Biochemical and molecular pathways involved in plant responses to biotic and abiotic stress

Supervisor: Marco Zancani

The aim of the work is to study oxidative phenomena involved in biotic and abiotic stress, in two different plant models. Specifically, biotic stress was studied in apple plants infected by Candidatus Phytoplasma mali, while abiotic stress was investigated during storage and germination of green coffee beans. 
Regarding biotic stress, apple trees, after few years of infection by Ca. P. mali, typically show the disappearance of the symptoms and pathogen from the canopy, by a phenomenon called recovery. Recovered apple plants showed an overproduction of hydrogen peroxide in the phloem tissues that has been associated to a direct antimicrobial effect and/or a signalling function, in order to activate defence responses triggered by the phytohormones jasmonate and salicylate. The involvement of oxylipin pathway and phenylpropanoid pathway in the recovery phenomenon was investigated. Apple plants, infected by Ca. P. mali, initially showed a defence mechanism based on oxidative enzymes induced by salicylate but subsequently, during the recovery, an increase of jasmonate, synthesized by the oxylipin pathway, was observed.
Regarding abiotic stress, lipase activity was evaluated in coffee to investigate the involvement of free fatty acids in off-flavours production and lipid metabolism during germination. Lipase activity was characterized in some commercial coffee beans and in seedlings at different stages of germination, in the presence or absence of parchment (endocarp). Phenological phases of growing seedlings were influenced by the presence of endocarp, resulting in a slower growth with respect to seeds without parchment, paralleled by an increase of lipase activity and antioxidant capacity.

Biography and contacts
Luisa Clincon was born in Italy (1982) and graduated in 2008 with honours (110/110) in Agricultural Biotechnologies at University of Udine (Italy). Since 2009 she has worked as researcher at the Faculty of Agricultural and Environmental Sciences and in 2010 started the doctoral course at the PhD school in “Agriculture Science and Biotechnology” at the University of Udine.

Luisa.Clincon@uniud.it
[Phone +39 (0) 432 55 8786]