Flower development of Phalaenopsis orchid involves functionally divergent SEPALLATA-like genes.
Bottom Line: The tepal became a leaf-like organ when PeSEP3 was silenced by virus-induced silencing, with alterations in epidermis identity and contents of anthocyanin and chlorophyll.Silencing of the E-class genes PeSEP2 and PeSEP3 resulted in the downregulation of B-class PeMADS2-6 genes, which indicates an association of PeSEP functions and B-class gene expression.These findings reveal the important roles of PeSEP in Phalaenopsis floral organ formation throughout the developmental process by the formation of various multiple protein complexes.
Affiliation: Department of Life Sciences, National Cheng Kung University, Tainan, 701, Taiwan.Show MeSH
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Mentions: To determine whether floral organs of the PeSEP-silenced flowers were affected at the cellular level, we observed perianth epidermal cell shapes under cryo-SEM, indicated as the aspect ratio β, the ratio of the width to height of epidermal cell curvature (Fig.6e). In addition to the decreased cell size, cell shape and several ultrastructures were altered in epidermal cells of PeSEP-silenced flowers (Figs8). Among the three PeSEP-silenced lines, PeSEP3- and PeSEP2/3-silenced flowers showed the most severe defects in the overall cellular changes, whereas these changes in PeSEP2-silenced flowers were minor.
Affiliation: Department of Life Sciences, National Cheng Kung University, Tainan, 701, Taiwan.