Biology subjects

Sindalovskaya, M.

Publications and source records attributed to Sindalovskaya, M..

5 recordsLinked to original sources

bioRxiv2026

Broad-spectrum polerovirus resistance conferred by a potato TIR-NLR immune receptor

Potato leafroll virus (PLRV) is an economically important viral disease of potato (S. tuberosum). Genetic resistance to this phloem-limited virus is rare, and no cloned resistance (R) genes have been reported. Rladg confers resistance to PLRV in an Andean potato landrace, LOP-868 (Velasquez et al. 2007). We identified the functional Rladg gene as a homolog of the tomato TIR-NLR-encoding Bs4. Rladg interacts with the serine protease domain of the PLRV protein P1, which is essential for virus replication. This recognition is independent of the proteases enzymatic activity, and the Rladg immune receptor oligomerizes upon direct association with the protease. Like PLRV, many poleroviruses contain a serine protease. Despite their diverse amino acid sequences, these proteases are predicted to share similar structures. Rladg recognizes all ten tested polerovirus proteases, suggesting a conserved structural recognition mechanism. We propose that Rladgs broad recognition capacity could enable resistance to poleroviruses in many crop species. Rladg is the first R-gene reported to confer resistance to a phloem-limited pathogen and could provide enhanced resistance to many economically important poleroviruses.

plant biology↗

bioRxiv2025

Diverse haplotypes at a complex Solanum americanum locus confer resistance to Phytophthora infestans and P. capsici

Plants encounter diverse pathogens and have evolved a two-layered innate immune system to detect pathogen molecules and activate defense mechanisms that restrict infection. Most cloned plant Resistance (R) genes encode NLR immune receptors. NLR genes are often found in clusters of paralogs with sequence and copy number variation; whether these NLR clusters evolve in response to single or multiple pathogens has been unclear. We report here the isolation of a Phytophthora capsici resistance gene, Rpc2, along with a novel P. infestans resistance gene, Rpi-amr5, from two Solanum americanum accessions. These orthologous genes reside in the Rpi-amr1 cluster, which has previously been associated with resistance to P. infestans. By screening RXLR effector libraries of P. infestans and P. capsici, we identified multiple effectors recognized by both NLRs. Our findings highlight the complexity of NLR clusters and evolution driven by interactions with multiple pathogens. This work will underpin efforts to elevate resistance against Phytophthora pathogens and enhances our understanding of NLR evolution.

plant biology↗

bioRxiv2025

Co-transcriptional splicing changes combine with reduced productive transcription initiation for cold-induced repression of FLC

The Arabidopsis floral repressor locus FLC is epigenetically silenced during winter cold to align flowering with spring. During weeks of cold exposure, FLC transcription is progressively reduced both by transcriptional repression mediated by FLC antisense transcription, and epigenetic silencing implemented through a Polycomb-mediated epigenetic switch. In the warm, FLC is transcriptionally repressed by coordinated changes in transcription initiation and RNA PolII speed in a mechanism involving proximal termination. Whether similar mechanisms contribute to the cold-induced FLC transcriptional repression is unknown. Here, we combine mathematical modelling and transcription profiling to investigate FLC transcriptional changes during the cold. We find different dynamics of spliced and unspliced transcripts during cold exposure with only a small change in PolII speed. We also show that, unlike short-term cold, long-term cold temperatures drive an increase in splicing rates while simultaneously reducing productive transcription at FLC. This process is influenced by antisense COOLAIR transcription but does not rely on proximal COOLAIR termination. Cold-induced transcriptional repression of FLC thus involves a decoupling of changes in productive transcription initiation from PolII speed and rates of co-transcriptional splicing, a different mechanism to that repressing FLC in the warm.

molecular biology↗

bioRxiv2025

Recognition-dependent activation of the RRS1-R/RPS4 immune receptor complex

The Arabidopsis TIR-NLR immune receptors RPS4 and RRS1 function together to enable recognition of multiple effector proteins including AvrRps4 and PopP2. We show here that both in the presence and absence of effector, RPS4 and RRS1 form an oligomer that does not change in size upon effector provision. Oligomer formation involves interactions between the RPS4 and RRS1 TIR domains and requires nucleotide binding capacity in RPS4. RPS4 mutants that lose TIR domain NADase activity abrogate immune activation but retain oligomerization. A cysteine residue in the RPS4 LRR domain contributes to oligomer stabilization. We propose that upon effector recognition, conformational changes in the complex relieve inhibition of RPS4 TIR domains by RRS1 TIR domains, enabling proximity between RPS4 TIR domains to create NADase activity.

plant biology↗

bioRxiv2022

The Solanum americanum pangenome and effectoromics reveal new resistance genes against potato late blight

Late blight caused by the oomycete pathogen Phytophthora infestans continues to cause major worldwide losses in potato and tomato. Most accessions of Solanum americanum, a globally distributed, wild Solanaceae plant, are highly resistant to late blight. We generated high-quality reference genomes of four S. americanum accessions, re-sequenced 52 accessions, and we defined variation in the NLR immune receptor genes (the S. americanum NLRome). We further screened for variation in recognition of [~]315 P. infestans RXLR effectors in 52 S. americanum accessions. Using these genotypic and phenotypic data, we cloned three novel NLR-encoding genes Rpi-amr4, Rpi-amr16 and Rpi-amr17, and determined their corresponding RXLR effector genes Avramr4 (PITG_22825), Avramr16 (PITG_02860) and Avramr17 (PITG_04373) from P. infestans. These genomic resources and methodology will support efforts to convert potato into a "nonhost" of late blight and can be applied to diseases of other crops.

plant biology↗