Effects of Chemical inhibition of histone deacetylase proteins in the growth and virulence of Macrophomina phaseolina (Tassi) Goid / Efectos de la inhibición química de las proteínas desacetilasas de histonas en el crecimiento y la virulencia de Macrophomina phaseolina (Tassi) Goid

Abstract Chromatin remodeling enzymes are important "writers'', "readers'' and "erasers'' of the epigenetic code. These proteins are responsible for the placement, recognition, and removal of molecular marks in histone tails that trigger structural and functional changes in chromatin. This is also the case for histone deacetylases (HDACs), i.e., enzymes that remove acetyl groups from histone tails, signaling heterochromatin formation. Chromatin remodeling is necessary for cell differentiation processes in eukaryotes, and fungal pathogenesis in plants includes many adaptations to cause disease. Macrophomina phaseolina (Tassi) Goid. is a nonspe-cific, necrotrophic ascomycete phytopathogen that causes charcoal root disease. M. phaseolina is a frequent and highly destructive pathogen in crops such as common beans (Phaseolus vulgaris L.), particularly under both water and high temperature stresses. Here, we evaluated the effects of the classical HDAC inhibitor trichostatin A (TSA) on M. phaseolina in vitro growth and virulence. During inhibition assays, the growth of M. phaseolina in solid media, as well as the size of the microsclerotia, were reduced (p <0.05), and the colony morphology was remark-ably affected. Under greenhouse experiments, treatment with TSA reduced (p <0.05) fungal virulence in common bean cv. BAT 477. Tests of LIPK, MAC1 and PMK1 gene expression during the interaction of fungi with BAT 477 revealed noticeable deregulation. Our results provide additional evidence about the role of HATs and HDACs in important biological processes of M. phaseolina.

Resumen Las enzimas remodeladoras de la cromatina son «escritores¼, «lectores¼ y «borradores¼ importantes del código epigenético. Estas proteínas son responsables de la localización, el reconocimiento y la remoción de las marcas moleculares sobre las terminaciones de las histonas que desencadenan cambios funcionales y estructurales en la cromatina. Es el caso de las desacetilasas de histonas (HDAC), enzimas que remueven grupos acetilo de las «colas¼ de las histonas, señalizando la formación de heterocromatina. La anterior es una actividad necesaria en los procesos de diferenciación celular de los eucariotas, y se conoce que la patogénesis fúngica en las plantas requiere de adaptaciones diversas para ocasionar enfermedad. Macrophomina phaseolina (Tassi) Goid. es un ascomiceto fitopatógeno, necrótrofo e inespecífico, causante de la pudrición carbonosa. Este es un hongo frecuente y altamente destructivo en cultivos como fríjol común (Phaseolus vulgaris L.), particularmente bajo estrés hídrico y térmico. En este trabajo evaluamos los efectos del inhibidor de HDAC clásicas tricostatina A (TSA) sobre el crecimiento in vitro y la virulencia de M. phaseolina. El TSA redujo el crecimiento de M. phaseolina en medio sólido y el tamano de los microesclerocios (p < 0,05), lo que afectó la morfología colonial. En invernadero, el tratamiento con TSA disminuyó (p<0,05) la gravedad de la infección en la variedad de frijol BAT 477. La expresión de los genes de patogenicidad LIPK, MAC1 y PMK1 durante la interacción del hongo con la planta reveló una desregulación importante. Estos resultados proporcionan evidencia adicional del papel que cumplen las HDAC en la regulación de procesos biológicos fundamentales de M. phaseolina. © 2023 Asociación Argentina de Microbiología. Publicado por Elsevier Espana, S.L.U.

Effects of chemical inhibition of histone deacetylase proteins in the growth and virulence of Macrophomina phaseolina (Tassi) Goid.

Chromatin remodeling enzymes are important "writers", "readers" and "erasers" of the epigenetic code. These proteins are responsible for the placement, recognition, and removal of molecular marks in histone tails that trigger structural and functional changes in chromatin. This is also the case for histone deacetylases (HDACs), i.e., enzymes that remove acetyl groups from histone tails, signaling heterochromatin formation. Chromatin remodeling is necessary for cell differentiation processes in eukaryotes, and fungal pathogenesis in plants includes many adaptations to cause disease. Macrophomina phaseolina (Tassi) Goid. is a nonspecific, necrotrophic ascomycete phytopathogen that causes charcoal root disease. M. phaseolina is a frequent and highly destructive pathogen in crops such as common beans (Phaseolus vulgaris L.), particularly under both water and high temperature stresses. Here, we evaluated the effects of the classical HDAC inhibitor trichostatin A (TSA) on M. phaseolinain vitro growth and virulence. During inhibition assays, the growth of M. phaseolina in solid media, as well as the size of the microsclerotia, were reduced (p<0.05), and the colony morphology was remarkably affected. Under greenhouse experiments, treatment with TSA reduced (p<0.05) fungal virulence in common bean cv. BAT 477. Tests of LIPK, MAC1 and PMK1 gene expression during the interaction of fungi with BAT 477 revealed noticeable deregulation. Our results provide additional evidence about the role of HATs and HDACs in important biological processes of M. phaseolina.

Different histone deacetylase inhibitors reduce growth, virulence as well as changes in the morphology of the fungus Macrophomina phaseolina (Tassi) Goid.

Fungal phytopathogens require different skills to infect plants and complete their lifecycle. Some proteins in fungi are essential for pathogenesis and their expression is regulated by epigenetic mechanisms via chromatin-remodeling. Macrophomina phaseolina is an important phytopathogenic fungus that leads to considerable losses of different crops, especially during drought conditions. Some biological features of the fungus have been described. However, the epigenetics mechanisms involved in the development and virulence of M. phaseolina have not been fully studied. In this work, chemical inhibition was used to evaluate the role of histone deacetylases (HDACs) in the biology of M. phaseolina. The effect of two histone deacetylase inhibitors (iHDAC), valproic acid (VPA) and sodium butyrate (SBT), was analyzed. The results showed that the treated fungus presented a decrease in microsclerotia diameter, aerial mycelia production, vegetative growth, and cell pigmentation. In addition, VPA and SBT also affected the ability of the fungus to grow on complex carbon sources and virulence in the bean variety, BAT 477. Thus, it can be concluded that the alteration of histone deacetylation by VPA and SBT affects M. phaseolina growth, morphology, and virulence.