SuberSafe - Desenvolvimento de estratégias sustentáveis para a proteção de florestas de sobreiro contra fitopatógenos

The main objetive of SuberSafe is to devise sustainable strategies for managing the causal agents responsible for the most severe diseases affecting cork oak trees, including Phytophthora cinnamomi (Pc), Biscogniauxia mediterranea (Bm), and Diplodia corticola (Dc). These pathogens, all endophytic opportunistic microorganisms, collectively induce vascular diseases in cork oaks, ultimately leading to the widespread of decline of cork oak forests. Several evidences suggest that the increasing frequency and severity of water shortages, coupled with rising temperatures, aggravate this decline and elevate mortality rates among cork oak populations. This aspect holds particular significance considering the ecological importance of cork oak forests, which also have a substantial economic value for Portugal. Globally, Portugal produces the highest volume of raw cork, being also the primary processor of cork. The idea of SuberSafe is to follow a multi-strategic approach, using the previously isolated microorganisms and designing new cutting-edge approaches for developing tools for controlling cork oak diseases. These strategies include a range of approaches, from the traditional application of biocontrol agents (BCAs) to the development of innovative strategies, such as using antimicrobial compounds derived from BCAs and exploring gene silencing techniques to create a vaccine-like solution. The specific goals of SuberSafe include: - Expanding the previous collection of cork oak endophytes with biocontrol potential by identifying BCA agents against Phytophthora cinnamomi (Pc). While there is already a large collection of potential BCAs for Bm and Dc, BCAs for the oomycete Pc were overlooked by the project team. - Selecting the most effective antimicrobial BCA agents against cork oak pathogens, while also exploring the synergistic effects through the combination of different BCAs, in order to anticipate the use of biocontrol synthetic communities (SynComs). - Evaluating the combined effects of SynComs for controlling cork oak pathogens with previously identified plant growth-promoting rhizobacteria (PGPR) for supporting cork oak development. - Demonstrating the proof of concept for RNA gene silencing as a means of combating cork oak pathogenic agents - Producing effective dsRNA silencing molecules with antimicrobial activity and devise a delivery system for their introduction in cork oaks, - Optimizing endotherapy via trunk injection for the direct application of BCAs, extracts, and dsRNA into the vascular system of cork oaks. While the use of biocontrol SynComs is a recent and relatively underexplored idea for controlling forest diseases, SuberSafe aims to explore new frontiers beyond conventional strategies that do not rely on the release of microbial BCA into the environment. By applying compounds directly into the vascular system or employing RNAi silencing strategies, which circumvent the spread of microorganisms in nature and the potential disruption of microbiota balance, SuberSafe prioritizes the design of safe tools for forest management. Ultimately, SuberSafe aims to develop novel approaches and tools that enable the sustainable control of the primary diseases affecting cork oaks, facilitating the implementation of more viable forest management strategies.