Initiation of shoot meristem stem cells during Arabidopsis embryogenesis
Final Report Abstract
In higher plants, the stem cells of the shoot meristem provide the cells for forming leaves, side branches, and flower buds throughout the plant's life. In our previous work, we showed that the initiation of the shoot meristem stem cell program is controlled by the WOX2 transcription factor, partly through balancing the phytohormones cytokinin and auxin. We found that WOX2 is expressed only in the outermost cell layer of the embryo at the stage of stem cell establishment, suggesting that this layer serves as a signaling source to switch the underlying cells to the stem cell program. These results provided an exciting opportunity to reveal the fundamental molecular mechanisms underlying shoot meristem stem cell initiation in plants. This project aims to understand how WOX2 regulates stem cell initiation in Arabidopsis embryogenesis. In the past funding period, we discovered a novel role of the ATPase molecular chaperone CELL DIVISION CYCLE 48A (CDC48A) as a WOX2 interactor during embryo patterning and shoot meristem initiation. Furthermore, we found that WOX2 function in shoot meristem initiation is tightly linked to its functions in early embryo patterning. Therefore, we expanded our analysis to earlier developmental stages, revealing a novel role of WOX2 in apical-basal embryo axis development and in protoderm initiation. In addition to these published results, we are finalizing two manuscripts on the interplay between WOX2 and miR165/166 and the WOX2-regulated transcriptome during shoot meristem initiation.
Publications
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A tripartite transcriptional module regulates protoderm specification during embryogenesis in Arabidopsis. New Phytologist, 245(5), 2038-2051.
Wang, Chenchen; Gao, Yang; Gong, Wen; Laux, Thomas; Li, Sha & Xiong, Feng
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CDC48A, an interactor of WOX2, is required for embryonic patterning in Arabidopsis thaliana. Plant Cell Reports, 43(7).
Gong, Wen; Bak, Deniz Tiambeng; Wendrich, Jos R.; Weijers, Dolf & Laux, Thomas
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Integration of basal and apical embryo lineage regulators controls F-actin cable integrity and zygote asymmetry in Arabidopsis. Proceedings of the National Academy of Sciences, 122(1).
Xiong, Feng; Zhang, Zhongjuan; Gong, Wen; Hermann, Marita; Bak, Deniz Tiambeng; Garbsch, Frauke & Laux, Thomas
