title: Dynamic changes of transcript profiles after fertilization are associated with de novo transcription and maternal elimination in tobacco zygote, and mark the onset of the maternal-to-zygotic transition.
abstract: The maternal-to-zygotic transition (MZT) is characterized by the turnover of zygote development from maternal to zygotic control, and has been extensively studied in animals. A majority of studies have suggested that early embryogenesis is maternally controlled and that the zygotic genome remains transcriptionally inactive prior to the MZT. However, little is known about the MZT in higher plants, and its timing and impact remain uncharacterized. Here, we constructed cDNA libraries from tobacco (Nicotiana tabacum) egg cells, zygotes and two-celled embryos for gene expression profiling analysis, followed by RT-PCR confirmation. These analyses, together with experiments using zygote microculture coupled with transcription inhibition, revealed that a marked change in transcript profiles occurs approximately 50 h after fertilization, and that the MZT is initiated prior to zygotic division in tobacco. Although maternal transcripts deposited in egg cells support several early developmental processes, they appear to be insufficient for zygotic polar growth and subsequent cell divisions. Thus, we propose that de novo transcripts are probably required to trigger embryogenesis in later zygotes in tobacco.
authors.affiliation: Key Laboratory of Ministry of Education for Plant Developmental Biology, College of Life Science, Wuhan University, 430072, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Zhao
authors.affiliation: Key Laboratory of Ministry of Education for Plant Developmental Biology, College of Life Science, Wuhan University, 430072, China.
authors.forename: Haiping
authors.initials: H
authors.lastname: Xin
authors.affiliation: Key Laboratory of Ministry of Education for Plant Developmental Biology, College of Life Science, Wuhan University, 430072, China.
authors.forename: Lianghuan
authors.initials: L
authors.lastname: Qu
authors.affiliation: Key Laboratory of Ministry of Education for Plant Developmental Biology, College of Life Science, Wuhan University, 430072, China.
authors.forename: Jue
authors.initials: J
authors.lastname: Ning
authors.affiliation: Key Laboratory of Ministry of Education for Plant Developmental Biology, College of Life Science, Wuhan University, 430072, China.
authors.forename: Xiongbo
authors.initials: X
authors.lastname: Peng
authors.affiliation: Key Laboratory of Ministry of Education for Plant Developmental Biology, College of Life Science, Wuhan University, 430072, China.
authors.forename: Tingting
authors.initials: T
authors.lastname: Yan
authors.affiliation: Key Laboratory of Ministry of Education for Plant Developmental Biology, College of Life Science, Wuhan University, 430072, China.
authors.forename: Ligang
authors.initials: L
authors.lastname: Ma
authors.affiliation: Key Laboratory of Ministry of Education for Plant Developmental Biology, College of Life Science, Wuhan University, 430072, China.
authors.forename: Shisheng
authors.initials: S
authors.lastname: Li
authors.affiliation: Key Laboratory of Ministry of Education for Plant Developmental Biology, College of Life Science, Wuhan University, 430072, China.
authors.forename: Meng-Xiang
authors.initials: MX
authors.lastname: Sun
mesh_terms: D018076:DNA, Complementary / Q000235:genetics; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014026:Nicotiana / Q000166:cytology / Q000196:embryology*; D015053:Zygote / Q000166:cytology*
chemical_list: D018076:DNA, Complementary