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Molecular cloning of cDNAs for three tau‐type glutathione S ‐transferases in pumpkin ( Cucurbita maxima ) and their expression properties
Author(s) -
Fujita Masayuki,
Hossain Mohammad Z.
Publication year - 2003
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 - 10.1034/j.1399-3054.2003.1170111.x
Subject(s) - cucurbita maxima , cucurbita , callus , biology , microbiology and biotechnology , hypocotyl , complementary dna , antiserum , cdna library , blot , botany , gene , biochemistry , genetics , antibody
cDNAs of three major glutathione S ‐transferases (GSTs), Puga, Pugb and Pugc, in 2,4‐D‐treated pumpkin ( Cucurbita maxima Duch.) callus were individually obtained through immuno‐screenings with corresponding antisera from a pumpkin cDNA library. Comparison of the predicted protein sequences with ones of other plant GSTs reported previously and recognition of the presence of a single intron in each genomic gene indicated that they could be classified into tau‐type GST group. Hence, Puga, Pugb and Pugc were named Cm GSTU1, Cm GSTU2 and Cm GSTU3, respectively. Expression of the GSTs in various organs of pumpkin plants, and in hypocotyls of seedlings under various stress conditions were examined by Western blotting and Northern blotting analyses. Cm GSTU1 tended to be expressed more in fully expanded mature organs, and Cm GSTU2 seemed to be expressed preferentially in leaves and petioles. Cm GSTU1 and Cm GSTU2 were induced by dehydration. Cm GSTU1 was also induced by high temperature stress. In this study, the expression pattern of Cm GSTU3 could not be determined because the contents were too low to detect with the antiserum. After 2,4‐ d treatment, GST activity in the pumpkin callus increased rapidly until day one and then slowly increased at a constant rate up to day 6. The increase seemed to be dependent on post‐transcriptional enhancement as well as transcriptional induction.