Corn is one of the most economically important cereal crops cultivated around the world, and understanding the proper mobilization and utilization of starches, sugars, pectin, and metabolites in seeds is crucial for enhancing effective germination and promoting the development of healthy seedlings. Salt stress hinders seed germination by limiting water uptake, damaging cell structures, disrupting key metabolic processes, and impairing the function of endosperm and embryo tissues. However, visual representations and imaging of biochemical changes in the tissues and cells of the embryo and endosperm within corn seeds during germination under salt stress have been limited in the literature. In this study, we aimed to compare the structural changes and visualize the biochemical alterations occurring within the seed tissues (i.e., the outermost layer of the corn seed, endosperm, and embryo) at 6, 24, 48, and 96 h during germination under non-stress control conditions (0 dS m⁻¹) and salt stress conditions (4 dS m⁻¹ and 8 dS m⁻¹) using light fluorescence and scanning electron microscopy (SEM). We observed that pores between the pericarp cells (epidermis), the outermost part of the seed, did not shrink or deform under salt stress. In contrast, under non-salt stress conditions, the intercellular spaces between the pericarp cells opened rapidly. This limited porosity in the outermost layer cells could lead to inadequate water absorption, significantly contributing to delayed or failed germination under salt stress. Starch, the primary storage carbohydrate found in the endosperm, decreased rapidly under non-salt stress conditions; however, starch degradation slowed under salt stress. Almost no starch grains were detected in the embryo or scutellum cells. Protein depletion in aleurone cells occurred rapidly during germination in the absence of salt stress but slowed as salt stress increased. We also observed that the movement of metabolites from the embryo to the root and shoot regions within the seed was slowed or diminished under saline conditions. Alterations in cellulose and tannins were observed during seed germination under both salt and non-salt stress conditions; however, the scutellum cell walls retained their structural integrity due to partial, localized degradation. During germination, endosperm cell walls became more distinct, with an increased presence of pectin and mucopolysaccharides. The shoot region, initially rich in proteins, sugars, tannins, and pectins, was also found in the mesocotyl cells and intercellular spaces. Visualizing these changes in seed structure throughout our study enhances our understanding of the adverse conditions.

Traditional paradigms in basic emotion research, largely grounded in animal and human psychology, are problematic when extended to plants due to fundamental biological and neurophysiological differences. This paper criticizes the anthropocentric tendency to equate plant responses with human emotional states, emphasizing that plants, lacking a central nervous system and brain, cannot experience feelings in the human sense. Instead, we propose a novel conceptual framework: emotus plantarum. This term defines a plant-specific signaling system that fulfills a role functionally analogous to emotions in animals—coordinating adaptive responses to environmental stimuli. Unlike cognitive models that presuppose centralized information processing, emotus plantarum reframes abilities such as learning, memory, anticipation, and decision-making as emergent, decentralized properties of plant physiology that serve emotion system functions. These processes modulate plant behavior, such as tropisms, nastic movements, and chemical signaling enabling flexible, context-dependent reactions that enhance survival and fitness. This framework shift allows for a more biologically appropriate interpretation of plant behavior, bypassing the need to force-fit plant responses into anthropomorphic categories. By repositioning these attributes within an emotion system framework unique to plants, the concept of emotus plantarum offers a more nuanced approach to understanding plant-environment interactions. Ultimately, this perspective promotes a deeper integration of plant-specific biology into the study of adaptive behavior, opening new avenues for research in plant signaling, communication, and responsiveness.

Galls alter the tissue organization of host plants, including modifications in cell wall composition. This study investigated tissue development and cell wall dynamics in galls of Sapium glandulosum to identify key steps involved in their establishment. Samples of young, mature, and senescent galls, as well as nongalled leaves, were analyzed using structural and immunocytochemical approaches. For histology, samples were fixed, embedded in resin, sectioned, stained with toluidine blue, and mounted with Entellan®. For immunocytochemistry, resin-embedded samples were tested for epitopes of cell wall proteins, pectins, and hemicelluloses using antibodies. The leaves of S. glandulosum are glabrous, hypostomatic, and exhibit dorsiventral mesophyll. Gall development alters the typical leaf morphogenetic pattern, giving rise to structures with a parenchymatic cortex. In young galls, hypertrophy and hyperplasia were observed, followed by tissue maturation in mature galls. Senescent galls showed signs of cytoplasmic degradation in most cortical cells. Structural modifications in the side chains of rhamnogalacturonan I and increased cross-linking of pectic polymers affect cell wall properties, playing roles in both development and defense responses. The low immunolabeling with JIM5 in young and mature galls suggests the suppressed activity of pectin methylesterases, which may reflect a strategy by which gall-inducing organisms inhibit host defense signaling. Xyloglucan epitopes were detected in the vascular bundles of mature galls, suggesting the reinforcement of cell walls and possibly supporting the feeding activity of the gall inducer. The combination of anatomical and immunocytochemical data provided a basis for understanding how gall induction modulates cell differentiation and cell wall composition in S. glandulosum.

When the journal Protoplasma was founded 100 years ago in 1926, scientists used two different concepts to describe what we would now consider one and the same object: the cell for the membrane-bound structural unit of life, and protoplasm for the living fluid mass or body of the cell. The flourishing of both concepts together dates back to the 1850s, when biologists revised the original cell theory of 1838/39 while also unifying the definition of the cell across plant and animal kingdoms. However, at the beginning of the 20th century a methodological debate over fixation and staining artifacts divided cell researchers in two polarized groups. Cytologists preferred continuing descriptive research on fixed images of chromosomes and organelles, while general physiologists or "protoplasmologists" sought to develop new physical chemical experiments to study living, uninjured protoplasts. This historical essay shows how the journal Protoplasma emerged from one side of these longer debates over the definition of cellular life, and places the origins of the journal in the context of a changing disciplinary landscape of the life sciences in the first half of the 20th century. It also argues that cross-kingdom research in cell biology has been a foundational source of innovation in cell theory's longer history.

Little is known about the dynamics of pollen germination in palms. Mauritia flexuosa (buriti) is native to the Amazon but also occurs in wetland areas (veredas) within the Cerrado. The species is dioecious and, in this environment, exhibits supra-annual flowering, which underscores the importance of post-pollination events for its reproductive success. The aim of this study was to define the stages of buriti pollen germination, to describe the mobilization of reserve compounds, and to examine subcellular changes during pollen tube development. Cytochemical tests and ultrastructural analyses were performed throughout the germination process and the in vitro development of the pollen tube. The pollen of M. flexuosa is sphero-oblate and monoporate. The exine is thick and impregnated with structural phenolic compounds, with pointed spicules and pollenkitt. The intine is thin, becoming thicker in the pore region, where it exhibits a mixed composition. The protoplast of the vegetative cell is rich in reserve compounds. Germination occurs in four phases. In the pore region, the pectin-rich intine ensures effective rehydration. The mobilization of starch and lipids, in coordinated stages, provides energy for pollen tube elongation, accompanied by continuous wall synthesis. Protoplast reorganization supports pollen tube growth, with proliferation of dictyosomes, endoplasmic reticulum, mitochondria, and ribosomes. The second mitosis takes place shortly after pollen tube emergence, contributing to rapid fertilization. The structural features of the pollen and the dynamics of germination favor the reproductive success of M. flexuosa, particularly in semiarid environments.