Fruit load modulates flowering-related gene expression in buds of alternate-bearing 'Moncada' mandarin

Background and Aims Gene determination of flowering is the result of complex interactions involving both promoters and inhibitors. In this study, the expression of flowering-related genes at the meristem level in alternate-bearing citrus trees is analysed, together with the interplay between buds and leaves in the determination of flowering. Methods First defruiting experiments were performed to manipulate blossoming intensity in `Moncada¿ mandarin, Citrus clementina. Further defoliation was performed to elucidate the role leaves play in the flowering process. In both cases, the activity of flowering-related genes was investigated at the flower induction (November) and differentiation (February) stages. Key Results Study of the expression pattern of flowering-genes in buds from on (fully loaded) and off (without fruits) trees revealed that homologues of FLOWERING LOCUS T (CiFT), TWIN SISTER OF FT (TSF), APETALA1 (CsAP1) and LEAFY (CsLFY) were negatively affected by fruit load. CiFT and TSF activities showed a marked increase in buds from off trees through the study period (ten-fold in November). By contrast, expression of the homologues of the flowering inhibitors of TERMINAL FLOWER 1 (CsTFL), TERMINAL FLOWER 2 (TFL2) and FLOWERING LOCUS C (FLC) was generally lower in off trees. Regarding floral identity genes, the increase in CsAP1 expression in off trees was much greater in buds than in leaves, and significant variations in CsLFY expression (approx. 20 %) were found only in February. Defoliation experiments further revealed that the absence of leaves completely abolished blossoming and severely affected the expression of most of the flowering-related genes, particularly decreasing the activity of floral promoters and of CsAP1 at the induction stage. Conclusions These results suggest that the presence of fruit affects flowering by greatly altering gene-expression not only at the leaf but also at the meristem level. Although leaves are required for flowering to occur, their absence strongly affects the activity of floral promoters and identity genes.This work was supported by a grant from the Instituto Nacional Investigaciones Agrarias, Spain (RTA2009-00147). M. C. Gonzalez was the recipient of a contract by the Fundacion Agroalimed (Conselleria d'Agricultura, Pesca i Alimentacio, Generalitat Valenciana).Muñoz Fambuena, N.; Mesejo Conejos, C.; Gonzalez Más, MC.; Primo-Millo, E.; Agustí Fonfría, M.; Iglesias, DJ. (2012). Fruit load modulates flowering-related gene expression in buds of alternate-bearing 'Moncada' mandarin. Annals of Botany. 110(6):1109-1118. doi:10.1093/aob/mcs190S110911181106Abe, M. (2005). FD, a bZIP Protein Mediating Signals from the Floral Pathway Integrator FT at the Shoot Apex. Science, 309(5737), 1052-1056. doi:10.1126/science.1115983Bustin, S. (2002). Quantification of mRNA using real-time reverse transcription PCR (RT-PCR): trends and problems. 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Mechanisms and Biomarkers of Exercise-Induced Bronchoconstriction.

Exercise is a common trigger of bronchoconstriction. In recent years, there has been increased understanding of the pathophysiology of exercise-induced bronchoconstriction. Although evaporative water loss and thermal changes have been recognized stimuli for exercise-induced bronchoconstriction, accumulating evidence points toward a pivotal role for the airway epithelium in orchestrating the inflammatory response linked to exercise-induced bronchoconstriction. Overproduction of inflammatory mediators, underproduction of protective lipid mediators, and infiltration of the airways with eosinophils and mast cells are all established contributors to exercise-induced bronchoconstriction. Sensory nerve activation and release of neuropeptides maybe important in exercise-induced bronchoconstriction, but further research is warranted

"Laceratio famae" : invective as facework in Cicero's "In Pisonem".

Recent discussions of Cicero’s In Pisonem have approached the functioning of invective in the speech mainly in terms of the orator’s ability to fashion rhetorical weapons from the audience’s social biases and, consequently, have focused on evidence of his success in injuring his opponent’s reputation and dignity. That Piso, his opponent, had an equal opportunity and success in fighting back against Cicero’s attacks is, as I will argue, a crucial factor in determining the possible outcomes of this contest. I argue that when the In Pisonem is viewed as a 'character contest', the conflict between Piso and Cicero appears to have been both unavoidable and yet inconclusive, despite evidence of Cicero's victory in the speech itself. While Cicero's attack on Piso displays superior rhetorical skill, humour and poise, the fact that Piso responded to the publication of the In Pisonem by publishing his own speech demonstrates that he was able to continue his side of the battle beyond Cicero's apparent victory. Although Cicero can claim a victory as the 'manifest outcome' of the Senate debate, it is clear that 'interpretological outcomes' came into play on both sides. Piso's persistence in the quarrel permits him a secondary claim to victory when Cicero, believing he has already won, decides not to respond. Comparison with Cicero's handling of Clodius' victory in the Bona Dea scandal, reinforces the importance of interpretation in determining the outcomes of invective contests. Win or lose, Roman orators will put the best face on their performance and emerge relatively unscathed from the 'character contests' in which their careers seem to hang in the balance. Piso's success in the conflict is seen as well in his continuation as Caesar's father-in-law, a role that Cicero clearly attempted to put in jeopardy in his attack. In this regard, Goffman's account of 'character contest' proves a reliable guide to understanding the grey areas which obscure the outcome of the conflict.Arts, Faculty ofClassical, Near Eastern and Religious Studies, Department ofGraduat