Hydrogen sulphide alleviates cadmium stress in <i>Trigonella foenum‐graecum</i> by modulating antioxidant enzymes and polyamine content
Sumera Javad, Anis Ali Shah, Musarrat Ramzan, Rehana Sardar, Talha Javed, Arwa Abdulkreem AL‐Huqail, Hayssam M. Ali, Ozair Chaudhry, Nasim Ahmad Yasin, Shakil Ahmed, R. A. Hussain, Iqtidar Hussain
Abstract
ABSTRACT Cadmium (Cd) toxicity reduces growth and yield of crops grown in metal‐polluted sites. Research was conducted to estimate the potential of hydrogen sulphide (H 2 S) to mitigate toxicity caused by Cd in fenugreek seedlings ( Trigonella foenum‐graecum L.). Different concentrations of CdCl 2 (Cd1—1 mM, Cd2—1.5 mM, Cd3—2mM) and H 2 S (HS1—100 µM, HS2—150 µM, HS3—200 µM) were assessed. Seeds of fenugreek were primed with sodium hydrosulphide (NaHS), as H 2 S donor. Seedlings growing in Cd‐spiked media treated with H 2 S were harvested after 2 weeks. Cd stress affected growth of fenugreek seedlings. Cd toxicity decreased leaf relative water content (LRWC), intercellular CO 2 concentration, net photosynthesis, stomatal conductance and transpiration. However, application of H 2 S significantly improved seedling morphological attributes by increasing the activity of antioxidant enzymes, i.e . APX, CAT and SOD, in Cd‐contaminated soil. H 2 S treatment also regulated phenolic and flavonoid content. H 2 S‐induced biosynthesis of spermidine (Spd) and putrescine (Put) could account for the enhancement of growth and physiological performance of fenugreek seedlings under Cd stress. H 2 S treatment also reduced H 2 O 2 production (38%) and electrolyte leakage (EL, 51%) in seedlings grown in different concentrations of Cd. It is recommended to evaluate the efficacy of H 2 S in alleviating Cd toxicity in other crop plants.