Genome-wide and organ-specific landscapes of epigenetic modifications and their relationships to mRNA and small RNA transcriptomes in maize.
Maize (Zea mays) has an exceptionally complex genome with a rich history in both epigenetics and evolution. We report genomic landscapes of representative epigenetic modifications and their relationships to mRNA and small RNA (smRNA) transcriptomes in maize shoots and roots. The epigenetic patterns differed dramatically between genes and transposable elements, and two repressive marks (H3K27me3 and DNA methylation) were usually mutually exclusive. We found an organ-specific distribution of canonical microRNAs (miRNAs) and endogenous small interfering RNAs (siRNAs), indicative of their tissue-specific biogenesis. Furthermore, we observed that a decreasing level of mop1 led to a concomitant decrease of 24-nucleotide siRNAs relative to 21-nucleotide miRNAs in a tissue-specific manner. A group of 22-nucleotide siRNAs may originate from long-hairpin double-stranded RNAs and preferentially target gene-coding regions. Additionally, a class of miRNA-like smRNAs, whose putative precursors can form short hairpins, potentially targets genes in trans. In summary, our data provide a critical analysis of the maize epigenome and its relationships to mRNA and smRNA transcriptomes.
Wang
Xiangfeng
X
Peking-Yale Joint Center of Plant Molecular Genetics and Agrobiotechnology, College of Life Sciences, Peking University, Beijing 100871, China.
Elling
Axel A
AA
Li
Xueyong
X
Li
Ning
N
Peng
Zhiyu
Z
He
Guangming
G
Sun
Hui
H
Qi
Yijun
Y
Liu
X Shirley
XS
Deng
Xing Wang
XW
D019175:DNA Methylation; D044127:Epigenesis, Genetic; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D018745:Genome, Plant; D006657:Histones / Q000378:metabolism; D035683:MicroRNAs / Q000737:chemistry / Q000378:metabolism; D009690:Nucleic Acid Conformation; D012333:RNA, Messenger / Q000737:chemistry / Q000378:metabolism; D018749:RNA, Plant / Q000737:chemistry / Q000378:metabolism*; D034741:RNA, Small Interfering / Q000737:chemistry / Q000378:metabolism; D017423:Sequence Analysis, RNA; D003313:Zea mays / Q000235:genetics* / Q000378:metabolism
D006657:Histones; D035683:MicroRNAs; D012333:RNA, Messenger; D018749:RNA, Plant; D034741:RNA, Small Interfering