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Characterization of a gene family encoding abscisic acid- and environmental stress-inducible proteins of alfalfa
The phytohormone abscisic acid (ABA) has been proposed as a common mediator controlling adaptive plant responses to a variety of environmental stresses, including water deficit, salinity, wounding, and low temperature. We have recently isolated three cDNAs, pUM90-1, pUM90-2, and pUM91-4, from a cDNA...
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Published in: | The Journal of biological chemistry 1992-08, Vol.267 (22), p.15367-15374 |
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Main Authors: | , , , , |
Format: | Article |
Language: | English |
Subjects: | |
Citations: | Items that this one cites Items that cite this one |
Online Access: | Get full text |
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Summary: | The phytohormone abscisic acid (ABA) has been proposed as a common mediator controlling adaptive plant responses to a variety
of environmental stresses, including water deficit, salinity, wounding, and low temperature. We have recently isolated three
cDNAs, pUM90-1, pUM90-2, and pUM91-4, from a cDNA library of ABA-induced mRNAs of alfalfa. These cDNA clones exhibit a very
high degree of sequence homology with one another and sequence similarities with certain regions of several stress- and ABA-inducible
genes. The polypeptides encoded by these cDNAs are very rich in glycine (35-40%), histidine (7-15%), asparagine (8-14%), and
tyrosine (5-10%) and have no tryptophan and proline. All of the encoded polypeptides contain characteristic tandem repeats
comprising glycine residues intercepted with histidine and/or tyrosine. The RNAs corresponding to a representative cDNA, pUM90-1,
were induced after treatment of seedlings with low temperature, drought, salt, and wounding stress, but not by heat; the induction
was maximal under low temperature treatment. ABA and ABA analog rapidly induced the expression of these genes, whereas gibberellic
acid treatment exhibited no induction whatsoever. These genes appear to be specifically induced in the shoot tissues. Analysis
of ABA induction of genes corresponding to pUM90-1 in alfalfa seedlings of different age groups demonstrated that these genes
were inducible in seedlings/plants of all age groups examined. Taken together these results suggest that these cDNA clones
encode a group of proteins that are inducible by ABA and multiple environmental stresses and correspond to a new family of
genes of plants, designated as ABA- and environmental stress-inducible genes. |
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ISSN: | 0021-9258 1083-351X |
DOI: | 10.1016/s0021-9258(19)49543-4 |