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Kharbech O, Sakouhi L, Mahjoubi Y, Ben Massoud M, Debez A, Zribi OT, Djebali W, Chaoui A, Mur LAJ. Nitric oxide donor, sodium nitroprusside modulates hydrogen sulfide metabolism and cysteine homeostasis to aid the alleviation of chromium toxicity in maize seedlings (Zea mays L.). JOURNAL OF HAZARDOUS MATERIALS 2022; 424:127302. [PMID: 34583165 DOI: 10.1016/j.jhazmat.2021.127302] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Revised: 09/03/2021] [Accepted: 09/17/2021] [Indexed: 05/12/2023]
Abstract
The current research aimed to assess the protective role of nitric oxide (NO) against chromium (Cr) toxicity in maize seedlings. Chromium (200 µM) lowered osmotic potential in epicotyls and mostly in radicles (by 38% and 63%, respectively) as compared to the control. Sodium nitroprusside (SNP, NO donor) restored seedling biomass (+90% for both organs) and water potential, whereas application of Nω-nitro-L-arginine methylester (L-NAME, a NOS inhibitor) increased sensitivity to Cr. SNP suppressed Cr-triggered proline accumulation by inhibiting Δ1-pyrroline-5-carboxylate synthetase activity and stimulating proline dehydrogenase activity, leading to glutamate over-accumulation (~30% for both organs). Cr stimulated cysteine metabolism and this was further enhanced by SNP which stimulated serine acetyl-transferase and O-acetylserine (thiol) lyase activities. This was followed by an increase in endogenous hydrogen sulfide (H2S) generation by up-regulating L-cysteine desulfhydrase (+205%), D-cysteine desulfhydrase (+150%) and cyanoalanine synthase (+65%) activities in radicles compared to Cr-treatments plants. These positive effects were reduced in L-NAME compared to control. Combined Cr+SNP affected the levels of compounds involved in glutathione metabolism (γ-glutamyl-cysteinyl, γ-glutamyl-cysteinyl-clycine, γ-cysteinyl-glycine, and glycine.). All together, our findings indicate that NO and elicited cellular H2S act synergistically to alleviate Cr stress in maize seedlings by influencing a metabolic interplay between cysteine, proline, and glutathione.
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Affiliation(s)
- Oussama Kharbech
- University of Carthage, Faculty of Sciences of Bizerte, LR18ES38 Plant Toxicology and Environmental Microbiology, 7021 Zarzouna, Tunisia; Aberystwyth University, Institute of Biological, Environmental and Rural Sciences, Penglais Campus, SY23 2DA, Aberystwyth, Wales, UK.
| | - Lamia Sakouhi
- University of Carthage, Faculty of Sciences of Bizerte, LR18ES38 Plant Toxicology and Environmental Microbiology, 7021 Zarzouna, Tunisia
| | - Yethreb Mahjoubi
- University of Carthage, Faculty of Sciences of Bizerte, LR18ES38 Plant Toxicology and Environmental Microbiology, 7021 Zarzouna, Tunisia
| | - Marouane Ben Massoud
- University of Carthage, Faculty of Sciences of Bizerte, LR18ES38 Plant Toxicology and Environmental Microbiology, 7021 Zarzouna, Tunisia; School of Biological, Earth & Environmental Sciences, University College Cork, Distillery Fields, North Mall, Cork, Ireland T23 N73K, Ireland
| | - Ahmed Debez
- Centre of Biotechnology of Borj-Cedria (CBBC), Laboratory of Extremophile Plants (LPE), BP 901, Hammam-Lif 2050, Tunisia
| | - Ons Talbi Zribi
- Centre of Biotechnology of Borj-Cedria (CBBC), Laboratory of Extremophile Plants (LPE), BP 901, Hammam-Lif 2050, Tunisia
| | - Wahbi Djebali
- University of Carthage, Faculty of Sciences of Bizerte, LR18ES38 Plant Toxicology and Environmental Microbiology, 7021 Zarzouna, Tunisia
| | - Abdelilah Chaoui
- University of Carthage, Faculty of Sciences of Bizerte, LR18ES38 Plant Toxicology and Environmental Microbiology, 7021 Zarzouna, Tunisia
| | - Luis Alejandro Jose Mur
- Aberystwyth University, Institute of Biological, Environmental and Rural Sciences, Penglais Campus, SY23 2DA, Aberystwyth, Wales, UK
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