Zinc oxide nanoparticles and Klebsiella sp. SBP-8 alleviates chromium toxicity in Brassica juncea by regulation of antioxidant capacity, osmolyte production, nutritional content and reduction in chromium adsorption

• Published in: Plant physiology and biochemistry Vol. 210; p. 108624
• Main Authors: Shah, Anis Ali, Zafar, Sadia, Usman, Sheeraz, Javad, Sumera, Zaib-un-Nisa, Aslam, Muhammad, Noreen, Zahra, Elansary, Hosam O., Almutairi, Khalid F., Ahmad, Aqeel
• Format: Journal Article
• Language: English
• Published: France Elsevier Masson SAS 01.05.2024
• Subjects: Adsorption; Antioxidants - metabolism; Brassica juncea; Chromium; Chromium - metabolism; Chromium - toxicity; Klebsiella - drug effects; Klebsiella - metabolism; Metal Nanoparticles - chemistry; Microbes; Mustard Plant - drug effects; Mustard Plant - metabolism; Mustard Plant - microbiology; Nanoparticles; Nanoparticles - chemistry; Plants; Soil Pollutants - toxicity; Stress; Zinc Oxide - pharmacology; Nanoparticles; Chromium; Plants; Microbes; Stress; Brassica juncea
• ISSN: 0981-9428; 1873-2690
• DOI: 10.1016/j.plaphy.2024.108624

Heavy metals are one of the most damaging environmental toxins that hamper growth of plants. These noxious chemicals include lead (Pb), arsenic (As), nickel (Ni), cadmium (Cd) and chromium (Cr). Chromium is one of the toxic metal which induces various oxidative processes in plants. The emerging role of nanoparticles as pesticides, fertilizers and growth regulators have attracted the attention of various scientists. Current study was conducted to explore the potential of zinc oxide nanoparticles (ZnONPs) alone and in combination with plant growth promoting rhizobacteria (PGPR) Klebsiella sp. SBP-8 in Cr stress alleviation in Brassica juncea (L.). Chromium stress reduced shoot fresh weight (40%), root fresh weight (28%), shoot dry weight (28%) and root dry weight (34%) in B. juncea seedlings. Chromium stressed B. juncea plants showed enhanced levels of malondialdehyde (MDA), electrolyte leakage (EL), hydrogen peroxide (H2O2) and superoxide ion (O2• −). However, co-supplementation of ZnONPs and Klebsiella sp. SBP-8 escalated the activity of antioxidant enzymes i.e., superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX) in B. juncea grown in normal and Cr-toxic soil. It is further proposed that combined treatment of ZnONPs and Klebsiella sp. SBP-8 may be useful for alleviation of other abiotic stresses in plants. [Display omitted] •Cr stress reduced growth and physiological attributes of B. juncea.•Cr stress increased MDA, H2O2, EL and O2.•‾ ions, hence imposed oxidative stress in B. juncea.•Co-supplementation of ZnONPs and Klebsiella sp. SBP-8 enhanced gene expression for SOD, CAT, POD and APX enzymes.•Cr stress alleviation in B. juncea is credited to enhanced activity of antioxidant enzymes.