Enhancement of Non-photochemical Quenching as an Adaptive Strategy under Phosphorus Deprivation in the Dinoflagellate Karlodinium veneficum

Abstract

Intensified water column stratification due to global warming has the potential to decrease nutrient availability while increasing excess light for the photosynthesis of phytoplankton in the euphotic zone, which together will increase the need for photoprotective strategies such as non-photochemical quenching (NPQ). We investigated whether NPQ is enhanced and how it is regulated molecularly under phosphorus (P) deprivation in the dinoflagellate Karlodinium veneficum. We grew K. veneficum under P-replete and P-depleted conditions, monitored their growth rates and chlorophyll fluorescence, and conducted gene expression and comparative proteomic analyses. The results were used to characterize NPQ modulation and associated gene expression dynamics under P deprivation. We found that NPQ in K. veneficum was elevated significantly under P deprivation. Accordingly, the abundances of three light-harvesting complex stress-related proteins increased under P-depleted condition. Besides, many proteins related to genetic information flow were down-regulated while many proteins related to energy production and conversion were up-regulated under P deprivation. Taken together, our results indicate that K. veneficum cells respond to P deprivation by reconfiguring the metabolic landscape and up-tuning NPQ to increase the capacity to dissipate excess light energy and maintain the fluency of energy flow, which provides a new perspective about what adaptive strategy dinoflagellates have evolved to cope with P deprivation.

Physiological and Biochemical Responses of Cucumis melo L. Chloroplasts to Low-Phosphate Stress

“…Decreasing g H + will increase transthylakoid proton motive force ( pmf ), thus lowering lumen pH and contributing to the activation of NPQ ( Kanazawa and Kramer, 2002 ). Earlier studies have indicated that NPQ is associated with the regulation of the photoprotective mechanism against high-light stress ( Lambrev et al, 2012 ; Cui et al, 2017 ).…”

Transcriptomic responses associated with carbon and energy flows under high salinity stress suggest the overflow of acetyl-CoA from glycolysis and NADPH co-factor induces high lipid accumulation and halotolerance inChlorellasp. HS2

“…Given that the relative amount of carotenoid pigments in HS2 was increased under high salinity stress (Yun et al, 2019), enhancing the content of zeaxanthin by either upregulating VDE or downregulating ZEP may further enhance the halotolerance of HS2. Furthermore, although NPQ was not changed under high salinity stress, the elevation of NPQ has been denoted as one of the common algal responses under stress conditions (Cui, Zhang, & Lin, 2017). It would be, therefore, interesting to modulate the NPQ activity of HS2 as part of an effort to confer a greater halotolerance or induce a higher lipid productivity.…”

Bacterial Community Diversity and Screening of Growth-Affecting Bacteria From Isochrysis galbana Following Antibiotic Treatment

“…For example, it has been reported that high light intensity stress induces a decrease of F v /F m and an increase of NPQ of T. pseudonana (Zhang R. et al, 2017). In addition, Karlodinium veneficum cells respond to P deprivation by reconfiguring the metabolic landscape and up-tuning NPQ to increase the capacity to dissipate excess light energy and maintain the fluency of energy flow (Cui et al, 2017). In the present study, the values of NPQ in both AT and CK groups were low, while NPQ in the AT group was even lower than that of the CK group (Figure 2).…”