RESUMEN
Seed germination in many plant species is triggered by sunlight, which is rich in the red (R) wavelength and repressed by under-the-canopy light rich in far red (FR). R:FR ratios are sensed by phytochromes to regulate levels of gibberellins (GAs) and abscisic acid (ABA), which induce and inhibit germination respectively. In this study we have discovered that, under FR light conditions, germination is repressed by MOTHER-OF-FT-AND-TFL1 (MFT) through the regulation of the ABA and GA signaling pathways. We also show that MFT gene expression is tightly regulated by light quality. Previous work has shown that under FR light conditions the transcription factor PHYOCHROME-INTERACTING-FACTOR1 (PIF1) accumulates and promotes expression of SOMNUS (SOM) that, in turn, leads to increased ABA and decreased GA levels. PIF1 also promotes expression of genes encoding ABA-INSENSITIVE5 (ABI5) and DELLA growth-repressor proteins, which act in the ABA and GA signaling pathways, respectively. Here we show that MFT gene expression is promoted by FR light through the PIF1/SOM/ABI5/DELLA pathway and is repressed by R light via the transcription factor SPATULA (SPT). Consistent with this, we also show that SPT gene expression is repressed under FR light in a PIF1-dependent manner. Furthermore, transcriptomic analyses presented in this study indicate that MFT exerts its function by promoting expression of known ABA-induced genes and repressing cell wall expansion-related genes.
Asunto(s)
Proteínas de Arabidopsis/fisiología , Arabidopsis/fisiología , Proteínas Portadoras/fisiología , Germinación/fisiología , Reguladores del Crecimiento de las Plantas/fisiología , Ácido Abscísico/fisiología , Proteínas de Arabidopsis/genética , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/fisiología , Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/genética , Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/fisiología , Proteínas Portadoras/genética , Giberelinas/fisiología , Péptidos y Proteínas de Señalización Intracelular , Luz , Transducción de Señal/fisiologíaRESUMEN
BACKGROUND: A program to eliminate obstetric urogenital fistula (OUGF) was set up on February 19, 2004 in Niger. Though the consultations were free of charge, there was a cost involved, which constitutes the objective of this study. METHOD: The data were obtained from a documentary study completed by discussions with the principal management participants and interviews targeting the women suffering from OUGF attending the national hospital of Niamey during the surgery sessions of April and November 2006. Cost assessment included all resources devoted to activities involved in the program: hospital stay, hygiene education, medical and surgical treatment, social rehabilitation interventions (preparation for revenue generating activities and return to residence). Data analysis was performed with Excel and Epi2000 software. Average cost per item and patient was determined. RESULTS: The cost of the stay at the National hospital of Niamey was 96,445 francs CFA divided between transportation (4,688), room and board (21,572), assistance bonus (3,708) and indirect costs (66,477). The hygiene education cost 194,140 francs CFA: 30,150 for human resources, 143,965 for material resources and 20,025 for operational costs. The medical and surgery treatment had a cost of 144,009 francs CFA divided between consultations (15,000), complementary explorations (44,900), surgical operation (50,000) and consumables (34,109). The preparation for revenue generating activities had a cost of 118,244 francs CFA including training for clothes dying (22,084), soap manufacture (46,160) and the financial supportive grant (50,000). The return to the community cost 295,000 francs CFA, included room and board (2,500), human resources (65,000) and material resources (227,500). Altogether, the cost of the OUGF program came up to 742,018 francs CFA for our sample (76% of women with revenue generating activity), and was assessed at a maximum of 781,362 francs CFA if none of the woman had a revenue generating activity, and a minimum of 729,594 francs CFA if all of them did. CONCLUSION: Without the free consultations, the high cost of the OUGF program at the national hospital of Niamey would be inaccessible to Nigerian women owing to poverty and ignorance. Because of this observation, a long-term program is warranted for the treatment of overt cases and the reduction of prevalence, to enable Nigerian women to contribute to the development activities of their country.