OsCSD2 and OsCSD3 Enhance Seed Storability by Modulating Antioxidant Enzymes and Abscisic Acid in Rice

Area of Science:

• Plant Biology
• Genetics
• Agricultural Science

Background:

• Seed deterioration impacts rice quality, viability, and yield.
• Previous research identified quantitative trait loci (QTLs) for seed storability.

Purpose of the Study:

• Investigate candidate genes within QTLs for rice seed storability.
• Elucidate the role of OsCSD2 and OsCSD3 in maintaining seed quality during storage.

Main Methods:

• Genome association analysis to screen candidate genes.
• Generation of transgenic rice lines (overexpression and CRISPR/Cas9 mutants) for OsCSD2 and OsCSD3.
• Physiological assays including relative electrical conductivity measurements.
• Enzyme activity assays for superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD).
• Hormone profiling to assess abscisic acid (ABA) levels.

Main Results:

• OsCSD2 and OsCSD3 positively regulate rice seed storability.
• Overexpression lines showed reduced cell membrane damage (lower relative electrical conductivity).
• Mutant lines exhibited increased cell membrane damage.
• Transgenic lines had elevated SOD, CAT, and POD activities, indicating an enhanced antioxidant system.
• Abscisic acid (ABA) levels correlated with improved seed storability.

Conclusions:

• OsCSD2 and OsCSD3 are key regulators of rice seed storability.
• Enhanced antioxidant defense and ABA signaling contribute to improved seed quality during storage.
• Findings have implications for reducing grain loss and enhancing food security.