The Salicylic Acid and Jasmonic Acid-mediated Different Fate of Nickel Phytoremediation in Two Populations of Alyssum inflatum Nyár

Abstract

The availability of nickel (Ni) in root environment and its absorption by plants is a serious concern for plant products and human health. In stressful conditions, phytohormones such as salicylic acid (SA) and jasmonic acid (JA) play an essential role in modulating the physio-biochemical processes of plants. The current study was conducted to investigate Ni phytoremediation and accumulation potential in the presence of SA (0, 50 and 200 µM) and JA (0, 5 and 10 µM) in two populations of Alyssum inflatum, as a Ni-hyperaccumulator plant, under various Ni doses (0, 100 and 400 µM). Accordingly, by measuring Ni levels in shoot and root, values of bioaccumulation coefficient (BAC), biological concentration factor (BCF) and translocation factor (TF) were calculated to quantify Ni accumulation and translocation between plant organs. Furthermore, the amount of histidine (His), citric acid (CA) and malic acid (MA) as important chelators of Ni in shoots and roots were explored. The results displayed that plant mass and chlorophyll content declined in plants under high Ni concentration, while the amount of MA, CA and His increased. However, SA and JA moderated the harmful impact of Ni on physiological parameters and reduced organic acids and His contents in both populations. The values of phytoremediation indexes in both populations exposed to Ni (400 µM) were above one. In presence of the SA and JA, a decreasing trend was observed in these indexes. Overall, the results indicated that SA and JA could reduce phytoremediation potential in the two populations through different mechanisms.