Restricted Nitrate Influx and Reduction in Corn Seedlings Exposed to Ammonium

MacKown, Charles T.; Jackson, W. A.; Volk, Richard J.

doi:10.1104/pp.69.2.353

Cited by 58 publications

(34 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…There have also been reports of stimulated NO3-uptake arising as a consequence of NH4' pretreatment as in the case of seedlings of wheat (21) and corn (18).…”

Section: Introductionmentioning

confidence: 99%

Short Term Studies of Nitrate Uptake into Barley Plants Using Ion-Specific Electrodes and ³⁶ClO₃⁻

Deane‐Drummond¹,

Glass²

1983

Plant Physiol.

View full text Add to dashboard Cite

The influence of NH4', in the external medium, on fluxes of NO3-and K were investigated using barley (Hordeum vulgare cv Betzes) plants.NWV was without effect on NO3-(3'10C3-) influx whereas inhibition of net uptake appeared to be a function of previous N03-provision. Plants grown at 10 micromolar NO3-were sensitive to external NHW when uptake was measured in 100 micromolar NO3-. By contrast, NO3-uptake (from 100 micromolar NO3-) by plants previously grown at this concentration was not reduced by NI-14 treatment. Plants pretreated for 2 days with 5 millimolar NO3-showed net efflux of NO3-when roots were transferred to 100 micromolar NO3-. This efflux was stimulated in the presence of NH4'. NH4' also stimulated NO3-efflux from plants pretreated with relatively low nitrate concentrations. It is proposed that short term effects on net uptake of NO3-occur via effects upon efflux.By contrast to the situation for NO3-, net K' uptake and influx of 'Rb+-labeled K' was inhibited by NH4' regardless of the nutrient history of the plants. Inhibition of net K' uptake reached its maximum value within 2 minutes of NH4' addition. It is concluded that the latter ion exerts a direct effect upon K' influx.In barley, Lewis et al. (15), for example, showed that NH4' inhibited NO3-accumulation in the root and shoot and NO3-translocation to shoots although NO3-uptake was not measured directly. Recently, MacKown et al. (17,18) have shown that NH14' inhibits NO3-uptake and NO3-reduction in corn plants.Their results suggest that almost all the effect of NH4' on uptake of N03-is via its effect on the reduction step. There have also been reports of stimulated NO3-uptake arising as a consequence of NH4' pretreatment as in the case of seedlings of wheat (21) and corn (18).The almost universal choice of relatively long experimental periods (usually 2 to 24 h) for the investigation ofeffects of NH4+ upon nitrate uptake has made it extremely difficult to distinguish between effects on nitrate uptake per se and subsequent effects upon the properties (selectivity, turnover, etc.) of the nitrate transporter or effects on nitrate reduction and translocation (e.g. 17, 18). Both inhibition (9, 23, 24, 26) and stimulation (21) of in vitro nitrate reductase activity, following NH4' pretreatment, have been documented. Other workers using corn have shown that NH4+ inhibits NO3-reduction in vivo (18). However, the possible direct or indirect effects of NH4+ on the turnover of the nitrate transport proteins (presuming they are in fact proteins) will remain an open question until such proteins can be biochemically characterized.The potential importance of NH4, in the regulation of N03-metabolism has been widely recognized and explored in numerous studies of nitrate assimilation in micro-organisms and higher plants (e.g. 2-4, 12, 14). Considering the intermediary role of NH4+ in nitrate utilization, the former ion must represent a likely candidate for feedback effects on uptake and/or reduction of nitrate. Both short term (direct) effects of NH4' on...

show abstract

“…There have also been reports of stimulated NO3-uptake arising as a consequence of NH4' pretreatment as in the case of seedlings of wheat (21) and corn (18).…”

Section: Introductionmentioning

confidence: 99%

Short Term Studies of Nitrate Uptake into Barley Plants Using Ion-Specific Electrodes and ³⁶ClO₃⁻

Deane‐Drummond¹,

Glass²

1983

Plant Physiol.

View full text Add to dashboard Cite

show abstract

“…Also, ⌽* xylem in NO 2 Ϫ -induced plants was substantially lower than in NO 3 Ϫ -induced plants, and approximated that of plants induced at 0.1 mm [NO 3 Ϫ ] o after the application of 1 mm NH 4 ϩ . Because significant suppression of NO 3 Ϫ reductase activity by NH 4 ϩ is well documented (MacKown et al, 1982a(MacKown et al, , 1982bBreteler and Siegerist, 1984;Pan et al, 1985;de la Haba et al, 1990;Aslam et al, 1997;however, see Oaks et al, 1979), ⌽* xylem under these conditions will be mostly in the form of 13 NO 3 Ϫ after NH 4 ϩ addition. Therefore, the lack of an effect of NH 4 ϩ on Figure 2.…”

Section: N-flux Partitioningmentioning

confidence: 99%

“…Although early reports suggested that NH 4 ϩ enhanced NO 3 Ϫ efflux (Jackson et al, 1976;Doddema and Telkamp, 1979;MacKown et al, 1982a;Deane-Drummond and Glass, 1983;Deane-Drummond, 1985, 1986, later studies using 13 NO 3 Ϫ clearly documented an inhibition of influx (Glass et al, 1985;Lee and Clarkson, 1986;Ingemarsson et al, 1987;Oscarson et al, 1987;Lee and Drew, 1989;Ayling, 1993;King et al, 1993). The debate has recently been revived by Aslam andcoworkers (1994, 1997), who concluded that the main effect of NH 4 ϩ on net NO 3 Ϫ uptake was through stimulation of NO 3 Ϫ efflux; they discounted the significance of influx inhibition.…”

mentioning

confidence: 99%

“…In absolute terms, the reduction of influx made the dominant contribution to the observed reduction of net uptake of NO 3 ؊ . Differences in response between plants induced with NO 3 ؊ and those induced with NO 2 ؊ indicate that NO 2 ؊ may not be an appropriate analog for NO 3 ؊ under all conditions.The inhibitory effects exerted by the NH 4 ϩ ion upon NO 3 Ϫ uptake by the roots of higher plants have been studied extensively (Weissman, 1950;Lycklama, 1963; Fried et al, 1965;Minotti et al, 1969;Jackson et al, 1976; Rao and Rains, 1976; Doddema and Telkamp, 1979;MacKown et al, 1982a; Deane-Drummond and Glass, 1983; Rufty et al, 1983; Breteler and Siegerist, 1984; Glass et al, 1985; Ingemarsson et al, 1987; Oscarson et al, 1987;Lee and Drew, 1989; Warner and Huffaker, 1989; de la Haba et al., 1990; Ayling, 1993; Aslam et al, 1994 Aslam et al, , 1997 Chaillou et al., 1994). It is evident that there are short-term effects of NH 4 ϩ on NO 3 Ϫ uptake that are presumed to result from the direct effects of NH 4 ϩ on the plasma membrane; these short-term effects are apparent within minutes of exposure to NH 4 ϩ .…”

mentioning

confidence: 99%

See 1 more Smart Citation

Inhibition of Nitrate Uptake by Ammonium in Barley. Analysis of Component Fluxes1

1999

View full text Add to dashboard Cite

NO 3؊ uptake by plant roots is rapidly inhibited by exposure to NH 4 ؉ . The rapidity of the effect has led to the presumption that the inhibition results from the direct effects of NH 4 ؉ at the plasma membrane. The mechanism of this inhibition, however, has been in contention. In the present study we used the radiotracer 13 N to determine the relative effects of short-term exposures to NH 4 ؉ on the 13 4 ؉ inhibition of influx was mediated via effects on the inducible high-affinity transport system rather than on the constitutive high-affinity transport system or the low-affinity transport system. Exposure to NH 4 ؉ also caused increased NO 3 ؊ efflux; the largest effect was at low external [NO 3 ؊ ] in uninduced plants. In absolute terms, the reduction of influx made the dominant contribution to the observed reduction of net uptake of NO 3 ؊ . Differences in response between plants induced with NO 3 ؊ and those induced with NO 2 ؊ indicate that NO 2 ؊ may not be an appropriate analog for NO 3 ؊ under all conditions.The inhibitory effects exerted by the NH 4 ϩ ion upon NO 3 Ϫ uptake by the roots of higher plants have been studied extensively (Weissman, 1950;Lycklama, 1963; Fried et al., 1965;Minotti et al., 1969;Jackson et al., 1976; Rao and Rains, 1976; Doddema and Telkamp, 1979;MacKown et al., 1982a; Deane-Drummond and Glass, 1983; Rufty et al., 1983; Breteler and Siegerist, 1984; Glass et al., 1985; Ingemarsson et al., 1987; Oscarson et al., 1987;Lee and Drew, 1989; Warner and Huffaker, 1989; de la Haba et al., 1990; Ayling, 1993; Aslam et al., 1994 Aslam et al., , 1997 Chaillou et al., 1994). It is evident that there are short-term effects of NH 4 ϩ on NO 3 Ϫ uptake that are presumed to result from the direct effects of NH 4 ϩ on the plasma membrane; these short-term effects are apparent within minutes of exposure to NH 4 ϩ . Moreover, longer-term effects due to NH 4 ϩ and/or assimilation products of NH 4 ϩ are thought to operate at the transcriptional level (Glass and Siddiqi, 1995;Krapp et al., 1998; Zhuo et al., 1999).Despite the efforts of many investigators, a lack of consensus persists concerning the mechanism(s) responsible for the short-term inhibition of NO 3 Ϫ uptake by NH 4 ϩ ; specifically, whether the NH 4 ϩ effect is achieved by the direct inhibition of influx or by stimulating efflux. Although early reports suggested that NH 4 ϩ enhanced NO 3 Ϫ efflux (Jackson et al., 1976; Doddema and Telkamp, 1979;MacKown et al., 1982a; Deane-Drummond and Glass, 1983; Deane-Drummond, 1985, 1986, later studies using 13 NO 3 Ϫ clearly documented an inhibition of influx (Glass et al., 1985;Lee and Clarkson, 1986; Ingemarsson et al., 1987; Oscarson et al., 1987;Lee and Drew, 1989; Ayling, 1993;King et al., 1993). The debate has recently been revived by Aslam and coworkers (1994, 1997), who concluded that the main effect of NH 4 ϩ on net NO 3 Ϫ uptake was through stimulation of NO 3 Ϫ efflux; they discounted the significance of influx inhibition. A resolution of this controversy has ...

show abstract

“…By using 36C103-as an analog for NO3-, it was shown that NH4+ stimulated NO3-efflux in several species (4)(5)(6)(7), although no such effect was found in barley using '3N03- (17). Studies with '5NO3- (18) and '3N03- (11,22) rather pointed to an inhibition of the influx component of net NO3-uptake. There is only limited knowledge on the cause for inhibition of NO3-uptake; it has been attributed to NH4+-induced membrane depolarization (27), or to a regulatory compound formed in primary NH4' assimilation (1,10).…”

mentioning

confidence: 96%

Nitrogen Utilization in Lemna

Ingemarsson¹,

Oscarson²,

Ugglas³

et al. 1987

Plant Physiol.

View full text Add to dashboard Cite

The effects ofammonium application on nitrate utilization were studied in N-limited cultures of Lemna gibba L. G3. Addition of ammonium instantaneously inhibited net nitrate uptake by at least 60%, followed by a slight recovery. The inhibition was equally clear after near-complete inactivation of glutamine synthetase by application of L-methionine-D,Lsulfoximine. Experiments where "MN-abeled nitrate was used as an influx tracer revealed that ammonium specifically inhibited influx, but did not promote nitrate efflux. Nitrate accumulation was relatively more inhibited than nitrate reduction and net uptake. Nitrate reductase, extracted and assayed in vitro in the presence of the thiol proteinase inhibitor leupeptin, was unaffected by short-term treatment of the plants with either nitrate, ammonium, or ammonium nitrate. Nitrate reductase activity recovered in the absence of leupeptin was considerably lower, however, it was enhanced by all the nitrogen sources, with ammonium as the most potent. It is argued that the effect of ammonium on nitrate utilization in Lemna is due to inhibition of nitrate influx, and that the effect should be attributed to ammonium itself, not to a newly formed nitrogen derivative. The decreased nitrate flux caused a decrease in nitrate reduction, whereas the activity of nitrate reductase per se rather is stabilized by presence of ammonium.Short-term inhibition of net NO3-uptake by supply of NH4' is well documented for cyanobacteria and algae (26). In higher plants, however, the effect of NH4' is more variable, ranging from a transient stimulation (1) to a total inhibition of net N03 uptake (6,8). Ammonium could affect net NO3-uptake by interfering either with membrane NO3-transport or with utilization of NO3-within the plant tissue. By using 36C103-as an analog for NO3-, it was shown that NH4+ stimulated NO3-efflux in several species (4-7), although no such effect was found in barley using '3N03-(17). Studies with '5NO3-(18) and '3N03-(11, 22) rather pointed to an inhibition of the influx component of net NO3-uptake. There is only limited knowledge on the cause for inhibition of NO3-uptake; it has been attributed to NH4+-induced membrane depolarization (27), or to a regulatory compound formed in primary NH4' assimilation (1, 10).Ammonium has also been reported to affect NR2; thus, some of the observed effects of NH4+ might be due to altered NRA. In algae, however, the effect of NH41 on NRA is normally too slow to account for the usually prompt inhibition of NO3-uptake ' Supported by the Swedish Natural Science Research Council. 2 Abbreviations: NR, nitrate reductase; FW, fresh weight; GS, glutamine synthetase; MSO, L-methionine-D,L-sulfoximine; NRA, nitrate reductase activity.(16). The NRA in green tissues of higher plants seems to be generally unaffected or stabilized by NHI4+ (3, 19, 24) whereas a pH-dependent inhibition has been noted in roots (20,24). This pattern is, however, not universal (for Lemna, see [21]) and seems to be very much dependent on plant material, the way of ...

show abstract

Restricted Nitrate Influx and Reduction in Corn Seedlings Exposed to Ammonium

Abstract: The effect of ambient ammonium (0.5 (10,23,24,25,28,31). In contrast, either no effect or an enhancement of NRA in the presence of ammonium has been reported (3,23,24,31).

Cited by 58 publications

References 25 publications

Short Term Studies of Nitrate Uptake into Barley Plants Using Ion-Specific Electrodes and ³⁶ClO₃⁻

Short Term Studies of Nitrate Uptake into Barley Plants Using Ion-Specific Electrodes and ³⁶ClO₃⁻

Inhibition of Nitrate Uptake by Ammonium in Barley. Analysis of Component Fluxes1

Nitrogen Utilization in Lemna

Contact Info

Product

Resources

About

Restricted Nitrate Influx and Reduction in Corn Seedlings Exposed to Ammonium

Abstract: The effect of ambient ammonium (0.5 (10,23,24,25,28,31). In contrast, either no effect or an enhancement of NRA in the presence of ammonium has been reported (3,23,24,31).

Cited by 58 publications

References 25 publications

Short Term Studies of Nitrate Uptake into Barley Plants Using Ion-Specific Electrodes and 36ClO3−

Short Term Studies of Nitrate Uptake into Barley Plants Using Ion-Specific Electrodes and 36ClO3−

Inhibition of Nitrate Uptake by Ammonium in Barley. Analysis of Component Fluxes1

Nitrogen Utilization in Lemna

Contact Info

Product

Resources

About

Short Term Studies of Nitrate Uptake into Barley Plants Using Ion-Specific Electrodes and ³⁶ClO₃⁻

Short Term Studies of Nitrate Uptake into Barley Plants Using Ion-Specific Electrodes and ³⁶ClO₃⁻