Researchers Reveal a Novel Mechanism of Root Stem Cell Controlled by DA1 Cleaving and destabilizing WOX5 in Arabidopsis

The root system is necessary for the normal growth of plants as it absorbs nutrients and water to support plant growth. In plants, root apical meristem sustains continuous root development. The root stem cells maintained and replenished by the quiescent center (QC) are essential for the formation of the specific root structure. In Arabidopsis, the WUSCHEL-RELATED HOMEOBOX 5 (WOX5) plays a key role in regulating root stem cell fate. However, which factor can directly modulate the stability of WOX5 protein remains totally unknown.

 

Recently, the research group of LI Yunhai at the Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, identified a new mechanism of root stem cell control by DA1 cleaving and destabilizing WOX5 in Arabidopsis.

 

The peptidase DA1 interacts with and cleaves WOX5, resulting in the destabilization of WOX5. Genetic analyses suggest that DA1 acts through WOX5 to control root stem cell function. Further analysis found that the cytokinin (CK) signaling induces the accumulation of DA1 protein, thereby decreasing the abundance of WOX5 protein in the root. Consistent with these results, the mutation in DA1 increases the layers of columella stem cells and influences CK-induced differentiation of columella stem cells.

 

This study reveals a previously unrecognized mechanism by which the cleavage of WOX5 by DA1 connects CK signaling and root stem cell maintenance and homeostasis in Arabidopsis. DA1 is the first factor identified to directly modulate the abundance of WOX5 protein in plants.

 

The research results were published online on October 21, 2024, in Current Biology with the title “The cleavage of WOX5 by the peptidase DA1 connects cytokinin signaling and root stem cell regulation” (https://doi.org/10.1016/j.cub.2024.09.052).

 

This work was supported by grants from the National Natural Science Foundation of

China (32370357) and the strategic priority research program of the Chinese Academy of Sciences (XDB27010102).

 

Contact:

Prof. LI Yunhai

Institute of Genetics and Developmental Biology, Chinese Academy of Science

Email:yhli@genetics.ac.cn