Dear Silvio,
a good place to start is Robinson et al. (1998): A theory for 15N/14N
fractionation in nitrate grown vascular plants, Planta, 205, 397-406.

I assume that there is a lot of work done on nitrate assimilation in the
agricultural-biological literature.

Stefano


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Dr. Stefano Bernasconi
Geologisches Institut
ETH-Zentrum
CH-8092 Zuerich
Switzerland
Tel. ..41-1-632 3693
fax:  ..41-1-632 1080
e-mail: [log in to unmask]
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