Class V chitin synthase and β(1,3)-glucan synthase co-travel in the same vesicle in Zymoseptoria tritici

Highlights

• •

  Native chitin (Chs5) and glucan synthase (Gsc1) visualised in the pathogen Zymoseptoria tritici.

• •

  Chs5 and Gsc1 are transported along microtubules.

• •

  Chs5 and Gsc1 do localise to the apical plasma membrane, but not the Spitzenkörper.

• •

  Light and electron microscopy how co-travel of Chs5 and Gsc1 in the same secretory vesicle.

• •

  Enzyme delivery in Z. tritici is different from Neurospora crassa, but similar to Ustilago maydis.

Abstract

The fungal cell wall consists of proteins and polysaccharides, formed by the co-ordinated activity of enzymes, such as chitin or glucan synthases. These enzymes are delivered via secretory vesicles to the hyphal tip. In the ascomycete Neurospora crassa, chitin synthases and β(1,3)-glucan synthase are transported in different vesicles, whereas they co-travel along microtubules in the basidiomycete Ustilago maydis. This suggests fundamental differences in wall synthesis between taxa. Here, we visualize the class V chitin synthase ZtChs5 and the β(1,3)-glucan synthase ZtGcs1 in the ascomycete Zymoseptoria tritici. Live cell imaging demonstrate that both enzymes co-locate to the apical plasma membrane, but are not concentrated in the Spitzenkörper. Delivery involves co-transport along microtubules of the chitin and glucan synthase. Live cell imaging and electron microscopy suggest that both cell wall synthases locate in the same vesicle. Thus, microtubule-dependent co-delivery of cell wall synthases in the same vesicle is found in asco- and basidiomycetes.