title: Peroxidase activity in scutella of maize in association with anatomical changes during germination and grain storage.
abstract: The embryo of the maize grain (Zea mays L.) is separated from the starchy endosperm by a fibrous structure, which is called the fibrous layer (FL). Using histochemical staining, it was determined that the FL is composed of collapsed cellular layers that contain phenols, neutral lipids, and 1,3-β-glucan. Due to its composition, the FL prevents free diffusion and separates the embryo from the endosperm during germination. Twenty-four hours after imbibition, the scutellum epidermis initiated a series of asynchronous spatial modifications, including cell growth, the perforation of cell walls, increased peroxidase activity in the apoplastic space, and elevated levels of superoxide, phenols, and other components that interact with the fibrous layer, enabling its transformation in addition to the free flow between compartments. During storage at high relative humidity levels, which leads to fast or slow deterioration depending on the temperature, the activity of phenol peroxidase in the scutellum was associated with a loss of vigor and reduced germination capacity when compared with low temperature and low relative humidity conditions. Such deterioration is associated with alterations in autofluorescent emissions from endogenous compounds in the scutellum, indicating changes in the microenvironment or in the differential proportions of epidermal and FL components.
authors.affiliation: Department of Health Sciences, Division of Biological and Health Sciences, Laboratory for Tissue Biochemistry, Universidad Autónoma Metropolitana-Iztapalapa, Mexico City, Mexico ; Posgrado en Biología Experimental, Division of Biological and Health Sciences, Universidad Autónoma Metropolitana-Iztapalapa, Mexico City, Mexico.
authors.forename: José Isaac
authors.initials: JI
authors.lastname: Corona-Carrillo
authors.affiliation: Department of Health Sciences, Division of Biological and Health Sciences, Laboratory for Tissue Biochemistry, Universidad Autónoma Metropolitana-Iztapalapa, Mexico City, Mexico.
authors.forename: Mitzi
authors.initials: M
authors.lastname: Flores-Ponce
authors.affiliation: Department of Health Sciences, Division of Biological and Health Sciences, Laboratory for Tissue Biochemistry, Universidad Autónoma Metropolitana-Iztapalapa, Mexico City, Mexico.
authors.forename: Gerardo
authors.initials: G
authors.lastname: Chávez-Nájera
authors.affiliation: Department of Health Sciences, Division of Biological and Health Sciences, Laboratory for Tissue Biochemistry, Universidad Autónoma Metropolitana-Iztapalapa, Mexico City, Mexico.
authors.forename: David Manuel
authors.initials: DM
authors.lastname: Díaz-Pontones
keywords: Controlled deterioration; Epidermis; Fibrous layer; Maize (Zea mays L.); Peroxidase; Scutellum