A szimbiotikus gümő kialakulásában résztvevő két gén azonosítása Medicago truncatula-ból térképezésen alapuló génizolálással. = Isolation of two Medicago truncatula genes involved in the development of the symbiotic nodule by map-based cloning.

A pályázat célja a Sinorhizobium meliloti és a Medicago truncatula között létrejövő szimbiotikus nitrogénkötő kapcsolat kialakításában résztvevő két M. truncatula gén (DMI1 és PDL) azonosítása volt. A mutánsok szimbiotikus fenotípusa azt valószínűsítette, hogy a mutációt szenvedett gének termékei a szimbiotikus gümő kialakulásának korai szakaszában, a bakteriális jelmolekula (Nod faktor) által elindított szignálútban, illetve a gümő organogenezisben vesznek részt. A gének azonosítását térképezésen alapuló génizolálással végeztük el, az izolált gének azonosságát pedig genetikai komplementációs kísérletekkel igazoltuk. Az DMI1 gén egy olyan fehérjét kódol, amely nem mutat hasonlóságot semmilyen eddig ismert növényi fehérjével, vagy annak alegységével. Tartalmaz viszont egy konzervativ domént, amely kisebb mértékű, de az egész doménre kiterjedő hasonlóságot mutatott bakteriális kálium csatornák TrkA doménjével, így a DMI1 fehérje feltételezhetően kation csatornaként, vagy annak alegységeként működik. A PDL gén klónozása során azonosítottunk egy AP2-típusú domént tartalmazó ERF típusú transzkripciós faktort kódoló gént, amely tartalmazott egy mutációt a pdl mutánsban. Együttműködő partnerünkkel bizonyítottuk a gén azonosságát és kimutattuk, hogy a gén szükséges a Nod faktor által indukált nodulin gén expresszióhoz, és meghatároztuk a Nod factor szignálútban elfoglalt helyét. | The aim of this project was to identify two Medicago truncatula genes, DMI1 and PDL which are required to establish symbiotic nitrogen fixing interaction between Sinorhizobium meliloti and M. truncatula. Based on the mutant phenotype, DMI1 and PDL were proposed to act in the Nod factor signal transduction pathway and revealed that the DMI protein is essential to enable mycorrhizal associations. The DMI1 and PDL genes were identified in cooperation with other laboratories by map-based cloning; that is 'chromosomal walking' starting from the closely linked molecular markers to the mutant genes were carried out. Transformation experiments were performed using the wild type genes to complement the mutant phenotypes genetically. The DMI1 gene encodes a protein with low global similarity to a ligand-gated cation channel domain of archaea. The pdl mutant was allelic to the bit1 mutant that shows a slightly different mutant phenotype and the two genes were renamed as ERN (ERF Required for Nodulation). ERN encodes a protein containing a highly conserved AP2 DNA binding domain. We identified the position of ERN in the Nod factor signal transduction pathway and showed that ERN is necessary for Nod factor?induced gene expression

Analysis of parameters affecting the shelf life of liquid whole egg

In our measurements we tested the changes in viable cell count in liquid whole eggs. Central complex rotation design was used in planning our experiments, and response surface method (RSM) was applied to analyze the effect of each parameter (pH, storage temperature, storage time and preservative content) on the viable cell count. Based on our measurements, in addition to the storage time, the pH value and storage temperature of liquid egg samples significantly affect (p < 0.01) the viable cell count, but any inhibitory effect of preservatives (Na benzoate, K sorbate mixture) on microbial growth could not be clearly detected. Using the secondary polynomial model which was adjusted to our data, the measurements were defined very well; therefore it is hoped that our results will afford real help in estimation of the microbiological condition of liquid whole egg products which are preserved by various methods

Genome-Wide Identification of RNA Silencing-Related Genes and Their Expressional Analysis in Response to Heat Stress in Barley (Hordeum vulgare L.)

Barley (Hordeum vulgare L.) is an economically important crop cultivated in temperate climates all over the world. Adverse environmental factors negatively affect its survival and productivity. RNA silencing is a conserved pathway involved in the regulation of growth, development and stress responses. The key components of RNA silencing are the Dicer-like proteins (DCLs), Argonautes (AGOs) and RNA-dependent RNA polymerases (RDRs). Despite its economic importance, there is no available comprehensive report on barley RNA silencing machinery and its regulation. In this study, we in silico identified five DCL (HvDCL), eleven AGO (HvAGO) and seven RDR (HvRDR) genes in the barley genome. Genomic localization, phylogenetic analysis, domain organization and functional/catalytic motif identification were also performed. To understand the regulation of RNA silencing, we experimentally analysed the transcriptional changes in response to moderate, persistent or gradient heat stress treatments: transcriptional accumulation of siRNA- but not miRNA-based silencing factor was consistently detected. These results suggest that RNA silencing is dynamically regulated and may be involved in the coordination of development and environmental adaptation in barley. In summary, our work provides information about barley RNA silencing components and will be a ground for the selection of candidate factors and in-depth functional/mechanistic analyses

Rapid and cost-effective molecular karyotyping in wheat, barley, and their cross-progeny by chromosome-specific multiplex PCR

Interspecific hybridisation is a powerful tool for increasing genetic diversity in plant breeding programmes. Hexaploid wheat (Triticum aestivum, 2n = 42) × barley (Hordeum vulgare, 2n = 14) intergeneric hybrids can contribute to the transfer of agronomically useful traits by creating chromosome addition or translocation lines as well as full hybrids. Information on the karyotype of hybrid progenies possessing various combinations of wheat and barley chromosomes is thus essential for the subsequent breeding steps. Since the standard technique of chromosome in situ hybridisation is labour-intensive and requires specific skills. a routine, cost-efficient, and technically less demanding approach is beneficial both for research and breeding

Towards the map based cloning of a recessive Fusarium resistance determinant from diploid Medicago sativa

A monogenic recessive Fusarium resistance determinant was identified in a diploid Medicago sativa population. The Fusarium susceptible and resistant phenotypes of the individuals in an F2 segregation population was inferred from a biological test using injured root test. The resulting phenotypes were used to position the Fusarium resistance determinant on linkage group 6 of the Medicago sativa genetic map. Using the DNA based molecular markers genome walk was initiated from both sides of the genetic region constructing two contigs which are about 0.5 centiMorgan (∼500 kilobasepairs) apart. The introduction of this genetic determinant into tetraploid alfalfa cultivars was unsuccessful since only triploid and pentaploid hybrids could be recovered from the 4×-2× crosses. The isolation of the gene and establishment of the function of this recessive Fusarium determinant is under progress

Additional file 6 of Correction: Rapid and cost-effective molecular karyotyping in wheat, barley, and their crossprogeny by chromosome-specific multiplex PCR

Supplementary Material

Additional file 4 of Correction: Rapid and cost-effective molecular karyotyping in wheat, barley, and their crossprogeny by chromosome-specific multiplex PCR

Supplementary Material

Additional file 5 of Correction: Rapid and cost-effective molecular karyotyping in wheat, barley, and their crossprogeny by chromosome-specific multiplex PCR

Supplementary Material