Open Access

ARTICLE

Nitric oxide alleviates cadmium-impeded growth by limiting ROS accumulation in pea seedlings

by EKHLAQUE A. KHAN^1,2,*, HAMDINO M. I. AHMED³, MEENA MISRA¹, PALLAVI SHARMA^1,4, AMARENDRA N. MISRA^1,5, MIRZA HASANUZZAMAN^6,*

1 Department of Life Sciences, Central University of Jharkhand, Ranchi, 835205, India
2 Department of Biotechnology, Chaudhary Bansi Lal University, Bhiwani, 127021, India
3 Horticulture Research Institute (HRI), Agricultural Research Center (ARC), Giza, 12619, Egypt
4 School of Environment and Sustainable Development, Central University of Gujrat, Gandhinagar, 382030, India
5 School of Applied Sciences, Centurion University of Technology and Management, Bhubaneswar, 752050, India
6 Department of Agronomy, Faculty of Agriculture, Sher-e-Bangla Agricultural University, Dhaka, 1207, Bangladesh

* Corresponding Authors: EKHLAQUE A. KHAN. Email: ; MIRZA HASANUZZAMAN. Email:

(This article belongs to the Special Issue: Physiology and Molecular Biology of Plant Stress Tolerance)

BIOCELL 2022, 46(12), 2583-2593. https://doi.org/10.32604/biocell.2022.021732

Received 31 January 2022; Accepted 18 April 2022; Issue published 10 August 2022

Abstract

Cadmium (Cd) causes oxidative stress, which leads to the oxidation of various biomolecules by the production of reactive oxygen species (ROS) to facilitate programmed cell death (PCD). The antioxidant defense system fails to detoxify ROS when it is produced in excess. Nitric oxide (NO), a gaseous free radical and a phytohormone, regulates various physiological processes of plants. Therefore, this work was undertaken to study the effects of the application of exogenous sodium nitroprusside (SNP, a NO donor) on growth parameters, oxidative stress, accumulation of secondary metabolites, and activities of antioxidant enzymes under Cd stress. Mild (50 µM) and severe (200 µM) Cd stress were applied to hydroponically grown pea (Pisum sativum L.) plants with or without 50 µM SNP. Severe Cd stress had a substantial impact on the plants. The effectiveness of NO in reducing Cd-induced negative effects on plant height, fresh weight, dry weight, protein content, nitrite content, nitrate reductase (NR) activity, catalase activity, and peroxidase activity were investigated. Seedling development, protein content, nitrite content, nitrate reductase (NR) activity, antioxidant defense systems disruption, overproduction of reactive oxygen species, and oxidative damage were observed. The antioxidant defense system (catalase and peroxidase activities) was activated by NO, which resulted in lower lipid peroxidation and lower hydrogen peroxide (H₂O₂) levels in Cd-exposed plants. SNP treatment boosted endogenous NO levels and NR activity in Cd-stressed plants while also enhanced proline levels to preserve osmotic equilibrium. The presence of total phenols and flavonoids increased after SNP treatment, indicating that SNP enhanced stress recovery and boosted plant development in Cd-stressed plants.

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