ISSN:
1573-5036
Keywords:
Nitrate-efflux
;
Nitrate-influx
;
Pisum sativum L
;
Substrate-cycle
Source:
Springer Online Journal Archives 1860-2000
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Notes:
Summary Net nitrate uptake (J) intoPisum sativum L. seedlings has been investigated. J was high initially, but declined with time as NO 3 − efflux (E) approached that of NO 3 − influx (I). Both I and E were higher in plants which had been grown without N. J could be reversibly and immediately inhibited by 5 mmol m−3 NH 4 + , although plants grown in the presence of nitrate were less sensitive. A theoretical model which involves substrate cycling across the plasmalemma is shown to increase the sensitivity to substrate and effectors. It predicts that during growth of Pisum in N free media the cycling rate (E/I) is increased and the sensitivity of net flux of inhibition by NH 4 + is highest. The model also provides a means for control of cytoplasmic nitrate pool size [NO 3 − ] c.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02198113
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