Biology subjects

Matros, A.

Publications and source records attributed to Matros, A..

3 recordsLinked to original sources

bioRxiv2021

The genetic diversity of Ethiopian barley genotypes in relation to their geographical origin

Ethiopia is recognized as a center of diversity for barley, and its landraces are known for the distinct genetic features compared to other barley collections. The genetic diversity of Ethiopian barley likely results from the highly diverse topography, altitude, climate conditions, soil types, and farming systems. To get detailed information on the genetic diversity a panel of 260 accessions, comprising 239 landraces and 21 barley breeding lines, obtained from the Ethiopian biodiversity institute (EBI) and the national barley improvement program, respectively were studied for their genetic diversity using the 50k iSelect single nucleotide polymorphism (SNP) array. A total of 983 highly informative SNP markers were used for structure and diversity analysis. Three genetically distinct clusters were obtained from the structure analysis comprising 80, 71, and 109 accessions, respectively. Analysis of molecular variance (AMOVA) revealed the presence of higher genetic variation (89%) within the clusters than between the clusters (11%), with moderate genetic differentiation (PhiPT=0.11) and adequate gene flow (Nm=2.02). The Mantel test revealed that the genetic distance between accessions is poorly associated with their geographical distance. Despite the observed weak correlation between geographic distance and genetic differentiation, for some regions like Gonder, Jimma, Gamo-Gofa, Shewa, and Welo, more than 50% of the landraces derived from these regions are assigned to one of the three clusters.

genetics↗

bioRxiv2020

Function and regulation of chloroplast peroxiredoxin IIE

Peroxiredoxins (PRX) are thiol peroxidases which are highly conserved throughout all biological kingdoms. Increasing evidence suggests that their high reactivity toward peroxides has a function not only in antioxidant defense but in particular in redox regulation of the cell. Peroxiredoxin IIE is one of three PRX types found in plastids and has previously been linked to pathogen defense and protection from protein nitration. However, its posttranslational regulation and its function in the chloroplast protein network remained to be explored. Using recombinant protein, it was shown that the peroxidatic Cys121 is subjected to multiple posttranslational modifications, namely disulfide formation, S-nitrosation, S-glutathionylation and hyperoxidation. Slightly oxidized glutathione fostered S-glutathionylation and inhibited activity in vitro. Immobilized recombinant PRX-IIE allowed trapping and subsequent identification of interaction partners by mass spectrometry. Interaction with the 14-3-3 {nu} protein was confirmed in vitro and was shown to be stimulated under oxidizing conditions. Interactions did not depend on phosphorylation as revealed by testing phospho-mimicry variants of PRX-IIE. Based on these data it is proposed that 14-3-3{nu} guides PRX-IIE to certain target proteins, possibly for redox regulation. These findings together with the other identified potential interaction partners of type II PRXs localized to plastids, mitochondria and cytosol provide a new perspective on the redox regulatory network of the cell.

plant biology↗

bioRxiv2020

GWAS reveals the genetic complexity of fructan accumulation patterns in barley grain

We profiled the grain oligosaccharide content of 154 two-row spring barley genotypes and quantified 27 compounds, mainly fructans, that exhibited differential abundance. Clustering revealed two major profile groups where the ‘high’ set contained greater amounts of sugar monomers, sucrose and overall fructans, but lower fructosylraffinose. GWAS identified a significant association for the variability of two fructan types; neoseries-DP7 and inulin-DP9 which showed increased strength when a compound-ratio GWAS was applied. Gene models within this region included five fructan biosynthesis genes, of which three (fructan:fructan 1-fructosyltransferase, sucrose:sucrose 1-fructosyltransferase, and sucrose:fructan 6-fructosyltransferase) have already been described. The remaining two, 6(G)-fructosyltransferase and vacuolar invertase1 have not previously been linked to fructan biosynthesis in barley and showed expression patterns distinct from those of the other three genes, including exclusive expression of 6(G)-fructosyltransferase in outer grain tissues at the storage phase. From exome capture data several SNPs related to inulin- and neoseries-type fructan variability were identified in fructan:fructan 1-fructosyltransferase and 6(G)-fructosyltransferase genes Co-expression analyses uncovered potential regulators of fructan biosynthesis including transcription factors. Our results provide evidence for the distinct biosynthesis of neoseries-type fructans during barley grain maturation plus new gene candidates likely involved in the differential biosynthesis of the various fructan types.Highlight Grain fructan profiles in barley are more complex than previously expected and variations in a diversity panel relate to a genomic region where fructan biosynthesis genes cluster.Abbreviations1-FFTfructan:fructan 1-fructosyltransferase1-SSTsucrose:sucrose 1-fructosyltransferase6-SFTsucrose:fructan 6-fructosyltransferase6G-FFT6(G)-fructosyltransferaseDAPdays after pollinationDPdegree of polymerisationDMdry matterELSDevaporative light scattering detectionFDRfalse discovery rateFOSfructooligosaccharidesFPKMfragments per kilobase, per million mapped readsGWAgenome wide associationGWASgenome wide association studyHAIhours after imbibitionHPAEC–PADhigh pH anion exchange chromatography with pulsed amperometric detectionHPLChigh performance liquid chromatographyKPkestopentaoseKTkestotetraoseLCliquid chromatographyLDlinkage disequilibriumLODlogarithm of oddsMAFminimum allele frequencyMSmass spectrometryNGNeural GasNSneoseries-type fructanPprobability valuePEGpolyethylene glycolQTLquantitative trait lociRFOraffinose family oligosaccharidesRTretention timeSNPsingle nucleotide polymorphismsSPEsolid phase extractionTFAtrifluoroacetic acidTPMtranscripts per millionVI-1vacuolar invertase1View Full Text

plant biology↗