Long-Day Photoperiod Enhances Jasmonic Acid-Related Plant Defense

[EN] Agricultural crops are exposed to a range of daylengths, which act as important environmental cues for the control of developmental processes such as flowering. To explore the additional effects of daylength on plant function, we investigated the transcriptome of Arabidopsis (Arabidopsis thaliana) plants grown under short days (SD) and transferred to long days (LD). Compared with that under SD, the LD transcriptome was enriched in genes involved in jasmonic acid-dependent systemic resistance. Many of these genes exhibited impaired expression induction under LD in the phytochrome A (phyA), cryptochrome 1 (cry1), and cry2 triple photoreceptor mutant. Compared with that under SD, LD enhanced plant resistance to the necrotrophic fungus Bottytis cinerea. This response was reduced in the phyA cry1 cry2 triple mutant, in the constitutive photomorphogenicl (cop1) mutant, in the myc2 mutant, and in mutants impaired in DELLA function. Plants grown under SD had an increased nuclear abundance of COP1 and decreased DELLA abundance, the latter of which was dependent on COP1. We conclude that growth under LD enhances plant defense by reducing COP1 activity and enhancing DELLA abundance and MYC2 expression.This study was supported by a Guggenheim Foundation fellowship (to J.J.C), by Agencia Nacional de Promocion Cientifica y Tecnologica (PICT-2015-1796), by the University of Buenos Aires (20020100100437, to J.J.C.), by the Howard Hughes Medical Institute (J.I.C.), and by the SIGNAT-Research and Innovation Staff Exchange (H2020-MSCA-RISE-2014, to P.D.C., M.A.B., D.A., and J.J.C.).Cagnola, J.; Cerdan, P.; Pacín, M.; Andrade, A.; Rodríguez, V.; Zurbriggen, M.; Legris, M.... (2018). Long-Day Photoperiod Enhances Jasmonic Acid-Related Plant Defense. PLANT PHYSIOLOGY. 178(1):163-173. https://doi.org/10.1104/pp.18.00443S163173178

Diagnostic Applicability of Neutralizing Antibodies to Trypanosoma cruzi Trans-sialidase

The trans-sialidase (TS), a virulence factor expressed on the surface of Trypanosoma cruzi, the agent of Chagas disease, is an enzyme that transfers sialic acids between glycoconjugates. In humans and most tested mammals, the onset of the chronic phase of T. cruzi infection correlates with the elicitation of antibodies directed to the TS catalytic domain, which inhibit the sialyl residues transfer reaction in vitro and in vivo. The method described here, termed trans-sialidase inhibition assay (TIA), enables the detection of TS-neutralizing antibodies in serum samples of different mammalian species, without the use of conjugated secondary reagents. The high specificity and exquisite sensitivity displayed by the TIA allow to overcome the limitations of routinely used Chagas disease serodiagnostic assays.Fil: Leguizamon, Maria Susana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas; Argentin