Biologia Plantarum (Aug 2024)

Insights into some key parameters involved in the variability of tolerance to phosphorus deficiency in the legume model Medicago truncatula

  • W. M'SEHLI,
  • H. HOUMANI,
  • N. KALLALA,
  • G. ABID,
  • I. HAMMAMI,
  • H. MHADHBI

DOI
https://doi.org/10.32615/bp.2024.005
Journal volume & issue
Vol. 68, no. 1
pp. 128 – 137

Abstract

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Phosphorus is a key limiting factor for plant growth. Several approaches are developed to mitigate the impact of P shortage on plants and to the selection of crops with high P mobilizing capacity from P-deficient soils. In this work, four Medicago truncatula genotypes (A17, TN8.20, TN1.11, and TN6.18) were compared for their efficiency to cope with P limiting conditions using several criteria. Significant differences between genotypes, P deficiency treatments, and the interaction of genotypes with P deficiency treatments were found. P limitation resulted in an important decrease in shoot biomass, P content, P use efficiency, and photosynthetic parameters. A significant variability was found between the four genotypes, with A17 and TN8.20 being the most tolerant genotypes to P deficiency. This was consistent with the better ability of these genotypes to acidify rhizosphere and stimulate the activity of acid phosphatase and its relative gene (MtPAP1). The expression of P transporter genes (MtPT1, MtPT3, and MtPT5) was induced by P deficiency, however, the overexpression of those genes was more pronounced in tolerant genotypes. Overall, our data indicate that A17 and TN8.20 are more efficient in mobilizing P under limiting conditions and could be cultivated in P-deficient soils as forage crops.

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