Jens Léon

• PhD
• Professor (Full) at University of Bonn

Currently in wheat breeding, genome wide association studies (GWAS) have successfully revealed the genetic basis of complex traits such as nitrogen use efficiency (NUE) and its biological processes. In the GWAS model, thresholding is common strategy to indicate deviation of expected range of p‐value(s), and it can be used to find the distribution o...

Multi-environmental trials (MET) with temporal and spatial variance are crucial for understanding genotype-environment-management (GxExM) interactions in crops. Here, we present a MET dataset for winter wheat in Germany. The dataset encompasses MET spanning six years (2015–2020), six locations and nine crop management scenarios (consisting of combi...

Bread wheat is an important crop for the human diet, but the increasing soil salinization is reducing the yield. The Ca²⁺ signaling events at the early stages of the osmotic phase of salt stress are crucial for the acclimation response of the plants through the performance of calcium-sensing proteins, which activate or repress transcription factors...

Root architectural traits play pivotal roles in plant adaptation to drought stress, and hence they are considered promising targets in breeding programs. Here, we phenotyped eight root architecture traits in response to well‐watered and drought stress conditions in 200 spring barley (Hordeum vulgare L.) inbred lines over two consecutive field seaso...

Sustainable food production for a growing world population will pose a central challenge in the coming decades. Organic farming is among the feasible approaches to achieving this goal if the yield gap to conventional farming can be decreased. However, uncertainties exist to which extend-and for which phenotypes in particular-organic and conventiona...

Bread wheat is an important crop for the human diet, but the increasing soil salinization is reducing the yield. The Ca ²⁺ signaling events at the early stages of the osmotic phase of salt stress are crucial for the acclimation response of the plants through the performance of calcium-sensing proteins, which activate or repress transcription factor...

Climate change causes extreme conditions like prolonged drought, which results in yield reductions due to its effects on nutrient balances such as nitrogen uptake and utilization by plants. Nitrogen (N) is a crucial nutrient element for plant growth and productivity. Understanding the mechanistic basis of nitrogen use efficiency (NUE) under drought...

Allele frequency shifts can result from adaptation or selection and indicate strategies for coping with stress scenarios. Observing these requires genotyping of hundreds of lines individually or in a pooled sample – both rather costly, especially for species with large genomes. Constructing virtual haplotypes from SNP allele frequencies can drasti-...

In cereal crops, environmental fluctuations affect different physiological processes during various developmental phases associated with the formation of yield components. Because these effects are coupled with cultivar-specific phenology, studies investigating environmental responses in different cultivars can give contradictory results regarding...

Estimation and prediction play a key role in breeding programs. Currently, phenotyping of complex traits such as nitrogen use efficiency (NUE) in wheat is still expensive, requires high-throughput technologies and is very time consuming compared to genotyping. Therefore, researchers are trying to predict phenotypes based on marker information. Gene...

Estimating the FDR significance threshold in genome-wide association studies remains a major challenge in distinguishing true positive hypotheses from false positive and negative errors. Several comparative methods for multiple testing comparison have been developed to determine the significance threshold; however, these methods may be overly conse...

Barley is the fourth most cultivated cereal worldwide, and drought is a major causeof its yield loss by negatively affecting its development. Hence, better understandingdevelopmental mechanisms that control complex polygenic yield-related traits underdrought is essential to uncover favorable yield regulators. This study evaluated sevenabove-ground...

Background The frequency of droughts has dramatically increased over the last 50 years, causing yield declines in cereals, including wheat. Crop varieties with efficient root systems show great potential for plant adaptation to drought stress, however; genetic control of root systems in wheat under field conditions is not yet well understood. Resu...

The environments where the progenitors are grown have the potential to affect the expression of traits in their offspring. Currently, there are various hypotheses regarding the evolutionary and ecological importance of stress memory effects. There is uncertainty regarding its occurrence, persistence, predictability, and adaptive value. In this stud...

Proline is an important metabolite that plays an adaptive role in plants under water-deficit stress. Understanding the genetic basis of water-deficit-induced proline accumulation remains elusive in crop plants, especially in wheat. Here, we investigated proline accumulation under control and water-deficit conditions using a diversity panel which co...

Understanding the genetic and molecular function of nitrate sensing and acquisition across crop species will accelerate breeding of cultivars with improved nitrogen use efficiency (NUE). Here, we performed a genome‐wide scan using wheat and barley accessions characterized under low and high N inputs that uncovered the NPF2.12 gene, encoding a homol...

Developing stress-tolerant plants continues to be the goal of breeders due to their realized yields and stability. Plant responses to drought have been studied in many different plant species, but the occurrence of stress memory as well as the potential mechanisms for memory regulation is not yet well described. It has been observed that plants hol...

Knowing the extent of genetic variability among and within barley accessions provide bases of selection for breeders. However, given the heterogeneous nature of the germplasm, genetic information about barley landraces stored in gene bank of Ethiopia is not well archived. Therefore, genetic diversity study was conducted among and within 20 barley a...

Background The transition from vegetative to floral phase is the result of complex crosstalk of exogenous and endogenous floral integrators. This critical physiological event is the response to environmental interaction, which causes biochemical cascades of reactions at different internal tissues, organs, and releases signals that make the plant mo...

Background Proline (Pro) and hydrogen peroxide (H 2 O 2 ) play a critical role in plants during drought adaptation. Genetic mapping for drought-induced Pro and H 2 O 2 production under field conditions is very limited in crop plants since their phenotyping with large populations is labor-intensive. A genome-wide association study (GWAS) of a divers...

A beneficial root system is crucial for efficient nutrient uptake and stress tolerance. Therefore, evaluating the root system variation for breeding crop plants towards stress adaptation is critically important. Here, we phenotyped root architectural traits of naturally adapted populations from organic and conventional cropping systems under hydrop...

Salt stress is one the most destructive abiotic stressors, causing yield losses in wheat worldwide. A prerequisite for improving salt tolerance is the identification of traits for screening genotypes and uncovering causative genes. Two populations of F3 lines developed from crosses between sensitive and tolerant parents were tested for salt toleran...

Salt stress is one the most destructive abiotic stressors, causing yield losses in wheat worldwide. A prerequisite for improving salt tolerance is the identification of traits for screening genotypes and uncovering causative genes. Two populations of F3 lines developed from crosses between sensitive and tolerant parents were tested for salt toleran...

Proline accumulation is one of the major responses of plants to many abiotic stresses. However, the significance of proline accumulation for drought stress tolerance remains enigmatic in crop plants. First, we examined the natural variation of the pyrolline‐5‐carboxylate synthase (P5CS1) among 49 barley genotypes. Allele mining identified a previou...

The average sowing date of crops in temperate climate zones has been shifted forwards by several days, resulting in a changed photoperiod regime at the emergence stage. In the present study, we performed a global transcriptome profiling of plant development genes in the seedling stage of root and shoot apical meristems of a photoperiod-sensitive sp...

Water deficit is the most severe stress factor in crop production threatening global food security. In this study, we evaluated the genetic variation in photosynthetic traits among 200 wheat cultivars evaluated under drought and rainfed conditions. Significant genotypic, treatments, and their interaction effects were detected for chlorophyll conten...

Key message The genetic response to changing climatic factors selects consistent across the tested environments and location-specific thermo-sensitive and photoperiod susceptible alleles in lower and higher altitudes, respectively, for starting flowering in winter wheat. Abstract Wheat breeders select heading date to match the most favorable condi...

Breeding drought stress tolerance is an integral part of our current and future goals of sustainable agricultural production. In the present study, we examined the natural variation of HvP5cs1 and demonstrated the utility of a wild barley allele for drought stress adaptation in cultivated barley. Sequencing the 5-end regulatory region among 49 barl...

Developing stress tolerant plants continues to be the goal of breeders due to their realized yields and stability. Plant responses to drought in particular have been studied in many different plant species, but the occurrence of stress memory as well as the potential mechanisms for memory regulation are not yet well described. It has been observed...

Prediction of complex traits based on genome-wide marker information is of central importance for both animal and plant breeding. Numerous models have been proposed for the prediction of complex traits and still considerable effort has been given to improve the prediction accuracy of these models, because various genetics factors like additive, dom...

Drought is one of the major abiotic stress factors limiting wheat production worldwide, thus threatening food security. The dissection of the genetic footprint of drought stress response offers strong opportunities toward understanding and improving drought tolerance in wheat. In this study, we investigated the genotypic variability for drought res...

Background In addition to heterogeneity and artificial selection, natural selection is one of the forces used to combat climate change and improve agrobiodiversity in evolutionary plant breeding. Accurate identification of the specific genomic effects of natural selection will likely accelerate transfer between populations. Thus, insights into chan...

The average sowing date of crops in temperate climate zones has been shifted forwards by several days, resulting in a changed photoperiod regime at the emergence stage. In the present study, we performed a global transcriptome profiling of plant development genes in the seedling stage of root and shoot apical meristems of a photoperiod-sensitive sp...

Wheat is an important cereal and half of the world population consumed it. Wheat faces environmental stresses and different techniques (CRISPR, gene silencing, GWAS, etc.) were used to enhance its production but RNA editing (RESs) is not fully explored in wheat. RNA editing has a special role in controlling environmental stresses. The genome-wide i...

Drought is a big challenge for agricultural production. Root attributes are the important target traits for breeding high-yielding sustainable wheat varieties against ever changing climatic conditions. However, the transcriptomic of wheat concerning root architecture remained obscure. Here, we explored RNA-Seq based transcriptome to dissect putativ...

A beneficial root system is crucial for efficient nutrient uptake and stress tolerance. Therefore, it is critically important to evaluate the root system variation for breeding crop plants towards stress adaptation. We phenotyped root architectural traits of naturally adapted populations from organic and conventional cropping systems under hydropon...

Exploring the relationship between grain yield and heading date traits and their stability parameters at phenotypic, genetic, and molecular levels is the milestone for improving yield and adaptation in barley. We evaluated a mapping population comprising 298 doubled haploid lines in multienvironmental trials in Egypt. Composite interval mapping rev...

Flag leaf serves as an essential source of assimilates during grain filling, thereby contributing to grain yield up to 48%. Thus, high-throughput phenotyping of flag leaves is crucial to determine their physiological and genetic basis of yield formation and drought adaptation. Here, we utilized 200 wheat cultivars to identify drought-adaptive loci...

Understanding the growth and development of individual plants is of central importance in modern agriculture, crop breeding, and crop science. To this end, using 3D data for plant analysis has gained attention over the last years. High-resolution point clouds offer the potential to derive a variety of plant traits, such as plant height, biomass, as...

Drought is one of the major abiotic stress factors limiting wheat production worldwide, thus threatening food security. The dissection of the genetic footprint of drought stress response offers strong opportunities toward understanding and improving drought tolerance (DT) in wheat. In this study, we investigated the genotypic variability for drough...

Aegilops tauschii, the progenitor of the wheat D genome, contains extensive diversity for biotic and abiotic resistance. Lr21 is a leaf rust resistance gene which did not enter the initial gene flow from Ae. tauschii into hexaploid wheat due to restrictive hybridization events. Here, we employed population genetics and high-resolution comparative g...

Nitrogen (N) is a vital component of crop production. Wheat yield varies significantly under different soil available N. Knowing how wheat responds to or interacts with N to produce grains is essential in the selection of N use efficient cultivars. We assessed in this study variations among wheat genotypes for productivity-related traits under thre...

Modern bread wheat has a huge genetic potential to adjust its heading date with favorable conditions that has remained largely unexplored so far. In this study, we used an association panel of in Germany adapted cultivars that was tested in multi-location field trials across Germany over three years. The genotypic response to climatic parameters va...

Background The identification of environmentally specific alleles and the observation of evolutional processes is a goal of conservation genomics. By generational changes of allele frequencies in populations, questions regarding effective population size, gene flow, drift, and selection can be addressed. The observation of such effects often is a t...

Advanced Backcross (AB) populations have been widely used to identify and utilize beneficial alleles in various crops such as rice, tomato, wheat and barley. For the development of an AB population, a controlled crossing scheme is used and this controlled crossing along with the selection (both natural and artificial) of agronomically-adapted allel...

Proline accumulation is one of the most common adaptive responses of higher plants against abiotic stresses like drought. It plays multiple roles in osmotic adjustment, cell homeostasis and stress recovery. Genetic regulation of proline accumulation under drought is complex, and transcriptional cascades modulating proline is poorly understood. Here...

Marker assisted breeding, facilitated by reference genome assemblies, can help to produce cultivars adapted to changing environmental conditions. However, anomalous linkage disequilibrium (LD), where single markers show high LD with markers on other chromosomes but low LD with adjacent markers, is a serious impediment for genetic studies. We used a...

Organic farming has the potential to tackle the imminent task of sustainable food production, if the yields could be raised. Here, the benefits of additional exotic alleles, the necessity of increased genetic heterogeneity in organically farmed systems and the buffering capacities by the pronounced plasticity of root traits are demonstrated. Two ba...

Cereals are important crops worldwide that help meet food demands and nutritional needs. In recent years, cereal production has been challenged globally by frequent droughts and hot spells. A plant’s root is the most relevant organ during drought-stress adaptation, playing pivotal roles in anchorage and the acquisition of soil-based resources. Thus...

Background Bread wheat is one of the most important crops for the human diet, but the increasing soil salinization is causing yield reductions worldwide. Improving salt stress tolerance in wheat requires the elucidation of the mechanistic basis of plant response to this abiotic stress factor. Although several studies have been performed to analyze...

Water deficit is one of the major limitations to food production worldwide and most climate change scenarios predict an aggravation of the situation. To face the expected increase in drought stress in the coming years, breeders are working to elucidate the genetic control of barley growth and productivity traits under water deficit. Barley is known...

Background: To ensure further genetic gain, genomic approaches in plant breeding rely on precise phenotypic data, describing plant structure, function and performance. A more precise characterization of the environment will allow a better dealing with genotype-by-environment-by-management interactions. Therefore, space and time dependencies of the...

Fusarium crown rot (FCR) is one of the most important diseases of wheat (Triticum aestivum L.). fcR is mainly caused by the fungal pathogens Fusarium culmorum and F. pseudograminearum. In order to identify new sources of resistance to FCR and to dissect the complexity of FCR resistance, a panel of 161 wheat accessions was phenotyped under growth ro...

Flowering time is a complex trait and has a key role in crop yield and adaptation to environmental stressors such as heat and drought. This study aimed to better understand the interconnected dynamics of epistasis and environment and look for novel regulators. We investigated 534 spring barley MAGIC DH lines for flowering time at various environmen...

Roots perform vital roles for adaptation and productivity under water‐deficit stress, even though their specific functions are poorly understood. In this study, the genetic control of the nodal‐root architectural and anatomical response to water‐deficit were investigated among diverse spring barley accessions. Water‐deficit induced substantial vari...

Soil salinity is a major threat to crop production worldwide. The global climate change is further accelerating the process of soil salinization, particularly in dry areas of the world. Increasing genetic variability of currently used wheat varieties by introgression of exotic alleles/genes from related progenitors’ species in breeding programs is...

Bread wheat is one of the most important crops for human diet but the increasing soil salinization is causing yield reductions worldwide. Physiological, genetic, transcriptomics and bioinformatics analyses were integrated to study the salt stress adaptation response in bread wheat. A comparative analysis to uncover the dynamic transcriptomic respon...

Potato, Solanum tuberosum, is one of the major consumed food in the world, being the basis of the diet of millions of people. The main limiting and destructive disease of potato is late blight, caused by Phytophtora infestans. Here, we present a multi-environmental analysis of the response to P. infestans using an association panel of 150 accession...

The world cropping area for wheat exceeds that of any other crop, and high grain yields in intensive wheat cropping systems are essential for global food security. Breeding has raised yields dramatically in high-input production systems; however, selection under optimal growth conditions is widely believed to diminish the adaptive capacity of culti...

Hexaploid wheat evolved through a spontaneous hybridization of tetraploid wheat (Triticum turgidum, AABB) with diploid wild grass (Aegilops tauschii, DD). Recent genome sequencing found alarmingly low genetic diversity and abundance of repeated sequences across D genome as compared to AB genomes. This characteristic feature of D genome often result...

In this paper, we investigate the usage of unmanned aerial vehicles (UAV) to assess the crop geometry with special focus on the crop height extraction. Crop height is classified as a reliable trait in crop phenotyping and recognized as a good indicator for biomass, expected yield, lodging or crop stress. The current industrial standard for crop hei...

Root growth angle (RGA) in response to gravity controlled by auxin is a pertinent target trait for obtainment of higher yield in cereals. But molecular basis of this root architecture trait remain obscure in wheat and barley. We selected four cultivars two each for wheat and barley to unveil the molecular genetic mechanism of Deeper Rooting 1-like...

Potato, Solanum tuberosum, is one of the highest consumed food in the world, being the basis of the diet of millions of people. The main limiting and destructive disease of potato is late blight, caused by Phytophtora infestans. Here, we present a multi-environmental analysis of the response to P. infestans using an association panel of 150 accessi...

Key message: SNP alleles on chromosomes 4BL and 6AL are associated with sensitivity to salt tolerance in wheat and upon validation can be exploited in the development of salt-tolerant wheat varieties. The dissection of the genetic and molecular components of salt stress response offers strong opportunities toward understanding and improving salt t...

Trait variation among natural populations and their cultivated relatives occurs due to evolutionary forces, including selection and drift. In the present study, we analyzed these forces at the locus level in genotypes belonging to a diverse barley population using PCR-based methods. Genome-wide outlier loci detection found a locus on chromosome 2H...

Water scarcity is a critical threat to global crop production. Here, we used the natural diversity of barley (Hordeum vulgare) to dissect the genetic control of proline-mediated drought stress adaptation. Genetic mapping and positional cloning of a major drought-inducible quantitative trait locus (QTL; QPro.S42-1H) revealed unique allelic variation...

Background: Multi-parent advanced generation intercross (MAGIC) populations are a newly established tool to dissect quantitative traits. We developed the high resolution MAGIC wheat population WM-800, consisting of 910 F4:6 lines derived from intercrossing eight recently released European winter wheat cultivars. Results: Genotyping WM-800 with 7...