Dynamic DNA methylation changes reveal tissue-specific gene expression
in sugarcane
Abstract
DNA methylation is an important mechanism for the dynamic regulation of
gene expression and silencing of transposons during plant developmental
processes. Here, we analyzed genome-wide methylation patterns in
sugarcane (Saccharum officinarum) leaves, roots, rinds, and piths at
single-base resolution. DNA methylation patterns were similar among the
different sugarcane tissues, whereas DNA methylation levels differed. We
also found that DNA methylation in different genic regions or sequence
contexts plays different roles in gene expression. Differences in
methylation among tissues resulted in many differentially methylated
regions (DMRs) between tissues, particularly CHH DMRs. Genes overlapping
with DMRs tended to be differentially expressed (DEGs) between tissues,
and these DMR-associated DEGs were enriched in biological pathways
related to tissue function, such as photosynthesis, sucrose synthesis,
stress response, transport, and metabolism. Moreover, we observed many
DNA methylation valleys (DMVs), which always overlapped with
transcription factors (TFs) and sucrose-related genes, such as WRKY,
bZIP, WOX, SPS, and FBPase. Collectively, these findings provide
significant insights into the complicated interplay between DNA
methylation and gene expression and shed light on the epigenetic
regulation of sucrose-related genes in sugarcane.