Ana Rosa Ballester Frutos

My research topic has been mainly focused on the study of fruit-pathogen interactions, mostly on orange-Penicillium digitatum and apple-Penicillium expansum interactions. I have used genomics, transcriptomics and metabolomics to increase our knowledge on the fruit responses after the infection of the pathogen or after elicitation of induced resistance, and on the mechanisms of virulence and pathogenicity of the pathogen.

From the point of view of the fruit, my results have shown that secondary metabolites, mainly phenylpropanoids, and ethylene play important roles in the induction of resistance in citrus fruit. I have also participated in unravelling the molecular responses of citrus fruit to moderate dehydration by using a fruit-specific ABA-deficient mutant. During my last contracts I was more focused on the pathogen and our analysis of the P. digitatum genome has established the molecular basis for the inability of this species to assimilate nitrate or produce the secondary metabolites patulin and penicillin. P. expansum is the Penicillium species with the largest potential for the production of secondary metabolites; however, neither patulin nor citrinin are required by the fungus to successfully infect apples.

During my research career I have also been involved in the study of the quality of tomatoes and pepper. We have identified the MYB12 transcription factor, which plays an important role regulating the flavonoid pathway, as responsible for the pink colour in tomato. Regarding pepper fruits, we have explored the biochemical diversity present within the wild and cultivated pepper germplasm using metabolomics, and we have elucidated the molecular mechanisms underlying the production of flavour and health-related compounds. I have also participated in the study of differential tomato transcriptomic responses induced by Pepino mosaic virus isolates, and in the characterization of the tomato FRUITFULL transcription factor that regulates ethylene-independent aspects of fruit ripening.

At present, I am focused on two main research lines that build on my previous experience, but also aim to improve methodologies, designs and analyses:

• Using the genome-wide analysis of different Penicillium spp. to reveal and characterize putative gene clusters and master regulators for different secondary metabolites, such as mycotoxins. I am part of MICOFOOD (National network on mycotoxins and toxigenic fungi and their decontamination processes).
• Taking advantage of omics analysis and the availability of fungal genomes to provide a comprehensive understanding of pathogenicity/virulence specificity. After high-throughput analysis, and based on the comparison of different Penicillium spp. and other necrotrophic pathogens, we can discover putative effectors involved in the pathogenicity/virulence of P. digitatum and P. expansum.