Role of acid phosphatase and enzymatic and non-enzymatic antioxidant systems in tolerance of alfalfa (Medicago sativa L.) populations to low phosphorus availability
Received: April 27th, 2022 ; Accepted: July 25th, 2022 ; Published: October, 12th, 2022 ;
Correspondence: [email protected] study aims at evaluating the tolerance of four alfalfa (Medicgao sativa L.)
populations to low phosphorus (P) in rooting medium. The experiment was carried out under
controlled conditions. The seedlings of 15 old days were subjected to P deficiency using
Ca3HPO4, insoluble form and P sufficiency using KH2PO4, as soluble form, at a final
concentration of 250 μmol P plant−1. week−1. After 60 days P deficit, several agro–physiological
and biochemical traits were measured and determined in both conditions. The obtained results
indicated that the P–starvation significantly (P < 0.001) reduced the agroeconomic traits
evaluated such as plant dry weight and leaf area. The root and shoot P contents were found
(P < 0.001) decreased by low–P availability in the rooting medium. This constraint induced
significant (P < 0.001) increase in phosphatase acid activity and caused lipid peroxidation and
oxidative damage to cells, evaluated through malondialdehyde and hydrogen peroxide contents.
Our results showed also, that low P availability significantly (P < 0.001) increased the enzymatic
antioxidant responses reflected by the activities of superoxide dismutase (SOD), guaiacol
peroxidase and catalase. The non-enzymatic antioxidant molecule such as proline and total
polyphenols were found significantly increased in alfalfa stressed plants. The behavior of alfalfa
populations tested was significantly different (P >0.05). The OL population was found to be the
least affected and the DEM was most sensitive one, whereas the populations TATA and RICH
showed a moderate tolerance. Our study advises that the tolerance of Moroccan alfalfa
populations to low P–availability was associated with increased acid phosphate activity and
ability to induce enzymatic and non-enzymatic antioxidant responses leading to cell
detoxification from reactive oxygen species (ROS)
