TY - JOUR

T1 - Inhibition of endogenous urease activity by NBPT application reveals differential N metabolism responses to ammonium or nitrate nutrition in pea plants

T2 - a physiological study

AU - Cruchaga, S.

AU - Lasa, B.

AU - Jauregui, I.

AU - González-murua, C.

AU - Aparicio-tejo, P. M.

AU - Ariz, I.

PY - 2013/12/1

Y1 - 2013/12/1

N2 - Background and aimsUrea is the predominant form of N applied as fertilizer to crops, but it is also a significant N metabolite of plants themselves. As such, an understanding of urea metabolism in plants may contribute significantly to subsequent N fertilizer management. It currently appears that arginase is the only plant enzyme that can generate urea in vivo. The aim of this work was, therefore, to gain a more in-depth understanding of the significance of the inhibition of endogenous urease activity and its role in N metabolism depending on the N source supplied.MethodsPea (Pisum sativum cv. Snap-pea) plants were grown with either ammonium or nitrate as the sole N source in the presence or absence of the urease inhibitor NBPT.ResultsWhen supplied, NBPT is absorbed by plants and translocated from the roots to the leaves, where it reduces endogenous urease activity. Different N metabolic responses in terms of N-assimilatory enzymes and N-containing compounds indicate a different degree of arginine catabolism activation in ammonium- and nitrate-fed plants.ConclusionsThe arginine catabolism is more highly activated in ammonium-fed plants than in nitrate-fed plants, probably due to the higher turnover of substrates by enzymes playing a key role in N recycling and remobilization during catabolism and in early flowering and senescence processes, usually observed under ammonium nutrition.

AB - Background and aimsUrea is the predominant form of N applied as fertilizer to crops, but it is also a significant N metabolite of plants themselves. As such, an understanding of urea metabolism in plants may contribute significantly to subsequent N fertilizer management. It currently appears that arginase is the only plant enzyme that can generate urea in vivo. The aim of this work was, therefore, to gain a more in-depth understanding of the significance of the inhibition of endogenous urease activity and its role in N metabolism depending on the N source supplied.MethodsPea (Pisum sativum cv. Snap-pea) plants were grown with either ammonium or nitrate as the sole N source in the presence or absence of the urease inhibitor NBPT.ResultsWhen supplied, NBPT is absorbed by plants and translocated from the roots to the leaves, where it reduces endogenous urease activity. Different N metabolic responses in terms of N-assimilatory enzymes and N-containing compounds indicate a different degree of arginine catabolism activation in ammonium- and nitrate-fed plants.ConclusionsThe arginine catabolism is more highly activated in ammonium-fed plants than in nitrate-fed plants, probably due to the higher turnover of substrates by enzymes playing a key role in N recycling and remobilization during catabolism and in early flowering and senescence processes, usually observed under ammonium nutrition.

KW - Ammonium nutrition

KW - Arginine catabolism

KW - NBPT

KW - Protein turnover

KW - Urea metabolism

KW - Urease

KW - Urease inhibitor

U2 - 10.1007/s11104-013-1830-x

DO - 10.1007/s11104-013-1830-x

M3 - Journal article

VL - 373

SP - 813

EP - 827

JO - Plant and Soil

JF - Plant and Soil

SN - 0032-079X

IS - 1-2

ER -