Soybean Hydrophobic Protein is Present in a Matrix Secreted by the Endocarp Epidermis during Seed Development.

Hydrophobic protein from soybean (HPS) is present in soybean dust and is an allergen (Gly m 1) that causes asthma in allergic individuals. Past studies have shown that HPS occurs on the seed surface. To determine the microscopic localization of HPS during seed development, monoclonal antibodies to HPS were used to visualize the protein by fluorescence and transmission electron microscopy. Seed coat and endocarp sections were also examined for pectin, cellulose, callose, starch, and protein by histochemical staining. HPS is present in the endocarp epidermal cells at 18 to 28 days post anthesis. At later stages of seed development, HPS occurs in extracellular secretions that accumulate unevenly on the endocarp epidermis and seed surface. HPS is synthesized by the endocarp epidermis and deposited on the seed surface as part of a heterogeneous matrix.

A re-examination of the root cortex in wetland flowering plants with respect to aerenchyma.

AIMS: We review literature and present new observations on the differences among three general patterns of aerenchyma origin and their systematic distributions among the flowering plants, and we clarify terminology on root aerenchyma. SCOPE: From our own previous works and some new observations, we have analysed the root cortex in 85 species of 41 families in 21 orders of flowering plants that typically grow in wetlands to determine the characteristic patterns of aerenchyma. FINDINGS: A developmental and structural pattern that we term expansigeny, as manifested by honeycomb aerenchyma, is characteristic of all aquatic basal angiosperms (the Nymphaeales) and basal monocots (the Acorales). Expansigenous aerenchyma develops by expansion of intercellular spaces into lacunae by cell division and cell expansion. Schizogeny and lysigeny, so often characterized in recent reviews as the only patterns of root cortex lacunar formation, are present in most wetland plants, but are clearly not present in the most basal flowering plants. CONCLUSION: We conclude that expansigeny is the basic type of aerenchyma development in roots of flowering plants and that the presence of expansigenous honeycomb aerenchyma in root cortices was fundamental to the success of the earliest flowering plants found in wetland environments.