RXLR effectors of Phytophthora infestans: delivery, host targets and immune suppression

A review in Molecular Biology Reports identifies cytoplasmic RXLR effector proteins as major determinants of the pathogenic success of Phytophthora infestans , the pathogen responsible for potato late blight. The article synthesizes current knowledge of how these effectors enter host cells, localise within them, target host processes and interfere with plant immune responses, including pattern-triggered immunity and effector-triggered immunity. RXLR effectors accumulate inside host cells and act on several cellular processes involved in the interaction between pathogen and plant.

The review reports that their targets include transcriptional regulation, post-translational modifications, vesicle trafficking, autophagy, chloroplast-mediated immune signalling and protein stability. Rather than being associated with only one immune pathway, the effectors converge on multiple host cellular systems, reprogramming cellular networks in ways that support pathogen colonisation and disease progression. The available evidence describes this diversity at the level of established target processes; the supplied abstract and preview do not specify the mechanism or contribution of each individual effector.

The review also examines the subcellular localisation of P. infestans RXLR effectors and their relationships with host susceptibility factors. Advances in genomics, structural biology and host–interactor screening have expanded knowledge of effector diversity and helped clarify the molecular mechanisms through which these proteins interact with host components. The resulting picture is that different effectors can influence distinct, yet functionally connected, immune and cell-biological processes, allowing a plant pathogen to suppress resistance across multiple layers of defence.

This publication is a review, not a report of a new experiment, field trial or intervention. It assembles findings from earlier studies rather than presenting a new quantitative assessment of late blight severity. The supplied text does not quantify how much the overall effector repertoire contributes to disease, establish the precise molecular function of every RXLR protein or show whether modifying a particular host target improves resistance in agricultural conditions.

Those limits are important when interpreting the review’s broader conclusion about immune suppression and host manipulation. The practical significance discussed in the review lies in its implications for developing durable resistance strategies against late blight. Understanding the host targets used by RXLR effectors may provide a basis for resistance approaches that account for the pathogen’s capacity to influence several cellular processes at once.

Instead, it identifies effector–host interactions as an area relevant to the pursuit of more durable forms of plant resistance.

Subject of Research: RXLR effector proteins, host targets and immune suppression in the potato late blight pathogen

Article Title: RXLR effectors of Phytophthora infestans: delivery, host targets and immune suppression

Article References: Saini, O., Arora, A., Kaur, A., & Saini, S. (2026). RXLR effectors of Phytophthora infestans: delivery, host targets and immune suppression. Molecular Biology Reports, 53(1), Article 1776. https://doi.org/10.1007/s11033-026-12983-5

Image Credits: AI Generated

DOI: 10.1007/s11033-026-12983-5

Keywords: Phytophthora infestans, late blight, RXLR effectors, plant immunity, host-pathogen interaction, oomycetes, vesicle trafficking, autophagy, chloroplast signalling, protein stability, RXLR, effectors