M. Robertson et Pm. Chandler, A DEHYDRIN COGNATE PROTEIN FROM PEA (PISUM-SATIVUM L) WITH AN ATYPICAL PATTERN OF EXPRESSION, Plant molecular biology, 26(3), 1994, pp. 805-816
Dehydrins are a family of proteins characterised by conserved amino ac
id motifs, and induced in plants by dehydration or treatment with ABA.
An antiserum was raised against a synthetic oligopeptide based on the
most highly conserved dehydrin amino acid motif, the lysine-rich bloc
k (core sequence KIKEKLPG). This antiserum detected a novel M(r) 40000
polypeptide and enabled isolation of a corresponding cDNA clone, pPsB
61 (B61). The deduced amino acid sequence contained two lysine-rich bl
ocks, however the remainder of the sequence differed markedly from oth
er pea dehydrins. Surprisingly, the sequence contained a stretch of se
rine residues, a characteristic common to dehydrins from many plant sp
ecies but which is missing in pea dehydrin. The expression patterns of
B61 mRNA and polypeptide were distinctively different from those of t
he pea dehydrins during seed development, germination and in young see
dlings exposed to dehydration stress or treated with ABA. In particula
r, dehydration stress led to slightly reduced levels of B61 RNA, and A
BA application to young seedlings had no marked effect on its abundanc
e. The M(r) 40 000 polypeptide is thus related to pea dehydrin by the
presence of the most highly conserved amino acid sequence motifs, but
lacks the characteristic expression pattern of dehydrin. By analogy wi
th heat shock cognate proteins we refer to this protein as a dehydrin
cognate.