Expression of a phosphate-starvation inducible fructose-1,6-bisphosphatase gene in common bean nodules correlates with phosphorus use efficiency.
While increased P-hydrolysing acid phosphatases (APase) activity in bean nodules is well documented under phosphorus (P) limitation, gene expression and subcellular localization patterns within the N2-fixing nodule tissues are poorly understood. The aim of this research was to track the enzyme activity along with the intra-nodular localization of fructose-1,6-bisphosphatase (FBPase), and its contribution to P use efficiency (PUE) under symbiotic nitrogen fixation (SNF) in Phaseolus vulgaris. The FBPase transcript were localized in situ using RT-PCR and the protein activity was measured in nodules of two contrasting recombinant inbred lines (RILs) of P. vulgaris, namely RILs 115 (P-efficient) and 147 (P-inefficient), that were grown under sufficient versus deficient P supply. Under P-deficiency, higher FBPase transcript fluorescence was found in the inner cortex as compared to the infected zone of RIL115. In addition, both the specific FBPase and total APase enzyme activities significantly increased in both RILs, but to a more significant extent in RIL115 as compared to RIL147. Furthermore, the increased FBPase activity in nodules of RIL115 positively correlated with higher use efficiency of both the rhizobial symbiosis (23%) and P for SNF (14% calculated as the ratio of N2fixed per nodule total P content). It is concluded that the abundant tissue-specific localized FBPase transcript along with induced enzymatic activity provides evidence of a specific tolerance mechanism where N2-fixing nodules overexpress under P-deficiency conditions. Such a mechanism would maximise the intra-nodular inorganic P fraction necessary to compensate for large amount of P needed during the SNF process.
Faculté des Sciences de la Nature et de la Vie & des Sciences de la Terre, Université Djilali Bounaama de Khemis Miliana, Route Theniet El Had, Soufay, 44225 Ain Defla, Algeria; Institut National de la Recherche Agronomique, UMR Eco&Sols, Ecologie Fonctionnelle & Biogéochimie des Sols et Agroécosystèmes, INRA-IRD-CIRAD-SupAgro, Place Pierre Viala, 34060 Montpellier, France. Electronic address: m.lazali@yahoo.fr.
Mohamed
M
Lazali
Swedish University of Agricultural Sciences, Department of Biosystems and Technology, PO Box 103, SE-230 53 Alnarp, Sweden.
Adnane
A
Bargaz
Faculté des Sciences de la Nature et de la Vie & des Sciences de la Terre, Université Djilali Bounaama de Khemis Miliana, Route Theniet El Had, Soufay, 44225 Ain Defla, Algeria.
Samira
S
Brahimi
Institut National de la Recherche Agronomique, UMR Eco&Sols, Ecologie Fonctionnelle & Biogéochimie des Sols et Agroécosystèmes, INRA-IRD-CIRAD-SupAgro, Place Pierre Viala, 34060 Montpellier, France.
Laurie
L
Amenc
Institut National de la Recherche Agronomique, UMR Eco&Sols, Ecologie Fonctionnelle & Biogéochimie des Sols et Agroécosystèmes, INRA-IRD-CIRAD-SupAgro, Place Pierre Viala, 34060 Montpellier, France.
Josiane
J
Abadie
Institut National de la Recherche Agronomique, UMR Eco&Sols, Ecologie Fonctionnelle & Biogéochimie des Sols et Agroécosystèmes, INRA-IRD-CIRAD-SupAgro, Place Pierre Viala, 34060 Montpellier, France.
Jean Jacques
JJ
Drevon
D006597:Fructose-Bisphosphatase / Q000235:genetics* / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D009586:Nitrogen Fixation; D027805:Phaseolus / Q000166:cytology / Q000201:enzymology* / Q000235:genetics / Q000382:microbiology; D010758:Phosphorus / Q000378:metabolism*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D012231:Rhizobium / Q000502:physiology*; D053204:Root Nodules, Plant / Q000166:cytology / Q000201:enzymology / Q000235:genetics / Q000382:microbiology; D013559:Symbiosis
D010940:Plant Proteins; D010758:Phosphorus; D006597:Fructose-Bisphosphatase
Fructose-1,6-bisphosphatase; Legumes; Nodule; Phaseolus vulgaris; Phosphorus; Symbiosis; Transcript