In the Global Change (GC) context, plants face multiple environmental stresses, of natural origin (drought, heat and frost, plant pathogens) or anthropogenic (tropospheric ozone, O3, NOx, heavy metals, Particulate Matter, PM). The effects of individual stressors have been well explored, but the effects caused by their interaction should be assessed to highlight the potential damages to food production and to the provisioning of regulating Ecosystem Services by vegetation, especially in urban areas, where the GC impacts are expected to increase in the next decade. This scenario requires a new series of reliable experiments to forecast the responses of natural and cultivated species to GC and implement biodiversity conservation practices in the future. For addressing all these challenging and open research questions, the project proposed by the Department of Environmental Biology consists of an Integrated Smart PHYTOTRON (ISP) to realize interdisciplinary experiments on different biological systems, with particular reference to plant organisms. The ISP, divided into two walk-in growth chambers (one used as a control, the second for treatments), represents an innovative facility that allows the control of the main environmental parameters and the manipulation of water availability, the concentration of CO2 and air pollutants (O3, NOx, PM). The effects of the interaction between abiotic stress and plant pathogens on the performance of plants will be evaluated. The functional traits will be analyzed through an advanced integrated system that combines the measures of gas exchange (CO2, H2O) with the analysis of the volatilome of the plants. The expected results can fulfil the different targets of the Sustainable Development Goals such as the SDG 11, "make cities inclusive, safe, resilient and sustainable", the SDG 13, "take urgent action to combat climate change and its impacts" and the SDG 2, "zero hunger".
The Integrated Smart PHYTOTRON is a high-tech infrastructure that will give to Sapienza the capability to lead research lines related to the plant's response mechanisms to stress, focusing the attention to abiotic and biotic stress, carrying out experiments with wide purposes, addressing base research questions as well as set experiments for applied solutions. This facility will allow establishing and implementing international collaborations in the various fields of ecology, plant pathology, biochemistry, physiology, cytology, and morphogenesis increasing the possibility to attract European research funds. Indeed, few facilities are available in Europe similar to the phytotron that this project intends to design. The Max Plant Institute of Molecular Plant Physiology has plant cultivation facilities of great interest, equipped with different instruments for general molecular biology, biochemistry, and cell biology and the range of species cultivated is restricted to crops or model species such as Arabidopsis thaliana, tobacco, maize (https://www.mpimp-golm.mpg.de/5692/facilities). Otherwise, the Smart PHYTOTRON will be designed to hold different species, from herbaceous to tree¿s seedlings, in order to exploit wider research questions relative to different ecosystem types, oriented to an integrated and ecological research approach. The facility owned by the Helmholtz Zentrum München, German Research Center for Environmental Health (https://www.helmholtz-muenchen.de/eus/facilities/PHYTOTRON/index.html), presents differences relative to the Sapienza PHYTOTRON since it is characterized by three sun simulators and reproduces environmental conditions that typically occur at the mid-latitudes, and similarly to Sapienza PHYTOTRON, it controls the composition of the chamber's atmosphere. However, the Sapienza PHYTOTRON intends to develop an advanced system to carry out measures at the plant level by means of customizing cuvette. This approach has high experimental potential, representing a new frontier in the field of plant ecology providing the possibility to work with different species contemporary, to understand the stress response at species and community level, working on mesocosms.
In this context, the expected scientific incomes will include:
1. set up complex experimental designs to investigate the response of different species to the multi-stress. Experiments in controlled condition are essential for testing the experimental hypothesis, being able to exclude confounding factors such as environmental variables that can act as stressors but not easily quantifiable in the field (i.e. soil types and nutrient content, water availability)
2. obtain innovative results for the definition of the biotic and abiotic stress action mechanisms. In particular, the response of gas exchanges and secondary metabolite production will be tracked continuously, providing key information about how plant metabolism changes during the day in response to stress. Moreover, the set up of Integrated Smart PHYTOTRON will allow distinguishing the functional signature of the response to acute or chronic stress exposure.
3. identify the functional traits, from cell to whole organism level, that are more responsive to stressful conditions, thus implementing the knowledge about which are the most important response traits to take into account for monitoring vegetation functionality in natural and semi-natural ecosystems. Experiments in controlled conditions can support the process-based models used for forecasting the global change effects on vegetation functionality and ecosystems processes.
4. contribute to the improvement of metrics and critical levels to protect natural and semi-natural vegetation from negative effects of O3. The best metrics for O3-risk assessment should be based on O3 flux instead of atmospheric concentrations of this pollutant. However, the main challenges to estimate O3 flux is the accurate prediction of stomatal conductance in response to environmental drivers such as light, vapor pressure deficit, and air temperature, but also quantify the impact of stress on the gas exchange between plant and atmosphere.
5. Explore the multiple-way interactions system in plant/environment/organism interaction. This is one of the most important ambition to achieve through this integrated system. In fact, plants experience constantly multiple inputs from outside: change in environmental parameters, pests, pathogens, pollutants. The belief that plants reactions relate to single stress is actually naive. Plants respond to multiple stimuli and the "mirror" of these responses is represented by the volatilome. BVOCs are signals that plant and their related biota exchange for communicating, challenging and growing. This system actually provides an innovative mean for understanding these messages and drive the amelioration of plant growth conditions to improve crop productivity in a sustainable way.