# Exploring the Role of the Processing Body in Plant Abiotic Stress Response
## 1 Introduction  
Various complex biochemical reactions within cells take place in separate cellular compartments. Apart from membrane-bound organelles, there also exist membrane-less organelles (MLOs) formed through liquid-liquid phase separation (LLPS) involving proteins and nucleic acids [1; 2]. These MLOs compartmentalize within the cell to provide stable and non-interfering internal environments for specific biochemical reactions, such as nucleolus in the cell nucleus, Cajal bodies, stress granule (SG), and processing body (P-Body). [PERSON] et al. first discovered in yeast that mRNA can be accepted and 5\({}^{\prime}\)-3\({}^{\prime}\) degraded in some discrete cytoplasmic foci and called these cytoplasmic foci P-Bodies [3; 4; 5]. Subsequent research found that P-Bodies are formed from aggregation among proteins and mRNA molecules driven by LLPS under specific conditions, such as pH, salt concentration, and temperature [6; 7]. The P-Body is widely distributed in different cell types.  
The P-Body is primarily involved in mRNA decapping, translational repression, degradation, and storage at the post-transcriptional level [8]. The mRNA degradation mediated by P-Bodies includes the AU-rich element-mediated mRNA decay (AMD) pathway, the 5\({}^{\prime}\)-3\({}^{\prime}\) degradation pathway, and the nonsense-mediated mRNA decay (NMD) [9; 10]. mRNA degradation not only regulates the expression levels of normal proteins but also prevents the synthesis of abnormally folded proteins. Notably, not all mRNAs in P-Bodies are degraded; several mRNAs can be stored in the P-Body under abiotic stresses and re-enter the polysomes when conditions become favorable, restoring translation. For instance, mRNA levels in P-Bodies were elevated in glucose deficiency and decreased after glucose supplementation by a shift in the cellular polysome count from a decrease to an increase [11].  
The P-Body has been reported to play a crucial role in various cell types. The results in mammals indicate that the P-Body is involved in defense against viral infections and the regulation of oocyte maturation [12; 13; 14]. In plants, the P-Body also plays a significant role in regulating cellular physiological activities. During seed germination, the unnecessary mRNAs for seedling growth were degraded in the P-Body; then, the ribosomal translation sites were free for synthesizing essential proteins to sustain plant normal growth and development [15]. Additionally, P-Bodies are indispensable in plant responses to stress. Under heat, salt, and pathogen stress conditions, the size and number of P-Bodies increased, and the protein composition of the P-Bodies degrades mRNAs unfavorable to the stress response [16; 17; 18]. The protein composition of the P-Body varies in different cell types, growth stages, and external environmental stresses. The review primarily elucidates the protein composition of P-Bodies in plants, the protein structures that drive the formation of P-Bodies, and the mechanisms of P-Body assembly. Furthermore, we focus on how P-Bodies regulate mRNA decapping, degradation, translational repression, and storage in response to various abiotic stresses and the involvement in hormone signaling pathways. The review summarizes the dynamic changes and response mechanisms of P-Bodies in plants under abiotic stresses.