The Role of Thiols on Sclerotial Differentiation of Filamentous Phytopathogenic Fungi

ABSTRACT

Sclerotial differentiation in filamentous phytopathogenic fungi, represented by four main types of sclerotia, was studied in relation to thiol redox state (TRS) by the TRS modulators glutathione (GSH), N-acetylcysteine [AcCSH, a cysteine (CSH) source and a GSH biosynthesis inducer], and dithiothreitol (DTT, a non specific antioxidant –SH group provider). It was shown that GSH and AcCSH increased either GSH or CSH or both during transition from the undifferentiated to the differentiated state, and, together with DTT, they inhibited sclerotial differentiation. Given the fact that the control thiol DTT had an analogous effect on the unrelated to sclerotial differentiation GSH and CSH levels, these data suggest that the decrease of sclerotial differentiation is related to the antioxidant action of -SH groups and not particularly to GSH and CSH.

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