ABSTRACT
Dehydrins are highly hydrophilic, well-soluble proteins, which belong to a large family of late embryogenesis-abundant (LEA) proteins whose name comes from Galau et al. (1986) who studied them for the rst time in cotton (Gossypium hirsutum L.) embryos (Dure et al., 1981; Galau and Dure, 1981). They are classied as group 2 LEA (or LEA II) proteins (Bray, 1993; Ingram and Bartels, 1996) or LEA-D11 proteins according to one dehydrin member in cotton embryo (Dure et al., 1989). In Pfam database of protein domains (https://www.sanger.ac.uk/Software/Pfam; Bateman et al., 2004), they are simply named dehydrins and have a Pfam number PF00257. They have a relatively high glycine content (greater than 6%) and a hydrophilicity index (Kyte and Doolittle, 1982) greater than 1; thus they can be classied as hydrophilins (Garay-Arroyo et al., 2000; Battaglia et al., 2008). The rst reported dehydrin proteins were RAB21, a protein induced by salt and osmotic stress in rice (Oryza sativa L.) (Mundy and Chua, 1988) and D-11, a protein accumulating in maturating embryo of cotton (Gossypium hirsutum L.) (Baker et al., 1988). At the end of the 1980s, dehydrins were dened as “dehydration-induced proteins” according to their mode of expression (Close et al., 1989). Later, as their sequence characteristics became available, dehydrins were redened on the basis of their sequentional motifs. They were newly dened as proteins possessing at least one copy of a conserved lysine-rich amino acid (aa) sequence-a K-segment-in their molecules (Close, 1996, 1997). Due to this denition based on the presence of a unique amino acid motif, dehydrins can be easily detected by a specic primary antibody raised against the K-segment (Close et al., 1993).
