Biology subjects

Fatiukha, A.

Publications and source records attributed to Fatiukha, A..

4 recordsLinked to original sources

bioRxiv2020

Three previously characterized resistances to yellow rust are encoded by a single locus Wtk1

The wild emmer wheat (Triticum turgidum ssp. dicoccoides; WEW) yellow (stripe) rust resistance genes Yr15, YrG303 and YrH52 were discovered in natural populations from different geographic locations. They all localize to chromosome 1B but were thought to be non-allelic based on differences in resistance response. We recently cloned Yr15 as a Wheat Tandem Kinase 1 (WTK1) and showed here that these three resistance loci co-segregate in fine-mapping populations and share identical full-length genomic sequence of functional Wtk1. Independent EMS mutagenized susceptible yrG303 and yrH52 lines carried single nucleotide mutations in Wtk1 that disrupted function. A comparison of the mutations for yr15, yrG303 and yrH52 mutants showed that while key conserved residues were intact, other conserved regions in critical kinase subdomains were frequently affected. Thus, we concluded that Yr15-, YrG303- and YrH52-mediated resistances to yellow rust are encoded by a single locus Wtk1. Introgression of Wtk1 into multiple genetic backgrounds resulted in variable phenotypic responses, confirming that Wtk1-mediated resistance is part of a complex immune response network. WEW natural populations subjected to natural selection and adaptation have potential to serve as a good source for evolutionary studies of different traits and multifaceted gene networks. HighlightWe demonstrate that Yr15, YrG303 and YrH52 resistances are encoded by the Wtk1 locus, but express variable resistance responses to yellow rust in a genetic background dependent manner.

genetics↗

bioRxiv2019

Grain Protein Content QTLs Identified in a Durum x Wild Emmer Wheat Mapping Population Tested in Five Environments

AbstractWild emmer wheat (Triticum turgidum ssp. dicoccoides, WEW) was shown to exhibit high grain protein content (GPC) and therefore, possess a great potential for improvement of cultivated wheat nutritional value. A recombinant inbred line (RIL) population derived from a cross between T. durum var. Svevo and WEW acc. Y12-3 was used for construction of a high-density genetic map and genetic dissection of GPC. Genotyping of 208 F6 RILs with 15K wheat SNP array yielded 4,166 polymorphic SNP markers, of which 1,510 were designated as skeleton markers. A total map length of 2,169 cM was obtained with an average distance of 1.5 cM between SNPs. A total of 12 GPC QTLs with LOD score range of 2.7-35.9, and PEV of 2.6-26.6% were identified under five environments. Major QTLs with favorable alleles from WEW were identified on chromosomes 4BS, 5AS, 6BS and 7BL. The QTL region on 6BS coincided with the physical position of the previously cloned QTL, Gpc-B1. Comparisons of the physical intervals of the GPC QTLs described here with the results previously reported in other durumxWEW RIL population led to the identification of four common and two homoeologous QTLs. Exploration of the large genetic variation within WEW accessions is a precondition for discovery of exotic beneficial alleles, as we have demonstrated here, by the identification of seven novel GPC QTLs. Therefore, our research emphasizes the importance of GPC QTL dissection in diverse WEW accessions as a source of novel alleles for improvement of GPC in cultivated wheat.\n\nKey messageGenetic dissection of GPC in tetraploid durum x WEW RIL population, based on high-density SNP genetic map, revealed 12 QTLs, with favorable WEW allele for 11 QTLs.

genetics↗

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↗