Biological evaluation of 24-hidroxy-4-cholen-3-one as a potencial tool for controlling root knot nematode infection

BURTON, G.; RODRIGUEZ, C; SANTILLAN, VANESA; MUNARRIZ, E.R.; MODENUTTI, C.; CASTRO, OLGA; KRONBERG, M. F.; VELEIRO, A.; DEL VALLE, ELEODORO

CABA

Congreso; Reunión Conjunta de Sociedades de BioCiencias; 2017

The root-knot nematode Meloidogyne incognita is one of the most damaging parasites because it infects almost all cultivated plants..Second-stage juveniles (J2) penetrate the root and migrate to the vascular cylinder inducing the development of root knots. J2 becomes sedentary and undergoes three molts to become an adult female that lays eggs. After egg eclosion, J2 larvae move in the soil,locate root tips and initiate a new cycle of infection. We have previously demonstrated that the synthetic 24-hydroxy-4-cholen-3-one (C24OH), a dafachronic acid (DA) analogue, is able tocontrol C.elegans life cycle by interfering with the DAF-12 regulated endocrine network(C24OHdisplays an antagonistic activity).Since C.elegansand parasitic nematodes share the DA system,we decided to test if C24OHhas an effect onM.incognita life cycle. Eggs were incubated in presence of increasing concentrations of C24OHand significant differences were observed in the hatching at 96 h (p< 0,0001) between 100 and 200 µM C24OHtreated ones compared to the control.In addition, a significant dose response effect of C24OHin M. incognita J2 mortalitywas observed. After 48 h incubation 16, 28 and 53% of dead J2 were found in the presence of50, 100 and 200 µM C24OHrespectively, whereas only an 8% of dead J2 were found in the control.The effect of C24OHonM. incognita infection was evaluated in tomato plants.Roots were treated for 48 h with increasing concentrations ofC24OHand then infected. C24OHtreatment decreased significantly the number of galls/root system in a dose response manner (100 µMC24OH produced a 72% reduction). Moreover, plants presented a general improvement in their growth parameters. Specifically, root and aerial part fresh weight from 100 µMC24OHtreatedplants were a 150% and 215% higher than those of untreated plants respectively.Altogether, our study supports a novel use of C24OHas a nematicide