AUTHOR=Mayo Sara , Gutierrez Santiago , Malmierca Monica G., Lorenzana Alicia , Campelo María P., Hermosa Rosa , Casquero Pedro A.

TITLE=Influence of Rhizoctonia solani and Trichoderma spp. in growth of bean (Phaseolus vulgaris L.) and in the induction of plant defense-related genes

JOURNAL=Frontiers in Plant Science

VOLUME=6

YEAR=2015

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2015.00685

DOI=10.3389/fpls.2015.00685

ISSN=1664-462X

ABSTRACT=<p>Many <italic>Trichoderma</italic> species are well-known for their ability to promote plant growth and defense. We study how the interaction of bean plants with <italic>R. solani</italic> and/or <italic>Trichoderma</italic> affect the plants growth and the level of expression of defense-related genes. <italic>Trichoderma</italic> isolates were evaluated <italic>in vitro</italic> for their potential to antagonize <italic>R. solani</italic>. Bioassays were performed in climatic chambers and development of the plants was evaluated. The effect of <italic>Trichoderma</italic> treatment and/or <italic>R. solani</italic> infection on the expression of bean defense-related genes was analyzed by real-time PCR and the production of ergosterol and squalene was quantified. <italic>In vitro</italic> growth inhibition of <italic>R. solani</italic> was between 86 and 58%. In <italic>in vivo</italic> assays, the bean plants treated with <italic>Trichoderma harzianum</italic> T019 always had an increased size respect to control and the plants treated with this isolate did not decrease their size in presence of <italic>R. solani</italic>. The interaction of plants with <italic>R. solani</italic> and/or <italic>Trichoderma</italic> affects the level of expression of seven defense-related genes. Squalene and ergosterol production differences were found among the <italic>Trichoderma</italic> isolates, T019 showing the highest values for both compounds. <italic>T. harzianum</italic> T019 shows a positive effect on the level of resistance of bean plants to <italic>R. solani</italic>. This strain induces the expression of plant defense-related genes and produces a higher level of ergosterol, indicating its ability to grow at a higher rate in the soil, which would explain its positive effects on plant growth and defense in the presence of the pathogen.</p>