# Transgenic Tobacco Plants Expressing Synthetic Peptides: A Functional and Structural Analysis for Pathogen Resistance

**Authors:** Karishma Biswas, Sudipta Mitra, Dibakar Roy, Sanhita Roy, Dibakar Sarkar, DeokHyun Son, Rohit Das, Anuradha Roy, Dulal Senapati, Humaira Ilyas, A. Harikishore, Ranjit Biswas, Suman Chakrabarty, DongKuk Lee, Indranil Biswas, Sudipto Saha, Pallob Kundu, Anirban Bhunia

PMC · DOI: 10.1111/pbi.70287 · 2025-09-15

## TL;DR

Scientists engineered tobacco plants to produce synthetic peptides that protect against bacteria without harming the plant or the environment.

## Contribution

The study demonstrates that VR18 and KG18 peptides can be transgenically expressed in tobacco to confer pathogen resistance without affecting plant health.

## Key findings

- VR18 and KG18 peptides showed selective antibacterial activity against plant and animal pathogens.
- Transgenic tobacco plants expressing VR18 and KG18 resisted Pseudomonas syringae without metabolic disruption.
- The peptides' structure was analyzed using NMR to understand their membrane-disrupting function.

## Abstract

The emergence of multidrug‐resistant pathogens poses a serious threat to human health and agriculture. Current antimicrobial strategies against phytopathogens are often ineffective, failing to ensure food security while contributing to environmental pollution. Synthetic antimicrobial peptides (AMPs) offer a promising alternative due to their broad‐spectrum activity and potential for recombinant production. In this study, we investigated the antibacterial potential of two synthetic peptides, VR18 and KG18, against animal as well as plant phytopathogens. Both peptides showed selective binding to bacterial membranes, while exhibiting no toxicity or allergenicity in animal cells. Using solution‐state NMR, we explored how their structure relates to their function in disrupting bacterial membranes. When expressed transgenically in 
Nicotiana tabacum
, VR18 and KG18 conferred resistance to 
Pseudomonas syringae
 pv. tabaci—a significant plant pathogen—without interfering with the plant's normal stress responses or metabolic activity. These results underscore the potential of AMPs as a sustainable, in vivo alternative to traditional antimicrobials in agriculture and open the door to broader applications in managing phytopathogenic threats.

Peptide Power: VR18 & KG18 Shield Tobacco from Bacterial Attack. A schematic shows how antimicrobial peptides VR18 and KG18 fight Pseudomonas syringae—bursting bacterial membranes and boosting disease resistance in transgenic tobacco, without harming plant health.

## Linked entities

- **Proteins:** l(2)49Fm (lethal (2) 49Fm)
- **Species:** Nicotiana tabacum (taxon 4097), Pseudomonas syringae (taxon 317)

## Full-text entities

- **Diseases:** toxicity (MESH:D064420)
- **Chemicals:** KG18 (-)
- **Species:** Homo sapiens (human, species) [taxon 9606], Nicotiana tabacum (American tobacco, species) [taxon 4097]

## Figures

9 figures with captions in the complete paper: https://tomesphere.com/paper/PMC12906832/full.md

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Source: https://tomesphere.com/paper/PMC12906832