Embryonic abnormalities and genotoxicity induced by 2,4-dichlorophenoxyacetic acid during indirect somatic embryogenesis in Coffea.

Indirect somatic embryogenesis (ISE) is a morphogenetic pathway in which somatic cells form callus and, later, somatic embryos (SE). 2,4-dichlorophenoxyacetic acid (2,4-D) is a synthetic auxin that promotes the proliferation and dedifferentiation of somatic cells, inducing the ISE. However, 2,4-D can cause genetic, epigenetic, physiological and morphological disorders, preventing the regeneration and/or resulting abnormal somatic embryos (ASE). We aimed to evaluate the toxic 2,4-D effect during the Coffea arabica and C. canephora ISE, assessing the SE morphology, global 5-methylcytosine levels (5-mC%) and DNA damage. Leaf explants were inoculated in media with different 2,4-D concentrations. After 90 days, the friable calli were transferred to the regeneration medium, and the number of normal and abnormal SE was monthly counted. The increase of the 2,4-D concentration increased the number of responsive explants in both Coffea. At 9.06, 18.08 and 36.24 µM 2,4-D, C. arabica presented the highest values of responsive explants, differing from C. canephora. Normal and abnormal SE regeneration increased in relation to the time and 2,4-D concentration. Global 5-mC% varied at different stages of the ISE in both Coffea. Furthermore, the 2,4-D concentration positively correlated with global 5-mC%, and with the mean number of ASE. All ASE of C. arabica and C. canephora exhibited DNA damage and showed higher global 5-mC%. The allotetraploid C. arabica exhibited greater tolerance to the toxic effect of 2,4-D than the diploid C. canephora. We conclude that synthetic 2,4-D auxin promotes genotoxic and phytotoxic disorders and promotes epigenetic changes during Coffea ISE.

Hanseníase em países fronteiriços na américa do sul: um estudo ecológico / Lepra en los territories fronterizos de sudamérica: estudio ecológico / Leprosy in border countries in south america: an ecological study

RESUMO Objetivo: caracterizar o perfil clínico epidemiológico e a distribuição espacial da incidência da hanseníase em territórios fronteiriços da América do Sul. Método: trata-se de um estudo ecológico. O estudo compreendeu a Província de Misiones na Argentina e a Região Sul do Brasil. A população foi composta por 10.319 casos novos de hanseníase, diagnosticados entre 2010 e 2016. Resultados: o estado do Paraná foi o mais endêmico, representando 70,2% (n=7,247) dos casos. Houve predomínio da classificação operacional multibacilar (79,8%, n=8.233) e Grau 0 de incapacidade física (50,6%, n=5.223). Em Misiones 18,9% utilizaram esquema de tratamento substitutivo. No período, notou-se uma situação hiperendêmica em 780 (65,5%) dos municípios/ departamentos estudados. Conclusão: o estudo mostrou que as regiões estudadas apresentam alta endemicidade, transmissão ativa e diagnóstico tardio da hanseníase. Essas tendências entrelaçadas à força de morbidade e de transmissão recente e persistente da doença, ampliam a relevância da hanseníase como problema de saúde pública na região.

RESUMEN Objetivo: caracterizar el perfil clínico epidemiológico y la distribución espacial de la incidencia de la lepra en los territorios fronterizos de Sudamérica. Metodología: se trata de un estudio ecológico. El estudio incluyó la Provincia de Misiones en Argentina y la Región Sur de Brasil. La población estaba compuesta por 10.319 nuevos casos de lepra diagnosticados entre 2010 y 2016. Resultados: el estado de Paraná fue el más endémico, representando el 70,2% (n=7.247) de los casos. Predominaron la clasificación operacional multibacilar (79,8%, n=8.233) y el Grado 0 de discapacidad física (50,6%, n=5.223). En Misiones, el 18,9% utilizó un régimen de tratamiento de sustitución. En el periodo se observó una situación hiperendémica en 780 (65,5%) de las ciudades/departamentos estudiados. Conclusión: El estudio mostró que las regiones estudiadas tienen alta endemicidad, transmisión activa y diagnóstico tardío de la lepra. Estas tendencias entrelazadas en cuanto a la fuerza de la morbilidad y la transmisión reciente y persistente de la enfermedad aumentan la importancia de la lepra como un problema de salud pública en la región.

ABSTRACT Objective: to characterize the epidemiological clinical profile and spatial distribution of the incidence of leprosy in border territories of South America. Method: this is an ecological study. The study included the Province of Misiones in Argentina and the Southern Region of Brazil. The population consisted of 10,319 new leprosy cases diagnosed between 2010 and 2016. Results: the state of Paraná was the most endemic, representing 70.2% (n=7.247) of the cases. There was a predominance of multibacillary operational classification (79.8%, n=8,233) and Grade 0 of physical disability (50.6%, n=5,223). In Misiones, 18.9% used a substitution treatment regimen. In the period, a hyperendemic situation was observed in 780 (65.5%) of the studied cities/departments. Conclusion: the study revealed that the regions studied have high endemicity, active transmission and late diagnosis of leprosy. These intertwined trends in the strength of morbidity and recent and persistent transmission of the disease increase the relevance of leprosy as a public health problem in the region.