Temporal accumulation and ultrastructural localization of dehydrins in Zea mays

Abstract

Egerton-Warburton, L. M., Balsamo, R. A. and Close, T. J. 1997. Temporal accumulation and ultrastructural localization of dehydrins in Zea mays. -Physiol. Plant. 101: 545-555.Immunolocalization using polyclonal antibodies raised against a conserved dehydrin amino acid sequence was used to establish the temporal and spatial patterns of dehydrin accumulation in embryo tissue of Zea mays L. (var. Ohio 43) kernels imbibed in the presence of abscisic acid. The temporal pattem of accumulation indicated an increase in dehydrins over time (particularly between 15 &nd 30 h) and with maximum levels detected 48 h after the onset of imbibition. Dehydrins were first evident, and also the most concentrated, in the cytosol throughout the accumulation period suggesting that the primary function of dehydrins involves the cytosol and the structures contained therein. Only after an accumulation of dehydrins in the cytosol was there an increase in the abundance of nuclear dehydrins. In addition, dehydrins were also observed in association with the proteinaceous matrix of protein bodies and menibranes of protein and lipid bodies; these findings have not been reported previously. The observed localization at a number of sites indicates that the specific biochemical roles of dehydrins are likely to be diverse.

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

“…The idea that DHNs interact with membranes is consistent with many immunolocalization studies, which have shown that DHNs accumulate near the plasma membrane or membrane-rich areas surrounding lipid and protein bodies (Asghar et al, 1994;Egerton-Warburton et al, 1997;Danyluk et al, 1998;Puhakainen et al, 2004). The K-segment is predicted to form a class A2 amphipathic a-helix, in which hydrophilic and hydrophobic residues are arranged on opposite faces (Close, 1996).…”

“…For example, 13 Dhn genes have been identified in barley (Hordeum vulgare), dispersed over seven genetic map locations (Choi et al, 1999;Svensson et al, 2002) and regulated variably by drought, low temperature, and embryo development (Tommasini et al, 2008). DHNs are localized in various subcellular compartments, including cytosol (Roberts et al, 1993), nucleus (Houde et al, 1995), chloroplast (Artus et al, 1996), vacuole (Heyen et al, 2002), and proximal to the plasma membrane and protein bodies (Asghar et al, 1994;Egerton-Warburton et al, 1997;Puhakainen et al, 2004). Elevated expression of Dhn genes generally has been correlated with the acquisition of tolerance to abiotic stresses such as drought (Whitsitt et al, 1997), salt (Godoy et al, 1994;Jayaprakash et al, 1998), chilling (Ismail et al, 1999a), or freezing (Houde et al, 1995;Danyluk et al, 1998;Fowler et al, 2001).…”

Plant dehydrins — Tissue location, structure and function

“…Subcellular localization data revealed that dehydrins are localized in various cell compartments including the cytosol, nucleus, vicinity of the plasma membrane, mitochondria and vacuole [34,35,37,[50][51][52]. However, they are primarily localized in the cytoplasm and nucleus.…”

Role of plant dehydrins in antioxidation mechanisms

“…Many dehydrins were detected to accumulate in nucleus and even interact with DNA. This localization of dehydrins indicates stabilization of chromosome and protection of the transcriptional machinery (Carjuzaa et al 2008;Egerton-Warburton et al 1997;Hara et al 2009). Some dehydrins also accumulated in the vicinity of plasma membrane and were suggested to inhibit lipid peroxidation caused by ROS (Danyluk et al 1998).…”