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Gene expression associated with water‐stress adaptation of rice cells and identification of two genes as hsp 70 and ubiquitin
Author(s) -
Borkird Chumpel,
Simoens Chris,
Villarroel Raimundo,
Montagu Marc
Publication year - 1991
Publication title -
physiologia plantarum
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.351
H-Index - 146
eISSN - 1399-3054
pISSN - 0031-9317
DOI - 10.1111/j.1399-3054.1991.tb02931.x
Subject(s) - gene , gene expression , biology , complementary dna , heat shock protein , microbiology and biotechnology , genetics
We have isolated polyethylene glycol (PEG)‐adapted rice cells that can proliferate in a medium with 20% PEG as well as in a medium with 1% NaCl. The adapted‐cells overproduce a set of proteins whose roles may be associated with water‐stress adaptation. To isolate genes encoding these proteins, we differentially screened a cDNA library and obtained 5 cDNA clones which showed preferential hybridization to mRNA of adapted cells. The present paper describes the pattern of expression and the sequence analysis of these 5 genes. Sequence analysis of partial cDNAs indicates that two genes encode the 70 kDa heat shock protein and the ubiquitin but the identities of the other 3 are not known. The expression of all 5 genes fluctuates slightly during the growth cycle of the PEG‐adapted cells grown in the control or in the PEG‐containing medium. In contrast, gene expression in the parental cells fluctuates to a much greater extent and always begins with an enhanced expression during the first day after subculture. Sub‐lethal concentrations of PEG or NaCl have no immediate effect on gene expression in parental cells but NaCl may have a long term effect in enhancing the expression of two genes after 5 days. Abscisic acid (ABA) has no effect on the expression of 4 genes but suppresses the expression of one gene. The roles of these genes in water‐stress adaptation of plant cells are discussed.