Quantitative expression analysis of selected COR genes reveals their differential expression in leaf and crown tissues of wheat (Triticum aestivum L.) during an extended low temperature acclimation regimen

Abstract

A number of COR genes (COld-Regulated genes) have been implicated in the acquisition of low temperature (LT) tolerance in wheat (Triticum aestivum L.). This study compared the relative expression patterns of selected COR genes in leaf and crown tissues of wheat near-isogenic lines to increase understanding of the molecular mechanisms underlying LT acclimation. Reciprocal near-isogenic lines were generated such that the dominant Vrn-A1 and recessive vrn-A1 loci were interchanged in a spring cv. Manitou and a winter cv. Norstar. Phenological development, acquisition of LT tolerance, and WCS120 polypeptide accumulation in these genotypes proceeded at rates similar to those previously reported for 6 °C acclimation from 0 to 98 d. However, a differential accumulation of WCS120 polypeptide and expression of the COR genes Wcs120, Wcor410, and Wcor14 was observed in the leaf and crown tissues. COR gene transcript levels peaked at 2 d of the acclimation period in both tissues and differences among genotypes were most evident at this time. COR gene expression was highest for the LT-tolerant and lowest for the tender genotypes. However, expression rates were divergent enough in genotypes with intermediate hardiness that comparisons among tissues and/or times during acclimation often resulted in variable interpretations of the relative expression of the COR genes in the determination of LT tolerance. These observations emphasize the need to pay close attention to experimental conditions, sampling times, and genotype and tissue selection in experiments designed to identify the critical genetic components that interact to determine LT acclimation.

Systemic Cold Stress Adaptation of Chlamydomonas reinhardtii

“…5B). Other general responses to cold-induced membrane damage are an increased accumulation of cryoprotectants (12,13,15); LEA, cold-and heat-shock proteins (HSP), which participate in membrane protection and refolding of denatured proteins (88,89); and the accumulation of antioxidants mostly at chloroplast level (90,91).…”

Hexadecyltrimethylammonium Bromide (CTAB)-based Protocol to Isolate High-Quality RNA in Adequate Quantities for Gene Expression Analyses in Developing Seeds of Lentils (Lens culinaris Medik.)

“…Considering all these factors, we first tested the Trizol method followed by column cleanup, since this is the most widely used method. We have successfully used the Trizol/column cleanup method for RNA isolation from wheat leaves 15 and developing wheat grains 6 for QPCR analyses. When tested with 100 mg leaf, stem, and root tissues of lentil, yield of RNA was high using this method, about 50, 25, and 65 µg, respectively.…”

“…Total RNA was isolated from lentil leaves, stems, and roots using the Trizol reagent (Life Technologies, Inc., Burlington, Ontario, Canada) and column cleanup by the PureLink RNA kit (Life Technologies, Inc., Burlington, Ontario, Canada) as optimized for total RNA isolation from wheat leaves. 15 Total RNA isolation from lentil seeds was then tested using this method. An isopropanol precipitation step prior to column cleanup was also performed with another set of samples.…”

The Omics of Cold Stress Responses in Plants

“…Two of these, DHN5 and DHN8 , were reported to express manifold during cold stress (Heidarvand and Maali Amiri 2010 ) in barley. Three COR genes that are well-identifi ed dehydrins, Wcs 120(K6), Wcor 410(SK3), and Wcor 14 have been shown to accumulate during the initial response to low temperature in wheat (Ganeshan et al 2008 ). Wcs120 and Wcor14 have CBF recognition sequences in their promoter region and they are activated by the CBF transcription factors (Heidarvand and Maali Amiri 2010 ).…”