Plant Growth-Promoting Bacteria (PGPBs) and Copper (II) Oxide (CuO) Nanoparticle Ameliorates DNA Damage and DNA Methylation in Wheat (Triticum Aestivum L.) Exposed to NaCl Stress

Abstract

Wheat is the second important cereal crop worldwide due to nutritional composition and role in meeting daily energy needs. Salinity is an abiotic stress factor that restricts crop productivity through influencing plant growth and development in arid and semi-arid regions. Nanomaterials and plant growth promoting bacteria (PGPBs) can be used in many different areas of agriculture for different purposes. In this study, changes in cytosine methylation and DNA damage levels in wheat (Triticum aestivum L.) exposed to salt stress (250 mM NaCl) were determined and possible preventive effects of copper (II) oxide nanoparticles (0, 50 and 100 mg/L; CuO-Nps > 100 nm) and plant growth promoting bacteria (no bacteria, Bacillus subtilis, Lactobacillus casei, Bacillus pumilis; PGPBs) treatments were investigated. Changes in cytosine methylation were analyzed by Coupled Restriction Enzyme Digestion-iPBS (CRED-iPBS) and genotoxic influences and genomic stability was analyzed with the aid of inter-primer binding site (iPBS) primers. Application of 250 mM NaCl remarkably increased polymorphism rate of iPBS profile. Besides, relieve effect of PGPBs with CuO-NPs was observed against adverse effect of 250 mM NaCl stress. The genomic template stability values clearly increased with PGPBs with CuO-NPs treatments, particularly Lactobacillus casei with 100 mg/L of CuO-Nps. In addition, DNA hypo-methylation was observed in all treatments. As a conclusion, PGPBs with CuO-NPs treatments showed a strong anti-genotoxic effect against NaCl stress and they could be used as an alternative molecule to alleviate genetic impairment in wheat under NaCl stress.