DRT111/SFPS Splicing Factor Controls Abscisic Acid Sensitivity during Seed Development and Germination

Area of Science:

• Plant Molecular Biology
• Gene Regulation
• Abiotic Stress Response

Background:

• RNA splicing is crucial for generating the cellular proteome under environmental conditions.
• DNA-DAMAGE REPAIR/TOLERATION PROTEIN111 (DRT111), also known as SPLICING FACTOR FOR PHYTOCHROME SIGNALING, is a splicing factor involved in photomorphogenesis.
• DRT111 interacts with phytochrome B and Arabidopsis Splicing Factor1, which recognizes 3' splice sites.

Purpose of the Study:

• To investigate the role of DRT111 in abscisic acid (ABA) signaling and seed development in Arabidopsis.
• To elucidate the molecular mechanisms by which DRT111 integrates light and ABA pathways.

Main Methods:

• Mutant analysis (double and triple mutants) to study gene splicing.
• Analysis of DRT111 expression patterns in seeds and stomata.
• Abscisic acid (ABA) and polyethylene glycol treatments.
• RNA-sequencing to identify DRT111-controlled genes.
• Seed germination assays and stomatal movement measurements.

Main Results:

• DRT111 controls the splicing of ABI3 and acts upstream of SUPPRESSOR OF ABI3-ABI5.
• DRT111 knock-out mutants exhibit defects in ABA-induced stomatal closure and hypersensitivity to ABA during seed germination.
• DRT111 overexpression leads to ABA-hyposensitive seed germination.
• RNA-seq reveals DRT111 regulates genes involved in ABA response, osmotic stress, light signaling, and splicing in dry seeds.
• DRT111 controls the expression of SOMNUS, an ABA- and PIF-induced germination inhibitor.

Conclusions:

• DRT111 plays a critical role in regulating ABA sensitivity during seed development, germination, and stomatal function in Arabidopsis.
• DRT111 integrates ABA and light signaling pathways to control seed germination.
• DRT111 influences the expression and splicing of key genes involved in stress and developmental responses.