AUTHOR=Castro Alexandra , Vidal Sabina , Ponce de León Inés 

TITLE=Moss Pathogenesis-Related-10 Protein Enhances Resistance to Pythium irregulare in Physcomitrella patens and Arabidopsis thaliana

JOURNAL=Frontiers in Plant Science

VOLUME=7

YEAR=2016

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2016.00580

DOI=10.3389/fpls.2016.00580

ISSN=1664-462X

ABSTRACT=<p>Plants respond to pathogen infection by activating signaling pathways leading to the accumulation of proteins with diverse roles in defense. Here, we addressed the functional role of <italic>PpPR-10</italic>, a pathogenesis-related (PR)-10 gene, of the moss <italic>Physcomitrella patens</italic>, in response to biotic stress. <italic>PpPR-10</italic> belongs to a multigene family and encodes a protein twice the usual size of PR-10 proteins due to the presence of two Bet v1 domains. Moss <italic>PR-10</italic> genes are differentially regulated during development and inoculation with the fungal pathogen <italic>Botrytis cinerea</italic>. Specifically, <italic>PpPR-10</italic> transcript levels increase significantly by treatments with elicitors of <italic>Pectobacterium carotovorum</italic> subsp. <italic>carotovorum</italic>, spores of <italic>B. cinerea</italic>, and the defense hormone salicylic acid. To characterize the role of PpPR-10 in plant defense against pathogens, we conducted overexpression analysis in <italic>P. patens</italic> and in <italic>Arabidopsis thaliana</italic>. We demonstrate that constitutive expression of <italic>PpPR-10</italic> in moss tissues increased resistance against the oomycete <italic>Pythium irregulare</italic>. PpPR-10 overexpressing moss plants developed less symptoms and decreased mycelium growth than wild type plants. In addition, PpPR-10 overexpressing plants constitutively produced cell wall depositions in protonemal tissue. Ectopic expression of <italic>PpPR-10</italic> in <italic>Arabidopsis</italic> resulted in increased resistance against <italic>P. irregulare</italic> as well, evidenced by smaller lesions and less cellular damage compared to wild type plants. These results indicate that PpPR-10 is functionally active in the defense against the pathogen <italic>P. irregulare</italic>, in both <italic>P. patens</italic> and <italic>Arabidopsis</italic>, two evolutionary distant plants. Thus, <italic>P. patens</italic> can serve as an interesting source of genes to improve resistance against pathogen infection in flowering plants.</p>