Extensive epigenetic reprogramming during the life cycle of Marchantia polymorpha

Area of Science:

• Plant biology
• Epigenetics
• Developmental biology

Background:

• The role and extent of epigenetic reprogramming in plants remain debated due to stable epiallele inheritance.
• While some evidence suggests reprogramming during plant reproduction, consensus is lacking.
• This study investigates DNA methylation dynamics throughout the life cycle of Marchantia polymorpha.

Purpose of the Study:

• To investigate DNA methylation dynamics during the life cycle of Marchantia polymorpha.
• To identify epigenetic states associated with different life cycle stages.
• To understand the mechanisms and timing of epigenetic reprogramming in plants.

Main Methods:

• Isolation of various life cycle stages of Marchantia polymorpha (thalli, meristems, gametophytes, sporophytes).
• Comparison of DNA methylation profiles across isolated tissues.
• Analysis of differentially methylated cytosines and associated genomic features.

Main Results:

• 42% of cytosines showed significant DNA methylation variation across the life cycle.
• Four distinct epigenetic states were identified: sporophytes, vegetative gametophytes, antherozoids, and archegonia.
• Reprogramming mechanisms differed between gametophytic and sporophytic generations, correlating with gene expression of DNA methylation machinery.

Conclusions:

• Epigenetic reprogramming occurs at least twice during the Marchantia polymorpha life cycle.
• The mechanisms underlying these two reprogramming events are likely distinct.
• These findings contribute to understanding epigenetic plasticity in plants.