Title: Relationship of nitrate supply with growth rate, plasma membrane‐bound and cytosolic nitrate reductase, and tissue nitrate content in tobacco plants
Abstract:cNR, cytosolic nitrate reductase PM‐NR, plasma membrane‐bound nitrate reductase Activities of plasma membrane‐bound nitrate reductase (PM‐NR) and cytosolic nitrate reductase (cNR) in tobacco ( Nicotia...cNR, cytosolic nitrate reductase PM‐NR, plasma membrane‐bound nitrate reductase Activities of plasma membrane‐bound nitrate reductase (PM‐NR) and cytosolic nitrate reductase (cNR) in tobacco ( Nicotiana tabacum L. cv . Samsun) are regulated differently, depending upon the nitrate supply to the culture medium (in sand culture). The cNR activity of roots was higher at low nitrate concentrations with the maximum at 5 m M nitrate supply and declined to low values beyond 5 m M . In contrast, the PM‐NR activity of roots increased with higher nitrate concentrations with the maximum at 25 m M nitrate and clearly decreased only at 40 m M . This high PM‐NR activity correlated with a low growth rate and might be one of the responses to excess nitrate. Internal nitrate and total nitrogen content of the tissues, however, showed a relative minimum in shoots and in roots of between 15 and 25 m M external nitrate. With declining PM‐NR activities beyond 25 m M external nitrate, the nitrate content in the tissue increased indicating an inverse relationship between tissue nitrate content and root PM‐NR activity. In leaves both NR activities (cNR and PM‐NR) correlated with the internal nitrate content, but with a different response at low nitrate.Read More
Publication Year: 1999
Publication Date: 1999-02-01
Language: en
Type: article
Indexed In: ['crossref']
Access and Citation
Cited By Count: 48
AI Researcher Chatbot
Get quick answers to your questions about the article from our AI researcher chatbot