Evolution of physiological performance in invasive plants under climate change

Ecophysiological and biochemical responses to cold and heat waves of native Spartina maritima, alien S. densiflora and their reciprocal hybrids

MAIN CONCLUSION

Spartina hybrids outperform parental species, showing transgressive acclimation to extreme climates. Native S. maritima demonstrates high seasonal adaptability and invasive S. densiflora low physiological impact, suggesting resilience under climate change. Extreme climatic events, such as cold and heat waves, are becoming more frequent, intense, and prolonged due to climate change. Simultaneously, invasive alien plant species are altering the composition of plant communities. Both climate change and the introduction of alien species pose significant threats to biodiversity. We studied the responses of 25 biochemical and physiological functional traits for native Spartina maritima, alien invasive S. densiflora and their reciprocal hybrids to changing environmental conditions during a cold snap in winter and a heat wave in summer in Guadiana Marshes (Southwest Iberian Peninsula). These four closely related taxa responded differently to seasonal environmental fluctuations. Both hybrid taxa, particularly S. maritima × densiflora, exhibited transgressive responses, allowing them to display a wider range of acclimation responses to air temperature compared to their parental species. Native S. maritima also demonstrated a relatively high acclimation capacity to seasonal meteorological changes. In contrast, alien S. densiflora presented few acclimation responses to seasonal environmental changes, responding primarily to sediment salinity rather than to air temperature. Even so, all four studied Spartina taxa appear to be well-adapted to the occurrence of cold and heat waves in the Gulf of Cadiz. These findings underscore the complexity of plant acclimation strategies in response to extreme climatic events and highlight the potential for hybrid taxa to face the future dynamics of salt marshes under climate change.

Fungal endophytes modulate the negative effects induced by Persistent Organic Pollutants in the antarctic plant Colobanthus quitensis

Antarctica has one of the most sensitive ecosystems to the negative effects of Persistent Organic Pollutants (POPs) on its biodiversity. This is because of the lower temperatures and the persistence of POPs that promote their accumulation or even biomagnification. However, the impact of POPs on vascular plants is unknown. Moreover, fungal symbionts could modulate the effects on host plants to cope with this stress factor. This study investigates the molecular and ecophysiological responses of the Sub-Antarctic and Antarctic plant Colobanthus quitensis to POPs in different populations along a latitudinal gradient (53°- 67° S), emphasizing the role of endophytic fungi. The results show that exposure of POPs in C. quitensis generates oxidative stress and alters its ecophysiological performance. Nevertheless, C. quitensis in association with fungal endophytes and POPs exposure, shows lower lipid peroxidation, higher proline content and higher photosynthetic capacity, as well as higher biomass and survival percentage, compared to plants in the absence of fungal endophytes. On the other hand, the antarctic plant population (67°S) with endophytic fungi presents better stress modulating upon POPs exposure. Endophytic fungi would be more necessary for plant performance towards higher latitudes with extreme conditions, contributing significantly to their general functional adaptation. We develop a transcriptomics analyses n the C. quitensis-fungal endophytes association from the Peninsula population. We observed that fungal endophytes promote tolerance to POPs stress through upregulated genes for the redox regulation based on ascorbate and scavenging mechanisms (peroxidases, MDAR, VTC4, CCS), transformation (monooxygenases) and conjugation of compounds or metabolites (glutathione transferases, glycosyltransferases, S-transferases), and the storage or elimination of conjugates (ABC transporters, C and G family) that contribute to detoxification cell. This work highlights the contribution of endophytic fungi to plant resistance in situations of environmental stress, especially in extreme conditions such as in antarctica exposed to anthropogenic impact. The implications of these findings are relevant for the biosecurity of one of the last pristine bastions worldwide.

Non-Additive Effects of Environmental Factors on Growth and Physiology of Invasive Solidago canadensis and a Co-Occurring Native Species (Artemisia argyi)

Changes in environmental factors, such as temperature and UV, have significant impacts on the growth and development of both native and invasive plant species. However, few studies examine the combined effects of warming and enhanced UV on plant growth and performance in invasive species. Here, we investigated single and combined effects of warming and UV radiation on growth, leaf functional and photosynthesis traits, and nutrient content (i.e., total organic carbon, nitrogen and phosphorous) of invasive Solidago canadensis and its co-occurring native species, Artemisia argyi, when grown in culture racks in the greenhouse. The species were grown in monoculture and together in a mixed community, with and without warming, and with and without increased UV in a full factorial design. We found that growth in S. canadensis and A. argyi were inhibited and more affected by warming than UV-B radiation. Additionally, there were both antagonistic and synergistic interactions between warming and UV-B on growth and performance in both species. Overall, our results suggested that S. canadensis was more tolerant to elevated temperatures and high UV radiation compared to the native species. Therefore, substantial increases in temperature and UV-B may favour invasive S. canadensis over native A. argyi. Research focusing on the effects of a wider range of temperatures and UV levels is required to improve our understanding of the responses of these two species to greater environmental variability and the impacts of climate change.

Single and interactive effects of variables associated with climate change on wheat metabolome

One of the key challenges linked with future food and nutritional security is to evaluate the interactive effect of climate variables on plants' growth, fitness, and yield parameters. These interactions may lead to unique shifts in the morphological, physiological, gene expression, or metabolite accumulation patterns, leading to an adaptation response that is specific to future climate scenarios. To understand such changes, we exposed spring wheat to 7 regimes (3 single and 4 combined climate treatments) composed of elevated temperature, the enhanced concentration of CO₂, and progressive drought stress corresponding to the predicted climate of the year 2100. The physiological and metabolic responses were then compared with the current climate represented by the year 2020. We found that the elevated CO₂ (eC) mitigated some of the effects of elevated temperature (eT) on physiological performance and metabolism. The metabolite profiling of leaves revealed 44 key metabolites, including saccharides, amino acids, and phenolics, accumulating contrastingly under individual regimes. These metabolites belong to the central metabolic pathways that are essential for cellular energy, production of biosynthetic pathways precursors, and oxidative balance. The interaction of eC alleviated the negative effect of eT possibly by maintaining the rate of carbon fixation and accumulation of key metabolites and intermediates linked with the Krebs cycle and synthesis of phenolics. Our study for the first time revealed the influence of a specific climate factor on the accumulation of metabolic compounds in wheat. The current work could assist in the understanding and development of climate resilient wheat by utilizing the identified metabolites as breeding targets for food and nutritional security.

Digest: Between invasive species and a hot place: Plant evolution under climate change. Evolution 2021;75:3214-3215. [PMID: 34541671 DOI: 10.1111/evo.14352] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

Will climate change lead to invasive species evolving faster than native or naturalized species? Gianoli and Molina-Montenegro showed that, under warming and drought, the evolution of photosynthetic capacity does not always favor invasive species. These data raise interesting questions for the study of evolution of invasive species under climate change.