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ARS Home » Midwest Area » Wooster, Ohio » Application Technology Research » Research » Publications at this Location » Publication #415576
Research Project: Sustainable Production and Pest Management Practices for Nursery, Greenhouse, and Protected Culture Crops

Location: Application Technology Research

Title: Transient Expression of Nicotiana tabacum Silicon-Induced Histidine-Rich defensins in N. benthamiana limits necrotic lesion development caused by phytopathogenic fungi

Author
item MUHINDI, STEPHEN - University Of Toledo
item ZELLNER, WENDY - University Of Toledo
item Marzano, Shin-Yi
item Boldt, Jennifer
item LEISNER, SCOTT - University Of Toledo

Submitted to: Phytopathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/24/2024
Publication Date: 1/9/2025
Citation: Muhindi, S., Zellner, W., Marzano, S.L., Boldt, J.K., Leisner, S. 2025. Transient Expression of Nicotiana tabacum Silicon-Induced Histidine-Rich defensins in N. benthamiana limits necrotic lesion development caused by phytopathogenic fungi . Phytopathology. 115:35-43. https://doi.org/10.1094/PHYTO-05-24-0162-R.
DOI: https://doi.org/10.1094/PHYTO-05-24-0162-R

Interpretive Summary: Growers lack effective genetic tools to manage losses caused by fungal pathogens such as Botrytis cinerea and Sclerotinia sclerotiorum because of a lack of resistance to the pathogen in germplasm. This necessitates the identification of alternative sources of resistance for the disease. Silicon supplementation delayed the infection of B. cinerea and S. sclerotiorum. Furthermore, overexpressing silicon responsive defensins in Nicotiana tabacum resulted in high antifungal activities against B. cinerea and S. sclerotiorum, indicating that these small proteins are promising for development as protein-based fungicides.

Technical Abstract: Silicon (Si) supplementation permits plants to better deter infection. Supplementing hydroponically-propagated Nicotiana tabacum with 1 mM potassium silicate (K2SiO3) delayed infection of detached leaves by both Botrytis cinerea and Sclerotinia sclerotiorum. One mM K2SiO3 was not directly toxic to either fungus, suggesting that the nutrient elicits an antimicrobial response in plants. Previously, a family of Si-induced genes was identified in N. tabacum. These genes were members of the Solanaceous Histidine-Rich Defensin (HRD) superfamily and were termed NtHRD1s (the first identified family of Nicotiana tabacum Histidine-Rich Defensins). Defensins were originally identified to participate in innate immunity. Thus, the NtHRD1s were tested for antimicrobial effects on plant pathogens. Transient expression of NtHRD1 genes within Nicotiana benthamiana leaves inhibited the growth of B. cinerea and S. sclerotiorum. Thus, the NtHRD1s may be an additional Si-responsive factor conferring beneficial effects on plants.