TEMPRANILLO is a direct repressor of the microRNA miR172

Area of Science:

• Plant Molecular Biology
• Developmental Genetics
• Arabidopsis thaliana Research

Background:

• MicroRNA 156 (miR156) is crucial for orchestrating developmental transitions in plants.
• miR156 regulates SPL genes, which are involved in juvenile-to-adult and floral transitions, partly via miR172.
• TEMPRANILLO (TEM1 and TEM2) repressors delay flowering by targeting FT and gibberellin genes, and influence juvenile phase length.

Purpose of the Study:

• To investigate the potential overlap between the TEM and miR156/SPL/miR172 genetic pathways.
• To determine if TEMs influence the levels of miR156, SPL, and miR172.
• To elucidate the role of TEMs in regulating developmental timing through the miR172 pathway.

Main Methods:

• Analysis of miR156, SPL, and miR172 levels under TEM regulation.
• Chromatin immunoprecipitation (ChIP) to test in vivo binding of TEMs to target genes.
• Genetic interaction analyses between TEMs and miR172.

Main Results:

• TEMs exhibit a more significant role in the floral transition compared to the juvenile-to-adult transition.
• TEM1 directly represses the expression of MIR172A, MIR172B, and MIR172C.
• TEM1 was shown to bind in vivo to MIR172C sequences.

Conclusions:

• TEM genes play a role in regulating plant developmental timing, particularly the floral transition.
• TEMs exert their regulatory function, at least in part, through the repression of miR172.
• The study supports a common genetic pathway involving TEMs and the miR172 module for controlling developmental timing.