Cellular Compartmentalization and the Role of Peptide Hormone

Plant cells are amazingly efficient and precise in their physiological responses by segregating biochemical activities into specific and distinct organelles such as the nucleus, endoplasmic reticulum (ER), vacuoles, plastids, and the Golgi apparatus, as these functions are regulated by peptide hormones. Peptide hormones play a key role within this highly compartmentalized cellular landscape, and orchestrate diverse functions, including stress adaptation, growth and development as well as immune responses. Specific receptor-like kinase receptors with plasma membrane and endomembrane localization accept peptide hormones such as systemin, phytosulfokine (PSK), CLAVATA3/ESR-Related (CLE) peptides, and rapid alkalinization factors (RALFs). Additionally, peptide hormone biosynthesis, maturation, and secretion are intimately associated with cellular compartmentation. Many peptide precursors are proteolytically processed in the ER and Golgi, as the secretion of mature peptides generally involves the regulated transport in vesicular compartments. Aberrant growth and stress susceptibility can result from dysfunction at any of the compartmentalization steps because they disrupt hormone signaling. Cellular compartmentalization and peptide hormone signaling have the potential to provide important insights into plant adaptation and resilience. If understood in joint conception, such things may help in developing new and innovative strategies for crop improvement to enhance tolerance and to increase growth efficiency and yield under various environmental conditions.