Luis Gonzalez-Candelas

Most of my scientific work can be grouped into two major thematic lines: biotechnology of microorganisms of agri-food interest, and plant pathology. I started the first line during my PhD Thesis, which focused on the cloning and characterisation of two genes from Bacillus polymyxa encoding ß-glucosidases. This work was part of a line aimed at the production of plant cell wall-degrading enzymes. My interest in these enzymes led me to become interested in plant pathology. Thus, the topic of my work during my postdoctoral stay was the molecular study of the pectate lyases of Fusarium solani and their possible role as pathogenicity factors.
During my return to the IATA as a contracted PhD researcher, I continued the work aimed at the use of microbial proteins of potential agri-food interest through the cloning and characterisation of the corresponding gene(s) and their heterologous production in industrial strains of Saccharomyces cerevisiae or in filamentous fungi. In most cases I worked with genes/enzymes related to the degradation of the plant cell wall. Once I joined the Postharvest group of the IATA, most of my work has focused on the study of the fruit-pathogen interaction. From the point of view of the fruit, I have worked on the biochemical, molecular, metabolomic and genomic characterisation of the defence responses and the induction of resistance of apple and citrus fruits to their main pathogens (Penicillium expansum and Penicillium digitatum, respectively). In the different studies carried out, the secondary metabolism of fruits stands out as one of the key factors in the defence response of fruits to infection.
From the point of view of the pathogen, the group I lead has developed a complete set of tools that allow us to dissect the pathogenicity and virulence factors of the main fungi of the genus Penicillium that are pathogens of fruits. Among these factors, several large groups of genes related to proteolysis, redox metabolism, plant cell wall degradation, secondary metabolism or effectors stand out. The functional characterisation of these genes is currently one of the most active lines of work. A distinctive aspect of the postharvest plant pathology studies carried out is the use of "omics" approaches, such as metabolomic analysis by HPLC-MS, transcriptomic approaches, including cDNA microarrays, subtractive libraries or RNA-Seq, to identify genes induced/repressed during the fungus-fruit interaction in both pathosystems. In this regard, it is worth highlighting that we have been pioneers in sequencing the genomes of several postharvest pathogenic fungi of the genus Penicillium. Part of the work has a more applied vision, as it focuses on the search for and development of alternative methods to the use of chemical fungicides. A parallel line is the molecular characterisation of genes of Aspergillus carbonarius involved in the synthesis of the mycotoxin OTA.