Signal storage in phytochrome action on nitrate-mediated induction of nitrate and nitrite reductases in mustard seedling cotyledons

Planta ◽  
1987 ◽  
Vol 171 (1) ◽  
pp. 136-143 ◽  
Author(s):  
C. Schuster ◽  
R. Oelm�ller ◽  
H. Mohr
Keyword(s):  
Mustard Seedling ◽  
Nitrite Reductases ◽  
Nitrate And Nitrite

scholarly journals Nitrate Respiration in Thermus thermophilus NAR1: from Horizontal Gene Transfer to Internal Evolution

Genes ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 1308
Author(s):  
Mercedes Sánchez-Costa ◽  
Alba Blesa ◽  
José Berenguer
Keyword(s):  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Nadh Dehydrogenase ◽  
Thermus Thermophilus ◽  
Nitrate Respiration ◽  
Small Plasmid ◽  
Nitrite Reductases ◽  
Nitrite Respiration ◽  
Nitrate And Nitrite ◽  
Internal Evolution

Genes coding for enzymes of the denitrification pathway appear randomly distributed among isolates of the ancestral genus Thermus, but only in few strains of the species Thermus thermophilus has the pathway been studied to a certain detail. Here, we review the enzymes involved in this pathway present in T. thermophilus NAR1, a strain extensively employed as a model for nitrate respiration, in the light of its full sequence recently assembled through a combination of PacBio and Illumina technologies in order to counteract the systematic errors introduced by the former technique. The genome of this strain is divided in four replicons, a chromosome of 2,021,843 bp, two megaplasmids of 370,865 and 77,135 bp and a small plasmid of 9799 pb. Nitrate respiration is encoded in the largest megaplasmid, pTTHNP4, within a region that includes operons for O2 and nitrate sensory systems, a nitrate reductase, nitrate and nitrite transporters and a nitrate specific NADH dehydrogenase, in addition to multiple insertion sequences (IS), suggesting its mobility-prone nature. Despite nitrite is the final product of nitrate respiration in this strain, the megaplasmid encodes two putative nitrite reductases of the cd1 and Cu-containing types, apparently inactivated by IS. No nitric oxide reductase genes have been found within this region, although the NorR sensory gene, needed for its expression, is found near the inactive nitrite respiration system. These data clearly support that partial denitrification in this strain is the consequence of recent deletions and IS insertions in genes involved in nitrite respiration. Based on these data, the capability of this strain to transfer or acquire denitrification clusters by horizontal gene transfer is discussed.

Co-regulated expression of nitrate and nitrite reductases

1991 ◽  
Vol 1 (1) ◽  
pp. 107-113 ◽  
Author(s):  
Jean-Denis Faure ◽  
Michel Vincentz ◽  
Jocelyne Kronenberger ◽  
Michel Caboche
Keyword(s):  
Nitrite Reductases ◽  
Regulated Expression ◽  
Nitrate And Nitrite

Nitrogen assimilation and regulation of nitrate and nitrite reductases in cultured Ipomoea cells

1977 ◽  
Vol 55 (12) ◽  
pp. 1557-1568 ◽  
Author(s):  
M. W. Zink ◽  
I. A. Veliky
Keyword(s):  
Nitrogen Source ◽  
Nitrogen Assimilation ◽  
Nitrate Assimilation ◽  
Time Interval ◽  
Low Level ◽  
Stages Of Growth ◽  
Nitrite Reductases ◽  
Nitrate And Nitrite ◽  
In Cells

Ipomoea cells grown in a medium containing ammonium and nitrate preferentially used ammonium during the initial stages of growth but in the later stages assimilated nitrate rapidly regardless of the presence or absence of ammonium. Cells grown on nitrate and maintained at pH 4.8 released ammonia into the medium, whereas when they were maintained at pH 6.5 they secreted nitrite. The enzymes of nitrate assimilation were inducible by nitrate and the activities changed considerably in response to nitrogen source. The addition of ammonium 3 days after inoculation to cells highly induced for the reductases did not result in the suppression of further synthesis of the enzymes. The levels of nitrate (EC 1.6.6.1) and nitrite (EC 1.6.6.4) reductases detected in cells grown on ammonium as the nitrogen source were about 25% and 66%, respectively, of the fully induced level. The addition of nitrate to ammonium-assimilating cells resulted in a low level of induction of both reductases. Addition of nitrite had no effect. With both ammonium and nitrate initially present in the medium, the ammonium was utilized quickly but no induction of the reductases was observed for 24 h. the time interval when the assimilation of nitrate was low. This was followed by the induction of the enzymes to a higher level than the activity in cultures of similar age that had been grown continually in nitrate, supplied at the same concentration. Thus, for nitrate and nitrite reductases, repression-like effects were produced by ammonium.

Sign in / Sign up

Export Citation Format

Share Document