Low-cost and efficient confocal imaging method for arabidopsis flower

Cell- and noncell-autonomous AUXIN RESPONSE FACTOR3 controls meristem proliferation and phyllotactic patterns

In cell-cell communication, noncell-autonomous transcription factors play vital roles in controlling plant stem cell fate. We previously reported that AUXIN RESPONSE FACTOR3 (ARF3), a member of the ARF family with critical roles in floral meristem maintenance and determinacy, has a distinct accumulation pattern that differs from the expression domain of its encoding gene in the shoot apical meristem (SAM). However, the biological meaning of this difference is obscure. Here, we demonstrate that ARF3 expression in Arabidopsis (Arabidopsis thaliana) is mainly activated at the periphery of the SAM by auxin where ARF3 cell autonomously regulates the expression of meristem-organ boundary-specific genes, such as CUP-SHAPED COTYLEDON1-3 (CUC1-3), BLADE ON PETIOLE1-2 (BOP1-2), and TARGETS UNDER ETTIN CONTROL3 (TEC3) to regulate the arrangement of organs in regular pattern, a phenomenon referred to as phyllotaxis. We also show that ARF3 is translocated into the organizing center where it represses cytokinin activity and WUSCHEL expression to regulate meristem activity noncell-autonomously. Therefore, ARF3 acts as a molecular link that mediates the interaction of auxin and cytokinin signaling in the SAM while coordinating the balance between meristem maintenance and organogenesis. Our findings reveal an ARF3-mediated coordination mechanism through cell-cell communication in dynamic SAM maintenance.

Imaging plant tissues: advances and promising clearing practices

The study of the organ structure of plants and understanding their physiological complexity requires 3D imaging with subcellular resolution. Most plant organs are highly opaque to light, and their study under optical sectioning microscopes is therefore difficult. In animals, many protocols have been developed to make organs transparent to light using clearing protocols (CPs). By contrast, clearing plant tissues is challenging because of the presence of fibers and pigments. We describe progress in the development of plant CPs over the past 20 years through a modified taxonomy of CPs based on their physical and optical parameters that affect tissue properties. We also discuss successful approaches that combine CPs with new microscopy methods and their future applications in plant science research.

Multi-Angle In Vivo Imaging of the Arabidopsis thaliana Shoot Apical Meristem (SAM)

Fluorescent imaging, especially in living tissue, has become a key method in modern life sciences, with the development of new tools for sample preparation, imaging, and data analysis continuously advancing our understanding of biological principles. Here, we present our strategy for in vivo imaging of the Arabidopsis shoot apical meristem (SAM), a central structure in plant development. We implement simplifications to previously published workflows and present a novel approach to subsequentially image the meristem from multiple angles at high resolution. This tool may represent a valuable resource for shoot meristem-centered research in general, but also for studies on plasmodesmata or intercellular connectivity within the SAM: via the analysis of fluorescently labeled plasmodesmata-localized proteins, via the tracing of fluorescent dyes, via analyzing the cell-to-cell mobility of fluorescently labeled proteins, but also via the analysis of morphological features of meristematic cells in mutants or upon perturbation of symplastic connectivity.