Transcriptomic responses of Antarctic plants to in situ warming: Uncovering molecular mechanisms behind physiological adjustments.

Background And Aims: Previous studies using open-top chambers to simulate warming in Antarctic field conditions have shown distinct physiological responses between the two Antarctic vascular plants Colobanthus quitensis and Deschampsia antarctica. While C. quitensis exhibited significantly increased photosynthetic capacity and growth under in situ warming conditions, D.

Exploring the Uniqueness of Photosynthetic and Hydraulic Traits of Antarctic Vascular Plants: A Comparative Study with Related Species.

Deschampsia antarctica and Colobanthus quitensis are extremophile species thriving from the Andes to the Subantarctic regions. Although they share this gradient with other species, notably, they are the only flowering plants growing naturally in Antarctica. These species exhibit traits typical of xeromorphy, such as high leaf mass area (LMA) and leaf density (LD), which influence mesophyll conductance and photosynthesis.

Hydraulic and Photosynthetic Performance of Antarctic Plants Under Successive Freeze-Thaw Cycles.

Climate change projections predict warming and increased weather variability, mainly in polar regions, altering freeze-thaw patterns. However, the effects of rising temperatures and more frequent freeze-thaw events on the water and CO management of Antarctic plants remain unclear. To address this, we conducted a laboratory experiment to investigate how growth temperature (5°C and 15°C) and successive freeze-thaw cycles influence the hydraulic and photosynthetic performance of Deschampsia antarctica (D.

Morpho-Physiological Traits and Dehydration Tolerance of High-Altitude Andean Wetland Vegetation in the Chilean Atacama Region.

High-altitude wetlands of the Andes (HAWA) are unique ecosystems influenced by substrate conditions and reliant on consistent water supply from precipitation, runoff, groundwater, and glacial melting. Considering the diverse ecosystem services provided by HAWAs and the increasing threat these ecosystems face from natural and anthropogenic factors, such as drought, land-use change, and climate change, it is crucial to conduct a comprehensive assessment of their vulnerability. In this study, we characterized the functional trait spectrum of dominant plant species within the Salar de Pedernales, Quebrada Leoncito (Leoncito) and Río Negro HAWAs and explored the relationships between these traits and key environmental variables.

In Situ Accumulation of CaOx Crystals in Leaves and Its Relationship with Anatomy and Gas Exchange.

The accumulation of crystal calcium oxalate (CaOx) in plants is linked to a type of stress-induced photosynthesis termed 'alarm photosynthesis', serving as a carbon reservoir when carbon dioxide (CO) exchange is constrained. is an extremophyte found from southern Mexico to Antarctica, which thrives in high-altitude Andean regions. Growing under common garden conditions, from different latitudinal provenances display significant variations in CaOx crystal accumulation.

Ecophysiology of Antarctic Vascular Plants: An Update on the Extreme Environment Resistance Mechanisms and Their Importance in Facing Climate Change.

Antarctic flowering plants have become enigmatic because of their unique capability to colonize Antarctica. It has been shown that there is not a single trait that makes and so special, but rather a set of morphophysiological traits that coordinately confer resistance to one of the harshest environments on the Earth. However, both their capacity to inhabit Antarctica and their uniqueness remain not fully explained from a biological point of view.

Transcriptome Analysis of Diurnal and Nocturnal-Warmed Plants, the Molecular Mechanism Underlying Cold Deacclimation Response in .

Warming in the Antarctic Peninsula is one of the fastest on earth, and is predicted to become more asymmetric in the near future. Warming has already favored the growth and reproduction of Antarctic plant species, leading to a decrease in their freezing tolerance (deacclimation). Evidence regarding the effects of diurnal and nocturnal warming on freezing tolerance-related gene expression in is negligible.

Vegetation drives the response of the active fraction of the rhizosphere microbial communities to soil warming in Antarctic vascular plants.

In the Antarctic Peninsula, increases in mean annual temperature are associated with the coverage and population density of the two Antarctic vascular plant species-Deschampsia antarctica and Colobanthus quitensis-potentially modifying critical soil processes. In this study, we characterized the diversity and community composition of active microorganisms inhabiting the vascular plant rhizosphere in two sites with contrasting vegetation cover in King George Island, Western Antarctic Peninsula. We assessed the interplay between soil physicochemical properties and microbial diversity and composition, evaluating the effect of an in situ experimental warming on the microbial communities of the rhizosphere from D.

Respiratory and Photosynthetic Responses of Antarctic Vascular Plants Are Differentially Affected by CO Enrichment and Nocturnal Warming.

Projected rises in atmospheric CO concentration and minimum night-time temperatures may have important effects on plant carbon metabolism altering the carbon balance of the only two vascular plant species in the Antarctic Peninsula. We assessed the effect of nocturnal warming (8/5 °C vs. 8/8 °C day/night) and CO concentrations (400 ppm and 750 ppm) on gas exchange, non-structural carbohydrates, two respiratory-related enzymes, and mitochondrial size and number in two species of vascular plants.

Anatomical and biochemical evolutionary ancient traits of Araucaria araucana (Molina) K. Koch and their effects on carbon assimilation.

The study of ancient species provides valuable information concerning the evolution of specific adaptations to past and current environmental conditions. Araucaria araucana (Molina) K. Koch belongs to one of the oldest families of conifers in the world, but despite this, there are few studies focused on its physiology and responses to changes in environmental conditions.

Low-temperature tolerance of the Antarctic species Deschampsia antarctica: A complex metabolic response associated with nutrient remobilization.

The species Deschampsia antarctica (DA) is one of the only two native vascular species that live in Antarctica. We performed ecophysiological, biochemical, and metabolomic studies to investigate the responses of DA to low temperature. In parallel, we assessed the responses in a non-Antarctic reference species (Triticum aestivum [TA]) from the same family (Poaceae).

Contrasting thermal acclimation of leaf dark respiration and photosynthesis of Antarctic vascular plant species exposed to nocturnal warming.

Leaf respiration and photosynthesis will respond differently to an increase in temperature during night, which can be more relevant in sensitive ecosystems such as Antarctica. We postulate that the plant species able to colonize the Antarctic Peninsula - Colobanthus quitensis (Kunth) Bartl. and Deschampsia antarctica Desv.

In situ warming in the Antarctic: effects on growth and photosynthesis in Antarctic vascular plants.

The Antarctic Peninsula has experienced a rapid warming in the last decades. Although recent climatic evidence supports a new tendency towards stabilization of temperatures, the impacts on the biosphere, and specifically on Antarctic plant species, remain unclear. We evaluated the in situ warming effects on photosynthesis, including the underlying diffusive, biochemical and anatomical determinants, and the relative growth of two Antarctic vascular species, Colobanthus quitensis and Deschampsia antarctica, using open top chambers (OTCs) and gas exchange measurements in the field.

Effects of temperature and water availability on light energy utilization in photosynthetic processes of Deschampsia antarctica.

Regional climate change in Antarctica would favor the carbon assimilation of Antarctic vascular plants, since rising temperatures are approaching their photosynthetic optimum (10-19°C). This could be detrimental for photoprotection mechanisms, mainly those associated with thermal dissipation, making plants more susceptible to eventual drought predicted by climate change models. With the purpose to study the effect of temperature and water availability on light energy utilization and putative adjustments in photoprotective mechanisms of Deschampsia antarctica Desv.

Photosynthetic limitations in two Antarctic vascular plants: importance of leaf anatomical traits and Rubisco kinetic parameters.

Particular physiological traits allow the vascular plants Deschampsia antarctica Desv. and Colobanthus quitensis (Kunth) Bartl. to inhabit Antarctica.

Light energy management in micropropagated plants of Castanea sativa, effects of photoinhibition.

The limited development of photoprotective mechanisms, specifically heat dissipation capacity, found in micropropagated plants may be the result of low xanthophyll cycle pigment content and reduced de-epoxidation capacity making them highly susceptible to photodamage. The effects of gradual or sudden increase of light on Castanea sativa in vitro cultured and during their ex vitro transference was evaluated. The results were compared with those determined in nursery-grown plants.