Mapping of Genes Involved in Glutathione, Carbohydrate and COR14b Cold Induced Protein Accumulation during Cold Hardening in Wheat

Using some of the chromosome substitution lines developed from the crosses of the donor Cheyenne to Chinese Spring we showed that the accumulation of water soluble carbohydrates during different stages of hardening was time dependent. Moreover there was a significant correlation between the rate of carbohydrate accumulation and the frost tolerance. The expression and regulation of a wheat gene homologous to the barley cold regulated cor14b gene was compared in frost sensitive and frost tolerant wheat genotypes at different temperatures. Studies made with chromosome substitution lines showed that the threshold induction temperature polymorphism of the cor14b wheat homologous gene was controlled by loci located on chromosome 5A of wheat, while cor14b gene was mapped, in Triticum monococcum, onto the long arm of chromosome 2Am. Our study on the effect of cold hardening on glutathione (GSH) metabolism showed that chromosome 5A of wheat has an influence on the GSH accumulation and on the ratio of reduced and oxidised glutathione as part of a complex regulatory function during cold hardening. In addition, the level of increase in GSH content during hardening may indicate the degree of the frost tolerance of wheat

Effects of ambient temperature in association with photoperiod on phenology and on the expressions of major plant developmental genes in wheat (Triticum aestivum L.)

Abstract In addition to its role in vernalization, temperature is an important environmental stimulus in determining plant growth and development. We used factorial combinations of two photoperiods (16H, 12H) and three temperature levels (11oC, 18oC, and 25oC) to study the temperature responses of 19 wheat cultivars with established genetic relationships. Temperature produced more significant effects on plant development than photoperiod, with This article is protected by copyright. All rights reserved. strong genotypic components. Wheat genotypes with PPD-D1 photoperiod sensitive allele were sensitive to temperature; their development was delayed by higher temperature, which intensified under non-inductive conditions. The effect of temperature on plant development was not proportional; it influenced the stem elongation to the largest extent, warmer temperature lengthened the lag phase between the detection of first node and the beginning of intensive stem elongation. The gene expression patterns of VRN1, VRN2 and PPD1 were also significantly modified by temperature, while VRN3 was more chronologically regulated. The associations between VRN1 and VRN3 gene expression with early apex development were significant in all treatments, but was only significant for later plant developmental phases under optimal conditions (16H and 18oC). Under 16H, the magnitude of the transient peak expression of VRN2 observed at 18oC and 25oC associated with the later developmental phases. Key words: wheat, temperature, photoperiod, apex and plant development, VRN1, VRN2, VRN3 and PPD1 gene expression

Wheat-barley hybridization – the last forty years

Abstract Several useful alien gene transfers have been reported from related species into wheat (Triticum aestivum), but very few publications have dealt with the development of wheat/barley (Hordeum vulgare) introgression lines. An overview is given here of wheat 9 barley hybridization over the last forty years, including the development of wheat 9 barley hybrids, and of addition and translocation lines with various barley cultivars. A short summary is also given of the wheat 9 barley hybrids produced with other Hordeum species. The meiotic pairing behaviour of wheat 9 barley hybrids is presented, with special regard to the detection of wheat– barley homoeologous pairing using the molecular cytogenetic technique GISH. The effect of in vitro multiplication on the genome composition of intergeneric hybrids is discussed, and the production and characterization of the latest wheat/barley translocation lines are presented. An overview of the agronomical traits (b-glucan content, earliness, salt tolerance, sprouting resistance, etc.) of the newly developed introgression lines is given. The exploitation and possible use of wheat/barley introgression lines for the most up-to-date molecular genetic studies (transcriptome analysis, sequencing of flow-sorted chromosomes) are also discussed

Transcriptome Analysis of the Vernalization Response in Barley (Hordeum vulgare) Seedlings

Temperate cereals, such as wheat (Triticum spp.) and barley (Hordeum vulgare), respond to prolonged cold by becoming more tolerant of freezing (cold acclimation) and by becoming competent to flower (vernalization). These responses occur concomitantly during winter, but vernalization continues to influence development during spring. Previous studies identified VERNALIZATION1 (VRN1) as a master regulator of the vernalization response in cereals. The extent to which other genes contribute to this process is unclear. In this study the Barley1 Affymetrix chip was used to assay gene expression in barley seedlings during short or prolonged cold treatment. Gene expression was also assayed in the leaves of plants after prolonged cold treatment, in order to identify genes that show lasting responses to prolonged cold, which might contribute to vernalization-induced flowering. Many genes showed altered expression in response to short or prolonged cold treatment, but these responses differed markedly. A limited number of genes showed lasting responses to prolonged cold treatment. These include genes known to be regulated by vernalization, such as VRN1 and ODDSOC2, and also contigs encoding a calcium binding protein, 23-KD jasmonate induced proteins, an RNase S-like protein, a PR17d secretory protein and a serine acetyltransferase. Some contigs that were up-regulated by short term cold also showed lasting changes in expression after prolonged cold treatment. These include COLD REGULATED 14B (COR14B) and the barley homologue of WHEAT COLD SPECIFIC 19 (WSC19), which were expressed at elevated levels after prolonged cold. Conversely, two C-REPEAT BINDING FACTOR (CBF) genes showed reduced expression after prolonged cold. Overall, these data show that a limited number of barley genes exhibit lasting changes in expression after prolonged cold treatment, highlighting the central role of VRN1 in the vernalization response in cereals

Light and Temperature Signalling at the Level of CBF14 Gene Expression in Wheat and Barley

The wheat and barley CBF14 genes have been newly defined as key components of the light quality-dependent regulation of the freezing tolerance by the integration of phytochrome-mediated light and temperature signals. To further investigate the wavelength dependence of light-induced CBF14 expression in cereals, we carried out a detailed study using monochromatic light treatments at an inductive and a non-inductive temperature. Transcript levels of CBF14 gene in winter wheat Cheyenne, winter einkorn G3116 and winter barley Nure genotypes were monitored. We demonstrated that (1) CBF14 is most effectively induced by blue light and (2) provide evidence that this induction does not arise from light-controlled CRY gene expression. (3) We demonstrate that temperature shifts induce CBF14 transcription independent of the light conditions and that (4) the effect of temperature and light treatments are additive. Based on these data, it can be assumed that temperature and light signals are relayed to the level of CBF14 expression via separate signalling routes

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

Genetic analysis of the expression of the cold-regulated gene cor14b: a way toward the identification of components of the cold response signal transduction in Triticeae.

Genetic analysis of the expression of the cold-regulated gene cor14b: a way toward the identification of components of the cold response signal transduction in Triticea