Experimental rice seed aging under elevated oxygen pressure: Methodology and mechanism

Area of Science:

• Agricultural Science
• Plant Biology
• Seed Physiology

Background:

• Seed aging leads to loss of vigor and germination due to oxidative damage.
• Experimental aging methods accelerate natural aging to study genetic variation.
• Elevated temperature, moisture, and oxygen increase oxidation rates.

Purpose of the Study:

• To investigate the effect of experimental rice seed aging under elevated partial pressure of oxygen (EPPO).
• To elucidate the mechanism of dry-EPPO aging in rice seeds.
• To compare EPPO aging with controlled deterioration (CD) and ambient storage.

Main Methods:

• Rice seeds from 20 accessions were aged under EPPO (200x oxygen) at 50% RH.
• Control groups included storage under high-pressure nitrogen and ambient conditions.
• Untargeted metabolomics analyzed lipid and volatile compounds; seed viability was assessed.

Main Results:

• EPPO storage caused significant rice seed aging, with average 50% germination loss in 21 days and total loss in 56 days.
• Significant variation in aging rates was observed among rice accessions.
• Oxidized lipids and volatiles correlated negatively with seed viability across all storage conditions.

Conclusions:

• Experimental aging of rice seeds under EPPO conditions is a suitable method for assessing genetic variation in seed longevity.
• Oxidation is a primary mechanism driving seed deterioration during experimental aging.
• EPPO aging at 50% RH correlates with traditional rice seed storage (TRSS) and controlled deterioration (CD) aging.