|Publication Type:||Journal Article|
|Year of Publication:||2011|
|Authors:||Xiang, D, Yang, H, Cao, Y, Wen, R, Ren, M, Stone, S, Wang, E, WANG, HONG, Xiao, W, Weijers, D, Berleth, T, Laux, T, Selvaraj, G, Datla, R|
|Journal:||The Plant Cell|
The shoot and root apical meristems (SAM and RAM) formed during embryogenesis are crucial for postembryonic plant development. We report the identification of POPCORN [PCN), a gene required for embryo development and meristem organization in Arabidopsis thaliana. Map-based cloning revealed that PCN encodes a WD-40 protein expressed both during embryo development and postembryonically in the SAM and RAM. The two pen alíeles identified in this study are temperature sensitive, showing defective embryo development when grown at 22°C that is rescued when grown at 29°C. In pen mutants, meristem-specific expression of WUSCHEL (WUS), CLAVATA3, and WUSCHEL-RELATED H0ME0B0X5 is not maintained; SHOOTMERISTEMLESS, BODENLOS (BDL) and MONOPTEROS (MP) are misexpressed. Several findings link PCN to auxin signaling and meristem function: ectopic expression of DR5 rev : green fluorescent protein (GFP), pBDL:BDLGFP, and pMP: MP-ß-glucuronidase in the meristem; altered polarity and expression of pPIN1: PIN1-GFP in the apical domain of the developing embryo; and resistance to auxin in the pen mutants. The bdl mutation rescued embryo lethality of pen, suggesting that improper auxin response is involved in pen defects. Furthermore, WUS, PINF0RMED1, PINOID, and TOPLESS are dosage sensitive in pen, suggesting functional interaction. Together, our results suggest that PCN functions in the auxin pathway, integrating auxin signaling in the organization and maintenance of the SAM and RAM.
|Short Title:||The Plant Cell|