Defective Kernel 1 (DEK1) is required for three‐dimensional growth in Physcomitrella patens. Issue 3 (21st May 2014)

• Record Type: Journal Article
• Authors: Perroud, Pierre‐François; Demko, Viktor; Johansen, Wenche; Wilson, Robert C.; Olsen, Odd‐Arne; Quatrano, Ralph S.
• Is Part Of: New phytologist. Volume 203:Issue 3(2014)
• Page Start: 794
• Page End: 804
• Publication Date: 2014-05-21
• Subjects: Botany -- Periodicals; 580
• DOI: 10.1111/nph.12844
• Languages: English
• ISSNs: 0028-646X

Abstract

<abstract abstract-type="main" id="nph12844-abs-0001"> <title>Summary</title> <p> <list id="nph12844-list-0001" list-type="bullet"> <list-item> <p>Orientation of cell division is critical for plant morphogenesis. This is evident in the formation and function of meristems and for morphogenetic transitions. Mosses undergo such transitions: from two‐dimensional tip‐growing filaments (protonema) to the generation of three‐dimensional leaf‐like structures (gametophores).</p> </list-item> <list-item> <p>The Defective Kernel 1 (DEK1) protein plays a key role in the perception of and/or response to positional cues that specify the formation and function of the epidermal layer in developing seeds of flowering plants. The moss <italic>Physcomitrella patens</italic> contains the highly conserved <italic>DEK1</italic> gene.</p> </list-item> <list-item> <p>Using efficient gene targeting, we generated a precise <italic>PpDEK1</italic> deletion (<italic>∆dek1</italic>), which resulted in normal filamentous growth of protonema. Two distinct mutant phenotypes were observed: an excess of buds on the protonema, and abnormal cell divisions in the emerging buds resulting in developmental arrest and the absence of three‐dimensional growth. Overexpression of a complete <italic>PpDEK1 </italic>cDNA, or the calpain domain of <italic>PpDEK1</italic> alone, successfully complements both phenotypes.</p> </list-item> <list-item> <p>These results in <italic>P. patens</italic> demonstrate the morphogenetic importance of the DEK1 protein in the control of oriented cell divisions. As it is not for protonema, it will allow dissection of the structure/function relationships of the different domains of DEK1 using gene targeting in null mutant background.</p> </list-item> </list> </p> </abstract>