Titanium dioxide nanoparticles elicited agro-morphological and physicochemical modifications in wheat plants to control Bipolaris sorokiniana

Abstract

The current study involves the biogenesis of titanium dioxide nanoparticles (TiO2 NPs) by using Moringa oleifera Lam. aqueous leaf extract for the reduction of titanium dioxide salt into TiO2 nanoparticles. The biosynthesized TiO2 nanoparticles were observed by using the UV-visible spectrophotometry, SEM, EDX and XRD analytical methods. It was confirmed that the nanoparticles are crystalline and exist in the size range of 10-100 nm. The FTIR analysis confirmed the presence of O-H (hydrogen bonding), N-H (amide), C-C (alkanes) and C-I (Iodo-stretch) functional groups responsible for the stabilization of nanoparticles. Various concentrations (20, 40, 60 and 80 mg/L) of TiO2 NPs were applied exogenously on wheat plants infected with a fungus Bipolaris sorokiniana responsible to cause spot blotch disease at different time intervals. The measurement of disease incidence and percent disease index showed the time-dependent response and 40 mg/L was reported a stable concentration of TiO2 NPs to reduce the disease severity. The effects of biosynthesized TiO2 NPs were also evaluated for agro-morphological (leaf and root surface area, plant fresh and dry weight and yield parameters), physiological (relative water content, membrane stability index and chlorophyll content) and non-enzymatic metabolites (soluble sugar, protein, soluble phenol and flavonoid content) in wheat plants under biotic stress and 40 mg/L concentration of TiO2 NPs was found to be effective to elicit modifications to reduce biotic stress. The current study highlights the significant role of biosynthesized TiO2 NPs in controlling fungal diseases of wheat plants and thus ultimately improving the quality and yield of wheat plants.

Fig 1

Morphological and optical characterization of bio-fabricated TiO₂ NPs (a) UV-visible spectrum (b) SEM image; Inset is showing the particle size distribution histogram (c) Elemental composition analysis (d) XRD analysis.

Fig 2. FTIR spectrum of the TiO₂ NPs.

Fig 3. Disease incidence and percent disease index of the wheat plants inoculated with Bipolaris sorokiniana.

Treatment; T0: Healthy Plants, T1: Plants Infected with Pathogen, T2: 20 mg/L, T3: 40 mg/L, T4: 60 mg/L and T5: 80 mg/L. Note: Different alphabets represent that the results are significantly different (p < 0.05).

Fig 4

Effect of different treatments of TiO₂ NPs on (a) Leaf surface area (b) Root surface area (c) Plant fresh weight and (d) Plant dry weight. Treatment; T0: Healthy Plants, T1: Plants Infected with Pathogen, T2: 20 mg/L, T3: 40 mg/L, T4: 60 mg/L and T5: 80 mg/L. Note: Different alphabets represent that the results are significantly different (p < 0.05).

Fig 5

Effect of different treatments of TiO₂ NPs on (a) Spikes per plant (b) Grains per spike and (c) 100 grains weight. Treatment; T0: Healthy Plants, T1: Plants Infected with Pathogen, T2: 20 mg/L, T3: 40 mg/L, T4: 60 mg/L and T5: 80 mg/L. Note: Different alphabets represent that the results are significantly different (p < 0.05).

Fig 6

Effect of different treatments of TiO₂ NPs on the physiological parameters of wheat plants under spot blotch stress (a) Relative water content (b) Membrane stability index (c) Chlorophyll a content (d) Chlorophyll b content (e) Total chlorophyll content. Treatment; T0: Healthy Plants, T1: Plants Infected with Pathogen, T2: 20 mg/L, T3: 40 mg/L, T4: 60 mg/L and T5: 80 mg/L. Note: Different alphabets represent that the results are significantly different (p < 0.05).

Fig 7

Effect of different treatments of TiO₂ NPs on non-enzymatic parameters of wheat plants under spot blotch stress (a) Total soluble sugar (b) Total proline content (c) Total phenol content (d) Total flavonoid content (e) Total protein content. Treatment; T0: Healthy Plants, T1: Plants Infected with Pathogen, T2: 20 mg/L, T3: 40 mg/L, T4: 60 mg/L and T5: 80 mg/L. Note: Different alphabets represent that the results are significantly different (p < 0.05).