Carbon Dot Nanozymes Rejuvenate Aged Seeds through ROS Homeostasis Regulation: A Three-Dimensional Coupled Seed...

Area of Science:

• Agricultural Science
• Materials Science
• Biotechnology

Background:

• Seed aging compromises global food security and crop genetic diversity.
• Carbon dots (CDs) show potential for enhancing plant growth and stress resistance.
• The rejuvenating effects and mechanisms of CDs in aged seeds are largely unexplored.

Purpose of the Study:

• To investigate the rejuvenation effects of citric acid-derived carbon dots (CA-CDs) on naturally aged flowering Chinese cabbage seeds.
• To elucidate the mechanisms by which CA-CDs regulate reactive oxygen species (ROS) homeostasis in aged seeds.
• To develop a novel seed quality hallmark and a coupled seed priming strategy using CD SOD nanozymes.

Main Methods:

• Synthesis of citric acid-derived carbon dots (CA-CDs) with superoxide dismutase (SOD)-like activity.
• Seed priming of naturally aged flowering Chinese cabbage seeds with varying concentrations of CA-CDs.
• Assessment of seed germination, seedling establishment, reserve mobilization, vigor, and ROS levels.
• Validation using metal-doped CDs and cross-species applicability testing on accelerated aging seeds (Chinese cabbage, mustard, tomato).

Main Results:

• CA-CDs priming significantly enhanced seed germination, seedling establishment, reserve mobilization, and vigor in aged seeds.
• CA-CDs regulated ROS homeostasis by boosting the antioxidant defense system and directly scavenging ROS.
• Optimal rejuvenation effects were observed with 0.4 mg/mL CA-CDs.
• A seed quality hallmark based on SOD-like activity and a three-dimensional coupled seed priming strategy were successfully developed and validated.

Conclusions:

• CA-CDs effectively rejuvenate naturally aged flowering Chinese cabbage seeds, demonstrating significant improvements in germination and vigor.
• The mechanism involves regulating ROS homeostasis through enhanced antioxidant defense and direct ROS scavenging.
• The study provides a novel approach for aged seed rejuvenation, including a new seed quality hallmark and priming strategy with potential for broad agricultural application.