Functional Characterization of PCF-like and CIN-like gene families in Phalaenopsis

Abstract

Phalaenopsis is one of the high economic value of flower crops As the beautiful floral morphology diverse flower colour and long florescence duration are widely loved by people A small family of Plant-specific TEOSINTE BRANCHED1 CYCLOIDEA PCF (TCP) transcription factors encoding proteins sharing TCP domain with a bHLH motif that allows DNA binding and protein–protein interactions According to slightly different TCP domains TCP proteins are separated into two clades including class I and class II They are the main regulators of plant form and architecture and constitute a tool through which evolution shapes plant diversity The TCP transcription factors act in a multiplicity of pathways related with cell proliferation and hormone responses This study characterized the class I PCF and class II CIN gene subfamilies in the Phalaenopsis We identified 20 genes belong to the PCF and CIN subfamilies in the OrchidBase Phylogenetic analysis showed that 11 PCF genes and 9 CIN genes exist in the Phalaenopsis genome RT-PCR results showed that 10 PCF genes and 8 CIN genes expressed in the vegetative tissue reproductive tissue and developmental ovule stages However 1 PCF gene and 1 CIN gene were not detected by RT-PCR Further we characterized the function of the class I TCP transcription factor PePCF10 and the class II TCP transcription factor PeCIN8 Yeast-two hybrid assay results showed that strong interaction of PeCIN8 homodimers However PeCIN8 can not form heterodimer with PePCF10 In addition PePCF10 could not form homodimers as well as heterodimers with PeCIN8 Subcellular localization experiments confirmed that both of two gene products localize in the nucleus In transgenic Arabidopsis thaliana plants (overexpression and SRDX dominantly represses) the two genes display a range of growth-related phenotypes consistent with their dynamic expression patterns The two genes influence plant stature flowering time plant reproduction and morphogenesis of shoot lateral organs that via modulate cell division Overall our results show that PePCF10 and PeCIN8 transcription factors are a nuclear protein with a widely expression pattern and both of them appear to be playing an important role during plant development and provide some insights about the function of PeTCPs in the development of Phalaenopsis

Date of Award	2014 Aug 29
Original language	English
Supervisor	Wen-Chieh Tsai (Supervisor)