Uridine diphosphate glucose confers oxidative stress tolerance in microalgae

Area of Science:

• Marine Biology
• Plant Physiology
• Biochemistry

Background:

• Microalgae are vital primary producers facing significant oxidative stress.
• Understanding microalgal oxidative stress resistance is crucial for their productivity and survival.
• Mechanisms of microalgal stress response remain largely unexplored.

Purpose of the Study:

• To identify key regulators of oxidative stress response in the model microalga Phaeodactylum tricornutum.
• To investigate the role of carbohydrate metabolism intermediates in stress tolerance.
• To elucidate the protective mechanisms conferred by identified regulators.

Main Methods:

• Exogenous application of uridine diphosphate glucose (UDPG).
• Genetic manipulation: Overexpression of UDP-glucose pyrophosphorylase (UGPase) and UGPase knockout.
• Physiological and biochemical assays: ROS, malondialdehyde, cell death, antioxidant enzyme activity.
• Molecular analyses: Transcriptomics and quantitative PCR.

Main Results:

• UDPG acts as a positive regulator of oxidative stress tolerance in P. tricornutum.
• Exogenous UDPG and UGPase overexpression enhanced stress tolerance, reducing ROS and cell damage.
• UGPG protected photosynthesis by upregulating associated genes and reducing damage to the electron transport chain.
• Reduced UDPG levels exacerbated oxidative damage.

Conclusions:

• UDPG plays a significant role in the oxidative stress response pathway in P. tricornutum.
• UDPG enhances microalgal stress tolerance by protecting photosynthetic processes.
• UDPG represents a promising target for engineering improved stress resilience in microalgae.