Thaumatin-Like Protein Functions in Plant Stress Responses

Thaumatin-like proteins (TLPs) are small, cysteine-rich members of the pathogenesis-related protein family 5 that accumulate in the extracellular space of plant tissues. They play a dual role in defending against fungal and bacterial pathogens through antifungal activity—often involving glycoside hydrolase-like mechanisms—and in mediating tolerance to abiotic stresses such as cold, drought and salinity. TLPs are typically induced by phytohormones including salicylic acid, jasmonic acid and ethylene, and their promoters contain cis-acting elements responsive to environmental signals. Structurally, TLPs share a conserved acidic cleft crucial for binding carbohydrate substrates or for disrupting microbial membranes. The TLP gene family has undergone extensive expansion and diversification in land plants, yielding paralogues with distinct expression patterns in roots, leaves, seeds and other organs. By integrating defence signalling pathways and directly targeting pathogen cell walls, TLPs contribute to systemic acquired resistance and to local stress adaptation, making them prime targets for engineering stress-resilient crops.

Research from Nature Portfolio

Recent studies have functionally characterised a basil-derived TLP whose expression in Arabidopsis enhances resistance to both fungal pathogens and abiotic stresses by up-regulating defence marker genes and improving osmotic tolerance. Another foundational investigation in grapevine demonstrated that specific grape TLP paralogues strengthen immunity against powdery mildew and bacterial pathogens by modulating salicylic acid and jasmonic acid/ethylene signalling, while also influencing stomatal closure and callose deposition during infection.

Thaumatin-Like Protein Functions in Plant Stress Responses publication trend

The graph below shows the total number of articles in thaumatin-like protein functions in plant stress responses across all publications each year (not limited to Nature Index journals).

Technical terms

Thaumatin-like protein (TLP): A plant protein in the PR-5 family with conserved structure and roles in antifungal defence and abiotic stress tolerance.

Pathogenesis-related protein (PR-5): A class of defence proteins induced by pathogens or stress, encompassing TLPs and osmotins.

Apoplast: The network of cell walls and intercellular spaces through which solutes and defence proteins such as TLPs move.

Cis-acting element: A DNA sequence in a gene promoter that binds transcription factors to regulate stress-responsive expression.

Glycoside hydrolase activity: An enzymatic function that degrades carbohydrate polymers, contributing to antifungal mechanisms of certain TLPs.

References

1. Natural SNP Variation in GbOSM1 Promotor Enhances Verticillium Wilt Resistance in Cotton. Advanced Science (2024).
2. Genome-Wide Analyses of Thaumatin-like Protein Family Genes Reveal the Involvement in the Response to Low-Temperature Stress in Ammopiptanthus nanus. International Journal of Molecular Sciences (2023).
3. A thaumatin-like protein of Ocimum basilicum confers tolerance to fungal pathogen and abiotic stress in transgenic Arabidopsis. Scientific Reports (2016).
4. Analysis of the grape (Vitis vinifera L.) thaumatin-like protein (TLP) gene family and demonstration that TLP29 contributes to disease resistance. Scientific Reports (2017).
5. Molecular Characterization Revealed the Role of Thaumatin-Like Proteins of Bread Wheat in Stress Response. Frontiers in Plant Science (2022).