OsMED14_2, a tail module subunit of Mediator complex, controls rice development and involves jasmonic acid

Area of Science:

• Molecular Biology
• Plant Science
• Genetics

Background:

• The Mediator complex is crucial for eukaryotic transcription, but its specific functions in plants, particularly rice, are not well-defined.
• Understanding individual subunit roles, like OsMED14_2 in the Mediator tail module, is essential for deciphering plant development regulation.

Purpose of the Study:

• To investigate the function of OsMED14_2, a rice Mediator complex subunit, in rice development.
• To elucidate the molecular mechanisms underlying OsMED14_2's influence on plant traits and gene expression.

Main Methods:

• Generated OsMED14_2 overexpression and knockout rice lines.
• Performed morphological and microscopic analyses of plant development and pollen.
• Utilized co-immunoprecipitation to identify interacting proteins.
• Quantified gene expression levels and jasmonic acid (JA) levels.

Main Results:

• OsMED14_2 manipulation altered panicle morphology and grain size.
• Overexpression led to impaired pollen maturation, reduced viability, and abnormal intine development.
• OsMED14_2 interacts with pollen development proteins (OsMADS62, OsMADS63, OsMADS68) and negatively regulates their expression.
• OsMED14_2 influences jasmonic acid homeostasis and the expression of JA-responsive genes, potentially via OsHDAC6 and OsJAZ repressors.

Conclusions:

• OsMED14_2 plays a significant role in rice development, impacting plant architecture and reproductive traits.
• The study identifies OsMED14_2 as a key regulator in pollen development and jasmonic acid signaling pathways.
• Findings enhance understanding of the Mediator complex's contribution to essential plant processes and trait regulation.