Cell death and changes in primary metabolism: The onset of defence in
Eucalyptus in the war against Leptocybe invasa
Ismael Pinto
Federal Institute of Tocantins (Instituto Federal de Tocantins - IFTO), Colinas do Tocantins Campus, Colinas do Tocantins, TO, Brazil; Federal University of Tocantins (Universidade Federal do Tocantins - UFT), Gurupi Campus, Gurupi, TO, Brazil
Author ProfileMaíra Sarmento
Federal University of Tocantins (Universidade Federal do Tocantins - UFT), Gurupi Campus, Gurupi, TO, Brazil; University of Aveiro (Universidade de Aveiro - UA), Campus de Santiago, Department of Biology & CESAM, Aveiro, Portugal
Author ProfileAuxiliadora Martins
Department of Plant Biology (Departamento de Biologia Vegetal - DBV), Federal University of Viçosa, Viçosa, MG, Brazil; Max Planck Partner Group at the Department of Plant Biology, Federal University of Viçosa, Viçosa, MG, Brazil
Author ProfileWagner Araújo
Department of Plant Biology (Departamento de Biologia Vegetal - DBV), Federal University of Viçosa, Viçosa, MG, Brazil; Max Planck Partner Group at the Department of Plant Biology, Federal University of Viçosa, Viçosa, MG, Brazil
Author ProfileAbstract
Here we investigated changes in primary metabolism and cell death around
oviposition sites in two hybrid clones of Eucalyptus with different
degree of resistance to Leptocybe invasa Fisher & La Salle
(Hymenoptera: Eulophidae), as well as, tolerance to water deficiency. We
showed that apices of the resistant clone with oviposition had a higher
content of amino acids organic acids, and the compound putrescine, than
those of the susceptible clone with oviposition. In contrast, apices of
the resistant clone with oviposition had lower sugar content and
pyruvate organic acid content than those of the susceptible clone with
oviposition. Small areas of necrosis were induced around the oviposition
sites in the stem apices of Eucalyptus 24 h after infestation. The
resistant clone developed larger necrotic areas that showed progressive
increases 24–72 h after infestation than the susceptible clone, in
which cell death was significantly lower and no changes were observed in
necrotic area over time. Thus, the programmed death of cells around the
egg, modulated by several amino acids, is likely the first defence
response of Eucalyptus against L. invasa. Our results serve as the basis
for the early identification of key metabolites produced in plants in
defence against galling insects.