ABA seed priming alleviates low-temperature-induced inhibition

Area of Science:

• Plant Physiology
• Stress Biology
• Agricultural Science

Background:

• Abscisic acid (ABA) regulates seed dormancy and stress responses, but its impact on germination is concentration- and condition-dependent.
• Low temperatures inhibit seed germination and early seedling establishment in direct-seeded rice.

Purpose of the Study:

• To investigate if exogenous ABA seed priming can overcome low-temperature-induced germination inhibition in direct-seeded rice.
• To assess ABA priming's effects on early seedling establishment under cold stress.

Main Methods:

• Rice seeds were primed with varying ABA concentrations and subjected to low-temperature stress.
• Evaluated germination, reserve mobilization, respiration, antioxidant activity, gene expression, and seedling growth.

Main Results:

• 40 μmol L^-1 ABA priming optimized germination and seedling establishment under cold stress.
• ABA priming enhanced reserve mobilization, respiration, and antioxidant capacity while reducing oxidative damage.
• Priming modulated endogenous ABA/GA balance and improved root growth and chlorophyll content.

Conclusions:

• Appropriate ABA seed priming effectively improves rice germination and seedling establishment under low-temperature stress.
• The benefits are attributed to enhanced physiological adjustments and a favorable hormonal status.
• Further research on ABA signaling and GA metabolism is warranted.