Differential expression of trehalose 6-P phosphatase and ascorbate peroxidase transcripts in nodule cortex of Phaseolus vulgaris and regulation of nodule O2 permeability
Bargaz, Adnane; Lazali, Mohamed; Amenc, Laurie; Abadie, Josiane; Ghoulam, Cherki; Farissi, Mohamed; Faghire, Mustapha; Drevon, Jean-Jacques
Although the role of phosphatases and antioxidantenzymes have been documented in phosphorus(P) deficiency tolerance, gene expression differences in thenodules of nitrogen fixing legumes should also affect toleranceto this soil constraint. In this study, root nodules wereinduced by Rhizobium tropici CIAT899 in two Phaseolusvulgaris recombinant inbred lines (RIL); RIL115 (lowP-tolerant) and RIL147 (low P-sensitive) under hydroaeroponicculture with sufficient versus deficient P supply.Trehalose 6-P phosphatase and ascorbate peroxidase transcriptswere localized within nodules in which O2 permeabilitywas measured. Results indicate that differentialtissues-specific expression of trehalose 6-P phosphatase andascorbate peroxidase transcripts within nodules was detectedparticularly in infected zone and cortical cells. UnderP-deficiency, trehalose 6-P phosphatase transcript wasincreased and mainly localized in infected zone and outercortex of RIL115 as compared to RIL147. Ascorbate peroxidase transcript was highly expressed under P-sufficiencyin the infected zone, inner cortex and vascular tracesof RIL115 rather than RIL147. In addition, significant correlationswere found between nodule O2 permeability andboth peroxidase (r = 0.66*) and trehalose 6-P phosphataseenzyme activities (r = 0.79*) under sufficient and deficientP conditions, respectively. The present findings suggest thatthe tissue-specific localized trehalose 6-P phosphatase andascorbate peroxidase transcripts of infected cells and nodulecortex are involved in nitrogen fixation efficiency and arelikely to play a role in nodule respiration and adaptation toP-deficiency.
2013, Volym: 238, nummer: 1, sidor: 107-119
Biochemistry and Molecular Biology
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