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Co‐regulated expression of nitrate and nitrite reductases
Author(s) -
Faure JeanDenis,
Vincentz Michel,
Kronenberger Jocelyne,
Caboche Michel
Publication year - 1991
Publication title -
the plant journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.058
H-Index - 269
eISSN - 1365-313X
pISSN - 0960-7412
DOI - 10.1111/j.1365-313x.1991.00107.x
Subject(s) - complementation , mutant , nitrate , nitrite , nitrite reductase , wild type , gene expression , biology , biochemistry , messenger rna , nitrate reductase , gene , microbiology and biotechnology , chemistry , ecology
Summary The regulation of nitrate and nitrite reductases (NR and NiR, respectively) expression was compared in wild‐type and NR‐deficient (n/a) Nicotiana plumbaginifolia plants. In wild‐type plants, NiR and NR mRNA levels fluctuated according to a circadian rhythm, with similar timing of maximal and minimal transcript accumulation. NiR and NR mRNA levels were also nitrate‐ and light‐inducible. It had been found previously that some of the n/a mutants over expressed NR mRNA. In mutant plants, irrespective of the mutation affecting the n/a gene, NiR mRNA and activity were over expressed. However, nitrate and light inducibility of NR and NiR mRNAs was still detectable. Normal NiR expression levels of mRNA were restored in n/a leaky mutants obtained by intragenic complementation which contained low levels of NR activity. These data support the hypothesis of a common regulation of NR and NiR expression by a nitrate‐derived metabolite. They also prove that the autogenous model of NR regulation described in fungi is not valid for higher plants.