Unveiling the embryo structure in Bromeliaceae Juss. (Poales): morphological diversity, anatomy, and character evolution.

Background And Aims: Recent studies have documented numerous morphoanatomical variations for the seed coat in Bromeliaceae. However, the structural diversity and character evolution of the embryo within this family remain largely unexplored. Given the embryo's significance in plant diversification, this research aims to investigate the morphology and key anatomical features of Bromeliaceae embryos, providing insights into character evolution, taxonomic applications, and reproductive biology.

Neither lysigenous nor just oil: Demystifying myrtaceous secretory cavities.

Premise: Leaf subepidermal secretory cavities are a notable trait in Myrtaceae, but their formation is still controversial because of the lack of consensus on their ontogeny among authors. Knowledge about the compounds present in these cavities has grown over the last few years, demonstrating that terpenoid-rich oils are not their unique content. These two points are the focus of this study on the ontogeny, structure, and contents of secretory cavities in neotropical Myrtaceae.

Reproductive biology of the "Brazilian pine" (Araucaria angustifolia-Araucariaceae): the pollen tube growth and the seed cone development.

In Araucaria angustifolia, the seed scale is part of the ovule, the female gametophyte presents a monosporic origin and arises from a coenocytic tetrad, and the pollen tube presents a single axis. The seed cone of conifers has many informative features, and its ontogenetic data may help interpret relationships among function, development patterns, and homology among seed plants. We reported the seed cone development, from pollination to pre-fertilization, including seed scale, ovule ontogeny, and pollen tube growth in Araucaria angustifolia.

Histochemical Localization of Phenolic Compounds and Reactive Oxygen Species in Eucalypt Microcuttings.

Among the main features of plant specialized metabolism are cell- and tissue- specific expression and responsiveness to oxidative stress conditions. Although quantitative techniques have significantly improved over time, allowing higher levels of resolution in plant metabolic studies, such analyses are often expensive and/or require relatively large amounts of starting material. The following protocols offer a relatively simple way to survey specialized and related metabolites (total phenolics, flavonoids, lignins), as well as reactive oxygen species (superoxide and hydrogen peroxide), using light and fluorescence microscopy.

Nuclear variations and tapetum polyploidy related to pollen grain development in Passiflora L. (Passifloraceae).

Tapetal cells comprise an anther tissue fundamental to pollen grain development. They are associated with endoreduplication events, which culminate in polyploid and multinucleated cells, high metabolic activity, and different organelle arrangements to support all the development of the pollen grains. Passiflora species present a secretory tapetum, with diversity in the number and size of nuclei.

Microcutting Redox Profile and Anatomy in spp. With Distinct Adventitious Rooting Competence.

Adventitious root (AR) development takes place in an intricate cellular environment. Reactive oxygen species (ROS) and antioxidant defenses, triggered by wounding in cuttings, can modulate this process. A comparative assessment of biochemical and anatomical parameters at critical rooting stages in hard- ( Labill.

Tightly controlled expression of OsbHLH35 is critical for anther development in rice.

Anther development is a complex process regulated by a myriad of transcription factors belonging to distinct protein families. In this study, we focus on the functional characterization of OsbHLH35, a basic Helix-Loop-Helix (bHLH) TF that regulates anther development in rice. Plants overexpressing OsbHLH35 presented small and curved anthers, leading to a reduction of 72 % on seed production.

Are unusual ultrastructural features occurring in the pollen endomembrane system of Cyperaceae and other angiosperms?

Cyperaceae representatives present peculiar microsporogenesis and microgametogenesis, which raises the question of how regular the sedge pollen is. In order to answer this question, preanthesis pollen grains of Cyperaceae individuals were analyzed under different tools such as light and transmission electron microscopy, which included cytochemistry and immunogold procedures. The results showed that maturing pollen in Cyperaceae presents some unusual endomembrane behaviors.

Heat transfer in the tank-inflorescence of Nidularium innocentii (Bromeliaceae): Experimental and finite element analysis based on X-ray microtomography.

In Bromeliaceae, various traits have evolved for the uptake and storage of water; however, their roles in bromeliad inflorescences remain unresolved. This study investigates the role of water in the flowers and inflorescences of Nidularium innocentii, and describes water as a protection mechanism. Individuals were divided into groups with and without water provision in inflorescences.

Characterization of the nucellus-specific dehydrin MdoDHN11 demonstrates its involvement in the tolerance to water deficit.

MdoDHN11 acts in the nucellus layer to protect the embryo and the endosperm from limited water availability during apple seed development. Dehydrins (DHNs) are protective proteins related to several plant developmental responses that involve dehydration such as seed desiccation and abiotic stresses. In apple (Malus × domestica Borkh.

Cytological differentiation and cell wall involvement in the growth mechanisms of articulated laticifers in Tabernaemontana catharinensis A.DC. (Apocynaceae).

The cellular mechanisms of laticifer growth are of particular interest in plant biology but are commonly neglected. Using transmission electron microscopy and immunocytochemical methods, we recorded cytological differentiation and evaluated the cell wall involvement in the growth of articulated laticifers with intrusive growth in the mature embryo and plant shoot apex of Tabernaemontana catharinensis. The incorporation of adjacent meristematic cells into the laticifer system occurred in the embryo and plant shoot apex, and the incorporated cells acquired features of laticifer, confirming the laticifers' action-inducing mechanism.

Manipulation of VviAGL11 expression changes the seed content in grapevine (Vitis vinifera L.).

Seedlessness in grapes is a desirable trait, especially for in natura consumption. Previously, we showed that VviAGL11 is the main responsible gene for seed morphogenesis in grapevine. Here we tested the function of this gene in grapevine with the use of plant plasmids.

The MADS-box gene Agamous-like 11 is essential for seed morphogenesis in grapevine.

Despite the wide appreciation of seedless grapes, little is known about the molecular mechanisms that drive the stenospermocarpic seedless-type phenotype in grapevine. In order to address the molecular mechanisms that control seedlessness in grapevine, our study aimed to characterize VviAGL11, a class D MADS-box transcription factor gene that has been proposed as the major candidate gene involved in Vitis vinifera seed morphogenesis. VviAGL11 allelic variations in seeded and seedless grapevine cultivars were determined, and its correlations with allele-specific steady-state mRNA levels were investigated.

Cold tolerance in rice germinating seeds revealed by deep RNAseq analysis of contrasting indica genotypes.

Rice productivity is largely affected by low temperature, which can be harmful throughout plant development, from germination to grain filling. Germination of indica rice cultivars under cold is slow and not uniform, resulting in irregular emergence and small plant population. To identify and characterize novel genes involved in cold tolerance during the germination stage, two indica rice genotypes (sister lines previously identified as cold-tolerant and cold-sensitive) were used in parallel transcriptomic analysis (RNAseq) under cold treatment (seeds germinating at 13 °C for 7 days).

Initial development of the endocarp in Lithraea brasiliensis Marchand (Anacardiaceae): with taxonomic notes.

Investigation into the initial developmental stages of a given structure is fundamental for precise characterization as well as for comparative analysis in relation to other taxa when homologies are established. For the Anacardiaceae family, investigations of the initial development of the pericarp or its basic histological sites, the epicarp, mesocarp and endocarp, are relevant since these regions are of taxonomic and phylogenetic importance. The initial stages of endocarp development in Lithraea brasiliensis were studied using light microscopy.

New insights into aluminum tolerance in rice: the ASR5 protein binds the STAR1 promoter and other aluminum-responsive genes.

Aluminum (Al) toxicity in plants is one of the primary constraints in crop production. Al³⁺, the most toxic form of Al, is released into soil under acidic conditions and causes extensive damage to plants, especially in the roots. In rice, Al tolerance requires the ASR5 gene, but the molecular function of ASR5 has remained unknown.

Developmental and cytogenetic analyses of pollen sterility in Valeriana scandens L.

Valeriana scandens presents perfect and pistillate flowers, the latter with sterile anthers. The species is composed of two varieties with different ploidy; V. scandens var.

Peripheral clear cell variant of calcifying epithelial odontogenic tumor affecting 2 sites: report of a case.

A case of clear cell variant of calcifying epithelial odontogenic tumor (CEOT) affecting 2 different extraosseous sites is described. A 43-year-old female patient presented with 2 gingival lesions (1 in the upper premolar and 1 in the lower incisor area), which were clinically diagnosed as inflammatory hyperplasia and surgically removed. Microscopically, both lesions were composed of polyhedral cells (some with clear cytoplasm); hyaline material and areas of calcification were also observed.