Extensive nuclear reprogramming and endoreduplication in mature leaf during floral induction

Area of Science:

• Plant Biology
• Developmental Biology
• Molecular Genetics

Background:

• The floral transition is crucial for plant reproduction, influenced by environmental cues.
• Leaves sense light signals and produce florigen, with CONSTANS and FLOWERING LOCUS T being key regulators.
• While shoot apical meristem changes are well-studied, leaf processes during floral transition are less understood.

Purpose of the Study:

• To investigate nuclear and molecular changes in mature leaves during the floral transition.
• To identify novel regulatory candidates and molecular events occurring in leaves.

Main Methods:

• Time-course analysis of nuclear changes in fully developed leaves.
• Gene expression profiling, including coding and non-coding RNAs.
• Ploidy level assessment.

Main Results:

• Identified new putative regulatory candidates for flowering in leaves.
• Observed differential gene expression in cellular, hormonal, and metabolic pathways.
• Detected increased gene expression of long non-coding RNAs and natural antisense transcripts.
• Found a significant increase in ploidy level, indicating endoreduplication.

Conclusions:

• Differentiated mature leaves possess physiological plasticity and undergo nuclear reprogramming during floral transition.
• Dynamic events involve networks of transcription factors, novel regulatory motifs, and hormonal/metabolic changes.
• These findings offer new insights into leaf function during reproductive development.