Can Rose Bengal resilience be used as a marker for photosynthetic resilience of Nannochloropsis oceanica strains in excess light environments?

Ascorbate‐glutathione cycle alleviates low‐temperature‐induced oxidative stress for augmented growth of Nannochloropsis oceanica Rose Bengal mutants

“…Possessing NPQ activity and truncated PSII remodeling as a protective mechanism against PSII‐derived 1 O 2 overproduction during LT‐HL conditions (Ben‐Sheleg et al, 2019, 2021) supports the hypothesis that the AGC system, through increased gene expression and enzyme activity, as well as enhanced availability of AsA and GSH, plays a pivotal role in ROS management (Figure S1). The regulation of ROS production and their effective scavenging through genetic engineering offers promise for enhancing plant tolerance to temperature stress and the combined challenges of low temperature and high‐light intensity (Allen, 1995).…”

“…As compared to the severe oxidative damage and cell mortality in the WT strain, the RB mutants still displayed a marked biomass production without oxidative stress under LT and LT‐HL conditions (Figure 1). In addition to the reduction of light absorption and NPQ‐mediated heat dissipation of excessive energy (Ben‐Sheleg et al, 2019,2021), AGC also plays a role in the RB mutants' acclimation to excess light energy under an LT environment. In these mutants, APX, as the central AGC enzyme important for ROS scavenging, is responsible for H 2 O 2 detoxification with the help of the AsA substrate, as an electron donor, against the oxidative stress generated by LT and LT‐HL conditions.…”

“…The Nannochloropsis oceanica wild‐type (WT) strain CCALA 804 (Pal et al, 2013) and RB2 and RB113 mutants (Ben‐Sheleg et al, 2019) were obtained from the Microalgal Biotechnology Laboratory, J. Blaustein Institutes for Desert Research, Ben‐Gurion University of the Negev, Sede Boqer Campus). The cells were photoautotrophically cultured in a reef salt (RSE) medium consisting of 34 g⋅L −1 salt (Seachem™) supplemented with nutrients as described earlier (Ben‐Sheleg et al 2019, 2021). Cells were cultivated in 500‐mL serum bottles, each containing 300 mL of the RSE medium.…”

“…A comprehensive metabolic network analysis, in conjunction with engineering strategies aimed at enhancing fatty acid unsaturation, such as the overexpression of Δ12 desaturase as demonstrated byKaye et al (2015), also requires further investigation into Nannochloropsis RB mutants. This research is essential to gain a more profound understanding of the hurdles encountered in large-scale microalgal cultivation and the establishment of economically sustainable commercial production of EPA.5 | CONCLUSIONPossessing NPQ activity and truncated PSII remodeling as a protective mechanism against PSII-derived 1 O 2 overproduction during LT-HL conditions(Ben-Sheleg et al, 2019, 2021 supports the hypothesis that the AGC system, through increased gene expression and enzyme activity, as well as enhanced availability of AsA and GSH, plays a pivotal role in ROS management (FigureS1). The regulation of ROS production and their effective scavenging through genetic engineering offers promise for enhancing plant tolerance to temperature stress and the combined challenges of low temperature and high-light intensity(Allen, 1995).…”