Environmental systems and anthropic impact

1. Ecophysiology of Plant- Plant Interactions

Definition and History of Allelopathy: Overview of allelochemicals; allelopathy vs. competition and differences between invasive and alien species.
Mechanisms of Allelopathy: Chemical interactions between plants; types of allelochemicals (e.g., phenolics, terpenes); methods of allelochemical release (litter deposition, root exudation, volatilization, leaching).
Ecological Implications of Allelopathy: Impact on plant communities and succession; potential role of allelopathy in ecosystem stability and disturbance (e.g., use of endemic allelopathic species to reduce the invasiveness of alien species); allelopathy in natural vs. disturbed ecosystems.
Allelopathy in Forest Ecosystems: Case studies evaluating the impact of invasive species (e.g., issues with the invasiveness of Ailanthus, eucalyptus, and Acacia dealbata on forest and anthropogenic systems); the role of allelopathy in forest regeneration.
Allelopathy and Invasive Species Control: Potential use of allelopathic species to reduce the invasiveness and impact of alien species and their potential role in ecosystem restoration; integration of allelopathic species in restoration projects.

Laboratory:

Biological Screenings: Rapid in-vitro screenings to evaluate the allelopathic potential of endemic species that may be used to control alien/invasive species.
In-Situ Experiments: In-situ evaluation of the ability of endemic allelopathic species to control invasive species and study their effects on the physiology and metabolism of these species (metabolomic approaches).
Data Analysis: Learning key statistical and bioinformatic techniques for the analysis of physiological and metabolomic data.


2. Plant-Microbial Interactions (5 CFU: 24 hours of lessons, 32 hours of integrative activities)

Microbial ecology and ecosystem services.
Interaction between microorganisms and plants (rhizosphere and phyllosphere) role of volatile compounds and root exudates. Specific microbial communities of allelopathic/invasive/alien plants in forestry (managed, productive and natural), agricultural (rotations, cover-crops) and urban contexts. Case studies related to: black walnut, eucalyptus, sunflower, sorghum, sesame, alfalfa and some staple crops such as rice, wheat, barley and sorghum.
Soil microorganisms and fertility generation. Biogeochemical cycles. Effects of allelopathic molecules on soil microbial communities, repercussions on biodiversity and fertility.
Ecosystem services of microorganisms in agroforestry and urban environments. Microorganisms in degraded environments. Impact of the use of non-endemic botanical species on soil micro and macro-organisms.
Production and transformation of allelopathic molecules.
Microbial metabolisms involved in the production and transformation of allelopathic molecules: the formation of benzoaxinoids in Graminaceae. Detoxification mechanisms. Degradation processes.
Biotransformation of mulching of allelopathic plants for the production of natural phytosanitary compounds and their industrial development: Brassicaceae, Camelina.

Practical laboratory and data discussions: Determination of the impact of bioactive molecules on soil microorganisms.
Incubation of a model molecule (chosen in collaboration) in soil. At the initial and final times, the following analyses are performed: 1) plate counts and MPN of total bacteria and fungi on generic and selective culture media (with model molecule and chromophore substrate); 2) enzymatic assays of generic and specific activities on soil. (2 hours explanation, 7 hours execution, 1 hour reading results and discussion)
Microbial characterization: Isolation and identification of bacterial colonies positive to plating with chromophore. Test setup with pure strain and GC-MS analysis of volatile compounds produced by plants or specific HPLC method set up by chemistry colleagues. (1 hour explanation, 4 hours execution, 1 hour reading results and discussion)
Toxicity tests of plant extracts (positive results for the production of allelopathic molecules in plant and chemistry laboratories) on isolated bacterial strains. (1 h explanation, 4 execution, 1 h reading results and discussion).

Main Classes of Natural Molecules with Allelopathic Activity Relevant to Agroforestry: (e.g., terpenes, polyphenols, flavonoids, chalcones, coumarins, quinones, alkaloids, benzofurans, benzoxazolinones): biosynthesis and structural characteristics.

Study of Mechanisms of Action and Structure-Activity Relationships of Specialized Metabolites: Analysis of interactions with biological targets (cell membranes, tubulin, mitochondria, enzymes, with a focus on structure-activity relationships) using bioactivity-based and computational approaches (molecular docking, GRID methodology, 3D QSAR). Conformational studies and structural optimization.

Extraction Techniques: Introduction to major green-chemistry techniques for the extraction of high-quality phytocomplexes. Fractionation, isolation, and identification.

Phytochemical Characterization: Basic principles of analytical techniques such as NMR, GC-MS, and HPLC for the identification and quantification of metabolites.

Study of Physicochemical Properties (stability, solubility) and Approaches to Enhance Bioavailability.

Use of Plant Extracts and Natural Molecules in Agroforestry (e.g. the case of Callisto, a commercial herbicide developed from the allelochemical leptospermone).

Study of the efficacy of plant extracts/pure molecules as alternatives to synthetic pesticides; examples of practical applications.

Laboratory:

Extraction of Metabolites from Complex Plant Matrices: Extraction methods using eco-friendly solvents/techniques.

Extract Characterization: Application of techniques such as NMR, GC-MS, and HPLC for qualitative and quantitative analysis.