Differential expression of a gene encoding an acidic dehydrin in chilling sensitive and freezing tolerant gramineae species

Abstract

We have characterized a new wheat cold-regulated cDNA clone, Wcor410, that accumulates to equivalent levels in root, crown and leaf tissues during cold acclimation. The Wcor410 cDNA contains an ORF encoding a dehydrin-like glutamate-rich protein of 28 kDa with a pI of 5.1. However, the acidic nature, the absence of the glycine-rich repeat and of the conserved N-terminal region, DEYGNP, suggest that Wcor410 belongs to a different subgroup of the Dl 1 protein family. Northern analysis showed that this gene is expressed only in freezing tolerant gramineae, whereas Southern analysis showed that the Wcor410 gene is present in all monocot species tested. The presence of freezing tolerance-associated genes in sensitive species such as rice and corn is interesting. Characterization of the regulatory factors controlling these genes may help to establish an appropriate strategy to improve freezing tolerance.

Overexpression of Multiple Dehydrin Genes Enhances Tolerance to Freezing Stress in Arabidopsis

“…The IEM results in the present study show indeed partial translocation of LTI29 towards membranes during cold acclimation. LTI29 (as well as COR47) belongs to a family of acidic SK-type dehydrins (classified by Danyluk et al, 1994), which previously have been identified as PM-specific proteins in Arabidopsis (Santoni et al, 1998;Uemura, 2002, 2003). Danyluk et al (1994) suggested that the presence of conserved sequence (V/T)EVTDRGLFDFLGKK(K/ E)EEE) in these proteins may be important for the function of this subgroup of proteins in freeze-induced dehydration or water stress.…”

“…LTI29 (as well as COR47) belongs to a family of acidic SK-type dehydrins (classified by Danyluk et al, 1994), which previously have been identified as PM-specific proteins in Arabidopsis (Santoni et al, 1998;Uemura, 2002, 2003). Danyluk et al (1994) suggested that the presence of conserved sequence (V/T)EVTDRGLFDFLGKK(K/ E)EEE) in these proteins may be important for the function of this subgroup of proteins in freeze-induced dehydration or water stress. One of the member of acidic SK-type dehydrins, WCOR410, has been shown to accumulate in the vicinity of PM of cells in the vascular transition area during cold acclimation of wheat and suggested to prevent membrane destabilization during dehydrative conditions (Danyluk et al, 1998).…”

Expression of a Late Embryogenesis Abundant Protein Gene, HVA1, from Barley Confers Tolerance to Water Deficit and Salt Stress in Transgenic Rice

“…Recently, both group 2 and group 3 LEA proteins have been characterized from salt-tolerant Indica rice varieties, and the accumulation of these LEA proteins in response to ABA and salt stress was correlated with varietal tolerance to salt stress (Moons et al, 1995). Recent studies showed that group 2 LEA genes are present in many plant species, but the expression of these genes is differentially regulated in stress-sensitive and -tolerant species (Close et al, 1993;Danyluk et al, 1994). As more LEA genes are characterized and their functions in stress tolerance are confirmed, manipulation of endogenous LEA gene expression, in combination with introduction of additional stress tolerance genes, may prove to be an efficient strategy for genetic crop improvement.…”

A cold-responsive wheat (Triticum aestivum L.) gene wcor14 identified in a winter-hardy cultivar 'Mironovska 808'.

“…Among them, wcs120 and wcor200 are the most well characterized members respectively encoding glycine-rich neutral proteins of 50 kDa (pI = 7.3) and 200 kDa (pI = 6.5) with characteristics of the group 2 LEA (or D-11) family, although they do not have a conserved polyserine sequence (Houde et al, 1992;Quellet et al, 1993). wcor410 encodes an acidic (pI = 5.1) DHNlike group 2 LEA protein of 28 kDa with 15-mer lysinerich motifs and a polyserine sequence (Danyluk et al, 1994). Tarc7 is another low-temperature specific wheat gene not belonging to the dhn family (Gana et al, 1997).…”