Expression of the Arabidopsis Sigma Factor SIG5 Is Photoreceptor and Photosynthesis Controlled

Plants

Marina Mellenthin²  Ulrike Ellersiek²  Anna Börger¹ 

[1] Plant Physiology, Freie Universität Berlin, Königin-Luise-Straße 12-16, Berlin 14195, Germany; E-Mail:;Plant Sciences, Heinrich-Heine-Universität, Universitätsstraße 1, Düsseldorf 40225, Germany; E-Mails:

关键词: SIG5;    sigma factor;    phytochrome;    cryptochrome;    photosynthesis;    plastoquinone;    photosystem II;    retrograde signal;   

DOI  :  10.3390/plants3030359

来源: mdpi

【 摘 要 】

Two collections of Arabidopsis GAL4 enhancer trap lines were screened for light-intensity dependent reporter gene activation. Line N9313 was isolated for its strong light-intensity regulation. The T-DNA element trapped distant enhancers of the SIG5 promoter, which drives expression of a sigma factor involved in regulation of chloroplast genes for photosystem II core proteins. The T-DNA insertion 715 bp upstream of the transcription initiation site splits the promoter in a distal and proximal part. Both parts are sensitive to blue and red light and depend on photosynthetic electron transport activity between photosystem II and the plastoquinone pool. The mainblue-light sensitivity is localized within a 196-bp sequence (–887 to –691 bp) in the proximal promoter region It is preferentially CRY1 and PHYB controlled. Type-I and type-II phytochromes mediate red-light sensitivity via various promoter elements spread over the proximal and distal upstream region. This work characterizes SIG5 as an anterograde control factor of chloroplast gene expression, which is controlled by chloroplast signals in a retrograde manner.

【 授权许可】

CC BY   
© 2014 by the authors; licensee MDPI, Basel, Switzerland.