Key message Gene expression analyses reveal tissue-specific and temporally regulated networks driving Posidonia oceanica development, and identify key hub genes that coordinate root, leaf, and seed maturation. Abstract Seagrasses are marine angiosperms that form extensive underwater meadows, providing habitat, stabilising sediments, storing carbon, and protecting coastlines. Posidonia oceanica is the endemic foundation seagras...

Populations at a species' distribution edges often present reduced gene flow, increased impact of genetic drift, and impoverished genetic variation, globally compromising their ability to adapt to environmental changes. This study assessed the genetic diversity, structure, and connectivity of the Mediterranean endemic seagrass Posidonia oceanica at its easternmost distribution limit, from diverse thermal regimes around Cyprus,...

Adaptation to local conditions is known to occur in seagrasses; however, knowledge of the genetic basis underlying this phenomenon remains scarce. Here, we analysed Posidonia oceanica from six sites within and around the Stagnone di Marsala, a semi‐enclosed coastal lagoon where salinity and temperature exceed the generally described tolerance thresholds of the species. Sea surface temperatures (SSTs) were measured and plant sa...

Introduction The rapid increase in sea-water temperatures and frequency of extreme thermal events have amplified the risk of functional extinction of Mediterranean species such as the endemic long-lived seagrass Posidonia oceanica . Because of the valuable ecological functions and ecosystem services the species provides, understanding the life-stage specific thermal vulnerability is crucial to accurately predict the consequenc...

Seagrass meadows are disappearing at rates comparable to those reported for mangroves, coral reefs, and tropical rainforests. One of the main causes of their decline is the so-called cultural eutrophication, i.e., the input of abnormal amounts of nutrients derived from human activities. Besides the impact of eutrophication at a local scale, the occurrence of additional stress factors such as global sea warming may create syner...

The Mediterranean Sea is particularly vulnerable to warming and the abrupt declines experienced by the endemic Posidonia oceanica populations after recent heatwaves have forecasted severe consequences for the ecological functions and socio‐economical services this habitat forming species provides. Nevertheless, this highly clonal and long‐lived species could be more resilient to warming than commonly thought since heat‐sensiti...

The capacity for ascidians to inhabit coastal sea floor worldwide relies on their peculiar tolerance to environmental variables and pollution, which is considered, together with high levels of genetic diversity, among the main drivers of their invasive potential. In spite of the continued interest in the genetics of invasive species, little attention has been paid toward the microevolutionary processes that drive structure and...

Here, we report the first use of massive‐scale RNA ‐sequencing to explore seagrass response to CO 2 ‐driven ocean acidification ( OA ). Large‐scale gene expression changes in the seagrass Cymodocea nodosa occurred at CO 2 levels projected by the end of the century. C. nodosa transcriptome was obtained using Illumina RNA ‐Seq technology and de novo assembly, and differential gene expression was explored in plants exposed to sho...

Understanding the factors that cause population divergence has long been of interest to marine biologists in their attempts to interpret the effect of human‐mediated vectors. Broadcast‐spawning species with limited dispersal capability are excellent candidates to measure the present‐day patterns of genetic diversity. The tunicate Ciona intestinalis (Ascidiacea) is comprised of a complex of morphologically cryptic species that...