AUTHOR=La Spada Federico , Stracquadanio Claudia , Riolo Mario , Pane Antonella , Cacciola Santa Olga 

TITLE=Trichoderma Counteracts the Challenge of Phytophthora nicotianae Infections on Tomato by Modulating Plant Defense Mechanisms and the Expression of Crinkler, Necrosis-Inducing Phytophthora Protein 1, and Cellulose-Binding Elicitor Lectin Pathogenic Effectors

JOURNAL=Frontiers in Plant Science

VOLUME=11

YEAR=2020

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2020.583539

DOI=10.3389/fpls.2020.583539

ISSN=1664-462X

ABSTRACT=<p>Decoding the mechanisms of plant defense against plant pathogens in a scenario where antagonistic activity and the plant growth-promoting effects of useful organisms intervene simultaneously is a new frontier of plant pathology. Here, we demonstrated that (i) two selected strains of <italic>Trichoderma asperellum</italic> and <italic>Trichoderma atroviride</italic> promoted tomato (<italic>Solanum lycopersicum</italic>) growth and reduced the severity of disease caused by the oomycete <italic>Phytophthora nicotianae</italic> and (ii) the genetic patterns of the components of the experimental model system tomato–<italic>Trichoderma</italic> spp.–<italic>P. nicotianae</italic> were differentially expressed. The beneficial effects in both the promotion of the growth of host plant and the biological control of the pathogen by two selected strains of different <italic>Trichoderma</italic> species were tested both <italic>in planta</italic> and <italic>in vitro</italic>. In both respects, <italic>T. atroviride</italic> demonstrated to be more effective than <italic>T. asperellum</italic>. Additionally, the simultaneous transcriptional reprogramming of several plant defense-related genes, pathogen effectors, and mycoparasitism-related genes in tomato, <italic>P. nicotianae</italic>, and <italic>Trichoderma</italic> spp., respectively, was evaluated during the three-component interaction. Results support the hypothesis that <italic>Trichoderma</italic> spp. elicit the expression of plant defense-related genes. As expected, a mycoparasitism-related gene was significantly up-regulated in <italic>Trichoderma</italic>-colonizing tomato plants infected by <italic>P. nicotianae</italic>. Finally, a marked up-regulation of the genes encoding two necrosis-inducing effectors was observed in <italic>P. nicotianae</italic> infecting tomato plants colonized by <italic>Trichoderma</italic>. In conclusion, this study is a contribution toward understanding the genetic pathways related with the ability of <italic>Trichoderma</italic> spp. to counteract the challenge of <italic>P. nicotianae</italic> infections on tomato. Additionally, the experiments revealed the beneficial effects in the tomato growth promotion of a new <italic>T. atroviride</italic> strain and its good antagonistic effectiveness in the biological control of root and crown rot incited by <italic>P. nicotianae</italic>, confirming that <italic>Trichoderma</italic> spp. can be a powerful tool in integrated pest management strategies of <italic>Phytophthora</italic> diseases of horticultural crops.</p>