Biological Interactions and Simulated Climate Change Modulates the Ecophysiological Performance of Colobanthus quitensis in the Antarctic Ecosystem

Abstract

Most climate and environmental change models predict significant increases in temperature and precipitation by the end of the 21st Century, for which the current functional output of certain symbioses may also be altered. In this context we address the following questions: 1) How the expected changes in abiotic factors (temperature, and water) differentially affect the ecophysiological performance of the plant Colobanthus quitensis? and 2) Will this environmental change indirectly affect C. quitensis photochemical performance and biomass accumulation by modifying its association with fungal endophytes? Plants of C. quitensis from King George Island in the South Shetland archipelago (62°09′ S), and Lagotellerie Island in the Antarctic Peninsula (65°53′ S) were put under simulated abiotic conditions in growth chambers following predictive models of global climate change (GCC). The indirect effect of GCC on the interaction between C. quitensis and fungal endophytes was assessed in a field experiment carried out in the Antarctica, in which we eliminated endophytes under contemporary conditions and applied experimental watering to simulate increased precipitation input. We measured four proxies of plant performance. First, we found that warming (+W) significantly increased plant performance, however its effect tended to be less than watering (+W) and combined warming and watering (+T°+W). Second, the presence of fungal endophytes improved plant performance, and its effect was significantly decreased under experimental watering. Our results indicate that both biotic and abiotic factors affect ecophysiological performance, and the directions of these influences will change with climate change. Our findings provide valuable information that will help to predict future population spread and evolution through using ecological niche models under different climatic scenarios.

Decreasing brown bear (Ursus arctos) habitat due to climate change in Central Asia and the Asian Highlands

“…Around the world, climate change has had significant direct and indirect impacts on terrestrial species, by being a major cause of speciation and species extirpation (Pound & Salzmann, 2017). Many studies have recently focused on the ecological (Etterson & Mazer, 2016;Wikelski & Tertitski, 2016), ethological (Munoz, Marquez, & Real, 2015) and biological changes (Torres-Diaz et al, 2016;Hulme, 2016) in relation to climatic change. For example, various ecosystems are vulnerable to climate change which may induce a broad array of adverse effects such as disturbances of phenological events, food web disruptions, pathogens and disease spread and ultimately, in worst case scenarios, may include extinction risks (Wu, Lu, Zhou, Chen, & Xu, 2016).…”

First Record of Juncaceicola as Endophytic Fungi Associated with Deschampsia antarctica Desv.

“…Antarctica is one of the regions on the planet with extreme environment [1]. The establishment and survival of living organisms are limited by conditions such as low temperature and nutrient availability, strong winds, high sublimation and evaporation, frequent freezing-thawing cycles, low annual precipitation, high solar incidence and ultraviolet radiation, and low water availability [2][3][4][5].…”

Root endophytes improve physiological performance and yield in crops under salt stress by up-regulating the foliar sodium concentration

“…Thus, this particular combination of environmental stresses is expected to favors symbiotic associations between soil microorganisms and Antarctic vascular plants though natural selection. A growing number of studies have shown that plant-microorganism’s mutualisms are common at extreme environments such as deserts (Oelmüller et al, 2009; Sangamesh et al, 2018), high-mountain (Molina-Montenegro et al, 2015; Kotilinèk et al, 2017) or polar ecosystems (Upson et al, 2009b; Newsham, 2011a; Torres-Díaz et al, 2016), for which those microbial symbionts appear to be great candidates for biotechnological applications (Khan et al, 2013; Rho et al, 2017).…”

“…As they did also here, those endophytes improved plant physiological parameters (i.e., A max and WUE) and the accumulation of the amino acid proline (Molina-Montenegro et al, 2016a), an osmotic molecule that has been previously associated to other symbionts conferring plant tolerance to water deficit (Nagabhyru et al, 2013; Ortiz et al, 2015). Interestingly, the beneficial effects of these Antarctic fungal endophytes seems to be ubiquitous as they are also able to establish functional symbioses with plant species from phylogenetically unrelated plant families such as the native Antarctic vascular plant Colobanthus quitensis (Torres-Díaz et al, 2016), three endangered shrubs from semiarid environments Flourensia thurifera (Asteraceae), Puya berteroniana (Bromeliacae) and Senna cumingii (Fabacae) (Molina-Montenegro et al, 2016b; Fardella et al, 2014) and the endangered south American tree Nothofagus alessandrii (Torres-Díaz, unpublished results).…”