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Wild tomato endosperm transcriptomes reveal common roles of genomic imprinting in both nuclear and cellular endosperm
Author(s) -
Roth Morgane,
FlorezRueda Ana M.,
Paris Margot,
Städler Thomas
Publication year - 2018
Publication title -
the plant journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.058
H-Index - 269
eISSN - 1365-313X
pISSN - 0960-7412
DOI - 10.1111/tpj.14012
Subject(s) - endosperm , biology , genomic imprinting , genetics , imprinting (psychology) , evolutionary biology , gene , genome , gene expression , dna methylation
Summary Genomic imprinting is a conspicuous feature of the endosperm, a triploid tissue nurturing the embryo and synchronizing angiosperm seed development. An unknown subset of imprinted genes ( IG s) is critical for successful seed development and should have highly conserved functions. Recent genome‐wide studies have found limited conservation of IG s among distantly related species, but there is a paucity of data from closely related lineages. Moreover, most studies focused on model plants with nuclear endosperm development, and comparisons with properties of IG s in cellular‐type endosperm development are lacking. Using laser‐assisted microdissection, we characterized parent‐specific expression in the cellular endosperm of three wild tomato lineages (Solanum section Lycopersicon). We identified 1025 candidate IG s and 167 with putative homologs previously identified as imprinted in distantly related taxa with nuclear‐type endosperm. Forty‐two maternally expressed genes ( MEG s) and 17 paternally expressed genes ( PEG s) exhibited conserved imprinting status across all three lineages, but differences in power to assess imprinted expression imply that the actual degree of conservation might be higher than that directly estimated (20.7% for PEG s and 10.4% for MEG s). Regardless, the level of shared imprinting status was higher for PEG s than for MEG s, indicating dissimilar evolutionary trajectories. Expression‐level data suggest distinct epigenetic modulation of MEG s and PEG s, and gene ontology analyses revealed MEG s and PEG s to be enriched for different functions. Importantly, our data provide evidence that MEG s and PEG s interact in modulating both gene expression and the endosperm cell cycle, and uncovered conserved cellular functions of IG s uniting taxa with cellular‐ and nuclear‐type endosperm.