Expression of SK3-type dehydrin in transporting organs is associated with cold acclimation in Solanum species

Abstract

The expression of a gene, encoding a dehydrin protein designated as DHN24 was analyzed at the protein level in two groups of Solanum species differing in cold acclimation ability. The DHN24 protein displays consensus amino acid sequences of dehydrins, termed K- and S-segments. The S-segment precedes three K-segments, classifying the protein into SK3-type dehydrins. A group of Solanum species able to cold acclimation constituted by S. sogarandinum and S. tuberosum, cv. Aster, and a second one composed of a S. sogarandinum line, that lost ability to cold acclimation, and of S. tuberosum, cv. Irga, displaying low ability to cold acclimation were studied. Under control conditions, noticeable levels of the DHN24 protein was observed in stems, tubers, and roots of Solanum species. No protein was detected in leaves. During low temperature treatment the DHN24 protein level substantially increased in tubers, in transporting organs and in apical parts, and only a small increase was observed in leaves. The increase in protein abundance was only observed in the plants able to cold acclimate and was found to parallel the acclimation capacity. Upon drought stress, the DHN24 level decreased in stems and in leaves, but increased in apical parts. These results suggest that Dhn24 expression is regulated by organ specific factors in the absence of stress and by factors related to cold acclimation processes during low temperature treatment in collaboration with organ-specific factors. A putative function of the SK3-type dehydrin proteins during plant growth and in the tolerance to low temperature is discussed.

Differential expression of a poplar SK2-type dehydrin gene in response to various stresses

“…Accordingly, they are classified into five subclasses (YnSK2, Kn, SKn, Y2Kn, and KnS) depending on the number of Y-, S-and K-segments they individually contain (1). Specifically, most of the SKn-type dehydrins are either SK2-or SK3-type and contribute to tolerance to drought and cold stresses (1,7). Although SKn-type dehydrins from crops and herbaceous plants have been investigated in a number of studies (1,3), little attention has been paid to their role in trees, which are often exposed to both cold and drought stresses at various times in their life cycles.…”

The K-Segment of Maize DHN1 Mediates Binding to Anionic Phospholipid Vesicles and Concomitant Structural Changes

“…Some DHNs are expressed constitutively during normal growth (Nylander et al, 2001;Rorat et al, 2004Rorat et al, , 2006Rodriguez et al, 2005). DHNs exist in a wide range of photosynthetic organisms, including angiosperms, gymnosperms, algae, and mosses (Svensson et al, 2002).…”

Identification and characterization of genes encoding two novel LEA proteins in Antarctic and temperate strains of Chlorella vulgaris

“…We hypothesized that the difference in freezing tolerance is due to differences in contents of antifreeze or cryoprotective proteins in cells. Before our studies, LEA proteins had been found to be correlated to the anti-freeze capacities of some higher plants (Minami et al, 2005;Rorat et al, 2006;Nakayama et al, 2007;Peng et al, 2008). In this study, we showed that the levels of Ccor1 and Ccor2 were correlated to the freeze tolerance in the two Chlorella strains.…”