The WOX13 homeobox gene promotes replum formation in the Arabidopsis thaliana fruit

Abstract

SUMMARYThe Arabidopsis fruit forms a seedpod that develops from the fertilized gynoecium. It is mainly comprised of an ovary in which three distinct tissues can be differentiated: the valves, the valve margins and the replum. Separation of cells at the valve margin allows for the valves to detach from the replum and thus dispersal of the seeds. Valves and valve margins are located in lateral positions whereas the replum is positioned medially and retains meristematic properties resembling the shoot apical meristem (SAM). Members of the WUSCHEL-related homeobox family have been involved in stem cell maintenance in the SAM, and within this family, we found that WOX13 is expressed mainly in meristematic tissues including the replum. We also show that wox13 loss-of-function mutations reduce replum size and enhance the phenotypes of mutants affected in the replum identity gene RPL. Conversely, misexpression of WOX13 produces, independently from BP and RPL, an oversized replum and valve defects that closely resemble those of mutants in JAG/FIL activity genes. Our results suggest that WOX13 promotes replum development by likely preventing the activity of the JAG/FIL genes in medial tissues. This regulation seems to play a role in establishing the gradient of JAG/FIL activity along the medio-lateral axis of the fruit critical for proper patterning. Our data have allowed us to incorporate the role of WOX13 into the regulatory network that orchestrates fruit patterning.

Fruit Indehiscence Caused by Enhanced Expression of NO TRANSMITTING TRACT in Arabidopsis thaliana

“…FUL expression was slightly increased in rpl-2 mutants (Fig. 4B), consistent with the repression of a valve factor by a replum factor (Romera-Branchat et al, 2013). However, FUL expression was decreased in rpl-2 ntt-3D mutants, indicating that ntt-3D suppressed the effect of rpl mutation.…”

Characterization of the Early Events Leading to Totipotency in an Arabidopsis Protoplast Liquid Culture by Temporal Transcript Profiling

“…WOX5 is an auxin-inducible gene expressed in the quiescent center of the root meristem and in its direct precursor cells during the early globular stage of embryogenesis (Haecker et al, 2004;Gonzali et al, 2005). WOX8 is expressed in the egg cell and zygote, whereas WOX13 is expressed during primary and lateral root initiation and development, in the gynecium, and during embryo development (Deveaux et al, 2008;Romera-Branchat et al, 2012). The sequential reactivation of WOX13, WOX5, and then WOX8 suggests that these genes are also regulators of cell division during PdC culture.…”

Identification and expression dynamics of three WUSCHEL related homeobox 13 (WOX13) genes in peanut

“…WOX13 OG might be a good candidate to study the functional diversification of WOX genes (Chandler et al 2008). The WOX13 subfamily genes were proposed to be involved in replum development, lateral root formation, and vegetative to floral growth transition (Chandler et al 2008;Romera-Branchat et al 2012). Romera-Branchat et al (2012) found that WOX13 expressed mainly in the meristematic tissue in Arabidopsis (RomeraBranchat et al 2012).…”