Nitrogen assimilation. Plant Physiol Biotech, Biol 3470 Feb. 28, 2006 Lecture 12 Chapter 8. Nitrogen: an essential element. wps.prenhall.com . Fourth most common element Proteins, NAs, PGRs, chlorophyll,… Bioavailable forms: nitrate ( NO 3 - ) and ammonia ( NH 4 + )
Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.
Plant Physiol Biotech, Biol 3470
Feb. 28, 2006
and ammonia (NH4+)
Nitrification by bacteria
by prokaryotes and fungi
Organic N pools
Where does the biologically available soil N come from?
Alfalfa (Medicago sativa)
N assimilation is reliant on a steady supply of C !!
(via nitrification by bacteria or fertilizer)
+ nitrite reductase
ADP + Pi
NADP + H+
Biologically available but toxic!
(C skeleton from ______ )
Glutamate synthase cycle
ATP + NADH
ADP + Pi + NAD+
For export to N sinks
Glu + OAA αKG + Asp
Gln + Asp Glu + Asn
Exported from Glu synthase cycle
Siphoned from Glu synthase cycle
Nitrate reductase activity coordinates N and C assimilation
… which depends on soil pH, temp., O2, H2O
Natural ecosystems are also N limited