Research Progress of Cold Resistance Genes in Winter Wheat

Journal of Experimental Botany, 2001

Time-courses of the development of freezing tolerance and the expression of a cold-responsive gene wlt10 were monitored during cold acclimation in wheat (Triticum aestivum L.). Bioassay showed that cold acclimation conferred much higher freezing tolerance on a winter cultivar than a spring cultivar. Northern blot analysis showed that the expression of wlt10 encoding a novel wheat member of a cerealspecific LT-COR protein family was specifically induced by low temperature. A freezing-tolerant winter cultivar accumulated the mRNA more rapidly and for a longer period than a susceptible spring cultivar. The increase in the amount of mRNA was temporary but the peak occurred at the time when the maximum level of freezing tolerance was attained. The mRNA accumulated more in the leaves than in the roots, and different light /dark regimes modulated the level of mRNA accumulation. Genomic Southern blot analyses using the nulli-tetrasomic series showed that the wlt10 homologues were located on the homologous group 2 chromosomes.

Plant Molecular Biology, 2007

Freezing tolerance in plants develops through acclimation to cold by growth at low, above-freezing temperatures. Wheat is one of the most freezing-tolerant plants among major crop species and the wide range of freezing tolerance among wheat cultivars makes it an excellent model for investigation of the genetic basis of cold tolerance. Large numbers of genes are known to have altered levels of expression during the period of cold acclimation and there is keen interest in deciphering the signaling and regulatory pathways that control the changes in gene expression associated with acquired freezing tolerance. A 5740 feature cDNA amplicon microarray that was enriched for signal transduction and regulatory genes was constructed to compare changes in gene expression in a highly cold-tolerant winter wheat cultivar CDC Clair and a less tolerant spring cultivar, Quantum. Changes in gene expression over a time course of 14 days detected over 450 genes that were regulated by cold treatment and were differentially regulated between spring and winter cultivars, of these 130 are signaling or regulatory gene candidates, including: transcription factors, protein kinases, ubiquitin ligases and GTP, RNA and calcium binding proteins. Dynamic changes in transcript levels were seen at all periods of cold acclimation in both cultivars. There was an initial burst of gene activity detectable during the first day of CA, during which 90% of all genes with increases in transcript levels became clearly detectable and early expression differential between the two cultivars became more disparate with each successive period of cold acclimation.

2001

Barley is grown from northern countries to the limits of the desert. Its adaptation to such different environments underlines the existence of evolutionary-shaped mechanisms that allow barley to cope with physical stresses like cold or drought. Recent studies allowed the identification of the molecular bases of frost resistance and the isolation of many cold regulated genes (cor genes). These results depict a complex situation where several signal transduction pathways cooperate for the expression of different classes of cor genes. The accumulation of the corresponding cor proteins has been associated with development of frost resistance, although a clear function for many of these proteins is still lacking.

Zemdirbyste-Agriculture

Abiotic stresses alter the expression of multiple genes in plants allowing them to accommodate to hostile environmental conditions. Exposure to low temperatures in the autumn prior to winter is a crucial environmental factor determining an increase in freezing tolerance and winter hardiness in temperate plants. The objective of this study was to evaluate transcriptome changes under a short-term low temperature stress using an RNA-Seq approach in winter wheat (Triticum aestivum L.). Significant alterations were observed for nuclear transcriptome of winter wheat, whereas the expression profiles of organellar genes were much less responsive to low temperature stress. In total, there were 15,042 nuclear genes with significantly (FDR < 0.05) altered expression profiles caused by exposure to low temperature. From this number, a total of 2,466 genes had a substantially (log 2 FC > 2 or log 2 FC < −2) affected expression profile. The highest number of upregulated genes was observed from chromosomes in homoeologous group 5, followed by group 2. Differentially expressed genes (DEGs) with the most extreme upregulation encompassed CBFIIId-12.1, WRKY transcription factor 55-like, and a group of genes related to jasmonate signalling pathway.

Physiologia Plantarum, 2004

Expression profiles of a set of Cor/Lea genes were assessed during early stages of cold acclimation in seedlings of two wheat cultivars, which showed contrasting levels of freezing tolerance. These Cor/Lea family members consisted of three EST clones and 13 previously identified cDNA clones of wheat and rye. Northern blot analysis using RNA extracted from seedling leaves and roots showed that most of the genes exhibited a quite similar time-course of expression, although with different expression levels: They rapidly responded to low temperature and their transcript levels reached high plateaus within 3-5 days. The overall gene expression profiles were correlated with the time-dependent development and the level of freezing tolerance under low temperature in the two cultivars. Western blot analysis of protein accumulation further verified this observation. Abscissic acid response was proved for at least four genes. Light was stimulatory to most of the genes, and this positive light response associated with low temperature occurred not only in leaf-specific genes but also in leaf/root-expressed genes. Taken together, the present results suggest that the Cor/Lea gene family represents a major group of downstream genes involved in the ABA-dependent and -independent signal pathways and that most of them are co-regulated in determining freezing tolerance in wheat seedlings.

Molecular Genetics and Genomics, 2010

Cold hardening is necessary to achieve the genetically determined maximum freezing tolerance and to reduce yield losses in winter cereals. The aim of the present study was to determine a set of genes with an important role in this process, by comparing of chromosome 5A substitution lines with different levels of freezing tolerance, since chromosome 5A is a major regulator of this trait. During 21 days of treatment at 2°C, 303 genes were up-regulated, while 222 were down-regulated at most sampling points, and 156 at around half of them (out of the 10,297 unigenes studied). The freezing-tolerant substitution line exhibited 1.5 times as many differentially expressed genes than the sensitive one. The transcription of 78 genes (39 up-regulated) proved to be chromosome 5A-dependent. These genes encoded proteins involved in transcriptional regulation, defence processes and carbohydrate metabolism. Three of the chromosome 5A-related genes, coding for a cold-responsive, a Ca-binding and an embryo and meristem-related protein, were genetically mapped and characterized in further detail. The present experimental system was appropriate for the selection of chromosome 5A-related genes involved in short- and long-term cold acclimation in wheat. By modifying the expression of these genes it may be possible to improve freezing tolerance.

BMC Genomics, 2011

Background: To identify the genes involved in the development of low temperature (LT) tolerance in hexaploid wheat, we examined the global changes in expression in response to cold of the 55,052 potentially unique genes represented in the Affymetrix Wheat Genome microarray. We compared the expression of genes in winter-habit (winter Norstar and winter Manitou) and spring-habit (spring Manitou and spring Norstar)) cultivars, wherein the locus for the vernalization gene Vrn-A1 was swapped between the parental winter Norstar and spring Manitou in the derived near-isogenic lines winter Manitou and spring Norstar. Global expression of genes in the crowns of 3-leaf stage plants cold-acclimated at 6°C for 0, 2, 14, 21, 38, 42, 56 and 70 days was examined.

International Journal of Social Sciences and Management Review, 2022

This research work investigates Fraud and its effect in the banking industry: A study of selected banks in Nigeria. The main objective of this study is to determine the effects of Fraud and financial crimes on the Nigerian banking industry. Three research questions and three research hypotheses were raised. A sample size of 80 was utilized for the study. Primary data gotten from a well-structured research questionnaire was used for the study. The data were analyzed using frequencies, percentages, weighted mean, and z-test. The analysis was conducted based on the objectives of the study, which include; To determine the effects of fraud and financial crimes on the profitability of the Nigerian banking industry and examining the effects of fraud and financial crimes on the bank customers' confidence in the Nigerian banking industry. From the analysis it was established that; Fraud and financial crimes have a significant effect on the profitability of Nigerian banking industry. Fraud and financial crimes negatively affect the confidence of bank customers in the Nigerian banking industry. The study recommends amongst others that Nigerian Banks must follow a global pattern by identifying and reporting transactions of a suspicious nature to the financial intelligence unit in the respective country.