Characterization of a Developmental Root Response Caused by External Ammonium Supply in Lotus japonicus
Articolo
Data di Pubblicazione:
2010
Citazione:
Characterization of a Developmental Root Response Caused by External Ammonium Supply in Lotus japonicus / A. Rogato, E. D’Apuzzo, A. Barbulova, S. Omrane, A. Parlati, S. Carfagna,
A. Costa, F. Lo Schiavo, S. Esposito, M. Chiurazzi. - In: PLANT PHYSIOLOGY. - ISSN 0032-0889. - 154:2(2010 Oct), pp. 784-795. [10.1104/pp.110.160309]
Abstract:
Plants respond to changes of nutrient availability in the soil by modulating their root system developmental plan. This
response is mediated by systemic changes of the nutritional status and/or by local perception of specific signals. The effect of
nitrate on Arabidopsis (Arabidopsis thaliana) root development represents a paradigm of these responses, and nitrate
transporters are involved both in local and systemic control. Ammonium (NH4
+) represents an important nitrogen (N) source
for plants, although toxicity symptoms are often associated with high NH4
+ concentration when this is present as the only
N source. The reason for these effects is still controversial, and mechanisms associating ammonium supply and plant
developmental programs are completely unknown. We determined in Lotus japonicus the range of ammonium concentration
that significantly inhibits the elongation of primary and lateral roots without affecting the biomass of the shoot. The
comparison of the growth phenotypes in different N conditions indicated the specificity of the ammonium effect, suggesting
that this was not mediated by assimilatory negative feedback mechanisms. In the range of inhibitory NH4
+ conditions, only the
LjAMT1;3 gene, among the members of the LjAMT1 family, showed a strong increased transcription that was reflected by an
enlarged topology of expression. Remarkably, the short-root phenotype was phenocopied in transgenic lines by LjAMT1;3
overexpression independently of ammonium supply, and the same phenotype was not induced by another AMT1 member.
These data describe a new plant mechanism to cope with environmental changes, giving preliminary information on putative
actors involved in this specific ammonium-induced response.
Tipologia IRIS:
01 - Articolo su periodico
Elenco autori:
A. Rogato, E. D’Apuzzo, A. Barbulova, S. Omrane, A. Parlati, S. Carfagna, A. Costa, F. Lo Schiavo, S. Esposito, M. Chiurazzi
Link alla scheda completa: