AUTHOR=Raio Aida , Brilli Federico , Neri Luisa , Baraldi Rita , Orlando Francesca , Pugliesi Claudio , Chen Xiaoyulong , Baccelli Ivan 

TITLE=Stenotrophomonas rhizophila Ep2.2 inhibits growth of Botrytis cinerea through the emission of volatile organic compounds, restricts leaf infection and primes defense genes

JOURNAL=Frontiers in Plant Science

VOLUME=14

YEAR=2023

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2023.1235669

DOI=10.3389/fpls.2023.1235669

ISSN=1664-462X

ABSTRACT=<p>The bacterium <italic>Stenotrophomonas rhizophila</italic> is known to be beneficial for plants and has been frequently isolated from the rhizosphere of crops. In the present work, we isolated from the phyllosphere of an ornamental plant an epiphytic strain of <italic>S. rhizophila</italic> that we named Ep2.2 and investigated its possible application in crop protection. Compared to <italic>S. maltophilia</italic> LMG 958, a well-known plant beneficial species which behaves as opportunistic human pathogen, <italic>S. rhizophila</italic> Ep2.2 showed distinctive features, such as different motility, a generally reduced capacity to use carbon sources, a greater sensitivity to fusidic acid and potassium tellurite, and the inability to grow at the human body temperature. <italic>S. rhizophila</italic> Ep2.2 was able to inhibit <italic>in vitro</italic> growth of the plant pathogenic fungi <italic>Alternaria alternata</italic> and <italic>Botrytis cinerea</italic> through the emission of volatile compounds. Simultaneous PTR-MS and GC-MS analyses revealed the emission, by <italic>S. rhizophila</italic> Ep2.2, of volatile organic compounds (VOCs) with well-documented antifungal activity, such as furans, sulphur-containing compounds and terpenes. When sprayed on tomato leaves and plants, <italic>S. rhizophila</italic> Ep2.2 was able to restrict <italic>B. cinerea</italic> infection and to prime the expression of <italic>Pti5</italic>, <italic>GluA</italic> and <italic>PR1</italic> plant defense genes.</p>