Biology subjects

Martinez-Anaya, C.

Publications and source records attributed to Martinez-Anaya, C..

3 recordsLinked to original sources

bioRxiv2024

Helper NLR immune protein NRC3 evolved to evade inhibition by a cyst nematode virulence effector

Parasites can counteract host immunity by suppressing nucleotide binding and leucine-rich repeat (NLR) proteins that function as immune receptors. We previously showed that a cyst nematode virulence effector SPRYSEC15 (SS15) binds and inhibits oligomerisation of helper NLR proteins in the expanded NRC1/2/3 clade by preventing intramolecular rearrangements required for NRC oligomerisation into an activated resistosome. Here we examined the degree to which NRC proteins from multiple Solanaceae species are sensitive to suppression by SS15 and tested hypotheses about adaptive evolution of the binding interface between the SS15 inhibitor and NRC proteins. Whereas all tested orthologs of NRC2 were inhibited by SS15, some natural variants of NRC1 and NRC3 are insensitive to SS15 suppression. Ancestral sequence reconstruction combined with functional assays revealed that NRC3 transitioned from an ancestral suppressed form to an insensitive one over 19 million years ago. Our analyses revealed the evolutionary trajectory of coevolution between a parasite inhibitor and its NLR immune receptor target, identifying key evolutionary transitions in helper NLRs that counteract this inhibition. This work reveals a distinct type of gene-for-gene interaction between parasite or pathogen immunosuppressors and host immune receptors that contrasts with the coevolution between AVR effectors and immune receptors.

plant biology↗

bioRxiv2023

The NRC0 gene cluster of sensor and helper NLR immune receptors is functionally conserved across asterid plants

NLR (nucleotide-binding domain and leucine-rich repeat-containing) proteins can form complex receptor networks to confer innate immunity. NRCs are phylogenetically related nodes that function downstream of a massively expanded network of disease resistance proteins that protect against multiple plant pathogens. Here, we used phylogenomic methods to reconstruct the macroevolution of the NRC family. One of the NRCs, we termed NRC0, is the only family member shared across asterid plants, leading us to investigate its evolutionary history and genetic organization. In several asterid species, NRC0 is genetically clustered to other NLRs that are phylogenetically related to NRC-dependent disease resistance genes. This prompted us to hypothesize that the ancestral state of the NRC network is an NLR helper-sensor gene cluster that was present early during asterid evolution. We validated this hypothesis by demonstrating that NRC0 is essential for the hypersensitive cell death induced by its genetically linked sensor NLR partners in four divergent asterid species: tomato, wild sweet potato, coffee and carrot. In addition, activation of a sensor NLR leads to high-order complex formation of its genetically linked NRC0 similar to other NRCs. Our findings map out contrasting evolutionary dynamics in the macroevolution of the NRC network over the last 125 million years from a functionally conserved NLR gene cluster to a massive genetically dispersed network. One-sentence summaryNRC0 gene cluster is functionally conserved across divergent asterid species and predates the massively expanded NRC network.

plant biology↗

bioRxiv2021

Identification of Pectobacterium species isolated from the soft rot of tetecho (Neobuxbaumia tetetzo), a columnar cactus, and associated metagenomics

Neobuxbaumia tetetzo, commonly known as tetecho, is a columnar cactus endemic to Mexico. In the last 15 years, damage has been observed in young and adult plants of N. tetetzo, ranging from chlorotic spots with a wet appearance in early stages to tissue necrosis in advanced stages and finally the death of the plant; Pectobacterium brasiliense is the causal agent of the damages. Disease progression may be delayed or accelerated by the involvement of other bacteria, either pathogenic or endophytic, at the site of infection. Our goal was to confirm the presence of Pectobacterium brasiliense, in the soft rot of N. tetetzo and to determine the presence of other bacteria associated with the rot. We isolated three bacterial strains (A1, A3 and A8) from diseased tissue from three separate N. tetetzo plants, and compare them using biochemical and molecular techniques, such as whole-genome sequencing of strains A1 and A3. Phylogenetic analyzes confirmed that A1 corresponded to P. brasiliense, whereas A3 was more misimlar to P. polaris. Additionally, sequencing of 16S rRNA gene from metagenomic DNA isolated from healthy and diseased tissue of N. tetetzo indicated the presence of four operational taxonomic units (OTUs) at the order level, unique to the diseased tissue: Actinomycetales, Burkholderiales, Caulobacterales, and Sphingomonadales, with probable participation in the soft rot process.

microbiology↗