000			03344nab a22004097a 4500
001			68922
003			MX-TxCIM
005			20250620154712.0
008			250606s2006 ne |||p|op||| 00| 0 eng d
022			_a0032-079X
022			_a1573-5036 (Online)
024	8		_ahttps://doi.org/10.1007/s11104-006-9094-3
040			_aMX-TxCIM
041			_aeng
100	0		_aGuntur Venkata Subbarao _92828
245	1	2	_aA bioluminescence assay to detect nitrification inhibitors released from plant roots: a case study with Brachiaria humidicola
260			_aNetherlands : _bSpringer, _c2006.
500			_aPeer review
520			_aA bioluminescence assay using recombinant Nitrosomonas europaea was adopted to detect and quantify natural nitrification inhibitors in plant–soil systems. The recombinant strain of N. europaea produces a distinct two-peak luminescence due to the expression of luxAB genes, introduced from Vibrio harveyi, during nitrification. The bioluminescence produced in this assay is highly correlated with NO-2 production (r2 = 0.94). Using the assay, we were able to detect significant amounts of a nitrification inhibitor produced by the roots of Brachiaria humidicola (Rendle) Schweick. We propose that the inhibitory activity produced/released from plants be termed ‘biological nitrification inhibition’ (BNI) to distinguish it from industrially produced inhibitors. The amount of BNI activity produced by roots was expressed in units defined in terms of the action of a standard inhibitor allylthiourea (AT). The inhibitory effect from 0.22 μM AT in an assay containing 18.9 mM of NH+4 is defined as one AT unit of activity. A substantial amount of BNI activity was released from the roots of B. humidicola (15–25 AT unit g–1 root dry wt day–1). The BNI activity released was a function of the growth stage and N content of the plant. Shoot N levels were positively correlated with the release of BNI activity from roots (r2 = 0.76). The inhibitor/s released from B. humidicola roots suppressed soil nitrification. Additions of 20 units of BNI per gram of soil completely inhibited NO-3 formation in a 55-day study and remained functionally stable in the soil for 50 days. Both the ammonia monooxygenase and the hydroxylaminooxidoreductase enzymatic pathways in Nitrosomonas were effectively blocked by the BNI activity released from B. humidicola roots. The proposed bioluminescence assay can be used to characterize and determine the BNI activity of plant roots, thus it could become a powerful tool in genetically exploiting the BNI trait in crops and pastures.
546			_aText in English
650		7	_aBioluminescence _2AGROVOC _939206
650		7	_aNitrosomonas europaea _2AGROVOC _917175
650		7	_aNitrification inhibitors _2AGROVOC _94939
650		7	_aAmmonia _2AGROVOC _92028
650		7	_aOxidants _2AGROVOC _922508
650		7	_aBacteria _2AGROVOC _91017
650		7	_aVibrio harveyi _2AGROVOC _939207
650		7	_aBrachiaria humidicola _2AGROVOC _917173
650		7	_aRoots _2AGROVOC _91755
700	1		_aIshikawa, T. _920493
700	0		_aIto Osamu _920786
700	0		_aKazuhiko Nakahara _92831
700	1		_aWang, H.Y. _920788
700	1		_aBerry, W. _920496
773	0		_dNetherlands : Springer, 2006. _gv. 288, p. 101–112 _tPlant Soil _wG444682 _x0032-079X
942			_2ddc _cJA _n0
999			_c68922 _d68914