Are Cbf genes involved in copper tolerance?

A cluster of Cbf (C-repeat binding factor) genes have been shown to have a critical role in cold stress response in many plant species. Extensive cross-talk between abiotic stress-signalling pathways have also been described in recent publications. Since the expression of Cbf genes is known to be influenced by low-temperature, drought or salinity stress, it would be not surprising if their expression would be also influenced by other abiotic stresses such as heavy metal tolerance. In this work the expression pattern of 8 Cbf genes, located on chromosome 5A were investigated in wheat, subjected to different copper stress conditions (hydroponics and soil). Wheat cultivar ‘Chinese Spring’ (moderate copper tolerance) and two 5A chromosome substitution lines, especially ‘Chinese Spring /T. spelta 5A’ (copper sensitive) and ‘Chinese Spring /Cheyenne 5A’ (copper tolerant) showed different expression profiles in the course of copper stress. Cbf3 and Cbf10 were up-regulated by copper stress, especially in the tolerant genotype, however down-regulation of other Cbf genes was also found. These findings suggest that the Cbf genes might have roles in the enhanced copper tolerance

Micronutrient contents and nutritional values of commercial wheat flours and flours of field-grown wheat varieties-A survey in Hungary

Wheat-based food has great importance in human nutrition: in European countries they provide 20-30% of the daily calorie intake, and additionally, the wholemeal and healthy food becomes even more popular. Mineral content in grains is dependent on genetic and environmental factors (varieties, soil type, geographical location of the growing area, etc.), therefore, it is complicated to estimate how many percentage of the daily micronutrient requirements can be covered by wheat-based products. In this study, copper (Cu), iron (Fe), manganese (Mn), molybdenum (Mo), selenium (Se) and zinc (Zn) contents of 13 commercial wheat flour products, and the white flour and wholemeal of 24 winter type bread wheat varieties were studied to estimate the nutritional value of these products. All investigated samples were produced in Hungary. Significant variation was revealed in the case of all mineral elements in the different brands of wheat flours. Generally, the white flour enriched with germ showed higher mineral contents than the average values of normal white flours. Furthermore, the wholemeal has higher Cu, Fe, Mn and Zn, but not higher Se contents than the white flours. Mo content was also higher in some brands of white flour than in wholemeal.The investigated winter wheat varieties showed significant differences in the case of Fe, Mn, Se and Zn contents, but none of the varieties showed outstandingly high micronutrient content. The milling process-as it was expected-reduces the concentrations of four elements (Fe 33%; Mn 88%; Zn 71%; Cu 44%); however, the Se and Mo concentrations were not affected significantly. Using the average micronutrient content in the wholemeal of varieties, the daily Mn and Fe requirement can be covered by the consumption of about 250 g wholemeal. Additionally, the daily Mo requirement could be met by the daily consumption of 140-190 g of commercial white or wholemeal flour

Műszaki kerámiák kutatása és ipari alkalmazásaik: átlátszó AlON kerámiaanyagok előállítási módszerei és tulajdonságai

Az alumínium-oxinitrid (AlON) kerámiaanyagok hő- és kémiai stabilitása rendkívüli, éppen ezért széleskörűen alkalmazzák különféle iparágakban. Ebben a cikkben röviden összefoglaljuk és összehasonlítjuk a napjainkban használatos főbb AlON-előállítási eljárásokat, kitérve a módszerek előnyeire és hátrányaira. Habár napjainkban a megnövekedett ipari kereslet következtében intenzív fejlesztések és kutatások folynak AlON-kerámiák előállítására, még mindig igény van olyan átfogó kutatásra, újfajta porszintézis és megmunkálás kidolgozására, melynek segítségével költséghatékonyabban és nagyobb mennyiségben lehetne előállítani tömör, ellenálló, átlátszó kerámiákat. Emellett a szinterelési körülmények és az átmeneti folyadékfázisú szinterelés optimalizálása is szükséges lépés

A búza fagyállóságban szerepet játszó Cbf gének szerepének bizonyítása transzformációval = Proving the role of Cbf genes in wheat frost tolerance by transformation

A gabonafélék genomja sok CBF gént kódol. Nemrég mutattuk ki, hogy ezek közül melyek játszanak fontos szerepet a búza fagyállóságának kialakításában. A pályázatban direkt módon, transzformációval kívántuk bizonyítani e kulcsfontosságú transzkripciós faktorok szerepét. Búzából izolált génekkel Arabidopsis-t, búzát és árpát transzformáltunk; az ehhez készített konstrukciókban a beépített gént, annak folyamatos túltermelését biztosító szabályozó elem (u.n. konstitutív promóter) vezérelte. Meghatároztuk az előállított transzgénikus vonalakban a beépült gének számát, és igazoltuk azok működését. A gének hatását, a megnövekedett stressz-toleranciát kétféle fagyteszttel vizsgáltuk. Az első során - a természetes viszonyokat szimulálandó - hideg-edzést alkalmaztunk a fagyteszt előtt. A második típusú tesztben ilyet nem alkalmaztunk, mert a transzgén állandóan működött, így feltételezésünk szerint nem volt szükség hideg-indukcióra ahhoz, hogy a hatását kifejtse, azaz a fagyállóságot fokozza. Mindkét típusú fagyteszttel sikerült mindhárom növényfaj esetében olyan transzgénikus vonalakat azonosítanunk, amelyekben a fagyállóság szintje megnőtt a bevitt gén hatására. Mivel a bevitt gének más gének működést befolyásoló ún. transzkripciós faktort kódolnak, ezért vizsgáltuk az általuk szabályozott gének működését is. E kísérletek eredményei is a tanulmányozott CBF gének fagytűrés kialakításában betöltött szerepét igazolták. | Cereal genome encodes numerous CBF genes. Recently we have identified the ones that are involved in the regulation of frost tolerance. Based on these results, this project was aimed at proving directly their function by transformation methods. Arabidopsis, barley and wheat plants were transformed, with constructions that ensured the constitutive expression of the transformed CBF genes. The insertions of the transgenes were proved, the copy number estimated, and their functionality were verified in each transgenic lines developed. The effectiveness of the genes was tested in freezing tests. One type of test was applied with cold hardening period while the other was applied without it. The efficiency of the transgenes was proved in both test types for each plant species, i.e. transgenic Arabidopsis, barley and wheat lines with increased frost tolerance level were indeed identified. Since CBF genes code for transcription factors, the expression patterns of several downstream genes were also recorded. These experiments also proved the effectiveness of the candidate CBF genes in the regulation of cereal frost tolerance

Frost tolerance in winter wheat cultivars: different effects of chromosome 5A and association with microsatellite alleles

Frost tolerance of ten Bulgarian winter wheat (Triticum aestivum L.) cultivars (Milena, Pobeda, Sadovo-1, Enola, Kristal, Laska, Svilena, Russalka, No301, and Lozen) and five foreign cultivars (Mironovskaya 808, Bezostaya-1, Rannaya-12, Skorospelka-35, and Chinese Spring) was studied in two experimental seasons following natural cold acclimation and in one experiment carried out in controlled acclimation conditions. Considerable intercultivar variability in plant survival was observed after freezing at -21 ºC following sufficient cold acclimation, or at -18ºC following insufficient or controlled acclimation. In seven cultivars, the effects of chromosome 5A on frost tolerance were investigated in their F2 hybrids with chromosome 5A monosomic lines of cultivars with high, intermediate, and low frost tolerance. The effects of chromosome 5A depended on the stress severity and the genetic background of the hybrids and varied even in cultivars of similar frost tolerance and vernalization requirements. Effects of other chromosomes besides 5A on frost tolerance were assumed. The analysis of six microsatellite loci located in the interval from centromere to Vrn-1 on chromosomes 5AL, 5BL, and 5DL showed that the major loci determining frost tolerance in Bulgarian winter wheats were Fr-A2 on chromosome 5AL and, to a lesser extent, Fr-B1 on chromosome 5BL. A strong association of the 176 bp allele at locus wmc327 tightly linked to Fr-A2 with the elevated frost tolerance of cvs. Milena, Pobeda, Sadovo-1, Mironovskaya-808, and Bezostay a-1 was revealed. Relatively weaker association between frost tolerance and the presence of the 172 bp allele at locus Xgwm639 tightly linked to Fr-B1 was also observed