The ATP-Citrate Lyase Subunit ACLA, Coordinates Rice Pollen Development by Coupling Transcriptional Regulation with...

Area of Science:

• Plant Biology
• Molecular Biology
• Biochemistry

Background:

• ATP-citrate lyase A (ACLA) is vital for acetyl-CoA synthesis, crucial for lipid metabolism and protein modification.
• Previous research suggested ACLA's involvement in rice anther development, but its precise role in tapetal programmed cell death (PCD) and pollen wall formation was unknown.

Purpose of the Study:

• To investigate the function of ACLA in rice anther development, specifically its role in tapetal PCD and pollen wall formation.
• To elucidate the molecular mechanisms underlying ACLA's regulation of male fertility in rice.

Main Methods:

• Identification and characterization of a novel ACLA allelic mutant (acla) in rice.
• Biochemical assays to measure ACL enzyme activity.
• Transcriptome analysis to identify dysregulated genes.
• Protein-protein interaction assays (Co-IP), subcellular localization, and bimolecular fluorescence complementation (BiFC) assays.

Main Results:

• The acla mutant exhibited premature tapetal degradation, absence of Ubisch bodies, abnormal pollen exine, and microspore abortion.
• Reduced ACL enzyme activity was observed in the acla mutant.
• Transcriptome analysis revealed dysregulation of genes involved in ROS homeostasis, lipid metabolism, ubiquitination, and cell death pathways.
• ACLA was found to directly interact with transcription factors TDR and PTC1, and enzyme CAD8C, co-localizing with them in the nucleus.

Conclusions:

• ACLA plays a critical role in rice anther development by providing acetyl-CoA for metabolism and by interacting with transcription factors and enzymes involved in tapetal PCD and phenylpropanoid metabolism.
• ACLA likely functions within a synergistic transcription-metabolism regulatory network to ensure male fertility in rice.