Gain-of-function receptor-like kinase for enhanced pathogen resistance in brassica napus

Overview

This solution centres on a gain-of-function allele of a receptor-like kinase originally identified in Arabidopsis thaliana. A mutation in the kinase domain introduces a regulatory amino acid that renders the kinase hyperactive, leading to constitutive induction of pathogen defence genes. In controlled inoculation trials with Fusarium oxysporum f. sp. conglutinans, 65% of wild-type plants died after 20 days compared with only 18% of plants carrying the gain-of-function allele, a statistically significant improvement in survival.

The proposed next stage is to translate this resistance mechanism into Brassica napus, a commercially important oilseed crop affected by soil-borne vascular pathogens. Because constitutive expression of the hyperactive kinase has detrimental effects on plant fitness, the gene will be placed under an inducible promoter so that defence activation can be triggered on demand.

Technical specifications

Key features:

• A single gain-of-function mutation in the kinase domain that produces a hyperactive receptor-like kinase
• Constitutive upregulation of native defence-response genes, enabling broad-spectrum readiness against soil-borne pathogens
• Demonstrated efficacy against Fusarium oxysporum, a major vascular wilt pathogen, in Arabidopsis with 65% versus 18% mortality at 20 days post-inoculation
• An inducible promoter strategy designed to avoid the fitness penalties associated with constant kinase expression in the crop
• Planned generation of transgenic Brassica napus lines followed by controlled pathogen-challenge assays to confirm translation of resistance

Technology readiness level

The Arabidopsis gain-of-function allele has been validated at the laboratory scale through replicated, randomised inoculation experiments with strong statistical support. Translational work in Brassica napus is at an early stage: transgenic line generation, controlled-environment cultivation, and pathogen assays are planned but not yet funded. The current readiness level corresponds to proof-of-concept in a model species, with crop-level validation pending approximately one year of additional development once resources are secured.