| Autor: |
Hikaru Endo, Hikari Moriyama, Yutaka Okumura |
| Jazyk: |
angličtina |
| Rok vydání: |
2023 |
| Předmět: |
|
| Zdroj: |
Antioxidants, Vol 12, Iss 2, p 357 (2023) |
| Druh dokumentu: |
article |
| ISSN: |
2076-3921 |
| DOI: |
10.3390/antiox12020357 |
| Popis: |
Plants and brown algae avoid photoinhibition (decline in photosystem II efficiency, Fv/Fm) caused by excess light energy and oxidative stress through several photoprotective mechanisms, such as antioxidant xanthophyll production and heat dissipation. The heat dissipation can be measured as non-photochemical quenching (NPQ) and is strongly driven by de-epoxidation of xanthophyll cycle pigments (XCP). Although NPQ is known to increase under high light acclimation and nutrient-deficient conditions, a few studies have investigated the combined effects of the conditions on both NPQ and associated xanthophyll-to-chlorophyll (Chl) a ratio. The present study investigated the photosynthetic parameters of the brown alga Sargassum fusiforme acclimated to three irradiance levels combined with three nutrient levels. Elevated irradiance decreased Fv/Fm but increased NPQ, XCP/Chl a ratio, and fucoxanthin/Chl a ratio, suggesting the photoprotective role of antioxidant fucoxanthin in brown algae. Reduced nutrient availability increased NPQ but had no effect on the other variables, including XCP/Chl a ratio and its de-epoxidation state. The results indicate that NPQ can be used as a sensitive stress marker for nutrient deficiency, but cannot be used to estimate XCP pool size and state. |
| Databáze: |
Directory of Open Access Journals |
| Externí odkaz: |
|
