Editorial: Biology of stress granules in plants

Abstract

Eukaryotic cells have developed sophisticated mechanisms to survive under ever-changing environments which include compartmentalization of translationally arrested mRNA molecules and proteins into a type of membraneless cytoplasmic foci called stress granules (SGs). Stress granules were first identified as phase-dense cytoplasmic particles formed in mammalian cells when subjected to heat shock (Arrigo et al., 1988). To date, intensive studies in yeast and animal model systems have helped elucidate the major molecular composition of SGs (Jain et al., 2016; Markmiller et al., 2018; Marmor-Kollet et al., 2020). SGs are typically consisted of small ribosomal subunits, various translation initiation factors (eIFs), poly(A)-binding proteins (PABs), and a variety of RNA-binding proteins (RBPs) and non-RNA-binding proteins. Although SGs were initially thought to facilitate mRNA translational arrest during stress, it has been well-documented that SGs play a more active role in stress response, mRNA triage and stress signaling, among other processes (Hofmann et al., 2021). The mechanisms governing the assembly of SGs have been recently extensively discussed (Schmit et al., 2021). Growing evidence have now suggested that SGs can be classified as droplets formed by liquid-liquid phase separation (LLPS) in the cytoplasm (Jain et al., 2016; Yang et al., 2020).

In contrast to mammalian or yeast model system, research in the plant SGs field is still in its infancy. Despite very recent works that have begun to provide a better understanding on some of the mechanistic questions, the investigation of plant SGs still represents an emerging field. Therefore, numerous knowledge gaps remain to be filled. Here, we share with the plant biology community a Research Topic that aims to highlight the most current findings in the field of SG biology in plants.