Chromatin remodeling analysis reveals the RdDM pathway responds to low-phosphorus stress in maize

Area of Science:

• Plant biology
• Genomics
• Molecular biology

Background:

• Plant phosphorus (Pi) signaling is crucial for growth and development.
• Existing research on Pi signaling primarily focuses on gene interactions, neglecting the role of 3D chromatin structure.
• Understanding the 3D genome's role in Pi signaling is essential for expanding current knowledge.

Purpose of the Study:

• To investigate the impact of low phosphorus (Pi) stress on plant chromatin 3D structure.
• To explore the relationship between the RNA-directed DNA methylation (RdDM) pathway and chromatin organization under Pi stress.
• To elucidate novel mechanisms of plant adaptation to low-Pi conditions.

Main Methods:

• Analysis of chromatin volume, insulation scores, and TAD-like domains under low-Pi treatment.
• Methylation profiling (RdDM levels) and analysis of RdDM site distribution near TAD-like boundaries.
• Gene expression analysis of RdDM pathway genes and ChIP-seq to identify ZmDDM1A binding targets.

Main Results:

• Low-Pi treatment increased chromatin volume, insulation scores, and TAD-like domains.
• RdDM levels peaked at TAD-like boundaries, with specific shifts observed at conserved boundaries.
• The RdDM pathway mutant ddm1a exhibited enhanced low-Pi tolerance, and ZmDDM1A binding was linked to Pi and root development genes.

Conclusions:

• Plant 3D chromatin structure is dynamically regulated by low-Pi stress, influencing gene expression via the RdDM pathway.
• The study provides a framework for analyzing biological processes using 3D genomics, expanding understanding of plant Pi signaling.
• Findings highlight the interplay between chromatin organization, RdDM, and root traits under nutrient stress.