A cDNA-based comparison of dehydration-induced proteins (dehydrins) in barley and corn

Abstract

Several cDNAs related to an ABA-induced cDNA from barley aleurone were isolated from barley and corn seedlings that were undergoing dehydration. Four different barley polypeptides with sizes of 22.6, 16.2, 14.4 and 14.2 kDa and a single corn polypeptide with a size of 17.0 kDa were predicted from the nucleotide sequences of the cDNAs. These dehydration-induced proteins (dehydrins) are very similar to each other and to a previously identified rice protein induced by ABA and salt, and have at least some similarity to a previously identified cotton embryo protein. Each dehydrin is extremely hydrophilic, glycine-rich, cysteine- and tryptophan-free and contains repeated units in a conserved linear order. A lysine-rich repeating unit occurs twice in each protein, once at the carboxy terminus and once partway through the polypeptide, adjacent to a succession of serines. This repeating unit and the adjacent flanking run of serines are conserved with minimal variation among all dehydrins. Another repeating unit is flanked by the two copies of the lysine-rich unit, and varies in number from one to five copies. This latter repeating unit is less conserved than the former, varying even within a singly dehydrin. The messenger RNAs corresponding to each cDNA are abundant in dehydrating, but not in well-watered seedlings. The amino acid sequence of tryptic peptides from purified dehydration-induced proteins of corn established that the corn cDNAs correspond to a protein that is produced in abundance during the response of corn seedlings to dehydration.

Abscisic Acid-Induced Heat Tolerance in Bromus inermis Leyss Cell-Suspension Cultures (Heat-Stable, Abscisic Acid-Responsive Polypeptides in Combination with Sucrose Confer Enhanced Thermostability)

“…Conversely, 15 RAB proteins were characterized that did not show heat stability but coagulated following a heat treatment. A numher of RAB and stress proteins resistant to heatinduced coagulation (boiling stable) have been identified in barley aleurone cells (Jacobsen and Shaw, 1989), in dehydrated barley and com seedlings (Close et al, 1989), and in the in vitro translation products of low-temperature-responsive mRNAs isolated from Arabidopsis and wheat (Lin et al, 1990). At present, however, the function of these proteins has not been elucidated.…”

“…A family of proteins called dehydrins (Close et al, 1989) accumulate in a wide range of plant species in response to dehydration stresses and ABA treatment. Dehydrin-like proteins also accumulate in osmotically stressed cyanobacteria (Close and Lammers, 1993), indicating that they have been evolutionarily conserved.…”

“…Dehydrin-like proteins also accumulate in osmotically stressed cyanobacteria (Close and Lammers, 1993), indicating that they have been evolutionarily conserved. A nove1 property of some ABAresponsive proteins (Jacobsen and Shaw, 1989) and dehydrins (Close et al, 1989) is their heat stability, or their resistance to heat-induced coagulation. Some Hsps also show heat stability (Jinn et al, 1989), and heat-stable proteins exist in cells under nonstressed conditions.…”

Promoter and expression studies on an Arabidopsis thaliana dehydrin gene

“…An Arabidopsis thaliana ecotype Landsberg erecta ~,EMBL 3 genomic library was screened with a radiolabelled maize M3 cDNA insert [15]. A clone with a 15 kb insert was further analysed.…”

Stress-Induced Gene ESI35 from Lophopyrum elongatum

“…The deduced amino acid sequence shows clear, although localized, sequence similarity to ABAand stress-inducible genes reported in rice (rabl6; Mundy and Chua, 1988) and barley (dhnl, dhn2, dhn3, dhn4;Close et al, 1989) and elsewhere (Baker et al, 1988, Piatkowski et al, 1990. A gene family with high sequence similarity to the rablbldhn family has also been identified in L. elongatum (Esil8; Gulick and Dvorak, 1992); however, the putative protein from ES135 has a number of sequence characteristics that differentiate it from rabldhn homologs found in L. elongatum as well as in other species (Table I).…”