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Udvardi, M.

Publications and source records attributed to Udvardi, M..

9 recordsLinked to original sources

The potential to breed for genetic legacy effects in sustainable farming systems

Legume crops provide protein-rich food, critical disease breaks in cereal rotations, and contribute to soil fertility through symbiotic nitrogen fixation. However, crop improvement programs typically focus on within-crop performance rather than system-level benefits. We hypothesise that legacy effects (the influence of one crops genotype on subsequent crop performance) are under genetic control and could be leveraged in breeding programs. To test this, we evaluated how 309 genetically diverse mungbean genotypes influence subsequent wheat performance. The mungbean panel was grown, followed by a single wheat cultivar sown in the same plot locations. Remarkably, wheat yield varied by nearly 1 t ha{square}{superscript 1} (2.52-3.49 t ha{square}{superscript 1}) depending solely on the preceding mungbean genotype, with legacy traits displaying moderate heritability (H{superscript 2}: 0.43-0.65), demonstrating untapped genetic potential for breeding. Analyses of mungbean traits, soil properties, and volatile organic compounds implicated root architecture, symbiotic nitrogen fixation and soil microbiome as potential biological drivers of legacy effects. Haplotype mapping identified genomic regions in mungbean associated with wheat yield and protein, revealing trade-offs between within-crop and legacy performance. Genetic simulations using empirically derived marker effects compared genomic selection strategies targeting mungbean yield, wheat yield, or both simultaneously. Balanced selection (50:50 weighting) achieved simultaneous gains in both crops (19.5% and 7.6%), highlighting the opportunity to breed for system-level productivity with reduced input requirements.

plant biology↗

A Multitrait Genome-Wide Association Study Reveals a Requirement for the Strigolactone Receptor DWARF14 in Optimal GOLVEN10 Signaling

GOLVEN/ROOT MERISTEM GROWTH FACTOR family of signaling peptides have been shown to control root lateral organ number, density and positioning in plants, although the signaling pathways involved remain obscure. A diverse set of 171 Medicago truncatula HapMap accessions with variation in responses to the GOLVEN 10 peptide, GLV10, were used to identify 74 significant loci controlling seven traits related to nodule formation and root architecture. Importantly, a single nucleotide polymorphism (SNP) in the upstream region of the MtGLV10 peptide-inducible strigolactone receptor gene, MtDWARF14 was significantly associated with insensitivity of nodule density to GLV10, suggesting a link between strigolactone signaling and GLV10 responsiveness. Three independent d14 mutants of the DWARF14 gene were found to hypernodulate, while overexpression of the gene led to reduction in nodule number, phenocopying GLV10. A null mutant, mtd14-1, remained sensitive to GLV10s effect on nodule density. However, at the transcriptional level, the mutant failed to effectively induce the expression of the GOLVEN marker genes, MtPLETHORA3 and MtPINLIKES2. Our study uncovers a hitherto unknown link between the strigolactone and GLV peptide signaling pathways using genotype x environment analysis of Medicago HapMap lines and provides a putative molecular mechanism for recovery from frost damage to fine roots.

plant biology↗

Peripheral vascular strand development in nodules is controlled by a bHLH/HLH heterodimer

Only the Leguminosae family can develop root nodules with peripheral vasculature, an adaptation that grants them an advantage in optimizing nitrogen fixation efficiency. Medicago truncatula develops indeterminate nodules that possess peripheral vascular-strands encircling the central infection zone. How vascular-strands shifted from the nodule central part to the periphery remains unresolved. Here we show, MtbHLH1 (renamed as Nodule Vascular bundle Development 1) is required for the proper organization of vascular strands. In nvd1 nodules, vascular strands pass through the infection zone. NVD2, an HLH transcription factor that lacks a DNA-binding domain, is activated by NVD1. Mutant nvd2 nodules display a similar partially central vasculature. NVD2 is expressed along the nodule vascular bundle and NVD2:GFP fusion protein localizes to the nodule vascular endodermis. The formation of the peripheral vasculature is dependent on the proper stoichiometry of NVD1 and NVD2 heterodimers, as NVD2 controls NVD1-mediated transcriptional activation by sequestering NVD1. Transcription of NVD1 is activated by auxin and Auxin Responsive transcription Factor (MtARF5). Transcriptome sequencing of nvd1 and nvd2 nodules and visualization of in situ auxin and cytokinin signal outputs indicated aberrant auxin/cytokinin balance in these nodules. Our findings showed that the NVD1-NVD2 heterodimer plays a key role in the formation of an orderly peripheral vascular bundle around Medicago nodules.

plant biology↗

The peptide GOLVEN10 controls nodule and lateral root organogenesis and positioning along the longitudinal root axis

O_LIGLV/RGF peptide encoding genes can be identified in genomes of all plants that can form roots or root-like structures suggesting they were essential for transition of plants to land. C_LIO_LIIn Medicago truncatula, five of fifteen GOLVEN(GLV)/ROOT MERISTEM GROWTH FACTOR (RGF) peptide coding genes were induced during nodule organogenesis and to a varying extent under nitrogen deficiency and auxin treatment. Expression of MtGLV9 and MtGLV10 at nodule initiation sites was dependent on the transcription factor NODULE INCEPTION. C_LIO_LIOverexpression of all five nodule-induced GLV genes in M. truncatula hairy roots as well as application of the corresponding synthetic peptides resulted in a 25-50% reduction in nodule number indicating GOLVENs are negative regulators of nodule organogenesis. C_LIO_LIThe peptide GOLVEN10 shifted the position of the first formed lateral root (rhizotaxis) as well as the first formed nodule along the longitudinal primary root axis, a phenomenon we term nodulotaxis, thereby reducing the absolute length of the zone of lateral organ formation on roots. C_LIO_LIApplication of synthetic GOLVEN10 peptide caused an increase in cell number but not cell length in each root cortical cell layer causing an increase in root length and a consequent spatiotemporal delay in formation of the first lateral organ. C_LI Plain Language SummaryNodule positioning is an understudied trait, yet it determines the length of the root that can support nodule formation and consequently the total number of functional nodules formed. We identify for the first time, genetic factors called GOLVEN peptides that alter nodule and lateral root positioning on the primary root along with several other traits including nodule organ initiation and root architecture.

plant biology↗

Application of synthetic peptide CEP1 increases nutrient uptake rates along plant roots

The root system of a plant provides vital functions including resource uptake, storage, and anchorage in soil. Uptake from the soil of macro-nutrients like nitrogen (N), phosphorus (P), potassium (K), and sulphur (S) is critical for plant growth and development. Small signaling peptide (SSP) hormones are best known as potent regulators of plant growth and development with a few also known to have specialized roles in macronutrient utilization. Here we describe a high-throughput screen of SSP effects on root uptake of multiple nutrients. The SSP, MtCEP1 enhanced nitrate uptake rate per unit root length in Medicago truncatula plants deprived of N. MtCEP1 and AtCEP1 enhanced uptake not only of nitrate, but also phosphate and sulfate in both Medicago and Arabidopsis. Transcriptome analysis of Medicago roots treated with different MtCEP1 encoded peptide domains revealed that hundreds of genes respond to these peptides, including several nitrate transporters and a sulfate transporter that may mediate the uptake of these macronutrients downstream of CEP1 signaling. Likewise, several putative signaling pathway genes were induced in roots by CEP1 treatment. Thus, a scalable method has been developed for screening synthetic peptides of potential use in agriculture, with CEP1 shown to be one such peptide.

plant biology↗

AhNGE : A Database for Arachis hypogaea Nodule Developmental Gene Expression

Symbiotic nitrogen fixation (SNF) inside root-nodules is a primary and sustainable source of soil nitrogen. Understanding nodule development and metabolism in crop legumes may lead to more effective SNF in agriculture. Peanut (Arachis hypogaea) is an economically important allotetraploid legume with non-canonical nodule developmental features. Recent genome sequencing of peanut has opened the possibility of making peanut a model for studying atypical nodule development. To help the community of nodule biologists, we have developed a database called AhNGE (Arachis hypogaea Nodule Developmental Gene Expression: http://nipgr.ac.in/AhNGE/index.php). AhNGE contains RNAseq data from six data points of nodule development in A. hypogagea cv. Tifrunner. This data represents a dynamic view of gene expression during peanut nodule development. Research in model legumes has generated a huge knowledgebase in the last twenty years. To streamline comparative genomics among legumes, we performed ortholog analysis among four legumes (Cicer, Glycine, Lotus, and Medicago) and one non-legume (Arabidopsis). This will facilitate the integration of existing knowledge in nodule development with the Arachis transcriptome. The available data can be retrieved using a single or batch query or searching using gene ID, from above mentioned five species. The output displays the gene expression pattern in graphical as well as tabular form, along with further options to download the sequence data. The database is linked with PeanutBase, the main genomic resource of peanut. Additionally, the expression level of different splicing variants can be retrieved from the database. In summary, AhNGE serves as an important resource for the scientific community working on nodule development.

bioinformatics↗

GmVTL1 is an iron transporter on the symbiosome membrane of soybean with an important role in nitrogen fixation.

O_LILegumes establish symbiotic relationships with soil bacteria (rhizobia), housed in nodules on plant roots. The plant supplies carbon substrates and other nutrients to the bacteria in exchange for fixed nitrogen. The exchange occurs across a plant-derived symbiosome membrane (SM), which encloses rhizobia to form a symbiosome. Iron supplied by the plant is crucial for the rhizobial enzyme nitrogenase that catalyses N2 fixation, but the SM iron transporter has not been identified. C_LIO_LIWe use complementation of yeast and plant mutants, real-time PCR, hairy root transformation, microscopy and proteomics to demonstrate the role of soybean GmVTL1 and 2. C_LIO_LIBoth are members of the vacuolar iron transporter family and homologous to Lotus japonicus SEN1 (LjSEN1), previously shown to be essential for N2 fixation. GmVTL1 expression is enhanced in nodule infected cells and both proteins are localised to the SM. C_LIO_LIGmVTL1 and 2 transport iron in yeast and GmVTL1 restores N2 fixation when expressed in the Ljsen1 mutant. C_LIO_LIThree GmVTL1 amino acid substitutions that reduce iron transport in yeast also block N2 fixation in Ljsen1 plants. C_LIO_LIWe conclude GmVTL1 is responsible for transport of iron across the SM to bacteroids and plays a crucial role in the N2-fixing symbiosis. C_LI

plant biology↗

Duplicated KAI2 receptors with divergent ligand-binding specificities control distinct developmental traits in Lotus japonicus

Karrikins (KARs), smoke-derived butenolides, are perceived by the /{beta}-fold hydrolase KARRIKIN INSENSITIVE2 (KAI2) and are thought to mimic endogenous, yet elusive plant hormones tentatively called KAI2-ligands (KLs). The sensitivity to different karrikin types as well as the number of KAI2 paralogs varies among plant species, suggesting diversification and co-evolution of ligand-receptor relationships. In legumes, which comprise a number of important crops with protein-rich, nutritious seed, KAI2 has duplicated. We report sub-functionalization of KAI2a and KAI2b in the model legume Lotus japonicus and demonstrate that their ability to bind the synthetic ligand GR24ent-5DS differs in vitro as well as in genetic assays in Lotus japonicus and in the heterologous Arabidopsis thaliana background. These differences can be explained by the exchange of a widely conserved phenylalanine in the binding pocket of KAI2a with a tryptophan in KAI2b, which occured independently in KAI2 proteins of several unrelated angiosperms. Furthermore, two polymorphic residues in the binding pocket are conserved across a number of legumes and may contribute to ligand binding preferences. Unexpectedly, L. japonicus responds to diverse synthetic KAI2-ligands in an organ-specific manner. Hypocotyl development responds to KAR1, KAR2 and rac-GR24, while root system development responds only to KAR1. This organ-specificity cannot be explained by receptor-ligand preferences alone, because LjKAI2a is sufficient for karrikin responses in the hypocotyl, while LjKAI2a and LjKAI2b operate redundantly in roots. Our findings open novel research avenues into the evolution and diversity of butenolide ligand-receptor relationships, their ecological significance and the mechanisms controlling diverse developmental responses to different KAI2 ligands.

plant biology↗

Medicago truncatula copper transporter1 (MtCOPT1) delivers copper for symbiotic nitrogen fixation

* Copper is an essential nutrient for symbiotic nitrogen fixation. This element is delivered by the host plant to the nodule, where membrane copper transporter would introduce it into the cell to synthesize cupro-proteins.\n\n* COPT family members in model legume Medicago truncatula were identified and their expression determined. Yeast complementation assays, confocal microscopy, and phenotypical characterization of a Tnt1 insertional mutant line were carried out in the nodule-specific M.truncatula COPT family member.\n\n* Medicago truncatula genome encodes eight COPT transporters. MtCOPT1 (Medtr4g019870) is the only nodule-specific COPT gene. It is located in the plasma membrane of the differentiation, interzone and early fixation zones. Loss of MtCOPT1 function results in a copper-mitigated reduction of biomass production when the plant obtains its nitrogen exclusively from symbiotic nitrogen fixation. Mutation of MtCOPT1 results in diminished nitrogenase activity in nodules, likely an indirect effect from the loss of a copper-dependent function, such as cytochrome oxidase activity in copt1-1 bacteroids.\n\n* These data are consistent with a model in which MtCOPT1 transports copper from the apoplast into nodule cells to provide copper for essential metabolic processes associated with symbiotic nitrogen fixation.

plant biology↗