Secretory cavities in Myrtaceae typically store lipophilic substances involved in plant defense. However, their structural and functional reorganization during gall development remains poorly understood, particularly regarding how gall complexity and biotic interactions influence these changes. Here, we analyzed the anatomical, histometric, and histochemical features of secretory cavities across eight gall morphotypes induced on three Eugenia species (E. astringens, E. copacabanensis, and E. uniflora). We hypothesized that gall induction modifies secretory cavities, which may result in functional alterations during cecidogenesis, and that the magnitude of these alterations relates to gall structural complexity. Across most morphotypes, we observed a suppression of cavities near the larval chamber and reduced secretory cavity density in gall wall, an integrated strategy that likely minimizes the inducer’s exposure to secondary metabolites. Conversely, in E. astringens fusiform galls, an associated fungal symbiont indicates that these are ambrosia galls. In these galls, we recorded higher cavity density, larger lumen area, and phenolic accumulation, suggesting a repurposing of these structures to maintain a microenvironment favorable to the fungal-insect association. The results partially supported our hypothesis: while gall complexity correlated with cavity reorganization in E. astringens, this pattern was inconsistent in the other host species, indicating that taxonomic identity, morphogenetic constraints, and biotic interactions also contribute to these traits. These findings demonstrate that secretory cavity reorganization is not a uniform process but a highly plastic response, revealing diverse functional trajectories that range from structural reduction to chemical enhancement, depending on the specific host plant-gall inducer system.
Plant responses to drought, salinity, heat and mechanical loading are usually interpreted through hormones, redox signals and transcriptional networks, but these frameworks incompletely capture the physical state of the nucleus. In wall-bounded, turgor-driven plant cells, environmental and growth-derived forces can be transmitted through the cytoskeleton to the nuclear envelope, nucleoskeleton and chromatin. Evidence from osmotic and heat-stress studies indicates that nuclear shape, stiffness, lamina organization, peripheral chromatin tethering and three-dimensional genome architecture are stress responsive. We synthesize these findings into the concept of the plant nuclear mechanome: an integrated system comprising nuclear geometry, viscoelasticity, envelope–cytoskeleton coupling, lamin-like scaffolds, nuclear pores, chromatin organization and nuclear-body dynamics. We propose that this system acts as a tunable interface that can buffer, transmit or amplify mechanical inputs and thereby influence chromatin accessibility, transcriptional competence, acclimation, stress memory and recovery. Particular attention is given to nuclear envelope and nucleoskeletal modules that may connect force transmission with genome regulation. We distinguish established observations from mechanistic hypotheses and outline experiments combining realistic stress treatments, live nuclear imaging, quantitative mechanics, targeted genetic perturbation, single-nucleus omics and physiological validation. This framework positions nuclear mechanics as a testable dimension of plant cell biology and environmental adaptation.
Plasmodesmata (PD) are conduits between plant cells that are essential to multicellularity: they allow a wide range of molecules, such as nutrients, phytohormones, RNAs and proteins including transcription factors, to be transported from cell to cell. PD are essential to intercellular communication and have been shown to be important for developmental transitions. PD were discovered using light microscopy. Since then, advanced imaging approaches have been utilised to resolve PD ultrastructure, analyse their spatial distribution, and probe the translocation of diverse cargo. In this review, we first summarise the microscopy techniques used for studying PD, with a focus on fluorescence and electron microscopy (EM). We then discuss emerging techniques and new advances, such as Correlative Light and Electron Microscopy (CLEM), single-molecule imaging, and cryo-electron tomography (cryo-ET), approaches that will likely lead to exciting discoveries in the field, such as capturing dynamics at PD and revealing previously unknown aspects of PD structure. This review discusses the strengths and weaknesses of the different techniques and how combining them could pave the way to a more detailed understanding of the diverse PD types, their distribution and function.
This study comprehensively evaluated the phytochemical composition and multidimensional biological activities of Sisymbrium altissimum L., a wild edible species belonging to the Brassicaceae family. Methanolic extracts obtained from aerial parts, flowers, fruits, and roots were successively fractionated using solvents of increasing polarity, and essential and fatty oils were characterized by GC–MS and GC-FID analyses. The essential oil composition showed marked organ-dependent variation, with methallyl cyanide dominating fruit (91.9
Fish use their mucosal barriers to interact with their surroundings while maintaining homeostasis. Gill-associated lymphoid tissue (GIALT) provides an important initial line of defense against waterborne infections. We examined the morphology and ultrastructural characteristics of immune cells in the branchial epithelium of silver carp (Hypophthalmichthys molitrix) using histology and transmission electron microscopy. We processed samples from silver carp (n = 10) for semi-thin sectioning and transmission electron microscopy. We stained semi-thin sections with toluidine blue and methylene blue and ultrathin sections with uranyl acetate and lead citrate. We identified several immune cell types in the gill mucosa, including polymorphonuclear leukocytes with multilobed nuclei and three granule types: eosinophilic granular cells with crystalloid cores in their specific granules, and rodlet cells at granular and mature developmental stages. We identified mononuclear phagocytes (macrophages) in the lamina propria and gill lumen. In the basal and intermediate layers of the branchial epithelium, we observed cells with abundant rough endoplasmic reticulum and endo-lysosomal systems. We also observed apoptotic characteristics in the surface layer, including chromatin condensation and the expansion of rough endoplasmic reticulum. Our findings illustrate the complex cellular architecture of the branchial mucosal immune barrier in silver carp and establish a morphological basis for understanding the cellular components that influence gill-associated immunity.
