Rosellinia necatrix RNA-seq infecting avocado roots

White root rot disease caused by Rosellinia necatrix is one of the most important pathogens affecting avocado productivity in temperate, tropical and subtropical climates. Control of this disease is complex and nowadays, lies in the use of physical and chemical methods, although none have proven to be fully effective. Detailed understanding of the molecular mechanisms underlying white root rot disease has the potential of aiding future developments in disease resistance and management. In this regard, this study used RNAseq technology to compare the transcriptomic profiles of R. necatrix during infection of susceptible avocado `Dusa´ roots with that obtained from the fungus cultured in rich medium. The transcriptomes from three biological replicates of R. necatrix colonizing avocado roots (RC) and R. necatrix growing on potato dextrose agar media (PDA) were obtained using Illumina sequencing. A total of 12,104 transcripts were obtained, among which 1937 were differentially expressed genes (DEG), 137 exclusively expressed in RC and 160 and PDA. Interestingly genes involved in the production of fungal toxins, detoxification of toxic compounds, hormone biosynthesis, gene silencing and plant cell wall degradation were overexpressed during the infection process. In addition, 23 out of the 137 contigs, only expressed during R. necatrix growth on avocado roots, were predicted as candidate effector proteins (CEP) by the CSIRO tool with a probability above 60%. The PHI (Pathogen Host Interaction) database revealed that 11 R. necatrix CEP were previously annotated as effectors genes proven experimentally via pathogen-host interaction. The analysis of the full-length transcriptome of R. necatrix during the infection process suggested that the success of this fungus to infect diverse crops might be attributed to the production of an extensive array of compounds which singly or in combination likely interfere with structural and functional features shared among different plant families. The transcriptome analysis of R. necatrix during the infection process will provide useful information and facilitate further research to a more in -depth understanding of the biology and virulence of this pathogen. This in turn, will make possible to evolve novel strategies for white root rot management in avocado. The transcriptomes from three biological replicates of R. necatrix colonizing avocado roots (RC) and R. necatrix growing on potato dextrose agar media (PDA) were obtained using Illumina sequencing.