Nitrate Reductase Activity of Sphagnum Species in the South Pennines

Press, M. C.; Lee, J. A.

doi:10.1111/j.1469-8137.1982.tb03406.x

Cited by 58 publications

(28 citation statements)

References 44 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Baxter et al 1992), a reduction of the amount of N reallocated from stem to capitulum (this study; Fig. 2), a reduced NH 4 + uptake rate (Press et al 1986;Twenhöven 1992a;Jauhiainen et al 1998) or a reduced nitrate reductase activity (Press and Lee 1982;Woodin et al 1985;Woodin and Lee 1987;Morgan et al 1992). When Sphagnum is exposed to a step increase of N, as is usually the case in an experimental setting, its uptake rate could exceed its assimilation rate, leading to an accumulation of toxic NH 4 + in the cell and a subsequent reduction in growth.…”

Section: Discussionmentioning

confidence: 55%

Growth reduction of Sphagnum magellanicum subjected to high nitrogen deposition: the role of amino acid nitrogen concentration

2003

View full text Add to dashboard Cite

We tested the relationship between Sphagnum growth and the amount of nitrogen stored in free amino acids in a fertilisation experiment with intact peat monoliths in an open greenhouse in The Netherlands. Three nitrogen deposition scenarios were used: no nitrogen deposition, field conditions and a doubling of the latter, corresponding to 0, 40 and 80 kg N ha(-1 )year(-1). Growth of Sphagnum as expressed by height increment was reduced in the 80 kg N treatment, but showed no correlation with the total nitrogen tissue concentration or with the concentration of individual or pooled free amino acids. The amount of nitrogen stored in free amino acids increased concomitantly with deposition, although it lagged more and more behind the total nitrogen concentration, the latter pointing to the accumulation of unmeasured nitrogen compounds. Asparagine clearly acted as the major storage compound for nitrogen in Sphagnum stem tissue, whereas arginine fulfilled this function to a lesser extent in the capitulum. It appears that nitrogen-induced growth inhibition of Sphagnum is related to acclimation rather than to certain threshold concentrations of amino nitrogen or total nitrogen. We propose that when Sphagnum is exposed to a step increase of nitrogen, its nitrogen metabolism does not adapt fast enough to keep up with the enhanced uptake rate. This imbalance between nitrogen uptake and assimilation may lead to an accumulation of toxic NH(4)(+ )in the cell and a subsequent reduction in growth.

show abstract

Section: Discussionmentioning

confidence: 55%

Growth reduction of Sphagnum magellanicum subjected to high nitrogen deposition: the role of amino acid nitrogen concentration

2003

View full text Add to dashboard Cite

show abstract

“…Both inter-specific and habitat-related intra-specific differences in nitrate assimilation ability have been reported from a wide range of taxa (Dirr et al, 1973;Gebauer et al, 1988;Gu¨leryu¨z and Arslan, 1999;Havill et al, 1974;Ho¨gberg et al, 1986Ho¨gberg et al, , 1990Lee and Stewart, 1978;Osborne and Whittington, 1981;Press and Lee, 1982;Woodin et al, 1985). In addition, the difference among organs (especially shoot and roots) of plants was reported by many authors (Andrews, 1986;Gebauer et al, 1984Gebauer et al, , 1988Gu¨leryu¨z and Arslan, 1999;Jiang and Hull, 1999;Pate, 1980;Scheurwater et al, 2002).…”

Section: Introductionmentioning

confidence: 85%

A study on nitrate reductase activity (NRA) of geophytes from Mediterranean environment

Arslan

Guleryuz

2005

Flora - Morphology, Distribution, Functional Ecology of Plants

View full text Add to dashboard Cite

“…Concomitant nitrate and ammonium spray treatment of S. capillifolium is also seen to result in a much reduced amount of nitrate reductase activity compared to nitrate only treatments in Figure 1. Press & Lee (1982) have proposed that an increase in tissue ammonium concentration in Sphagnum species may result in a reduction in nitrate reductase activity, a view supported by the fact that Sphagnum taken from a very polluted environment had a very high tissue ammonium concentration and low nitrate reductase inducibility (Woodin, 1986). Among the mechanisms by which such inhibition may be exerted are the reversible inactivation of nitrate reductase, as demonstrated in many algae (e.g.…”

Section: Discussionmentioning

confidence: 99%

THE EFFECTS OF NITRATE, AMMONIUM AND TEMPERATURE ON NITRATE REDUCTASE ACTIVITY IN SPHAGNUM SPECIES

Woodin

Lee

1987

New Phytologist

Self Cite

View full text Add to dashboard Cite

SUMMARYThe effects of the availability of inorganic nitrogen on in vivo activity of nitrate reductase in Sphagnum capillifolium (Ehrh.) Hedw. and Sphagnum fuscum (Schimp.) Klinggr. were investigated in both field and laboratory experiments. Nitrate reductase activity per unit mass was highest in the capitulum and declined down the stem. Nitrate reductase activity was substrateinducible, maximum and total activities induced being correlated with the natural logarithm of nitrate concentration in the range 0 to 10 mM. Repeated treatment with 05 mM nitrate did not give rise to repeated similar patterns of nitrate reductase activity, induction decreasing with later successive applications. An initial ammonium treatment in a field experiment did not affect nitrate-induced enzyme activity. However, repeated applications of ammonium caused marked changes in the patterns of induction and a general repression of total nitrate reduction. This repression may result from both an effect of ammonium on nitrate uptake and a direct effect of the accumulation of ammonium or ammonium assimilation products on the enzyme itself. Repression by repeated nitrate supply may also operate in a similar way. The effects of ammonium and nitrate supply on the induction of nitrate reductase were shown to interact.The initial rate of induction of nitrate reductase activity increased with temperature, but prolonged nitrate supply resulted in highest enzyme levels at lowest temperatures. This effect may be due to greater rates of activity giving rise to greater repression by the products of nitrate assimilation at the higher temperatures. The results are discussed in relation to the use of nitrate reductase activity as a monitor of atmospheric nitrate deposition in ombrotrophic bryophyte species.

show abstract

Nitrate Reductase Activity of Sphagnum Species in the South Pennines

Cited by 58 publications

References 44 publications

Growth reduction of Sphagnum magellanicum subjected to high nitrogen deposition: the role of amino acid nitrogen concentration

Growth reduction of Sphagnum magellanicum subjected to high nitrogen deposition: the role of amino acid nitrogen concentration

A study on nitrate reductase activity (NRA) of geophytes from Mediterranean environment

THE EFFECTS OF NITRATE, AMMONIUM AND TEMPERATURE ON NITRATE REDUCTASE ACTIVITY IN SPHAGNUM SPECIES

Contact Info

Product

Resources

About