Shade avoidance components and pathways in adult plants revealed by phenotypic profiling

Area of Science:

• Plant biology
• Genetics
• Physiology

Background:

• Plants exhibit shade avoidance syndrome (SAS) to compete for light, involving organ elongation and accelerated flowering.
• Current understanding of SAS mechanisms is primarily focused on seedling shade-induced elongation.

Purpose of the Study:

• To investigate the complex genetic networks underlying the shade avoidance syndrome (SAS).
• To identify shared and distinct molecular pathways regulating various SAS responses.
• To discover novel genes involved in plant shade responses.

Main Methods:

• Phenotypic profiling of seedling, leaf, and flowering time traits in response to shade.
• Utilizing over-representation analysis (ORA) of shade-responsive genes to select mutants.
• Systematic phenotyping of 59 known and candidate novel mutants.

Main Results:

• Auxin pathway components are crucial for hypocotyl, petiole, and flowering time responses to shade.
• Jasmonic acid pathway components are specifically required for petiole and flowering time shade avoidance responses.
• Seventeen novel shade avoidance mutants were identified through targeted phenotypic profiling.

Conclusions:

• Logical mutant selection enhances the success of phenotypic profiling for dissecting complex plant traits.
• Distinct molecular pathways, involving auxin and jasmonic acid, regulate specific aspects of the shade avoidance syndrome.
• This research provides a deeper mechanistic understanding of plant light competition strategies.