OsCYCD7;1 rigidly determines guard mother cell division in rice

Area of Science:

• Plant biology
• Molecular genetics
• Developmental biology

Background:

• Stomatal development relies on precise guard mother cell (GMC) division.
• Grass stomatal development, featuring dumbbell-shaped guard cells, has unique mechanisms.
• The molecular regulation of GMC division in grasses is not well understood.

Purpose of the Study:

• To identify key regulators of guard mother cell division in rice.
• To elucidate the molecular mechanism controlling symmetric GMC division in grasses.
• To understand how OsCYCD7;1 functions in rice stomatal development.

Main Methods:

• Gene knockout and overexpression studies in rice (Oryza sativa).
• Yeast one-hybrid (Y1H), EMSA, and dual-luciferase assays for protein-DNA interactions.
• Co-immunoprecipitation to confirm protein-protein interactions.

Main Results:

• OsCYCD7;1 is essential for GMC division; its knockout blocks division.
• OsSMR9 interacts with OsCYCD7;1 and inhibits GMC division.
• OsMUTE regulates OsCYCD7;1 expression and OsSMR9 activation, impacting GMC division symmetry.

Conclusions:

• OsCYCD7;1 is a critical component for rice GMC division.
• OsMUTE and OsSMR9 act in a pathway to regulate OsCYCD7;1 activity and expression.
• This regulatory mechanism ensures a single, symmetric GMC division, diverging from Arabidopsis patterns.