SbDef1 Antimicrobial Peptides for Cation-Tolerant Pathogen Resistance

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Solution Overview

Problem

Existing plant defensins lose antifungal activity at elevated concentrations of mono- and bivalent cations, limiting their effectiveness in transgenic crops, and there is a need for broad-spectrum antimicrobial agents to combat multiple pathogens and prevent resistance development.

Innovation Solution

Recombinant and edited polynucleotides encoding antimicrobial peptides with modified amino acid sequences, linked to heterologous promoters, are introduced into plant genomes to enhance resistance and inhibit a wide range of pathogens, including fungi and oomycetes, using CRISPR/Cas endonuclease-mediated editing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If plant defensins are used as antimicrobial agents, then antifungal activity is achieved, but activity is lost at elevated concentrations of mono- and bivalent cations

Engineering Contradiction:

Improveantifungal activityVSAvoidloss of activity at elevated cation concentrations

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent modifies the amino acid sequence of plant defensins by substituting specific residues (e.g., replacing cysteine with serine or threonine at positions 1-10) to alter the peptide's interaction with cations. This parameter change in sequence composition maintains antifungal activity while reducing sensitivity to elevated mono- and bivalent cation concentrations, resolving the contradiction between reliability and cation-induced activity loss.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If existing antimicrobial agents are used to control plant pathogens, then specific pathogens are inhibited, but resistance development occurs and multiple pathogens cannot be simultaneously controlled

Engineering Contradiction:

Improvepathogen controlVSAvoidbroad-spectrum effectiveness

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent creates chimeric peptides combining defensin core structures with antimicrobial peptide (AMP) motifs from diverse sources (e.g., magainin, cecropin, dermabin). These hybrid peptides exhibit broad-spectrum activity against multiple pathogen types including fungi, oomycetes, and bacteria, while the modular design allows tuning of specificity to prevent resistance development, achieving both reliability and versatility.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent employs composite peptide structures combining different functional domains: a defensin core providing structural stability and cation interaction, coupled with AMP motifs providing diverse antimicrobial mechanisms. This composite architecture enables simultaneous control of multiple pathogens through distinct modes of action, preventing resistance while maintaining broad-spectrum effectiveness.

Inventive Principle:

Principle #40Composite materials

Data Source

PatentUS20250369010A1Antimicrobial peptides

Publication Date: 2025.12.04 DONALD DANFORTH PLANT SCI CENT

AI summary

Antimicrobial SbDef1-type peptides and proteins are disclosed along with compositions comprising the SbDef1-type peptides and proteins and transgenic or genetically edited plants or microorganisms that express the SbDef1-type peptides and proteins to inhibit growth of pathogenic microbes. Such SbDef1-type peptides and proteins, compositions, plants, and microorganisms can provide for inhibition of microbial growth.