Asst. Prof. Dr. Igor Kryvoruchko
Molecular Biology and Genetics
Kuzey Park, 318
34342 Bebek - Istanbul
+90 (212) 359 7689
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Our research is mainly focused on fundamental and applied aspects of symbiotic nitrogen fixation. We are also interested in detection, annotation, and functional studies on translated alternative open reading frames in model plants species.
Unraveling the molecular mechanism of homocitrate transport across the symbiosome membrane in root nodules
Within last few years, the feasibility of making major cereal crops independent from nitrogen fertilizers is actively discussed by synthetic biologists. Transfer of the symbiotic nitrogen fixation ability to normally non-symbiotic plants requires comprehensive knowledge about major molecular determinants and regulators of this trait. Efforts aimed at such transfer may be unsuccessful if some of genes crucial for the symbiosis remain unknown.
One of such elusive long sought genes codes for a membrane transporter that exports homocitrate from plant cells to symbiotic bacteria to serve as an integral component of the bacterial nitrogenase enzyme. Nitrogen-fixing bacteria that form symbioses lack their own synthesis of this essential substance. Using ectopic expression of the plant homocitrate synthase in bacterial cells, we will create a symbiotic system with self-supply of homocitrate from the bacterial side. This modification will induce changes in expression of genes that regulate homocitrate export-import in normal nitrogen-fixing symbiosis.
We will capture relevant alterations in the plant and bacterial transcriptomes using RNA-Seq method. In combination with gene-network analysis, this approach will help us unravel major regulators of the homocitrate transfer from plant to bacteria and will ultimately enable isolation and functional characterization of the symbiotic homocitrate transporter and other crucial proteins.
Detection and functional analysis of alternative (short) open reading frames (altORFs) in model plants
Alternative open reading frames (altORFs) are thought to carry out important functions in animal organisms. The goal of this project is to detect and characterize altORFs in the model plants A. thaliana and M. truncatula. In addition, we would like to create the whole-transcriptome inventory of mutant phenotypes associated with “silent” mutations, which affect proteins coded by altORFs. The possibility of altORFs translation into functional proteins is very novel in plants. In order to detect such translated altORFs, we plan to compare their predicted peptide sequences with de novo proteome databases generated recently for A. thaliana and M. truncatula with high-throughput protein sequencing. Our interest to altORFs is fueled by high relevance of altORFs to the way geneticists currently interpret mutagenesis-based data, such as functional characterization of candidate genes using mutagenesis. altORFs add a layer of complexity to functional genetics in eukaryotes and call for due attention and research.
Zn-use efficiency for optimization of symbiotic nitrogen fixation in chickpea (Cicer arietinum L.)
Zn deficiency is widespread in traditional areas of chickpea cultivation worldwide. It limits chickpea productivity and causes significant losses to economies of the world’s largest chickpea exporters. We would like to contribute to the improvement of chickpea cultivation on Zn-depleted soils in an environmentally sustainable manner, namely, via development of genotypes with superior symbiotic performance under Zn-limited conditions. The broader goal of this project is to unravel the molecular basis of Zn-use efficiency, symbiotic nitrogen fixation efficiency, and of these two traits combined. This will be achieved via transcriptional analysis based on RNA-Seq. Genes differentially expressed at Zn-deplete conditions, but showing comparable expression at normal Zn levels, will be subjected to functional analysis, including mutagenesis studies, and will ultimately be transferred to commercially important chickpea genotypes via classical breeding methods.
- J. León-Mediavilla, M. Senovilla, J. Montiel, P. Gil-Díez, A. Saez, I.S. Kryvoruchko, M. Reguera, M.K. Udvardi, J. Imperial, M. González-Guerrero (2018)
MtMTP2-Facilitated Zinc Transport into Intracellular Compartments Is Essential for Nodule Development in Medicago truncatula.
Frontiers in Plant Science 9: 990.
- I.S. Kryvoruchko, P. Routray, S. Sinharoy, I. Torres-Jerez, M. Tejada-Jiménez, L.A. Finney, J. Nakashima, C.I. Pislariu, V.A. Benedito, M. González-Guerrero, D.M. Roberts, M.K. Udvardi (2018)
An Iron-Activated Citrate Transporter, MtMATE67, Is Required for Symbiotic Nitrogen Fixation.
Plant Physiology 176: 2315-2329.
- I.S. Kryvoruchko, S. Sinharoy, I. Torres-Jerez, D. Sosso, C.I. Pislariu, D. Guan, J. Murray, V.A. Benedito, W.B. Frommer, M.K. Udvardi (2016)
MtSWEET11, a Nodule-Specific Sucrose Transporter of Medicago truncatula Root Nodules.
Plant Physiology 171: 554-565.
- M. Tejada-Jiménez, R. Castro-Rodríguez, I. Kryvoruchko, M. Lucas, M. Udvardi, J. Imperial, M. González-Guerrero (2015)
Medicago truncatula Natural Resistance-Associated Macrophage Protein1 Is Required for Iron Uptake by Rhizobia-Infected Nodule Cells.
Plant Physiology 168: 258-272.
- F. Krajinski, P.E. Courty, D. Sieh, P. Franken, H. Zhang, M. Bucher, N. Gerlach, I. Kryvoruchko, D. Zoeller, M. Udvardi, B. Hause (2014)
The H+-ATPase HA1 of Medicago truncatula Is Essential for Phosphate Transport and Plant Growth during Arbuscular Mycorrhizal Symbiosis.
Plant Cell 26: 1808-1817.