Update date: 2021-08-20

Eukaryotic cells are physically compartmentalized to ensure the efficiency and efficacy of biochemical reactions and cellular functions. Membraneless organelle (MLO), which lacks a surrounding lipid membrane, represents a unique way for compartmentalization. It confers a wide range of functional advantages over membrane-bound organelles due to their ability to spontaneously and rapidly form and dissolve. MLOs are in most cases assembled through liquid-liquid phase separation (LLPS) of proteins and/or RNAs (Dignon et al., 2020; Hyman et al., 2014). Within a eukaryotic cell, there are numerous MLOs that are both spatially and temporarily localized (Figure 1).


Figure 1

Figure 1
Plants are quite unique due to their inability to move and need to rapidly cope with the continuous changes of light, temperature, water status, etc. MLOs, because of their reversibility, dynamicity and selectivity, are ideal for stress sensing. Moreover, a majority of MLOs are associated with RNA biology (Lin and Fang, 2021). Therefore, MLOs are able to directly relay stress signals to gene expression change, helping cells to cope with stresses.

Figure 2

Figure 2
Our lab are dedicated to understand how plant cells make use of MLOs to sense abiotic stresses and adjust their gene expression in order to adapt to these stresses. We mainly focus on heat, drought, oxidative and hyperosmotic stresses (Figure 2).

MLOs can have diverse material states, including liquid, gel and solid. The transition between these states can be induced by stress treatment. While the liquid-state MLOs are highly reversible after stress recovery, the gel and solid MLOs can last for longer period of time, providing potential memory of stresses. Our lab are also interested in dissecting the roles of MLOs in stress memory (Figure 2).

References

  1. Dignon, G.L., Best, R.B., and Mittal, J. (2020). Biomolecular Phase Separation: From Molecular Driving Forces to Macroscopic Properties. Annu Rev Phys Chem 71, 53-75.
  2. Hyman, A.A., Weber, C.A., and Julicher, F. (2014). Liquid-liquid phase separation in biology. Annu Rev Cell Dev Biol 30, 39-58.
  3. Lin, Y., and Fang, X. (2021). Phase Separation in RNA Biology. J Genet Genomics.