Molecular Response of Ulva prolifera to Short-Term High Light Stress Revealed by a Multi-Omics Approach

Abstract

The main algal species of Ulva prolifera green tide in the coastal areas of China are four species, but after reaching the coast of Qingdao, U. prolifera becomes the dominant species, where the light intensity is one of the most important influencing factors. In order to explore the effects of short-term high light stress on the internal molecular level of cells and its coping mechanism, the transcriptome, proteome, metabolome, and lipid data of U. prolifera were collected. The algae were cultivated in high light environment conditions (400 μmol·m−2·s−1) for 12 h and measured, and the data with greater relative difference (p < 0.05) were selected, then analyzed with the KEGG pathway. The results showed that the high light stress inhibited the assimilation of U. prolifera, destroyed the cell structure, and arrested its growth and development. Cells entered the emergency defense state, the TCA cycle was weakened, and the energy consumption processes such as DNA activation, RNA transcription, protein synthesis and degradation, and lipid alienation were inhibited. A gradual increase in the proportion of the C4 pathway was recorded. This study showed that U. prolifera can reduce the reactive oxygen species produced by high light stress, inhibit respiration, and reduce the generation of NADPH. At the same time, the C3 pathway began to change to the C4 pathway which consumed more energy. Moreover, this research provides the basis for the study of algae coping with high light stress.

Transcriptomic Changes Induced by Low and High Concentrations of Heavy Metal Exposure in Ulva pertusa

“…In addition, the mitochondria and chloroplasts are cell compartments that are very sensitive to oxidative damage due to the strong electron flux in the microenvironment, including increased oxygen and high metal ion concentrations [ 12 ]. The expression of chlorophyll-related genes ( CAB , CAB-151 , CAB1R , CAB5 , and Cabll-1 ) was reduced in the group exposed to high copper concentrations (MPS vs. MPS-Cu), indicating that copper ions have a particular impact on the chlorophyll-related mechanisms [ 19 , 21 ]. Diatoms exposed to copper showed increased carbohydrate production [ 62 ].…”

“…Studies have also explored the underlying mechanisms of action of these stress responsive genes in seaweeds. Some of the seaweeds that have been studied at the molecular level include Ulvaceae such as U. prolifera [ 18 , 19 ], U. linza [ 20 ], and U. compressa [ 21 , 22 ].…”

Review of Allelopathy in Green Tides: The Case of Ulva prolifera in the South Yellow Sea

“…Under high light, U. prolifera will change their carbon storage and improve their physiological photosynthetic activities. This strategy is mostly shown in the change from C3 to C4 photosynthesis [ 46 ]. The biological modification greatly enhances fatty acid synthesis and enables it to continue to be active in harsh conditions [ 46 ].…”

“…This strategy is mostly shown in the change from C3 to C4 photosynthesis [ 46 ]. The biological modification greatly enhances fatty acid synthesis and enables it to continue to be active in harsh conditions [ 46 ]. Furthermore, included in this survival strategy is precisely controlled energy expenditure and carbohydrate metabolism [ 58 ].…”

Ulva: An emerging green seaweed model for systems biology

“…Integration of omics approaches such as metabolomics and proteomics accompanied with the careful descriptions of phenotypes have proven to be especially successful in elucidating algal‐bacterial cross‐talk mechanisms, the effect of abiotic and biotic stimuli, and life cycle transitions (Alsufyani et al, 2017; Fan et al, 2022; Fort et al, 2019; Ghaderiardakani et al, 2022; Gu et al, 2022; He et al, 2019; Kessler et al, 2017; Liu et al, 2022).…”