Influence of Exopolysaccharide-Producing Bacteria and SiO2 Nanoparticles on Proline Content and Antioxidant Enzyme Activities of Tomato Seedlings (Solanum lycopersicum L.) under Salinity Stress

Abstract

A greenhouse experiment was conducted to evaluate the effects regarding inoculation of exopolysaccharide (EPS)-producing bacterium, the extracted EPS and silicon nanoparticles on Solanum lycopersicum L. seeds under salinity stress, in a completely randomized factorial design with three replicates. The inoculated seeds with silicon nanoparticles (8 gr L -1 ), bacterial EPS (0.01 M), and 1 mL of bacterial suspension (1×10 8 CFU mL -1 ) were sown in pots and irrigated with water at different salinity levels (0.3, 2, 4, 6, and 8 dS m -1 ). Results showed that treatment application could enhance salinity tolerance of tomato seeds and improve plant growth so that combined treatments of EPS and silicon nanoparticles (S.E.N), bacteria and silicon nanoparticles (S.B.N), and EPS with silicon nanoparticles and bacteria (S.E.B.N) were the best treatments for plant growth and improvement regarding salinity levels. The mentioned treatments significantly (p<0.01) increased root and shoot fresh or dry weight in comparison to the control sample. In addition, treatments significantly (p<0.01) decreased proline content and antioxidant enzyme activities. Thus, it can be concluded that applied treatments are suitable for agricultural and environmental applications and bring about less damage caused by salinity stress.

Bio-stimulating effect of endophytic Aspergillus flavus AUMC 16068 and its respective ex-polysaccharides in lead stress tolerance of Triticum aestivum plant

“…A study conducted by Naseem et al 124 indicated that Plants inoculated with EPS-producing bacteria showed a higher accumulation of proline, sugars, and free amino acids under water deficit stress. Also, Isfahani et al 125 recorded that the proline content was significantly decreased in tomatoes under salinity stress by the use of EPS, and bacterial treatments.…”

Metagenomic assembled genomes indicated the potential application of hypersaline microbiome for plant growth promotion and stress alleviation in salinized soils

“…This layer also serves as a site for symbiotic association with other microorganisms and nutrient cycling ( 55 ). EPS also aggregates soil particles together, enhances the water absorption capacity of the soil, quorum sensing and maintains the diversity of microorganisms in high salinity conditions ( 56 ). The stressed conditions stimulate the generation of reactive oxygen species (ROS) both in microbes and plants.…”

"Plant Mediated Green Synthesis of Nanoparticles and their Role in Mitigation of Abiotic Stress in Crop Plants: A Review"

“…Its small size, large surface area, easy absorbance/ penetration and the ease of finding the target site has given it an edge over the other conventional methods employed to overcome stress related problems. The positive response shown by a range of crop species under varying stress conditions like high salinity [302][303][304][305][306][307][308][309][310][311][312][313][314][315], presence of heavy metals, extreme temperatures, and drought conditions, subsequent upon nanoparticle treatment, underpins the positive role played by the nanoparticles in alleviating stress induced complications. Although nanoparticles are being widely used, its mechanism of action is still not yet clear.…”