- Microsporogenesis and regulatory processes involved in pollen tube emergence and growth. Studies are directed at gaining a better understanding of the basic mechanisms of sexual reproduction in flowering plants, and at evaluating methods for the manipulation of higher plant fertility. In particular, the role of the ubiquitin-dependent proteolytic pathway in the regulation of pollen tube organisation and growth, and the involvement of ubiquitin in the regulation/modulation of the signalling pathway related to this process are investigated. Pollen is a rather unique structure within the plant kingdom; it has certain qualities which make it an ideal model system for basic and applied investigations. It is a natural cellular “vector” and has potential for genetic transformation as it can provide a generally applicable approach to gene transfer in plants. Moreover, pollen grains recall the extraordinary adaptability of microorganisms; haploidy and large population sizes are also peculiar pollen features. Some other characteristics are: ease of storage from harvest until use, simple and quick in vitro culture techniques, fast growth, rapid uptake of externally applied compounds, and no retardation of the drug effect due to diffusion as occurs in a tissue. Most importantly, the high sensitivity of pollen-based assays makes them a suitable and relatively simple, yet reliable, tool to investigate the toxic action of a number of chemicals, both with reference to environmental pollution and acute human toxicity. In this context, we are also using pollen to assess the bioeffects of natural compounds and metabolic inhibitors, and the toxicity of heavy metals and nanoparticles. - Development of in vitro culture protocols (regeneration and micropropagation) mainly devoted to medicinal plants for secondary metabolite production. Studies on the role played by different endogenous and exogenous factors on in vitro differentiation of plant tissues and organs. - Extraction of secondary metabolites having antioxidant and antimicrobial activities. Evaluation of antioxidant activity. In vitro and in vivo tests against bacterial and fungal strains. - Analysis of essential oil composition as a chemotaxonomic marker.