Biology subjects

Chomentowska, A.

Publications and source records attributed to Chomentowska, A..

3 recordsLinked to original sources

bioRxiv2025

A reference genome and transcriptome of haustorial development in Pedicularis groenlandica reveal diverse trajectories of haustoria-associated gene evolution in parasitic plants

O_LINovel traits frequently evolve by co-opting existing genetic pathways through direct repurposing of existing genes or neofunctionalization of duplicated genes. Parasitism represents a major innovation in plants, where a novel organ--the haustorium--evolved to penetrate hosts and extract water and nutrients. Previous studies hypothesized that haustoria-associated genes primarily evolve from root and pollen-associated pathways. C_LIO_LITo examine evolutionary trajectories of haustoria-associated genes, we generated a chromosome-scale genome of Pedicularis groenlandica (Orobanchaceae) and sampled transcriptomes throughout haustorial development. We examined differential expression of haustoria-associated genes and their paralogs and investigated orthology among haustoria-associated genes in five parasitic plants. C_LIO_LIWe identified 5,635 haustoria-associated genes in P. groenlandica, of which a greater proportion were associated with pollen tubes (67%) than roots (33%), evidenced by being differentially expressed in pollen tubes, nested within pollen tube-associated gene families, or both. Haustoria-associated genes with paralogs that arose after the evolution of parasitism in Orobanchaceae are more likely to be uniquely expressed in haustoria, consistent with neofunctionalization. C_LIO_LIOur results support both pleiotropy and neofunctionalization as mechanisms by which genetic pathways are co-opted for haustorial function. Haustoria-associated genes are highly lineage-specific, highlighting a dynamic and ongoing process of haustorial co-option of genes among parasitic plant lineages. C_LI

evolutionary biology↗

bioRxiv2025

Phylogenomic analyses of the diverse desert-alpine plant lineage Cistantheae

Deserts and alpine habitats, though ecologically distinct, share similar environmental stressors such as drought and high radiation. Various plant lineages traverse both biomes, which is often associated with transitions in life history strategy, where annuality is more often associated with drier desert habitats and perenniality more common in higher elevations. One such lineage is Cistantheae (Montiaceae), a morphologically diverse herbaceous clade in western North and South America. We aimed to infer a robust phylogeny of the clade as a foundation for taxonomic and comparative work. We used double-digest RADSeq to generate reduced-representation genomic data from over 160 samples representing 48 putative species in Cistantheae. Maximum likelihood and coalescent-based phylogenetic methods were utilized to infer evolutionary relationships across the full clade and within major subclades. We tested for signatures of admixture and introgressive gene flow, and reconstructed ancestral life history and climate niche to identify patterns of correlated evolution. We inferred a well-resolved phylogeny of Cistantheae, providing strong support for relationships among subclades within Cistantheae. While many species relationships were clarified, we also found evidence of rampant gene flow and incomplete lineage sorting, particularly within the annual Cistanthe clade from the Atacama Desert. Life history is evolutionarily labile across the clade, and was strongly correlated with temperature/ precipitation-related bioclimatic variables: annuals tend to occur in hotter, drier environments, while perennials in cooler, wetter. Elevational range was also evolutionarily labile, with several species occupying broad elevational gradients. We present the first densely-sampled, phylogenomic analysis of Cistantheae, providing key insights into species relationships in the clade. Repeated transitions in life history and climate niche, alongside wide elevational ranges, suggest that many Cistantheae species may be preadapted to both arid and montane habitats. This phylogeny will underpin further comparative, taxonomic, and phylogenomic studies in this ecologically important lineage.

evolutionary biology↗

bioRxiv2024

A high-quality genome of the mass-blooming desert plant Cistanthe longiscapa and its photosynthetic behavior related to drought and life history

O_LICrassulacean acid metabolism (CAM) photosynthesis has independently evolved many times in arid-adapted plant lineages. Cistanthe longiscapa (Montiaceae), a desert mass-blooming annual, can upregulate CAM facultatively upon stress such as drought. Few studies, however, consider life history stages when measuring CAM activity or its facultative onset. C_LIO_LITo test the effect of drought and flowering on photosynthetic activity, we assayed Cistanthe individuals in fully-watered and drought conditions, as well as fully-watered individuals at pre-flowering and flowering life stages. We assembled and annotated a chromosome-scale genome of C. longiscapa and compared it with the genome of Portulaca amilis and analyzed differential gene expression. C_LIO_LIResults show significantly upregulated CAM in drought conditions as compared to fully-watered conditions; furthermore, flowering individuals showed slightly higher CAM activity as compared to pre-flowering plants, even when fully-watered. Differential gene expression analyses provide preliminary support for the possible co-regulation of CAM expression and reproduction. C_LIO_LIWe emphasize the potentially missed significance of life history in the CAM literature, and consider how the CAM biochemical module could become co-opted into other plant behaviors and responses, such as the shift to reproduction or flowering in annuals. C_LI

plant biology↗