Biology subjects

Korzun, V.

Publications and source records attributed to Korzun, V..

3 recordsLinked to original sources

bioRxiv2023

High-resolution mapping of Ryd4Hb, a major resistance gene to Barley yellow dwarf virus from Hordeum bulbosum

Virus diseases are causing high yield losses in crops worldwide. The Barley yellow dwarf virus (BYDV) complex is responsible for one of the most widespread and economically important viral diseases of cereals. While no complete resistance gene has been uncovered in the primary genepool of barley, sources of resistance were identified in the wild relative Hordeum bulbosum, representing the secondary genepool of barley. One such locus, Ryd4Hb, has been previously introgressed into barley, and was allocated to chromosome 3H, but is tightly linked to a sublethality factor that prevents the incorporation and utilization of Ryd4Hb in barley varieties. To solve this problem, we fine-mapped Ryd4Hb and separated it from this negative factor. We narrowed the Ryd4Hb locus to a 66.5 kbp physical interval in the barley Morex reference genome. The region comprises one complete and one partial gene from the nucleotide-binding and leucine-rich repeat immune receptor family, typical of dominant virus resistance genes. The closest homolog to these two Ryd4Hb candidate genes is the wheat Sr35 stem rust resistance gene. In addition to the fine mapping, we reduced the sublethality factor interval to 600 kbp in barley. Aphid feeding experiments demonstrated that Ryd4Hb provides a direct resistance to BYDV rather than a resistance to its vector. The presented results, including the high-throughput molecular markers, will permit a more targeted selection of the resistance in breeding, enabling the use of Ryd4Hb in barley varieties. Key messageWe mapped Ryd4Hb in a 66.5 kpb interval in barley and dissociated it from a sublethality factor. These results will enable a targeted selection of the resistance in barley breeding.

plant biology↗

bioRxiv2021

GiPS: Genomics-informed parent selection uncovers the breeding value of wheat genetic resources

The great efforts spent in the maintenance of past diversity in genebanks are rationalized by the potential role of plant genetic resources in future crop improvement - a concept whose practical implementation has fallen short of expectations. Here, we implement genomics-informed parent selection to expedite pre-breeding without discriminating against non-adapted germplasm. We collect dense genetic profiles for a large winter wheat collection and evaluate grain yield and resistance to yellow rust in representative coresets. Genomic prediction within and across genebanks identified the best parents for PGR x elite derived crosses that outyielded current elite cultivars in multiple field trials.

genomics↗

bioRxiv2019

Leaf Variegation and Impaired Chloroplast Development Caused by a Truncated CCT Domain gene in albostrians Barley

Chloroplasts fuel plant development and growth by converting solar into chemical energy. They mature from proplastids through the concerted action of genes in both the organellar and the nuclear genome. Defects in such genes impair chloroplast development and may lead to pigment-deficient seedlings or seedlings with variegated leaves. Such mutants are instrumental as tools for dissecting genetic factors underlying the mechanisms involved in chloroplast biogenesis. Characterization of the green-white variegated albostrians mutant of barley has greatly broadened the field of chloroplast biology including the discovery of retrograde signaling. Here, we report the identification of the ALBOSTRIANS gene HvAST by positional cloning as well as its functional validation based on independently induced mutants by TILLING and RNA-guided Cas9 endonuclease mediated gene editing. The phenotypes of the independent HvAST mutants imply residual activity of HvAST in the original albostrians allele conferring an imperfect penetrance of the variegated phenotype even at homozygous state of the mutation. HvAST is a homolog of the Arabidopsis thaliana CCT Motif transcription factor gene AtCIA2, which was reported to be involved in the expression of nuclear genes essential for chloroplast biogenesis. Interestingly, in barley we localized HvAST to the chloroplast indicating novel without any clear evidence of nuclear localization. One-sentence summaryLeaf variegation in the barley mutant albostrians is caused by mutation of a single CCT-domain containing gene with residual activity, which is directed to the chloroplast.

genetics↗