Research Reveals New Mechanism for Protein SUMO Modification to Fine-tune Plant Secondary Cell Wall

PLOS Genetics magazine published online a research paper titled SUMO modification of LBD30 by SIZ1 regulates secondary cell wall formation in Arabidopsis thaliana, a research group of Li Laigeng, Center for Excellence in Molecular Plant Science / Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, revealing the protein SUMO (small ubiquitin-related modifier) to fine-tune the new mechanism of plant secondary cell wall thickening.

The cell wall is one of the main features that distinguish plant cells from animal cells. All plant cells have primary cell walls, and some cell types, such as fibroblasts and tubular cells in vascular tissues, need to form thickened secondary cell walls to provide mechanical support and long-distance transportation channels for water and nutrients for the upright growth of plants. The formation of secondary cell walls directly affects plant growth and stress resistance traits. The thickening of secondary cell walls is subject to multiple levels of fine, complex and strict regulation in space and time.

SUMO (small ubiquitin-related modifier) is one of the important members of the ubiquitin-like protein family, which can be combined with a variety of proteins to play corresponding functions. Its molecular structure and SUMOylation reaction pathway are similar to ubiquitin, but both functions are completely functional. Different. SUMO-modified modification can participate in a variety of intracellular activities such as transcriptional regulation, nuclear transport, maintenance of genomic integrity, and signal transduction. The occurrence of certain diseases.

SUMO modification is a dynamic and reversible process. The SUMO molecule covalently binds to the lysine residue of the substrate protein with the participation of E1 activating enzyme, E2 binding enzyme and E3 ligase to regulate the structure and function of the substrate protein. SENPs, by specifically SUMO-modifying the target protein of the substrate, work together with SUMO molecules to regulate the SUMO status of the substrate protein, thereby regulating cell function.

SUMO modification is a post-translational modification of proteins. SUMOization modification plays a variety of regulatory functions in terms of protein interactions, protein localization in cells, and transcription factor activity. Recently, the research team of Li Laigeng discovered that the transcription factor LBD30 acts on the secondary cell wall thickening of Arabidopsis fibroblasts through SIZ1-mediated SUMOylation. Studies have shown that the SUMO-modified modification of LBD30 directly regulates the transcriptional process of fiber cell wall thickening. SUMOized LBD30 promotes the initiation of the transcription program for cell wall thickening. If LBD30 is not SUMOized, the cell wall thickening program cannot be started normally (as shown).

This study for the first time discovered the important function of protein SUMOylation in the regulation of secondary cell wall formation, and revealed a new way for the formation of multi-level regulatory networks in secondary cell walls, providing a new way to achieve precise and directed transformation of cell wall biomass Operational technology path.