Extracellular glycolytic activities in root endophytic Serendipitaceae and their regulation by plant sugars

0555990 - ÚVGZ 2023 RIV CH eng J - Journal Article
De Rocchis, V. - Roitsch, Thomas - Franken, P.
Extracellular glycolytic activities in root endophytic Serendipitaceae and their regulation by plant sugars.
Microorganisms. Roč. 10, č. 2 (2022), č. článku 320. E-ISSN 2076-2607
R&D Projects: GA MŠMT(CZ) LO1415
Research Infrastructure: CzeCOS III - 90123
Institutional support: RVO:86652079
Keywords : piriformospora-indica * cell-wall * monosaccharide transporters * carbohydrate-metabolism * arbuscular mycorrhiza * protein secretion * bacillus-subtilis * filamentous fungi * down-regulation * l-arabinose * endophytic fungi * sugar metabolism * glycolysis
OECD category: Microbiology
Impact factor: 4.5, year: 2022
Method of publishing: Open access
https://www.mdpi.com/2076-2607/10/2/320

Endophytic fungi that colonize the plant root live in an environment with relative high concentrations of different sugars. Analyses of genome sequences indicate that such endophytes can secrete carbohydrate-related enzymes to compete for these sugars with the surrounding plant cells. We hypothesized that typical plant sugars can be used as carbon source by root endophytes and that these sugars also serve as signals to induce the expression and secretion of glycolytic enzymes. The plant-growth-promoting endophytes Serendipita indica and Serendipita herbamans were selected to first determine which sugars promote their growth and biomass formation. Secondly, particular sugars were added to liquid cultures of the fungi to induce intracellular and extracellular enzymatic activities which were measured in mycelia and culture supernatants. The results showed that both fungi cannot feed on melibiose and lactose, but instead use glucose, fructose, sucrose, mannose, arabinose, galactose and xylose as carbohydrate sources. These sugars regulated the cytoplasmic activity of glycolytic enzymes and also their secretion. The levels of induction or repression depended on the type of sugars added to the cultures and differed between the two fungi. Since no conventional signal peptide could be detected in most of the genome sequences encoding the glycolytic enzymes, a non-conventional protein secretory pathway is assumed. The results of the study suggest that root endophytic fungi translocate glycolytic activities into the root, and this process is regulated by the availability of particular plant sugars.
Permanent Link: http://hdl.handle.net/11104/0330430