Biology subjects

Saranga, Y.

Publications and source records attributed to Saranga, Y..

5 recordsLinked to original sources

bioRxiv2024

Genomic Loci Associated with Grain Protein and Mineral Nutrients concentrations in Eragrostis tef under Contrasting Water Regimes

Climate change is becoming a global concern, threating agricultures capacity to meet the food and nutritional requirements of the growing population. Underutilized crops present an opportunity to address resilience to climate change and nutritional deficiencies. Tef is a stress-resilient cereal crop, producing gluten-free grain of high nutritional quality. However, knowledge is lacking on tefs diversity of grain nutritional properties, their interaction with environmental conditions (e.g., water availability) and the underlying genomic loci. We assessed the effect of water availability on tef grain nutrient concentrations and identify the associated genomic loci. A collection of 223 tef genotypes, a subset of tef diversity panel 300, were grown in the field under well-watered and water-limited conditions in 2021, and phenotyped for grain protein and mineral concentrations and seed color. A genome-wide association study was conducted using 28,837 single-nucleotide polymorphisms (SNPs) and phenotypic data to identify marker-trait associations (MTAs). Tef grain nutrient concentrations exhibited wide genetic diversity with a significant influence of environment. Protein and most micronutrients were more concentrated under water-limited conditions, whereas most macronutrients were higher in the well-watered environment. A total of 59 SNPs were associated with one or more of the studied traits, resulting in 65 MTAs detected under both water treatments, and providing insights into the genetic basis of grain nutrients. Five SNPs reflected multiple associations, with four detecting the same trait under both treatments (multiple-environment effect), and one associated with both Zn and K (pleiotropic effect). In addition, two pairs of closely linked SNPs reflected multiple-environment effects. While multiple-environment associations provide greater support for the integrity of these MTAs, the pleiotropic locus hints at a common mechanism controlling two mineral ions. The identified MTAs shed new light on the genomic architecture of tefs nutritional properties and provide the basis to enhance tef grain nutritional quality alongside drought resilience.

genomics↗

bioRxiv2023

RAMAN DEVELOPMENTAL MARKERS IN ROOT CELL WALLS ARE ASSOCIATED WITH LODGING TENDENCY IN TEF

Tef (Eragrostis tef (Zucc.) Trotter) is an important staple crop in Ethiopia and Eritrea. Its grains are gluten-free and protein rich, so it is considered as a "super-food". Adapting tef to modern farming practices could allow its intensive growth in other regions and enable larger communities to gain from its nutritional values. However, high lodging susceptibility prevents the application of mechanical harvest and causes significant yield losses. Lodging describes the displacement of roots (root lodging) or fracture of culms (stem lodging), forcing plants to bend or fall from their vertical position. Lodging is facilitated by various abiotic and biotic factors, and the lodging severity is increased in overpopulated fields. In this study, we aimed to understand the microstructural properties of crown roots, underlining tef tolerance/susceptibility to lodging. We analyzed plants at 5 and 10 weeks after emergence and compared trellised to lodged plants. Root cross sections from different tef genotypes were characterized by scanning electron microscopy, micro computed tomography and Raman micro spectroscopy. Lodging susceptible genotypes exhibited early tissue maturation, including developed aerenchyma, intensive lignification, and lignin with high levels of crosslinks. A comparison between trellised and lodged plants suggested that lodging itself does not affect the histology of root tissue. Furthermore, cell wall composition along plant maturation was typical to each of the tested genotypes independently of trellising. Our results suggest that it is possible to select lines that exhibit slow maturation of crown roots. Such lines are predicted to show reduction in lodging and facilitate mechanical harvest.

plant biology↗

bioRxiv2022

Novel diversity panel facilitates genomic dissection of lodging in tef (Eragrostis tef)

RationalUnderutilized species that are not widely cultivated (known as orphan crops) present opportunities to increase crop diversity and food security. Tef [Eragrostis tef (Zucc.) Trotter] is known for its high-quality grain and forage. Root-borne lodging is a major devastating problem in tef cultivation, leading to large economic losses and limiting its widespread adoption. ObjectiveThe aim of this study was to identify genomic regions that are associated with tef lodging. MethodsA tef diversity panel (TDP-300) comprised of 297 lines was assembled, genotyped, and phenotyped across 4 field environments. This unique panel, the first of its kind in tef, has the potential to facilitate tef research and breeding. ResultsGenome-wide association study identified 29 sites associated with lodging; in all cases with a minor allele conferring reduced lodging. The eleven sites of prime interest were located in or near genes, 5 of them with a putative role, of which 3 were found to be involved root development. ConclusionsThe identification of lodging-related sites in the current study may advance understanding of the mechanisms underlying tef lodging and crop improvement. The identification of genes related to root development support the importance of root traits in tef lodging, which should be targeted in future breeding.

plant biology↗

bioRxiv2019

Variation in phosphorus and sulfur content shapes the genetic architecture and phenotypic associations within wheat grain ionome

Dissection of the genetic basis of ionome is crucial for the understanding of the physiological and biochemical processes underlying mineral accumulation in seeds, as well as for efficient crop breeding. Most of the elements essential for plants are metals stored in seeds as chelate complexes with phytic acid or sulfur-containing compounds. We assume that the involvement of phosphorus and sulfur in metal chelation is the reason for strong phenotypic associations within ionome. Thus, we adjusted element concentrations for the effect of variation in phosphorus and sulfur seed content. The genetic architecture of wheat grain ionome was characterize by QTL analysis using a cross between durum and wild emmer wheat. Adjustment for variation in P and S drastically changed phenotypic associations within ionome and considerably improved QTL detection power and accuracy, resulting in identification of 105 QTLs and 437 QTL effects for 11 elements. A search for candidate genes revealed some strong functional associations of genes involved in transport and metabolism of ions and elements. Thus, we have shown that accounting for variation in P and S is crucial for understanding of the physiological and genetic regulation of mineral composition of wheat grain ionome and can be implemented for other plants.

genetics↗

bioRxiv2019

Genomic architecture of phenotypic plasticity of complex traits in tetraploid wheat in response to water stress

Phenotypic plasticity is one of the main mechanisms of adaptation to abiotic stresses via changes in critical developmental stages. Altering flowering phenology is a key evolutionary strategy of plant adaptation to abiotic stresses in order to achieve maximum possible reproduction. The current study is the first to apply the linear regression residuals as a drought plasticity scores, while taking into account the differences in flowering phenology and trait variation under non-stress conditions. We characterized the genomic architecture of 17 complex traits and their drought plasticity using a mapping population derived from a cross between durum wheat (Triticum durum) and wild emmer wheat (T. dicoccoides). We identified 79 QTLs, of which 33 were plastic in response to water stress and exhibited epistatic interactions and/or pleiotropy between the initial and plasticity traits. Vrn-B3 (TaTF1) residing within an interval of a major drought-escape QTL was proposed as a candidate gene. The favorable alleles for most of the plasticity QTLs were contributed by wild emmer, demonstrating the high potential of wild relatives for wheat improvement. Our study presents a new approach for quantification of plant adaptation to various stresses and provides new insights into the genetic basis of wheat complex traits under water-deficit stress.\n\nHighlightThe study presents a new approach for quantification of plant adaptation to various stresses and provides new insights into the genetic basis of wheat complex traits under water-deficit stress.

genetics↗