A conserved translational repression module buffers sugar-inducible root vascular proliferation.

Area of Science:

• Plant biology
• Molecular signaling
• Developmental biology

Background:

• Optimal carbon allocation requires balancing vascular proliferation with sugar availability.
• Molecular mechanisms integrating sugar status into vascular development are poorly understood.

Purpose of the Study:

• To elucidate how sugar status influences vascular development in Arabidopsis roots.
• To identify molecular regulators of sugar-induced vascular proliferation.

Main Methods:

• Histological analysis
• Genetic analysis
• Pharmacological treatments
• Phylogenetic and cross-species analyses

Main Results:

• Sugar acts as an instructive signal promoting vascular proliferation through the TARGET OF RAPAMYCIN (TOR) pathway.
• The RNA-binding protein JULGI1 (JUL1) and its target CLE41 mRNA form a translational repression module.
• This JUL1-CLE41 module negatively regulates vascular proliferation via a conserved motif in CLE41 mRNA.
• The JUL1-CLE41 module is conserved in cambium-bearing plant lineages.

Conclusions:

• Vascular proliferation is a sugar-responsive developmental process.
• The JUL1-CLE41 module provides negative feedback to balance sugar-driven vascular growth.
• This regulatory mechanism ensures homeostasis and may have been refined through evolution.