Inositolphosphorylceramide synthases, OsIPCSs, regulate plant height in rice.

Area of Science:

• Plant Biology
• Molecular Genetics
• Biochemistry

Background:

• Inositolphosphorylceramide synthase (IPCS) synthesizes inositolphosphorylceramide (IPC), crucial for plant growth and development.
• Three OsIPCS genes exist in rice, but their specific functions are largely uncharacterized.

Purpose of the Study:

• To elucidate the functions of rice OsIPCS genes in plant growth and development.
• To investigate the roles of OsIPCS genes in sphingolipid metabolism and plant height regulation.

Main Methods:

• CRISPR/Cas9 gene editing was employed to create single and multiple OsIPCS mutants in rice.
• Lipidomics analysis was performed to quantify sphingolipid levels in mutant lines.
• Transcriptomics analysis (RNA-seq) was used to identify differentially expressed genes (DEGs) in response to OsIPCS mutations.

Main Results:

• Single and multi-gene OsIPCS mutations resulted in dwarf phenotypes, with osipcs3 showing the most severe phenotype.
• Mutations led to reduced epidermal cell elongation in internodes and significant decreases in IPC and GIPC levels.
• RNA-seq revealed DEGs associated with cellular organization, morphogenesis, and cell growth in osipcs mutants.

Conclusions:

• OsIPCS genes play a vital, additive role in regulating rice plant height.
• OsIPCSs influence plant height by modulating cell growth and sphingolipid metabolism, particularly IPC and GIPC synthesis.