metabolism , Transcription Factors/genetics , Transcription Factors/metabolism , Triticum/physiology
4.
Nature ; 560(7720): 595-600, 2018 08.
Article in English | MEDLINE | ID: mdl-30111841

ABSTRACT

Enhancing global food security by increasing the productivity of green revolution varieties of cereals risks increasing the collateral environmental damage produced by inorganic nitrogen fertilizers. Improvements in the efficiency of nitrogen use of crops are therefore essential; however, they require an in-depth understanding of the co-regulatory mechanisms that integrate growth, nitrogen assimilation and carbon fixation. Here we show that the balanced opposing activities and physical interactions of the rice GROWTH-REGULATING FACTOR 4 (GRF4) transcription factor and the growth inhibitor DELLA confer homeostatic co-regulation of growth and the metabolism of carbon and nitrogen. GRF4 promotes and integrates nitrogen assimilation, carbon fixation and growth, whereas DELLA inhibits these processes. As a consequence, the accumulation of DELLA that is characteristic of green revolution varieties confers not only yield-enhancing dwarfism, but also reduces the efficiency of nitrogen use. However, the nitrogen-use efficiency of green revolution varieties and grain yield are increased by tipping the GRF4-DELLA balance towards increased GRF4 abundance. Modulation of plant growth and metabolic co-regulation thus enables novel breeding strategies for future sustainable food security and a new green revolution.


Subject(s)
Agriculture/methods , Crops, Agricultural/metabolism , Plant Development , Sustainable Development , Ammonium Compounds/metabolism , Carbon Cycle , Nitrogen/metabolism , Oryza/growth & development , Oryza/metabolism , Plant Proteins/metabolism , Triticum/growth & development , Triticum/metabolism , Whole Grains/growth & development , Whole Grains/metabolism
5.
J Integr Plant Biol ; 66(6): 1242-1260, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38656698

ABSTRACT

Leaf senescence is an essential physiological process related to grain yield potential and nutritional quality. Green leaf duration (GLD) after anthesis directly reflects the leaf senescence process and exhibits large genotypic differences in common wheat; however, the underlying gene regulatory mechanism is still lacking. Here, we identified TaNAM-A1 as the causal gene of the major loci qGLD-6A for GLD during grain filling by map-based cloning. Transgenic assays and TILLING mutant analyses demonstrated that TaNAM-A1 played a critical role in regulating leaf senescence, and also affected spike length and grain size. Furthermore, the functional divergences among the three haplotypes of TaNAM-A1 were systematically evaluated. Wheat varieties with TaNAM-A1d (containing two mutations in the coding DNA sequence of TaNAM-A1) exhibited a longer GLD and superior yield-related traits compared to those with the wild type TaNAM-A1a. All three haplotypes were functional in activating the expression of genes involved in macromolecule degradation and mineral nutrient remobilization, with TaNAM-A1a showing the strongest activity and TaNAM-A1d the weakest. TaNAM-A1 also modulated the expression of the senescence-related transcription factors TaNAC-S-7A and TaNAC016-3A. TaNAC016-3A enhanced the transcriptional activation ability of TaNAM-A1a by protein-protein interaction, thereby promoting the senescence process. Our study offers new insights into the fine-tuning of the leaf functional period and grain yield formation for wheat breeding under various geographical climatic conditions.


Subject(s)
Edible Grain , Gene Expression Regulation, Plant , Haplotypes , Plant Leaves , Plant Proteins , Triticum , Triticum/genetics , Triticum/physiology , Triticum/growth & development , Triticum/metabolism , Plant Leaves/genetics , Plant Leaves/metabolism , Plant Leaves/physiology , Plant Proteins/metabolism , Plant Proteins/genetics , Haplotypes/genetics , Edible Grain/genetics , Edible Grain/growth & development , Plant Senescence/genetics , Genes, Plant , Genetic Variation , Phenotype
6.
J Integr Plant Biol ; 2024 May 02.
Article in English | MEDLINE | ID: mdl-38695649

ABSTRACT

Cultivating high-yield wheat under limited water resources is crucial for sustainable agriculture in semiarid regions. Amid water scarcity, plants activate drought response signaling, yet the delicate balance between drought tolerance and development remains unclear. Through genome-wide association studies and transcriptome profiling, we identified a wheat atypical basic helix-loop-helix (bHLH) transcription factor (TF), TabHLH27-A1, as a promising quantitative trait locus candidate for both relative root dry weight and spikelet number per spike in wheat. TabHLH27-A1/B1/D1 knock-out reduced wheat drought tolerance, yield, and water use efficiency (WUE). TabHLH27-A1 exhibited rapid induction with polyethylene glycol (PEG) treatment, gradually declining over days. It activated stress response genes such as TaCBL8-B1 and TaCPI2-A1 while inhibiting root growth genes like TaSH15-B1 and TaWRKY70-B1 under short-term PEG stimulus. The distinct transcriptional regulation of TabHLH27-A1 involved diverse interacting factors such as TaABI3-D1 and TabZIP62-D1. Natural variations of TabHLH27-A1 influence its transcriptional responses to drought stress, with TabHLH27-A1Hap-II associated with stronger drought tolerance, larger root system, more spikelets, and higher WUE in wheat. Significantly, the excellent TabHLH27-A1Hap-II was selected during the breeding process in China, and introgression of TabHLH27-A1Hap-II allele improved drought tolerance and grain yield, especially under water-limited conditions. Our study highlights TabHLH27-A1's role in balancing root growth and drought tolerance, providing a genetic manipulation locus for enhancing WUE in wheat.

7.
New Phytol ; 225(4): 1667-1680, 2020 02.
Article in English | MEDLINE | ID: mdl-31581317

ABSTRACT

Seed vigour and early establishment are important factors determining the yield of crops. A wheat nitrate-inducible NAC transcription factor, TaNAC2, plays a critical role in promoting crop growth and nitrogen use efficiency (NUE), and now its role in seed vigour is revealed. A TaNAC2 regulated gene was identified that is a NRT2-type nitrate transporter TaNRT2.5 with a key role in seed vigour. Overexpressing TaNAC2-5A increases grain nitrate concentration and seed vigour by directly binding to the promoter of TaNRT2.5-3B and positively regulating its expression. TaNRT2.5 is expressed in developing grain, particularly the embryo and husk. In Xenopus oocyte assays TaNRT2.5 requires a partner protein TaNAR2.1 to give nitrate transport activity, and the transporter locates to the tonoplast in a tobacco leaf transient expression system. Furthermore, in the root TaNRT2.5 and TaNRT2.1 function in post-anthesis acquisition of soil nitrate. Overexpression of TaNRT2.5-3B increases seed vigour, grain nitrate concentration and yield, whereas RNA interference of TaNRT2.5 has the opposite effects. The TaNAC2-NRT2.5 module has a key role in regulating grain nitrate accumulation and seed vigour. Both genes can potentially be used to improve grain yield and NUE in wheat.


Subject(s)
Nitrates/metabolism , Plant Proteins/metabolism , Seeds/physiology , Transcription Factors/metabolism , Triticum/metabolism , Animals , Biological Transport , Gene Expression Regulation, Plant/physiology , Oocytes/metabolism , Plant Proteins/genetics , Protein Transport , Signal Transduction , Transcription Factors/genetics , Triticum/genetics , Xenopus
8.
Nucleic Acids Res ; 46(18): e107, 2018 10 12.
Article in English | MEDLINE | ID: mdl-29931324

ABSTRACT

Genetic diversity in plants is remarkably high. Recent whole genome sequencing (WGS) of 67 rice accessions recovered 10,872 novel genes. Comparison of the genetic architecture among divergent populations or between crops and wild relatives is essential for obtaining functional components determining crucial traits. However, many major crops have gigabase-scale genomes, which are not well-suited to WGS. Existing cost-effective sequencing approaches including re-sequencing, exome-sequencing and restriction enzyme-based methods all have difficulty in obtaining long novel genomic sequences from highly divergent population with large genome size. The present study presented a reference-independent core genome targeted sequencing approach, CGT-seq, which employed epigenomic information from both active and repressive epigenetic marks to guide the assembly of the core genome mainly composed of promoter and intragenic regions. This method was relatively easily implemented, and displayed high sensitivity and specificity for capturing the core genome of bread wheat. 95% intragenic and 89% promoter region from wheat were covered by CGT-seq read. We further demonstrated in rice that CGT-seq captured hundreds of novel genes and regulatory sequences from a previously unsequenced ecotype. Together, with specific enrichment and sequencing of regions within and nearby genes, CGT-seq is a time- and resource-effective approach to profiling functionally relevant regions in sequenced and non-sequenced populations with large genomes.


Subject(s)
Epigenesis, Genetic/physiology , Epigenomics/methods , Genetic Speciation , Genetic Variation/genetics , Genome Size/physiology , Whole Genome Sequencing/methods , Computational Biology/methods , Genome/genetics , Genotyping Techniques/methods , High-Throughput Nucleotide Sequencing/methods , Molecular Sequence Annotation/methods , Oryza/classification , Oryza/genetics , Sequence Analysis, DNA/methods , Transcriptome , Triticum/classification , Triticum/genetics
9.
Plant Biotechnol J ; 17(9): 1823-1833, 2019 09.
Article in English | MEDLINE | ID: mdl-30811829

ABSTRACT

Nitrogen (N) plays critical role in plant growth; manipulating N assimilation could be a target to increase grain yield and N use. Here, we show that ABRE-binding factor (ABF)-like leucine zipper transcription factor TabZIP60 mediates N use and growth in wheat. The expression of TabZIP60 is repressed when the N-deprived wheat plants is exposed to nitrate. Knock down of TabZIP60 through RNA interference (RNAi) increases NADH-dependent glutamate synthase (NADH-GOGAT) activity, lateral root branching, N uptake and spike number, and improves grain yield more than 25% under field conditions, while overexpression of TabZIP60-6D had the opposite effects. Further investigation shows TabZIP60 binds to ABRE-containing fragment in the promoter of TaNADH-GOGAT-3B and negatively regulates its expression. Genetic analysis reveals that TaNADH-GOGAT-3B overexpression overcomes the spike number and yield reduction caused by overexpressing TabZIP60-6D. As such, TabZIP60-mediated wheat growth and N use is associated with its negative regulation on TaNADH-GOGAT expression. These findings indicate that TabZIP60 and TaNADH-GOGAT interaction plays important roles in mediating N use and wheat growth, and provides valuable information for engineering N use efficiency and yield in wheat.


Subject(s)
Basic-Leucine Zipper Transcription Factors/genetics , Nitrogen/metabolism , Plant Proteins/genetics , Transcription Factors/genetics , Triticum/genetics , Edible Grain/growth & development , Gene Knockdown Techniques , Triticum/growth & development
10.
Plant Biotechnol J ; 17(1): 50-62, 2019 01.
Article in English | MEDLINE | ID: mdl-29729214

ABSTRACT

The optimization of plant architecture in order to breed high-yielding soya bean cultivars is a goal of researchers. Tall plants bearing many long branches are desired, but only modest success in reaching these goals has been achieved. MicroRNA156 (miR156)-SQUAMOSA PROMOTER BINDING PROTEIN-LIKE (SPL) gene modules play pivotal roles in controlling shoot architecture and other traits in crops like rice and wheat. However, the effects of miR156-SPL modules on soya bean architecture and yield, and the molecular mechanisms underlying these effects, remain largely unknown. In this study, we achieved substantial improvements in soya bean architecture and yield by overexpressing GmmiR156b. Transgenic plants produced significantly increased numbers of long branches, nodes and pods, and they exhibited an increased 100-seed weight, resulting in a 46%-63% increase in yield per plant. Intriguingly, GmmiR156b overexpression had no significant impact on plant height in a growth room or under field conditions; however, it increased stem thickness significantly. Our data indicate that GmmiR156b modulates these traits mainly via the direct cleavage of SPL transcripts. Moreover, we found that GmSPL9d is expressed in the shoot apical meristem and axillary meristems (AMs) of soya bean, and that GmSPL9d may regulate axillary bud formation and branching by physically interacting with the homeobox gene WUSCHEL (WUS), a central regulator of AM formation. Together, our results identify GmmiR156b as a promising target for the improvement of soya bean plant architecture and yields, and they reveal a new and conserved regulatory cascade involving miR156-SPL-WUS that will help researchers decipher the genetic basis of plant architecture.


Subject(s)
Glycine max/genetics , MicroRNAs/genetics , Plant Shoots/growth & development , Arabidopsis/genetics , Arabidopsis/growth & development , Gene Expression Regulation, Plant , Meristem/growth & development , Plant Leaves/growth & development , Plants, Genetically Modified/genetics , Plants, Genetically Modified/growth & development , Glycine max/anatomy & histology , Glycine max/growth & development
11.
Nature ; 496(7443): 87-90, 2013 Apr 04.
Article in English | MEDLINE | ID: mdl-23535596

ABSTRACT

Bread wheat (Triticum aestivum, AABBDD) is one of the most widely cultivated and consumed food crops in the world. However, the complex polyploid nature of its genome makes genetic and functional analyses extremely challenging. The A genome, as a basic genome of bread wheat and other polyploid wheats, for example, T. turgidum (AABB), T. timopheevii (AAGG) and T. zhukovskyi (AAGGA(m)A(m)), is central to wheat evolution, domestication and genetic improvement. The progenitor species of the A genome is the diploid wild einkorn wheat T. urartu, which resembles cultivated wheat more extensively than do Aegilops speltoides (the ancestor of the B genome) and Ae. tauschii (the donor of the D genome), especially in the morphology and development of spike and seed. Here we present the generation, assembly and analysis of a whole-genome shotgun draft sequence of the T. urartu genome. We identified protein-coding gene models, performed genome structure analyses and assessed its utility for analysing agronomically important genes and for developing molecular markers. Our T. urartu genome assembly provides a diploid reference for analysis of polyploid wheat genomes and is a valuable resource for the genetic improvement of wheat.


Subject(s)
Genome, Plant/genetics , Triticum/genetics , Base Sequence , Brachypodium/genetics , Crops, Agricultural/classification , Crops, Agricultural/genetics , Diploidy , Genetic Markers/genetics , Molecular Sequence Data , Oryza/genetics , Phylogeny , Sorghum/genetics , Synteny/genetics , Triticum/classification , Zea mays/genetics
12.
Plant Biotechnol J ; 16(11): 1858-1867, 2018 11.
Article in English | MEDLINE | ID: mdl-29577547

ABSTRACT

The plastidic glutamine synthetase isoform (GS2) plays a key role in nitrogen (N) assimilation. We introduced TaGS2-2Abpro::TaGS2-2Ab, the favourable allele of TaGS2-2A in the winter wheat (Triticum aestivum) variety Ji5265. Transgenic expression of TaGS2-2Ab significantly increased GS2 abundance and GS activity in leaves. Two consecutive field experiments showed the transgenic lines had higher grain yield, spike number, grain number per spike and 1000-grain weight than did the wild type under both low N and high N conditions. Analysis of N use-related traits showed that transgenic expression of TaGS2-2Ab increased root ability to acquire N, N uptake before and after flowering, remobilization of N to grains and N harvest index. Measurement of chlorophyll content and net photosynthesis rate in flag leaves during grain filling stage revealed that the transgenic lines had prolonged leaf functional duration as compared with the wild type. These results suggest that TaGS2 plays important role in N use, and the favourable allele TaGS2-2Ab is valuable in engineering wheat with improved N use efficiency and grain yield.


Subject(s)
Crop Production , Glutamate-Ammonia Ligase/genetics , Nitrogen/metabolism , Plants, Genetically Modified/genetics , Triticum/genetics , Chlorophyll/metabolism , Crop Production/methods , Glutamate-Ammonia Ligase/metabolism , Photosynthesis , Plant Leaves/enzymology , Plant Leaves/metabolism , Plants, Genetically Modified/growth & development , Plants, Genetically Modified/metabolism , Plastids/genetics , Quantitative Trait, Heritable , Triticum/growth & development , Triticum/metabolism
13.
Plant Physiol ; 174(4): 2274-2288, 2017 Aug.
Article in English | MEDLINE | ID: mdl-28626005

ABSTRACT

Controlling the major auxin biosynthetic pathway to manipulate auxin content could be a target for genetic engineering of crops with desired traits, but little progress had been made because low or high auxin contents often cause developmental inhibition. Here, we performed a genome-wide analysis of bread wheat (Triticum aestivum) to identify the Tryptophan Aminotransferase of Arabidopsis1/Tryptophan Aminotransferase-Related (TAA1/TAR) genes that function in the tryptophan-dependent pathway of auxin biosynthesis. Sequence mining together with gene cloning identified 15 TaTAR genes, among which 12 and three genes were phylogenetically close to Arabidopsis (Arabidopsis thaliana) AtTAR2 and AtTAR3, respectively. TaTAR2.1 had the most abundant transcripts in the TaTAR2 genes and was expressed mainly in roots and up-regulated by low nitrogen (N) availability. Knockdown of TaTAR2.1 caused vegetative and reproductive deficiencies and impaired lateral root (LR) growth under both high- and low-N conditions. Overexpressing TaTAR2.1-3A in wheat enhanced LR branching, plant height, spike number, grain yield, and aerial N accumulation under different N supply levels. In addition, overexpressing TaTAR2.1-3A in Arabidopsis elevated auxin accumulation in the primary root tip, LR tip, LR primordia, and cotyledon and hypocotyl and increased primary root length, visible LR number, and shoot fresh weight under high- and low-N conditions. Our results indicate that TaTAR2.1 is critical for wheat growth and also shows potential for genetic engineering to reach the aim of improving the grain yield of wheat.


Subject(s)
Biosynthetic Pathways , Indoleacetic Acids/metabolism , Seeds/enzymology , Triticum/enzymology , Tryptophan Transaminase/metabolism , Arabidopsis/drug effects , Arabidopsis/genetics , Arabidopsis/growth & development , Biomass , Biosynthetic Pathways/drug effects , Gene Expression Regulation, Plant/drug effects , Gene Knockdown Techniques , Genes, Plant , Glucuronidase/metabolism , Nitrogen/pharmacology , Organ Specificity/drug effects , Organ Specificity/genetics , Phenotype , Phylogeny , Plant Proteins/metabolism , Plant Roots/drug effects , Plant Roots/growth & development , Plant Shoots/drug effects , Plant Shoots/growth & development , Plants, Genetically Modified , Seedlings/drug effects , Seedlings/genetics , Seeds/drug effects , Triticum/drug effects , Triticum/genetics
14.
Plant Physiol ; 175(2): 746-757, 2017 Oct.
Article in English | MEDLINE | ID: mdl-28807930

ABSTRACT

The architecture of wheat (Triticum aestivum) inflorescence and its complexity is among the most important agronomic traits that influence yield. For example, wheat spikes vary considerably in the number of spikelets, which are specialized reproductive branches, and the number of florets, which are spikelet branches that produce seeds. The large and repetitive nature of the three homologous and highly similar subgenomes of wheat has impeded attempts at using genetic approaches to uncover beneficial alleles that can be utilized for yield improvement. Using a population-associative transcriptomic approach, we analyzed the transcriptomes of developing spikes in 90 wheat lines comprising 74 landrace and 16 elite varieties and correlated expression with variations in spike complexity traits. In combination with coexpression network analysis, we inferred the identities of genes related to spike complexity. Importantly, further experimental studies identified regulatory genes whose expression is associated with and influences spike complexity. The associative transcriptomic approach utilized in this study allows rapid identification of the genetic basis of important agronomic traits in crops with complex genomes.


Subject(s)
Inflorescence/genetics , Transcriptome , Triticum/genetics , Alleles , Gene Expression Profiling , Genotype , Inflorescence/anatomy & histology , Phenotype , Phylogeny , Seeds/anatomy & histology , Seeds/genetics , Species Specificity , Triticum/anatomy & histology
15.
Theor Appl Genet ; 131(12): 2677-2698, 2018 Dec.
Article in English | MEDLINE | ID: mdl-30255337

ABSTRACT

KEY MESSAGE: QTL for a wheat ideotype root system and its plasticity to nitrogen deficiency were characterized. Root system architecture-related traits (RRTs) and their plasticity to nitrogen availability are important for nitrogen acquisition and yield formation in wheat (Triticum aestivum L.). In this study, quantitative trait loci (QTL) analysis was conducted under different nitrogen conditions, using the seedlings of 188 recombinant inbred lines derived from a cross between Kenong 9204 and Jing 411. Fifty-three QTL for seven RRTs and fourteen QTL for the plasticity of these RRTs to nitrogen deficiency were detected. Thirty of these QTL were mapped in nine clusters on chromosomes 2B, 2D, 3A, 3D, 6B, 6D, 7A and 7B. Six of these nine clusters were also colocated with loci for nitrogen use efficiency (NUE)-related traits (NRTs). Among them, three QTL clusters (C2B, C6D and C7B) were highlighted, considering that they individually harbored three stable robust QTL (i.e., QMrl-2B.1, QdRs-6D and QMrl-7B). C2B and C7B stably contributed to the optimal root system, and C6D greatly affected the plasticity of RRTs in response to nitrogen deficiency. However, strong artificial selection was only observed for C7B in 574 derivatives of Kenong 9204. Covariance analysis identified QMrl-7B as the major contributor in C7B that affected the investigated NRTs in mature plants. Phenotypic analysis indicated that thousand kernel weight might represent a "concomitant" above-ground trait of the "hidden" RRTs controlled by C7B, which are used for breeding selection. Dissecting these QTL regions with potential breeding value will ultimately facilitate the selection of donor lines with both high yield and NUE in wheat breeding programs.


Subject(s)
Nitrogen/metabolism , Plant Roots/metabolism , Quantitative Trait Loci , Triticum/genetics , Phenotype , Plant Breeding , Plant Roots/genetics , Seedlings/genetics , Seedlings/metabolism , Triticum/metabolism
16.
BMC Plant Biol ; 17(1): 229, 2017 Dec 01.
Article in English | MEDLINE | ID: mdl-29191158

ABSTRACT

BACKGROUND: Plant roots are highly plastic to high salinity. However, the molecular mechanism by which root developmental plasticity is regulated remains largely unknown. Previously we reported that miR172c-NNC1 module plays a key role in soybean-rhizobial symbiosis. The fact that the miR172c promoter contains several stress-related cis elements indicates that miR172c may have a role in root response to abiotic stress. RESULTS: Here we showed that miR172c is greatly induced by salt stress in soybean. Overexpression of miR172c and knockdown of miR172c activity resulted in substantially increased and reduced root sensitivity to salt stress, respectively. Furthermore, we show that the target gene NNC1 (Nodule Number Control 1) of miR172c was downregulated by salt stress. The transgenic roots overexpressing or knocking down NNC1 expression also exhibited the altered root sensitivity to salt stress. CONCLUSION: The study reveals the crucial role of miR172c-NNC1 module in root stress tolerance to salt stress in soybean.


Subject(s)
Genes, Plant , Glycine max/genetics , MicroRNAs/genetics , Plant Roots/physiology , RNA, Plant/genetics , Promoter Regions, Genetic , Sodium Chloride/pharmacology , Glycine max/physiology , Stress, Physiological
17.
Theor Appl Genet ; 130(6): 1235-1252, 2017 Jun.
Article in English | MEDLINE | ID: mdl-28349175

ABSTRACT

KEY MESSAGE: The temporal and spatial expression patterns of stable QTL for plant height and their influences on yield were characterized. Plant height (PH) is a complex trait in wheat (Triticum aestivum L.) that includes the spike length (SL) and the internode lengths from the first to the fifth internode, which are counted from the top and abbreviated as FIRITL, SECITL, THIITL, FOUITL, and FIFITL, respectively. This study identified eight putative additive quantitative trait loci (QTL) for PH. In addition, unconditional and conditional QTL mapping were used to analyze the temporal and spatial expression patterns of five stable QTL for PH. qPh-3A mainly regulated SL, FIRITL, and FIFITL to affect PH during the booting-heading stage (BS-HS); qPh-3D regulated all internode lengths to affect PH, especially during the BS-HS; before HS, qPh-4B mainly affected FIRITL, SECITL, THIITL, and FOUITL and qPh-5A.1 mainly affected SECITL, THIITL, and FOUITL to regulate PH; and qPh-6B mainly regulated FIRITL to affect the PH after the booting stage (BS). qPhdv-4B, a QTL for the response of PH to nitrogen stress, was stable and co-localized with qPh-4B. All five stable QTL, except for qPh-3A, were related to the 1000 kernel weight and yield per plant. Regions of qPh-3A, qPh-3D, qPh-4B, qPh-5A.1, and qPh-6B showed synteny to parts of rice chromosomes 1, 1, 3, 9, and 2, respectively. Based on comparative genomics analysis, Rht-B1b was cloned and mapped in the CI of qPh-4B. This report provides useful information for fine mapping of the stable QTL for PH and the genetic improvement of wheat plant type.


Subject(s)
Quantitative Trait Loci , Triticum/growth & development , Triticum/genetics , Chromosome Mapping , Phenotype , Spatio-Temporal Analysis
18.
Implant Dent ; 26(4): 600-606, 2017 Aug.
Article in English | MEDLINE | ID: mdl-28639984

ABSTRACT

PURPOSE: This study investigated the effect of topography on cell behavior by screening polydimethylsiloxane (PDMS) molds with different nanoscale micropatterns to determine the ideal surface characteristics for attachment of human epithelial cells. MATERIALS AND METHODS: A soft PDMS mold with regular dot arrays was fabricated based on an aluminum oxide template with ordered nanotube arrays and used as a substrate for cell culture. Cell proliferation, spread, and morphology, as well as features of the extracellular matrix and the actin cytoskeleton were assessed. DISCUSSION: Cells grown on 100-nm regular dot arrays had the highest proliferation rate and spread, with the longest pseudopodia; they showed robust actin distribution relative to the control group. CONCLUSION: Three-dimensional PDMS microstructures with 100 nm regular dot arrays were the most effective surface for epithelial cell attachment. These findings can aid in the manufacture of superior materials for use in implants to better integrate into recipient tissue.


Subject(s)
Cell Culture Techniques , Dental Implants , Epithelial Cells/cytology , Gingiva/cytology , Actin Cytoskeleton/physiology , Cell Proliferation/physiology , Dimethylpolysiloxanes/pharmacology , Extracellular Matrix/physiology , Humans , Immunohistochemistry , In Vitro Techniques , Microscopy, Confocal , Microscopy, Electron, Scanning , Surface Properties
19.
Plant Physiol ; 169(3): 1991-2005, 2015 Nov.
Article in English | MEDLINE | ID: mdl-26371233

ABSTRACT

Nitrate is a major nitrogen resource for cereal crops; thus, understanding nitrate signaling in cereal crops is valuable for engineering crops with improved nitrogen use efficiency. Although several regulators have been identified in nitrate sensing and signaling in Arabidopsis (Arabidopsis thaliana), the equivalent information in cereals is missing. Here, we isolated a nitrate-inducible and cereal-specific NAM, ATAF, and CUC (NAC) transcription factor, TaNAC2-5A, from wheat (Triticum aestivum). A chromatin immunoprecipitation assay showed that TaNAC2-5A could directly bind to the promoter regions of the genes encoding nitrate transporter and glutamine synthetase. Overexpression of TaNAC2-5A in wheat enhanced root growth and nitrate influx rate and, hence, increased the root's ability to acquire nitrogen. Furthermore, we found that TaNAC2-5A-overexpressing transgenic wheat lines had higher grain yield and higher nitrogen accumulation in aerial parts and allocated more nitrogen in grains in a field experiment. These results suggest that TaNAC2-5A is involved in nitrate signaling and show that it is an exciting gene resource for breeding crops with more efficient use of fertilizer.


Subject(s)
Gene Expression Regulation, Plant , Nitrates/metabolism , Plant Proteins/metabolism , Triticum/genetics , Anion Transport Proteins/genetics , Anion Transport Proteins/metabolism , Arabidopsis/enzymology , Arabidopsis/genetics , Arabidopsis/growth & development , Crops, Agricultural , Fertilizers , Glutamate-Ammonia Ligase/genetics , Glutamate-Ammonia Ligase/metabolism , Nitrate Transporters , Nitrates/pharmacology , Nitrogen/metabolism , Plant Leaves/enzymology , Plant Leaves/genetics , Plant Leaves/growth & development , Plant Proteins/genetics , Plant Roots/enzymology , Plant Roots/genetics , Plant Roots/growth & development , Plant Shoots/enzymology , Plant Shoots/genetics , Plant Shoots/growth & development , Seeds/enzymology , Seeds/genetics , Seeds/growth & development , Transcription Factors/genetics , Transcription Factors/metabolism , Triticum/enzymology , Triticum/growth & development
20.
Plant Physiol ; 167(2): 411-23, 2015 Feb.
Article in English | MEDLINE | ID: mdl-25489021

ABSTRACT

Increasing fertilizer consumption has led to low fertilizer use efficiency and environmental problems. Identifying nutrient-efficient genes will facilitate the breeding of crops with improved fertilizer use efficiency. This research performed a genome-wide sequence analysis of the A (NFYA), B (NFYB), and C (NFYC) subunits of Nuclear Factor Y (NF-Y) in wheat (Triticum aestivum) and further investigated their responses to nitrogen and phosphorus availability in wheat seedlings. Sequence mining together with gene cloning identified 18 NFYAs, 34 NFYBs, and 28 NFYCs. The expression of most NFYAs positively responded to low nitrogen and phosphorus availability. In contrast, microRNA169 negatively responded to low nitrogen and phosphorus availability and degraded NFYAs. Overexpressing TaNFYA-B1, a low-nitrogen- and low-phosphorus-inducible NFYA transcript factor on chromosome 6B, significantly increased both nitrogen and phosphorus uptake and grain yield under differing nitrogen and phosphorus supply levels in a field experiment. The increased nitrogen and phosphorus uptake may have resulted from the fact that that overexpressing TaNFYA-B1 stimulated root development and up-regulated the expression of both nitrate and phosphate transporters in roots. Our results suggest that TaNFYA-B1 plays essential roles in root development and in nitrogen and phosphorus usage in wheat. Furthermore, our results provide new knowledge and valuable gene resources that should be useful in efforts to breed crops targeting high yield with less fertilizer input.


Subject(s)
Fertilizers , Plant Proteins/metabolism , Seeds/growth & development , Transcription Factors/metabolism , Triticum/growth & development , Triticum/metabolism , Agriculture , Base Sequence , Binding Sites , Blotting, Northern , Cloning, Molecular , Gene Expression Regulation, Plant , Genes, Plant , MicroRNAs/genetics , MicroRNAs/metabolism , Molecular Sequence Data , Nitrates/metabolism , Nitrogen/deficiency , Phosphate Transport Proteins/genetics , Phosphate Transport Proteins/metabolism , Phosphorus/deficiency , Phylogeny , Plant Proteins/genetics , Plant Roots/anatomy & histology , Plant Roots/genetics , Plant Roots/growth & development , Plant Shoots/genetics , Seeds/metabolism , Transcription Factors/genetics , Triticum/genetics
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