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Download or read book Regulation of Organ Morphogenesis written by Florian Brioudes and published by . This book was released on 2010 with total page 194 pages. Available in PDF, EPUB and Kindle. Book excerpt: In multicellular organisms, morphogenesis requires the tight regulation of cell proliferation, growth and death, in order to form organs with specific shapes and sizes. During my Ph.D. thesis work, I addressed the biological roles of two genes involved in organ morphogenesis in the plant model species Arabidopsis thaliana, namely TRANSLATIONALLY CONTROLLED TUMOR PROTEIN (AtTCTP) and BIGPETALp (BPEp). I showed that AtTCTP is essential for plant development and that AtTCTP controls the cell cycle progression, particularly at the G1/S transition. Furthermore I showed that this function of AtTCTP in regulating cell proliferation is evolutionarily conserved between plants and animals.BPEp encodes a bHLH transcription factor that regulates cell elongation in developing petals. I showed that the accumulation of BPEp transcript is positively controlled by a signal initiated by the phytohormone jasmonate and that this regulation occurs at the post-transcriptional level. I also demonstrated a role of jasmonate in the control of cell expansion during petal growth. Search for BPEp putative binding proteins identified an AUXIN RESPONSE FACTOR (ARF8) as putative interactor of BPEp. Studies of molecular and genetic interaction with ARF8 demonstrated that BPEp is inscribed in a network regulated by auxin, a second phytohormone. In summary my results together help to better understand how plants regulate organogenesis, thanks to the functional characterization of the conserved key player TCTP, which is involved in the control of mitotic growth, and of the phytohormone-dependent transcription factor BPEp, which regulates post-mitotic growth.