The fungus Macrophomina phaseolina is a phytopathogen of great importance attacking various crops and causing severe losses especially in sorghum, beans, soybeans and others. Since acetic indole acid (AIA) is a hormone that some authors associate with the pathogenic power of other fungi such as Fusarium oxysporum, it was decided to perform this work to detect whether M phaseolina isolated from beans is layers of producing AIA and which synthesis pathways are involved in its production. The analyses performed using HPLC showed the production of indole acetamide (ACM) that occurs in the first 60 hours of incubation. Another compound produced is Indole (IND) which is released after 60 hours when ACM production has ceased. Similarly, the fungus can metabolize AIA in the culture medium and tryptophan, the main precursor of AIA, apparently has no effect on the amount of AIA synthesized. Conclusion: The phytopathogenic fungus Macrophomina phaseolina can produce indole acetic acid, a hormone that stimulates plant growth through the TRP-D pathway via indole acetamide, which occurs mainly in the first 60 hours of growth of the fungus in the culture medium. In addition, the presence of indole was detected, which allows us to estimate that the fungus uses another little explored route that is TRP-I and that from this compound the AIA can be synthesized directly or transformed into TRP. This means that when a metabolic pathway of IAA is turned off (ACM) it is replaced by another pathway (Indole). The convenient is to correlate the release of indole acetic acid with the pathogenicity of M phaseolina.

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El hongo Fusarium oxysporumSchltdl es un agente fitopatógeno que tiene amplia distribución en el mundo, atacando cultivos anuales y perennes de diversas familias,como las solanáceas, cucurbitáceas y gramíneas;y en infección avanzada la apariencia de las plantas es marchitamiento y muerte. F oxysporumpuede producir ácido indol acético,que puede estar involucrado en el proceso patogénico de este hongo sobre sus hospederos. En este caso, empleando una cepa asilada de rizosfera de zarzamora,se estudiaron las rutas de síntesis del ácido indol acético (AIA),usando medio de cultivo LB adicionado o no con triptofano, principal cofactor en este tipo de estudios. El objetivo del estudio es determinar si Fusarium oxysporumcepa Poxy05es capaz de producir el AIA y las vías que emplea en ello. Para esto se aplicaron estándares comerciales para la detección por HPLC de los compuestos clave que intervienen en las vías de síntesis del AIA. Los resultados muestran que esta cepa produce AIA por la ruta del indol acetamida (IAM), una vía de la ruta Triptofano-Dependiente. Los compuestos involucrados en las rutas Triptofano-Independiente no fueron detectados, por lo que se estima que laIAMes la única vía empleada por el hongoen la síntesis del IAA.