P503
THE PLANT CRY FOR HELP: BIOTIC AND ABIOTIC STRESSES ATTRACT BENEFICIAL
MICROBES TO THE ROOTS
N. Lombardi1, A. Pascale1, M. Ruocco2, S. L. Woo1,2, R. Varlese1, G. Manganiello1, F. Vinale2, R.
Marra1, S. Lanzuise1, V. Matteoli1, M. Lorito1,2
1Dipartimento di Agraria, Università di Napoli Federico II, Via Università 100, 80055 Portici Napoli,
Italy
2Istituto di Protezione delle Piante, Consiglio Nazionale delle Ricerche, via Università 133, 80055
Portici Napoli, Italy E mail: lorito@unina.it
Trichoderma spp. are ubiquitous saprophytic fungi, known for their ability to colonize a variety of
niches, antagonize and control plant pathogenic microorganisms and establish a direct beneficial
interaction with plants, resulting in the enhancement of growth, nutrient uptake and systemic
resistance to diseases. It has been recently demonstrated that the root colonizing fungus T.
longibrachiatum strain MK1 positively affects the production by tomato of volatile compounds that
attract both predators and antagonists of the aphid Macrosiphum euphorbiae (Battaglia et al., 2013).
Therefore, we hypothesize that a similar mechanism is used by the plant to promote the growth and
the activity of beneficial root-colonizing microbes (RCM) upon the exposure to pathogen attack or
certain abiotic stresses. This may occur by the release of compounds that, more or less specifically,
modify the root microbiome in favour of species that help the plant to overcome the incoming stresses.
We observed in a split root experiment that the contact with Pythium ultimum on one side stimulates
the development of Trichoderma colonies located in a separated compartment, also increasing the
chemiotactic growth of the mycelium toward the plant.This suggests the release, through the root
system, of specific compounds that attract and stimulate beneficial root-colonizing microbes, which
helps the plant to overcome biotic and/or abiotic stresses.
Battaglia D., Bossi S., Cascone P., Digilio M.C., Duran Prieto J., Fanti P., Guerrieri E., Iodice L.,
Lingua G., Lorito M., Maffei M.E., Massa N., Ruocco M., Sasso R., Trotta V. (2013) Tomato
belowground-aboveground interactions: Trichoderma longibrachiatum affects the performance of
Macrosiphum euphorbiae and its natural antagonists. Mol Plant Microbe Interact. DOI: 10.1094/MPMI02-13-0059-R.