The Activity of Nodules of the Supernodulating Mutant Mt(sunn) Is not Limited by Photosynthesis under Optimal Growth Conditions

Cabeza, RA; Lingner A.; Liese R.; Sulieman S.; Senbayram, M; Trankner, M; Dittert K.; Schulze, J

Abstract

Legumes match the nodule number to the N demand of the plant. When a mutation in the regulatory mechanism deprives the plant of that ability, an excessive number of nodules are formed. These mutants show low productivity in the fields, mainly due to the high carbon burden caused through the necessity to supply numerous nodules. The objective of this study was to clarify whether through optimal conditions for growth and CO2 assimilation a higher nodule activity of a supernodulating mutant of Medicago truncatula (M. truncatula) can be induced. Several experimental approaches reveal that under the conditions of our experiments, the nitrogen fixation of the supernodulating mutant, designated as sunn (super numeric nodules), was not limited by photosynthesis. Higher specific nitrogen fixation activity could not be induced through short-or long-term increases in CO2 assimilation around shoots. Furthermore, a whole plant P depletion induced a decline in nitrogen fixation, however this decline did not occur significantly earlier in sunn plants, nor was it more intense compared to the wild-type. However, a distinctly different pattern of nitrogen fixation during the day/night cycles of the experiment indicates that the control of N-2 fixing activity of the large number of nodules is an additional problem for the productivity of supernodulating mutants.

Más información

Título según WOS: The Activity of Nodules of the Supernodulating Mutant Mt(sunn) Is not Limited by Photosynthesis under Optimal Growth Conditions
Título según SCOPUS: The activity of nodules of the supernodulating mutant Mtsunn is not limited by photosynthesis under optimal growth conditions
Título de la Revista: INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
Volumen: 15
Número: 4
Editorial: MDPI Open Access Publishing
Fecha de publicación: 2014
Página de inicio: 6031
Página final: 6045
Idioma: English
DOI:

10.3390/ijms15046031

Notas: ISI, SCOPUS