title: Protocorms and Protocorm-Like Bodies Are Molecularly Distinct from Zygotic Embryonic Tissues in Phalaenopsis aphrodite.
abstract: The distinct reproductive program of orchids provides a unique evolutionary model with pollination-triggered ovule development and megasporogenesis, a modified embryogenesis program resulting in seeds with immature embryos, and mycorrhiza-induced seed germination. However, the molecular mechanisms that have evolved to establish these unparalleled developmental programs are largely unclear. Here, we conducted comparative studies of genome-wide gene expression of various reproductive tissues and captured the molecular events associated with distinct reproductive programs in Phalaenopsis aphrodite Importantly, our data provide evidence to demonstrate that protocorm-like body (PLB) regeneration (the clonal regeneration practice used in the orchid industry) does not follow the embryogenesis program. Instead, we propose that SHOOT MERISTEMLESS, a class I KNOTTED-LIKE HOMEOBOX gene, is likely to play a role in PLB regeneration. Our studies challenge the current understanding of the embryonic identity of PLBs. Taken together, the data obtained establish a fundamental framework for orchid reproductive development and provide a valuable new resource to enable the prediction of gene regulatory networks that is required for specialized developmental programs of orchid species.
authors.affiliation: Biotechnology Center in Southern Taiwan, Academia Sinica, Tainan 741, Taiwan (S.-C.F., J.-C.C., M.-J.W.); andAgricultural Biotechnology Research Center, Academia Sinica, Taipei 115, Taiwan (S.-C.F., J.-C.C., M.-J.W.) scfang@gate.sinica.edu.tw.
authors.forename: Su-Chiung
authors.identifier: 0000-0001-6894-5025
authors.initials: SC
authors.lastname: Fang
authors.affiliation: Biotechnology Center in Southern Taiwan, Academia Sinica, Tainan 741, Taiwan (S.-C.F., J.-C.C., M.-J.W.); andAgricultural Biotechnology Research Center, Academia Sinica, Taipei 115, Taiwan (S.-C.F., J.-C.C., M.-J.W.).
authors.forename: Jhun-Chen
authors.initials: JC
authors.lastname: Chen
authors.affiliation: Biotechnology Center in Southern Taiwan, Academia Sinica, Tainan 741, Taiwan (S.-C.F., J.-C.C., M.-J.W.); andAgricultural Biotechnology Research Center, Academia Sinica, Taipei 115, Taiwan (S.-C.F., J.-C.C., M.-J.W.).
authors.forename: Miao-Ju
authors.initials: MJ
authors.lastname: Wei
mesh_terms: D015415:Biomarkers / Q000378:metabolism; D005306:Fertilization; D035264:Flowers / Q000235:genetics; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D029595:Orchidaceae / Q000033:anatomy & histology* / Q000196:embryology* / Q000235:genetics; D018520:Plant Shoots / Q000502:physiology; D058439:Plant Somatic Embryogenesis Techniques; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012038:Regeneration; D012098:Reproduction / Q000235:genetics; D012639:Seeds / Q000033:anatomy & histology*; D014157:Transcription Factors / Q000378:metabolism; D059467:Transcriptome / Q000235:genetics; D015053:Zygote / Q000378:metabolism*
chemical_list: D015415:Biomarkers; D012333:RNA, Messenger; D014157:Transcription Factors