Interactions Between the Transcription Factor BOL/DRNL/ESR2 and the Jasmonate Pathway

Area of Science:

• Plant Biology
• Molecular Biology
• Genetics

Background:

• BOL/DRNL/ESR2 is an AP2/ERF transcription factor regulating early organ development in Arabidopsis thaliana.
• Loss of BOL function leads to flower organ defects, while overexpression causes hormone-independent root callus formation.
• Jasmonates (JAs) are plant hormones involved in stress responses and organ development, including stamen development and growth.

Purpose of the Study:

• To investigate the interaction between the BOL transcription factor and the jasmonate (JA) signaling pathway.
• To elucidate the role of JA in BOL-mediated organ development and vice versa.

Main Methods:

• Exogenous application of methyl jasmonate (MeJA) to wild-type and mutant Arabidopsis plants.
• JA biosynthesis inhibition treatments.
• Analysis of phenotypic rescue and mimicry in response to treatments.
• Measurement of endogenous JA levels.
• Analysis of JA-responsive marker gene expression.
• Assessment of BOL expression domain changes.

Main Results:

• MeJA partially rescued stamen defects in bol-cr mutants, linking BOL to JA-mediated stamen development.
• MeJA treatments mimicked some bol-D mutant phenotypes (reduced size), and JA inhibition restored wild-type leaf curvature, indicating altered JA homeostasis in gain-of-function mutants.
• BOL overexpression increased JA levels, while loss-of-function reduced them. Inducible BOL activity downregulated a JA-responsive marker, and JA biosynthesis inhibition affected BOL-induced root callus and BOL expression domain.

Conclusions:

• BOL modulates aspects of the JA pathway, influencing organ development.
• Feedback from the JA pathway affects BOL transcription factor expression.
• This study reveals a complex interplay between BOL and JA signaling in Arabidopsis development.