Foliar spray and seed priming of titanium dioxide nanoparticles and their impact on the growth of tomato, defense enzymes and some bacterial and fungal diseases

Abstract

Bacterial and fungal pathogens are major constraints in successful cultivation of tomato resulting into rigorous yield losses. The impact of titanium dioxide nanoparticles (TiO₂ NPs) on bacteria, i.e. Pseudomonas syringae pv. tomato, Xanthomonas campestris pv. vesicatoria, Pectobacterium carotovorum subsp. carotovorum and Ralstonia solanacearum and fungi Fusarium oxysporum f. sp. lycopersici and Alternaria solani and on the growth of tomato, chlorophyll, carotenoid contents, proline and defense enzymes viz., superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX) and phenylalanine ammonia lyase (PAL) activities were determined. TiO₂ NPs were applied at 0.10 mL·L⁻¹ and 0.20 mL·L⁻¹concentration as foliar spray and seed priming. Inoculation of tomato with either of these pathogens reduced plant growth, chlorophyll and carotenoid contents, but increased proline and activities of SOD, CAT, APX and PAL. Maximum increase in plant growth, chlorophyll, carotenoid, proline, SOD, CAT, APX and PAL, and reduction in disease indices was observed at foliar spray with 0.20 mL·L⁻¹ TiO₂ NPs, followed by seed priming. Use of 0.10 mL·L⁻¹ NPs as seed priming was less effective. Scanning electron microscopy revealed the absorption of TiO₂ NPs by trichomes, stomata and seed surface. Foliar spray with 0.20 mL·L⁻¹ TiO₂ NPs was useful in increasing plant growth and provided substantial management of bacterial and fungal diseases of tomato.

Keywords:

• Diseases indices
• foliar spray
• management
• pathogens
• seed priming

Acknowledgement

The first author thanks Aligarh Muslim University and University grants Commission New Delhi for the award of University Research Fellowship.

Author’s contribution

AP conducted the experiments, analyzed the data, and prepare rough draft of the manuscript. ZAS designed the experiments, rewrite the manuscript and supervised the overall work.

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There is no other supportive data with this manuscript.

Consent for publication

Both authors give consent for the publication.

Disclosure statement

No potential conflict of interest was reported by the authors.

Ethical approval and consent to participate

This study does not contain any studies with human or animal subjects and informed consent is not applicable.

Additional information

Funding

No special funding was received for this study.