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Étude du métabolisme de la plante en réponse à l'apport de différents fertilisants et adjuvants culturaux. Influence des phytohormones sur le métabolisme azoté.

Abstract : We have investigated the uptake and assimilation of urea in plants. Three plant species and two growth conditions were compared for this study. First two crop species of economical interest, namely wheat and maize, were grown in hydroponic or soil cultures, in conditions close to field ones, to determine the influence of urea as nitrogen source on growth and metabolism. We have then used the model plant Arabidopsis in hydroponic cultures to follow urea uptake and its influence on the expression of the genome as revealed by microarray analysis. The impact of urea used as N source on plant growth and N status was determined by following biomass accumulation and measuring N metabolites. We have thus been able to show that plants can take up and assimilate urea per se and that urea influx was dependent of the initial N status of the plant. The urea influx was less efficient than that of nitrate and urea-grown plants showed symptoms of N deficiency. Moreover urea regulated the influxes of nitrate, ammonium and urea itself. The assimilation of urea and ammonium were found to be quite similar in terms of impact on N metabolism. The addition of urea to ammonium nitrate did not influence the growth, N metabolism and N uptake of plants. Thus a significant amount of urea could be added to fertilizers to lower the amount of nitrate used in agricultural systems. We have also tried to identify the molecules responsible for the positive effects of algal extracts on plant growth and metabolism as well as the targets of these compounds in the plant N metabolism. A systematic analysis of the effects of algal extract spaying on the expression of the Arabidopsis genome was undertaken using CATMA arrays. This has allowed us to identify genes expression of which was regulated by the spraying of an auxin-rich brown algal extract on plants grown in hydroponic conditions.
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https://pastel.archives-ouvertes.fr/pastel-00002273
Contributor : Ecole Agroparistech <>
Submitted on : Thursday, March 22, 2007 - 8:00:00 AM
Last modification on : Friday, October 23, 2020 - 4:38:04 PM
Long-term archiving on: : Thursday, September 30, 2010 - 7:51:16 PM

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  • HAL Id : pastel-00002273, version 1

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Patricia Mérigout. Étude du métabolisme de la plante en réponse à l'apport de différents fertilisants et adjuvants culturaux. Influence des phytohormones sur le métabolisme azoté.. Sciences of the Universe [physics]. INAPG (AgroParisTech), 2006. English. ⟨NNT : 2006INAP0019⟩. ⟨pastel-00002273⟩

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