Neofusicoccum parvum belongs to the Botryosphaeriaceae family, which contains endophytes and pathogens of woody plants. In this study, we isolated 11 strains from diseased tissue of Liquidambar styraciflua. Testing with Koch’s postulates—followed by a molecular approach—revealed that N. parvum was the most pathogenic strain. We established an in vitro pathosystem (L. styraciflua foliar tissue–N. parvum) in order to characterize the infection process during the first 16 days. New CysRPs were identified for both organisms using public transcriptomic and genomic databases, while mRNA expression of CysRPs was analyzed by RT-qPCR. The results showed that N. parvum caused disease symptoms after 24 h that intensified over time. Through in silico analysis, 5 CysRPs were identified for each organism, revealing that all of the proteins are potentially secreted and novel, including two of N. parvum proteins containing the CFEM domain. Interestingly, the levels of the CysRPs mRNAs change during the interaction. This study reports N. parvum as a pathogen of L. styraciflua for the first time and highlights the potential involvement of CysRPs in both organisms during this interaction.

Background Neofusicoccum parvum belongs to Botryosphaeriaceae family that groups endophytic and latent pathogens of woody plants responsible of diseases such as cankers, dieback and blight. Is a widespread pathogen in a broad host range including agricultural, horticultural and forestry plants, therefore is relevant to characterize molecular mechanisms involved in the disease. This work, report for first time a N. parvum as a pathogen of Liquidambar styraciflua. We established an in vitro pathosystem using foliar tissue in order to characterize the infection process through scanning electron microscopy. Because cysteine rich proteins (CysRPs) are well described for their important functions under plant-pathogen interaction, new CysRPs were identified for these organisms, and mRNAs expression of these proteins was analyzed at early times during the interaction.Results Since the first 24 hours post infection, the pathogen caused visible symptoms and the microscopic analysis at 16 days post infection revealed the presence of N. parvum pycnidium immersed in L. styraciflua leaf tissue. For both organisms, two databases with transcriptomic and genomic information were analyzed and new five CysRPs were identified for each organism, the amino acid length varied between 95 and 204 and in silico analysis revealed that all proteins are potentially secreted. The search of conserved domains and phylogenetic analyses bring to light that all proteins are novel including two of N. parvum that present the well-known CFEM domain. RT-qPCR analysis was conducted at 24- and 72-hours post infection and the results showed change levels of CysRPs mRNAs for both the plant and the fungus at early times during the interaction.ConclusionsIt is recognized for first time that N. parvum is a pathogen of L. styraciflua and this work represents an approach to begin to deeply understand the molecular mechanisms involved in this interaction highlighting the potential involvement of CysRPs of both organism during this biotic stress.

Background Neofusicoccum parvum belongs to the Botryosphaeriaceae family, which groups endophytic and latent pathogens of woody plants responsible for diseases such as cankers, dieback and blight. It is a widespread pathogen with a broad host range, including agricultural, horticultural and forestry plants; therefore, it is relevant to characterize the molecular mechanisms involved in the disease caused by this pathogen. This work reports for the first time N. parvum as a pathogen of Liquidambar styraciflua. We established an in vitro pathosystem using foliar tissue to characterize the infection process through scanning electron microscopy (SEM). Because cysteine-rich proteins (CysRPs) have been studied for their important functions in plant-pathogen interactions, new CysRPs were identified for these organisms, and mRNA expression of these proteins was analyzed at early time points during the interaction.Results 24 hours post infection, the pathogen caused visible symptoms, and microscopic analysis at 16 days post infection revealed the presence of N. parvum pycnidia embedded in L. styraciflua leaf tissue. For both organisms, two databases with transcriptomic and genomic information were analyzed, and five new CysRPs were identified for each organism. The length varied between 95 and 204 amino acids, and in silico analysis revealed that all the proteins are potentially secreted. The search for conserved domains and phylogenetic analyses revealed that all the proteins are novel, including two of N. parvum that present the well-known CFEM domain. RT-qPCR analysis was conducted at 24 and 72 hours post infection, and the results showed changes in the levels of CysRP mRNAs for both the plant and the fungus at early stages during the interaction.Conclusions N. parvum was identified for the first time as a pathogen of L. styraciflua, and this work presents an approach to comprehensively understand the molecular mechanisms involved in this interaction, highlighting the potential involvement of CysRPs of both organisms under this biotic stress.

Background: Neofusicoccum parvum belongs to the Botryosphaeriaceae family, which groups endophytic and latent pathogens of woody plants responsible for diseases such as cankers, dieback and blight. It is a widespread pathogen with a broad host range, including agricultural, horticultural and forestry plants; therefore, it is relevant to characterize the molecular mechanisms involved in the disease caused by this pathogen. This work reports for the first time N. parvum as a pathogen of Liquidambar styraciflua. We established an in vitro pathosystem using foliar tissue to characterize the infection process through scanning electron microscopy (SEM). Because cysteine-rich proteins (CysRPs) have been studied for their important functions in plant-pathogen interactions, new CysRPs were identified for these organisms, and mRNA expression of these proteins was analyzed at early time points during the interaction.Results: After the first 24 hours post infection, the pathogen caused visible symptoms, and microscopic analysis at 16 days post infection revealed the presence of N. parvum pycnidia embedded in L. styraciflua leaf tissue. For both organisms, two databases with transcriptomic and genomic information were analyzed, and five new CysRPs were identified for each organism. The length varied between 95 and 204 amino acids, and in silico analysis revealed that all the proteins are potentially secreted. The search for conserved domains and phylogenetic analyses revealed that all the proteins are novel, including two of N. parvum that present the well-known CFEM domain. RT-qPCR analysis was conducted at 24 and 72 hours post infection, and the results showed changes in the levels of CysRP mRNAs for both the plant and the fungus at early stages during the interaction.Conclusions: N. parvum was identified for the first time as a pathogen of L. styraciflua, and this work presents an approach to comprehensively understand the molecular mechanisms involved in this interaction, highlighting the potential involvement of CysRPs of both organisms under this biotic stress.