Biology subjects

Cabanac, S.

Publications and source records attributed to Cabanac, S..

4 recordsLinked to original sources

bioRxiv2026

Characterization of the conserved response of angiosperms to hypoxia through transcriptomic meta-analysis

Floods cause significant crop losses worldwide. Plant response mechanisms to flooding have been extensively studied, particularly the ethylene-meditated mechanisms of perception and initiation of the response. However, other mechanisms are often studied more marginally, and it is difficult to determine which are species-specific and which are part of a conserved angiosperm response to hypoxia. Here, we performed a meta-analysis of transcriptomic data under hypoxic or flooding conditions across 11 angiosperm species and identified 259 homologous gene clusters that constitute the core response to hypoxia in angiosperms. These include the previously identified main mechanisms linked to ethylene, as well as numerous novel genes whose role in the hypoxia response is often poorly characterized. In particular, many previously overlooked genes associated with oxidative stress were identified as part of the core response, such as HRU1, TIP1-2, OZF1, and OZF2. Our results reveal many new candidate genes with strong potential for improving plant resilience to flooding.

Plant Biology↗

bioRxiv2026

Pseudogenes confirm ongoing loss of ethylene biosynthesis in seagrasses

Many flowering plant species have adopted an aquatic lifestyle, contrasting with their terrestrial ancestors. Adapting to an aquatic environment required numerous evolutionary changes, including gene expansion and contraction. One of the most striking contractions has been observed in the genomes of seagrasses, where the ACO and ACS genes, involved in ethylene biosynthesis, are very few in number or even completely absent. To confirm this adaptation, we identified traces of gene loss in the genomes of four seagrass species, in the form of pseudogenes. Surprisingly, no gene loss was found in the species that had completely lost the function of ethylene synthesis, likely indicating an ancient loss of these genes. Conversely, several pseudogenes were found in the species where the ACO and ACS genes are contracting, indicating a recent and potentially ongoing process. We used the same approach on Utricularia gibba, a submerged freshwater plant, and also found a reduced number of ACO and ACS genes. In contrast, two terrestrial species closely related to seagrasses and U. gibba found a higher number of ACO and ACS genes, with no definitive evidence of gene loss. These results confirm that the loss of ethylene biosynthesis function in seagrasses is indeed linked to gene loss and suggests that it is an adaptation to a submerged rather than a marine lifestyle.

evolutionary biology↗

bioRxiv2026

Comparative Genomic Insights into the Evolution of Aquatic and Terrestrial Adaptations in Plants

Terrestrial plants emerged from the water about 500 million years ago. Thereafter, they have diversified and now inhabit most of the Earths surface. More recently, some species have re-adapted to an aquatic lifestyle, both in fresh and salt water, and fully or partially submerged. The mechanisms enabling these adaptations between terrestrial and aquatic life are extremely numerous, making it difficult to have a comprehensive overview of the phenomenon. Here, we performed a series of intraspecific measurements of the selection pressure affecting orthologous genes in eight aquatic and four terrestrial plants. Our analyses showed that aquatic plants have a relaxed selection pressure on nutrient assimilation mechanisms, probably linked to a greater bioavailability, as well as stronger adaptations to oxidative stress, while terrestrial plants evolution is linked to environment perception. Inter-species analyses have also highlighted a different evolution of chloroplast proteins between these two types of plants, suggesting adaptations to gas availability.

evolutionary biology↗

bioRxiv2023

P-GRe : an efficient pipeline to maximised pseudogene prediction in plants/eucaryotes

Formerly considered as part of "junk DNA", pseudogenes are nowadays known for their role in the post-transcriptional regulation of functional genes. In addition, their identification allows a better understanding of gene evolution in the frame of multigenic families. Despite this, there is, to our knowledge, no fully automatic user-friendly software allowing the annotation of pseudogenes on a whole genome. Here, we present Pseudo-Gene Retriever (P-GRe), a fully automated pseudogene prediction software requiring only a genome sequence and its corresponding GFF annotation file. P-GRe detects the sequences of the pseudogenes on a whole genome and returns to the user all their genomic sequences and their pseudo-coding sequences. The ability of P-GRe to finely reconstruct the structure of pseudogenes also allow to obtain a set of proteins virtually encoded by the predicted pseudogenes. We show here that in 70% of the cases, virtual proteins constructed by P-GRe from Arabidopsis thaliana proteome and genome aligned better to their parent protein than their annotated counterpart.

bioinformatics↗