Repository of University of Nova Gorica

Search the repository
A+ | A- | Help | SLO | ENG

Query: search in
search in
search in
search in
* old and bolonia study programme

Options:
  Reset


1 - 1 / 1
First pagePrevious page1Next pageLast page
1.
1,8-dihydroxy naphthalene (DHN) - melanin confers tolerance to cadmium in isolates of melanised dark septate endophytes
Marjana Regvar, Jože Grdadolnik, Iztok Arčon, Katarina Vogel-Mikuš, Matevž Likar, Mateja Potisek, 2021, original scientific article

Abstract: The contribution of 1,8-dihydroxy naphthalene (DHN) melanin to cadmium (Cd) tolerance in two dark septate endophytes (DSE) of the genus Cadophora with different melanin content was investigated in vitro. The DSE isolate Cad#148 with higher melanin content showed higher tolerance to Cd than the less melanised Cad#149. Melanin synthesis was significantly reduced by Cd in both isolates with uninhibited melanin synthesis, in a dosedependent manner. Inhibition of melanin synthesis by tricyclazole reduced the relative growth of Cad#148 exposed to Cd and did not affect Cad#149. Cd accumulation was not altered by tricyclazole in the two isolates, but it increased catalase and reduced glutathione reductase activity in more melanised Cad#148, indicating higher stress levels. In contrast, in Cad#149 the enzyme activity was less affected by tricyclazole, indicating a more pronounced role of melanin-independent Cd tolerance mechanisms. Cd ligand environment in fungal mycelia was analysed by extended EXAFS (X-ray absorption fine structure). It revealed that Cd was mainly bound to O- and S-ligands, including hydroxyl, carboxyl, phosphate and thiol groups. A similar proportion of S- and Oligands (~35% and ~65%) were found in both isolates with uninhibited melanin synthesis. Among O-ligands two types with Cd-O-C- and Cd-O-P- coordination were identified. Tricyclazole altered Cd-O- ligand environment in both fungal isolates by reducing the proportion of Cd-O-C- and increasing the proportion of Cd-O-P coordination. DHN-melanin, among other tolerance mechanisms, significantly contributes to Cd tolerance in more melanised DSE fungi by immobilising Cd to hydroxyl groups and maintaining the integrity of the fungal cell wall.
Found in: ključnih besedah
Summary of found: ...DSE, melanin, Cd tolerance, inhibitor tricyclazole, antioxidant enzymes, EXAFS...
Keywords: DSE, melanin, Cd tolerance, inhibitor tricyclazole, antioxidant enzymes, EXAFS
Published: 13.07.2021; Views: 365; Downloads: 0
.pdf Fulltext (1,73 MB)

Search done in 0 sec.
Back to top