ZmP5CS3 positively regulates drought tolerance by regulating proline biosynthesis and ROS homeostasis in maize...

Area of Science:

• Plant Biology
• Molecular Genetics
• Biochemistry

Background:

• Proline is crucial for plant stress adaptation, acting as an osmoprotectant and reactive oxygen species (ROS) scavenger.
• The maize Δ¹-pyrroline-5-carboxylate synthetase (P5CS) gene family, key to proline synthesis, is largely uncharacterized.
• Understanding P5CS function is vital for improving crop resilience to abiotic stresses like drought.

Purpose of the Study:

• To functionally characterize the ZmP5CS3 gene in maize.
• To elucidate the molecular mechanisms underlying ZmP5CS3's role in drought response.
• To explore ZmP5CS3 as a candidate for breeding drought-tolerant maize.

Main Methods:

• In vitro enzymatic assays to confirm ZmP5CS3's proline synthesis activity.
• Gene expression analysis under drought stress conditions.
• Genetic assays and physiological experiments in maize and Arabidopsis thaliana (heterologous expression).

Main Results:

• ZmP5CS3 protein localizes to the cytoplasm and exhibits enzymatic activity.
• Drought stress significantly upregulates ZmP5CS3 expression, increasing proline levels.
• ZmP5CS3 overexpression enhances drought tolerance by increasing proline, reducing ROS, and mitigating lipid peroxidation.

Conclusions:

• ZmP5CS3 plays a significant positive role in maize seedling drought tolerance.
• The gene coordinates proline biosynthesis and ROS detoxification pathways.
• ZmP5CS3 represents a promising genetic resource for developing drought-resistant maize cultivars.