Fine-tuning gibberellin improves rice alkali-thermal tolerance and yield

Area of Science:

• Plant Science
• Agricultural Science
• Genetics

Background:

• Soil alkalinization and global warming threaten global arable land and crop yields.
• Green Revolution varieties (GRVs) require enhanced tolerance to abiotic stresses for future agriculture.
• Phytohormone gibberellin (GA) regulation is proposed as a strategy to improve crop resilience and yield.

Purpose of the Study:

• To investigate the role of precise gibberellin (GA) regulation in conferring alkali-thermal tolerance to GRVs.
• To identify genetic factors for optimizing GA levels to enhance crop yield under stress conditions.
• To explore the potential of new genes for sustainable agriculture on marginal lands.

Main Methods:

• Investigated endogenous modulation of ALKALI-THERMAL TOLERANCE 1/2 (ATT1/2) genes encoding GA20-oxidases.
• Applied exogenous gibberellin (GA) to assess its effect on rice yield in sodic soils.
• Analyzed the mechanistic link between GA levels, reactive oxygen species, and H3K27me3 methylation in stress tolerance.

Main Results:

• Endogenous modulation of ATT1/2 and exogenous GA application minimized yield loss in rice under sodic soil conditions.
• High GA concentrations led to reactive oxygen species over-accumulation, while low GA repressed stress-tolerance genes via DELLA-NGR5-mediated H3K27me3 methylation.
• ATT2 was identified as a key gene for fine-tuning GA levels, balancing reactive oxygen species and H3K27me3 methylation for improved alkali-thermal tolerance and yield.

Conclusions:

• Precise GA regulation is crucial for enhancing alkali-thermal tolerance and yield in GRVs.
• The ATT2 gene offers a promising target for developing climate-resilient crops.
• Harnessing ATT2 can facilitate the use of marginal lands for sustainable agriculture.