Biology subjects

Zotta Mota, A. P.

Publications and source records attributed to Zotta Mota, A. P..

3 recordsLinked to original sources

bioRxiv2026

Large parallel deletions are associated with massive gene losses and virulence acquisition in Meloidogyne incognita

The root-knot nematode Meloidogyne incognita is a major constraint to crop production worldwide. The resistance gene Mi-1.2 has been widely deployed in tomato varieties to control this parasite. However, virulent nematode isolates, overcoming the Mi-1.2-mediated resistance, have increasingly emerged in fields. Understanding the genetic mechanisms underlying resistance circumvention is therefore essential towards sustainable crop protection. From two geographically distinct M. incognita avirulent isolates, previous experimental evolution assays have allowed producing two virulent M. incognita isolates that escaped Mi-1.2 resistance in tomato. Here, we investigated the transcriptomic and genomic changes in the two virulent M. incognita isolates, as compared to their avirulent progenitor isolates controlled by the resistance. First, our transcriptomic analyses revealed hundreds of strongly downregulated genes, in common, in both virulent isolates. Most of these downregulated genes are clustered in two main genome regions. Long-read whole-genome sequencing of the four isolates revealed parallel structural variations in both virulent isolates. This included two large deletions spanning ca. 1.3 Mb and 0.6 Mb. The two big deletions encompass clusters of downregulated genes, suggesting they have in fact been lost in both virulent isolates. Short-read genome sequencing and PCR validation confirmed the two deletions in the two virulent isolates. The largest deletion includes predicted effector and orphan genes. The parallel large-scale structural variations identified here are likely to underlie the rapid adaptation of M. incognita to Mi-1.2-mediated resistance. These findings highlight genome structural plasticity as one of the potential key drivers of virulence acquisition in these asexually reproducing parasites.

evolutionary biology↗

bioRxiv2024

Disentangling plant response to biotic and abiotic stress using HIVE, a novel tool to perform unpaired multi-omics integration

All organisms are subjected to multiple stresses usually occurring at the same time, requiring the activation of the appropriate signalling pathways to respond to all or by prioritizing the response to one stress factor. Plants, as sessile organisms, are particularly impacted by the constantly changing environment that is often unfavourable or even hostile. Because of the experimental complexity of studying the response of one organism to multiple stressors simultaneously, usually experiments are conducted considering one individual stress factor at the time. An alternative consists in performing in silico integration of those data on single stress response. Currently used methods to integrate unpaired experiments consist of performing meta-analysis or finding differentially expressed genes for each condition separately and then selecting the commonly regulated ones. Although these approaches allowed to find valuable results, they mainly identify specific signatures in response to one stress and very few signature responding to multiple stresses and lack those modulated differently in each condition. For this purpose, we developed HIVE (Horizontal Integration analysis using Variational AutoEncoders) to integrate multiple single-stress transcriptomics datasets composed of unpaired experiments. Briefly, we coupled a variational autoencoder, that alleviates batch effects, with a random forest regression and the SHAP explainer to select relevant genes modulated specifically in response to one or multiple stresses. We illustrate the functionality of HIVE to study the transcriptional changes of several different plants namely Arabidopsis thaliana, rice, maize, wheat, grapevine and peanut by collecting publicly available experiments on single stress, either biotic and/or abiotic, and jointly analyse them. HIVE performed better than the differential expression analysis, meta-analysis and the state-of-the-art tool for horizontal integration allowing to identify novel promising candidates responsible for triggering effective defence responses to multiple stresses.

plant biology↗

bioRxiv2023

Unzipped assemblies of polyploid root-knot nematode genomes reveal new kinds of unilateral complex telomeric repeats

Telomeres play central roles in senescence, aging and chromosome integrity. Using ONT long read sequencing we have assembled the genomes of Meloidogyne incognita, M. javanica and M. arenaria, the three most devastating plant-parasitic nematodes at unparalleled contiguity. The telomeric repeat (TTAGGC)n, evolutionarily conserved in nematodes, was not found in these genomes. Furthermore, no evidence for a telomerase enzyme or for orthologs of C. elegans telomere-associated proteins could be found. Instead, we identified species-specific composite repeats mostly present at one end of contigs. These repeats were G-rich, oriented and transcribed, similarly to known telomeric repeats. Using FISH we confirmed these repeats were present at one single end of M. incognita chromosomes. The discovery of a new kind of telomeric repeat in these species highlights the evolutionary diversity of chromosome protection systems despite their central roles and opens new perspectives towards the development of more specific control methods against these pests.

genomics↗