Dataset Information

Role of Sulfate Transporters in Chromium Tolerance in Scenedesmus acutus M. (Sphaeropleales).

ABSTRACT: Sulfur (S) is essential for the synthesis of important defense compounds and in the scavenging potential of oxidative stress, conferring increased capacity to cope with biotic and abiotic stresses. Chromate can induce a sort of S-starvation by competing for uptake with SO₄^2- and causing a depletion of cellular reduced compounds, thus emphasizing the role of S-transporters in heavy-metal tolerance. In this work we analyzed the sulfate transporter system in the freshwater green algae Scenedesmus acutus, that proved to possess both H⁺/SO₄^2- (SULTRs) and Na⁺/SO₄^2- (SLTs) plasma membrane sulfate transporters and a chloroplast-envelope localized ABC-type holocomplex. We discuss the sulfate uptake system of S. acutus in comparison with other taxa, enlightening differences among the clade Sphaeropleales and Volvocales/Chlamydomonadales. To define the role of S transporters in chromium tolerance, we analyzed the expression of SULTRs and SULPs components of the chloroplast ABC transporter in two strains of S. acutus with different Cr(VI) sensitivity. Their differential expression in response to Cr(VI) exposure and S availability seems directly linked to Cr(VI) tolerance, confirming the role of sulfate uptake/assimilation pathways in the metal stress response. The SULTRs up-regulation, observed in both strains after S-starvation, may directly contribute to enhancing Cr-tolerance by limiting Cr(VI) uptake and increasing sulfur availability for the synthesis of sulfur-containing defense molecules.

SUBMITTER: Ferrari M

PROVIDER: S-EPMC8780407 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Similar Datasets

Project description:BackgroundGenetic transformation of microalgae has been hampered by inefficient transgene expression, limiting the progress of microalgal biotechnology. Many vector tools and strategies have been developed in recent years to improve transgene expression in the model microalga Chlamydomonas, but these were hardly applied to other microalgae. In this work, naturally-isolated oleaginous microalgae were accessed for genetic transformation, and various expression systems were evaluated in a selected microalga to circumvent inefficient transgene expression.ResultsInitially, a strain of Scenedesmus acutus was selected from the oleaginous microalgal collection based on its highest transformation rate and transgene stability. This strain, which had very low or no GFP reporter expression, was first tested to improve transgene expression by using intron-containing constructs and the transcript fusion using ble::E2A. The intron-containing constructs yielded 2.5-7.5% of transformants with 2-4-fold fluorescence signals, while the majority of the transformants of the transcript fusion had the fluorescence signals up to 10-fold. Subsequently, three UV-induced S. acutus mutants were isolated with moderate increases in the level and frequency of transgene expression (2-3-fold and 10-12%, respectively). Finally, a transcript fusion system was developed using psy white mutants with an expression vector containing PSY::E2A for complementation and light selection. Transformants with green colonies were selected under light exposure, and the transgene expression was detected at protein levels. Although the improvement using PSY::E2A was only minor (1-2-fold increase and ~ 7% of transformants), this system provides an alternative selectable marker that is compatible with large-scale culture.ConclusionsHere, the overall improvement of transgene expression using the Chlamydomonas tools was moderate. The most effective tool so far is the transcript fusion using ble::E2A system. This work demonstrates that, so far, genetic engineering of non-model microalgae is still a challenging task. Further development of tools and strategies for transgene expression in microalgae are critically needed.

Dataset Information

Role of Sulfate Transporters in Chromium Tolerance in Scenedesmus acutus M. (Sphaeropleales).

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets